| Action Date |
Action |
Description |
DEC Staff |
| 9/1/1983 |
Update or Other Action |
IRP Phase I Records Search report. Referred to as Site SP-5 JP-4 Tank Spill. Site SP-5, Bulk Fuel Storage Tanks Nos. 601-604, has been the site of numerous spills since the tanks were installed in the early 1940's as Avgas* storage tanks. A 60,000 gallon Avgas spill was known to occur in the mid-1960's when the U.S. Army still managed the facility. None of the Avgas was recovered. On August 30, 1974, an estimated 33,000 gallon spill of JP-4 jet fuel occurred when an underground tank was filled beyond capacity. Approximately 16,000 gallons of fuel were recovered.
*Ethylene dibromide (EDB) and ethylene dichloride (EDC; also known as 1,2-dichloroethane or 1,2-DCA) are synthetic organic chemicals used in leaded gasoline as “lead scavengers” to prevent the buildup of lead deposits that foul internal combustion engines. Leaded gasoline containing lead scavengers is still used as aviation gasoline (Avgas). Avgas 100LL contains tetraethyl lead (TEL) as an additive, according to ASTM D910. The purpose of this compound is to prevent both knock and uncontrolled engine detonation during flight. In addition, the additive TEL is related to the power produced in the engine and is thus a critical safety item. Avgas 100LL contains a maximum of 2 g/gal of this additive which is sufficient to prevent engine damage.
The high performance planes used during World War II needed extremely high-octane fuels
and tetraethyl lead was used to help that fuel reach octane ratings of over 115 for these planes. The amount of lead used in gas to reach these high octane ratings was 4.6 grams per gallon, as opposed to the 1.2-2 grams/gal used for today’s 100LL avgas
The remainder (17,000 gallons) seeped into the ground northwest of the tanks. Cleanup efforts prevented fuel from reaching surface waters. During the site inspection conducted in May, 1983, several fuel seeps were observed in the drainage ditch over the hill (south) of the tanks & in the flat areas further south of the road. As a result of past spills & the present observed contamination, a potential exists at Site SP-5 for contaminant migration.
See site file for additional information. |
Louis Howard |
| 11/2/1983 |
Update or Other Action |
USAF William R. Hanson, P.E. Director, Engrg. & Envmtl. Planning to DEEV (Mr. Hostman) 21 CSG/DEEV RE: Memorandum of Understanding (MOU) between DOD and EPA.
1. The attached guidance has been received from HQ USAF/LEE (atch 1). It is subject to change as time progresses. It is important to note that all actions affected by this agreement will be implemented within the overall guidance of the Installation Restoration Program.
2. All queries or requests for action received from Federal or State agencies concerning releases from former Air Force installations (MOU para 3.2) or other releases for which the Air Force is a responsible party(MOU para 3.3) will be referred to HQ AAC/DEEV for forwarding to HQ USAF/LEEV. HQ USAF will task appropriate commands and/or staff agencies for response action. Any requests received from the State of Alaska or other Federal agencies will be reported by phone to this office, autovon 552-4151. All pertinent information will be provided to assist HQ AAC/DEEV in determining the exact nature of the information requested and required for the reply. The information requested will include any information on pending legislation or other enforcement actions that may have an effect on the situation.
Letter from Gary Alkire Brigadier General USAF Deputy Director, Directorate of Engineering & Services to ALMAJCOM/DE/SG/JA.
1. The attached MOU regarding implementation of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 is provided for your information. It deals, in general, with DoD and EPA responsibilities and procedures to be followed in identifying, evaluating, and controlling releases of hazardous pollutants from currently active and former DoD facilities and third party facilities at which DoD is a responsible party.
2. This letter provides interim implementation guidance concerning the MOU.
3. All Air Force actions in response to this MOU will be conducted within the framework of the existing Installation Restoration Program.
4. Affected major commands will continue to be responsible for releases from currently active Air Force installations (MOU para 3.1).
5. All queries or requests for action received from Federal or State agencies concerning releases from former Air Force installations (MOU para 3.2) or other releases for which the Air Force is a responsible party (MOU para 3.3) will be referred to HQ USAF/LEEV. HQ USAF will task appropriate commands and/or staff agencies for response action.
See site file for additional information. |
Louis Howard |
| 1/25/1988 |
Update or Other Action |
USEPA Assistant Administrator J. Winston Porter (OSWER) Memorandum for the record to Regional Administrators I-X Subj: Enforcement Actions under RCRA and CERCLA at Federal Facilities.
Statutory language makes it clear that Federal facilities must comply both procedurally and substantively with RCRA and CERCLA in the same manner as any non-Federal entity. The purpose of this memo is to lay out the statutory authorities under RCRA and CERCLA that EPA may use at Federal facilities to achieve compliance and expeditious cleanup.
EPA (The Agency) is viewing the Section 120 Interagency agreement as a comprehensive document to address hazardous substance response activities at a Federal facility from the remedial investigation/ feasibility study (RI/FS) through the implementation of the remedial action. All such interagency agreements must comply with the public participation requirements
of Section 117.
The timetables and deadlines associated with the RI/FS and all terms and conditions associated with the remedial actions (including operable units or interim actions) are enforceable by citizens and the States through the citizen suit provisions of Section 310 of CERCLA. In addition, Section 122(1) of CERCLA authorizes the imposition of civil penalties against Federal agencies for failure to comply with interagency agreements under Section 120. Procedures for imposing these penalties are provided for in Section 109 of CERCLA.
Executive Order 12580 clarifies that EPA is authorized to issue Section 104 and Section 106 administrative orders to other Federal agencies, with the concurrence of the Department of
Justice. Section 4(e) of the Executive Order provides that: Notwithstanding any other provision of this Order, the authority under Section 104(e)(5)(A) and Section 106(a) of the Act to seek information, entry, inspection, samples or response action from Executive Departments and agencies may be exercised only with the concurrence of the Attorney General.
States also have a variety of enforcement authorities under CERCLA, so the exercise of EPA's enforcement authorities should be closely coordinated with the States.
First, Section 121(e) (2) of CERCLA authorizes States to enforce ANY Federal or state standard, requirement, criteria or limitation to which the remedial action must conform under CERCLA.
Second, Section 310 authorizes citizen suits to require Federal agencies to comply with the standards, regulations, conditions, requirements, or orders which have become effective pursuant to CERCLA including IAGs under Section 120 of the Act.
Third, Section 120(a)(4) clarifies that State laws concerning removal and remedial action, including State laws regarding enforcement, are applicable at Federal facilities not included on the NP. In addition, Section 120(i) states that nothing in CERCLA Section 120 shall affect or impair the obligation of the Federal agency to comply with the requirements of RCRA, including corrective action requirements (see section IV.C., "Importance of the States as a Party to the IAG"). EPA enforcement actions against Federal agencies should therefore be carefully coordinated with States to avoid potentially duplicative or conflicting exercises of authority.
All RCRA Subtitle C permits issued after November 8, 1984, will contain provisions for implementing the corrective action requirements of 40 CFR Part 264 Subpart F (or authorized state requirements), and Section 3004(u) and (v) of RCRA. For facilities that have or are seeking a RCRA permit, the requirements for a "CERCLA" remedial investigation and cleanup could be met by implementing these requirements through RCRA corrective action.
It is important to keep in mind, however, that the extent of coverage of the RCRA permit is generally limited to hazardous wastes/constituents (e.g., some CERCLA hazardous substances such as radionuclides are not RCRA hazardous constituents and, therefore, the permit may not be able to address all of the releases at a facility).
The corrective action authority under Section 3008(h) of RCRA can be used at RCRA interim status facilities to address releases from RCRA regulated units and other solid waste management units. At a Federal facility that has interim status, a RCRA corrective action order could address the investigation and clean-up of releases in. lieu of a "CERCLA" response action or as an interim measure. Again, the extent of coverage in the RCRA corrective action order is limited to RCRA hazardous wastes/constituents.)
CERCLA Section 106 can be used to address releases from RCRA units or CERCLA sites when an "imminent and substantial endangerment" is shown. A Section 120 IAG could be drafted to incorporate all RCRA corrective action requirements and CERCLA statutory requirements. Where some or all of a Federal installation has been listed on the NPL, the CERCLA Section 120 IAG is required for remedial action by statute. |
Louis Howard |
| 4/18/1988 |
Update or Other Action |
AF (AAC) FY 1988 Military Construction Project Data SP-5 Interim Measures
SP5 Interim Measures
Oil/Water Separation/Treatment
Soil Boring/Monitoring Wells 6
Excavation
Trenching 150 cy
Description of Proposed Remedial Action
The scope of restoration work includes the following major elements: install six monitoring wells approximately 15 deep spaced 150 foot apart along Loop Road, excavate and inspect the oil/water separator installed in 1976, conduct test trenching operations at two sites to verify feasibility of trench system technology for final site design.
Requirement
Project: Install six monitoring wells and two test trenches at IRP site SP5. Obtain sufficient hydrogeologic information to verify application of trench system intercept technology at this site.
REQUIREMENT: Site SP5 is located north of Loop Road and south of four 1,000,000 gallon POL tanks. An active fuel seep occurs along hillside immediately north of Loop Road. Fuel seeps currently discharge into existing flightline storm drainage ditches. CERCLA applies.
CURRENT SITUATION: Existing four buried 1,000,000 gallon JP4 tanks were installed in 1942. Over the years several sizeable JP4 spills have occured at this site. A fuel seep has been observed on the hillside immediately north of Loop Road and apparently originates from "million
gallon hill". An oil/water separator was installed in 1976 at the site of the fuel seep to reduce the amount of oil being discharged into the drainage ditch paralleling Loop Road. Fuel seeps from this area continue to occur.
IMPACT IF NOT PROVIDED: Fuel will continue to seep out of million gallon hill and into flightline storm drainage ditches. Adverse environmental impacts associated with soil contamination and surface water fouling will continue to occur. State of Alaska officials verbally cited the base for improper storm water discharges in early 1987. Without prompt AF actions to eliminate this source, formal NOVs and/or fines are anticipated.
ADDITIONAL: This is an RA IRP (old Phase IVB, Priority IB) project. Proposed action is an interim response measure to IRP site SP-5.
Signed Terese D. LeFrancois GS-12 DAF, AAC DERA Program Manager.
|
Jennifer Roberts |
| 7/20/1988 |
Site Visit |
RCRA Facility Assessment Report and Preliminary Review and Visual Site Inspection (VSI) conducted in July 1988.
Site SP-5 JP-4 Tank Spill: Fuel from this tank system was observed seeping from the hillside into a fuel/water separator and into the ditch adjacent to the roadway northwest of the west end of the eastwest runway, immediately north of Loop Road, it was also evident during the VSI. Fuel seeps currently discharge into existing flightline storm drainage ditches. Groundwater flows to the south in the vicinity of this site.
Fuel seepage from this site was observed at the base of the hill west of the road, paralleling the runway on 9/15/87, fuel staining was also evident in the ditch line along the road running north and downhill. No evaluation was performed to determine the presence or absence of fuel seepage existing on the southwest or northeast side of the hill.
NOTE TO FILE: Naphthalene is a white solid or a liquid that occurs naturally in fossil fuels such as coal and crude oil and is best known as the primary ingredient of mothballs. It is extracted from these sources for other uses including jet fuel (as 1-3% of the fuel JP-4, JP-8, and commercial aviation gas or AvGas) |
Max Schwenne |
| 7/25/1988 |
Site Visit |
On July 25, 1988 ADEC and EPA conducted an UST/LUST compliance inspection on Elmendorf Air Force Base. During the inspection the petroleum product seep at the site known as Four Million Gallon Hill was visited. Petroleum product was seen seeping out of the base of the road cut and migrating east and west along the roadside drainage ditch. At the time of the inspection and in an August 31,1988 inspection report to the U.S. Environmental Protection Agency requested that actions be taken to collect and properly dispose of seeping product which enters the ditch. |
John Halverson |
| 8/2/1988 |
Update or Other Action |
CERCLA Operable Units' source areas that correspond to RCRA [solid waste management units] SWMUs from the RCRA RFA. Spill Sites: ST41 SP-5 JP4 Bulk Storage Tank spill - Bulk Fuel Storage Tank Numbers 601-604. Located north of Loop road & west of Brown Road. Numerous spill since their installation in 1942. They are interconnected & gravity fed without check values between tanks. A 60,000 gals AVGAS spill occurred in the mid- 1960s, & on 8/30/64 33,000 gals of JP-4 fuel was recovered. Several million of gallons of JP-4 were reported spilled 1973-1974. Visable seeps are seen from the hill side, into flightline storm drainage ditches. Monitoring wells were installed & reported contamination. This site has potenial for contamination & contamination migration. This site has been on the NPL, further investigation will be determined & performed pending determination of the appropriate authority, CERCLA-RCRA.
NOTE to FILE: Jet fuel 4 (JP-4) is a form of no. 1 fuel oil, & was one of the most commonly used petroleum products in the US Military. Jet fuel no. 4 is a middle distillate refined petroleum product that was primarily used in military planes. JP-4 was the standard fuel of the US Air Force & Army Aviation, & at one time constituted 85% of the turbine fuels used by the Department of Defense.
JP-4 is essentially a 50:50 mixture of heavy naphtha fraction (like gasoline) & kerosene. This fuel is not considered to be an acceptable substitute/alternate for diesel fuel. JP-4 is interchanged within NATO under NATO Code Number F-40. JP-4 is mainly procured as ASTM D 975 Jet B (or perhaps as CAN/CGSB 3.22). The chief difference between JP-4 & Jet B is that JP-4 contains the three mandatory additives while Jet B does not unless requested during procurement.
In terms of refining crude oil, JP-4 is a middle distillate. The middle distillates include kerosene, aviation fuels, diesel fuels, & fuel oil #1 & 2. These fuels contain paraffins (alkenes), cycloparaffins (cycloalkanes), aromatics, & olefins, from approximately C9 to C20. Aromatic compounds of concern included alkylbenzenes, toluene, naphthalenes, & polycyclic aromatic hydrocarbons (PAHs). Compositions range from avgas & JP-4, which are similar to gasoline, to Jet A & JP-8, which are kerosene-based fuels. JP-4 is a volatile, complex mixture of aliphatic & aromatic hydrocarbons that was principally used in military aircraft. The volatility meant that inhalation exposure is a potential problem near fueling facilities, either from spills or leaks. Once the soil has become saturated, remedial activities create both fire & inhalation hazards.
In 1973, EPA initiated a “phasedown” program for leaded gasoline. This program was designed to reduce lead content from 2.0 grams per gallon to 0.5 gram per gallon in large refineries by 1980 & in small refineries by 1982 (Ref. 2-14). The program allowed refineries to average their total (both leaded & unleaded) gasoline output to achieve the 0.5-gram per gallon standard.
In 1982, EPA lowered the standard for lead in fuel to 1.10 grams per gallon & eliminated the provision that allowed refineries to average their total leaded & unleaded gasoline output to meet the standard. In 1986, the standard was further reduced to 0.10 gram per gallon. By 1995, sales of leaded gasoline were reduced to 0.6 percent of total gasoline sales. Effective January 1, 1996, the Clean Air Act banned the sale of leaded fuel for May 2006 on-road vehicles. However, certain blends of automobile racing fuel continue to use alkyl lead compounds as a component of the fuel & EDB continues to be used as a lead scavenger in aviation gasoline (Avgas). |
Jennifer Roberts |
| 2/22/1989 |
Update or Other Action |
Telephone Memorandum
Steve M. Subject Vapor Extraction call with Jim Hayden (ADEC)
Called Jim Hayden to find out about 1. The effectiveness of vapor extraction on TPH; and 2. The effectiveness of vapor extraction on TPH in groundwater.
Jim informed me that vapor extraction would work on the lighter ends of TPH, but would not be effective on the lower ends. Vapor extraction would not be effective on groundwater cleanup. I then asked Jim if there were any soil cleanup requirements. He replied that there were not, but that the State of Alaska loosely follows 100 ppm TPH and 10 ppm total BTEX as standards. Each site is looked at on an individual basis.
|
Jim Hayden |
| 8/16/1989 |
Update or Other Action |
After numerous informal attempts to get the Air Force to take the requested corrective action to address the seeping product entering the drainage ditch, the Department was informed on August 7, 1989 that a horizontal pipe dam had finally been installed in the ditch to contain the petroleum product. The pipe dam was inspected during an August 16, 1989 visit escorted by Joe Williamson. Evidence of erosion was identified on the downgradient face of the dam. |
Ron Klein |
| 9/7/1989 |
Update or Other Action |
Ron Klein (ADEC) sent letter to Captain Brad Gerken (Departrient of the Air Force). SUBJECT: Oil and Hazardous Substance Spill and Contaminated Site Investigations. During a recent meeting with Ron Klein and Jennifer Roberts, Alaskan Air Command and Elmendorf Air Force Base Environmental Staff requested clarification of which ADEC office is responsible for coordinating the review of Air Force oil and hazardous substance spill assessment and contaminated site (OHSS-CS) and remediation plans and reports. The Anchorage/Western District
office is the designated office for coordinating Department review and comments of OHSS-CS plans and reports for U.S. Air Force installations in Anchorage, Southwest Alaska and the Aleutian Islands.
The designated contact is Ron Klein. The Department requests that three copies of each plan be provided to Mr. Klein who will then coordinate the document review among district, regional and central office staff. The Department requests that it be provided with a minimum thirty (30) day review period for single site plans and reports and forty-five (45) day review period
for mrulti-site plans and reports. Departures from these minimum review periods for specific documents will be considered upon request.
The Department is looking forward to maintaining a cooperative relationship with the U.S. Air Force in it's efforts to remedy its past and future environmental problems. |
Louis Howard |
| 9/25/1989 |
Update or Other Action |
Rastus O. Massey, Colonel, USAF Commander letter to Ron Klein. This letter is in response to the 13 September 1989 Notice of Violation/Request for Corrective Action for the JP-4 seep at Four Million Gallon Hill on Elmendorf AFB. In this Notice of Violation/Request for Corrective Action, you requested information on what actions the Air Force would take to contain the JP-4 seep.
As indicated in your letter, a "horizontal pipe dam" has been installed downgradient from the seep. The purpose of this dam is to contain the seep until we complete the final cleanup of the contaminated site. This dam was constructed during the first week of August 1989. For contingency purposes in case of the failure of the dam, an absorbent boom was installed immediately
downgradient of the dam.
During your 16 August 1989 inspection, it was noted erosion was occurring on the downstream side of the dam. This erosion problem prompted my staff to implement a weekly inspection of the dam and to repair it as necessary. Because of the potential failure of this dam, we have initiated the process to construct a new impermeable dam immediately downgradient. It is anticipated
this new structure will be constructed this October, depending on weather conditions; however, the construction may be delayed until next spring due to adverse weather conditions.
Until the new dam is constructed, the weekly inspection of the existing dam and the containment boom will continue. It will also be inspected after periods of intense rain storms and repaired as necessary. |
Ron Klein |
| 10/20/1989 |
Update or Other Action |
ADEC Ron Klein, Supervisor, Contaminated Site Investigations, sent letter to Captain Brad Gerken, Dept. of Air Force, 5099th Civil Engineering Operations Squadron (AAC) Subject: Response to September 27, 1989 Letter; Requirements for Temporary Storage of Petroleum Contaminated Soil.
Enclosed is a copy of the Southcentral Region Office's interim policy for storage and disposal of waste oil contaminated soil.
The guidance also applies to storage of soils contaminated with clean fuels if they are to be stored off the site where they were generated or stored on-site longer than thirty (30) days. The guidance document will be revised shortly to make that explicit. Petroleum contaminated soils generated on-site and stockpiled onsite for less than thirty (30) days must be placed on a bermed liner and covered. The liner and cover must be at least 6 mil reinforced polyethylene.
Alaska Department of Environmetal Conservation Southcentral Region Office - Interim Policy For Storage and Disposal of Waste Oil Contaminated Soil
The Southcentral Regional Office solid waste program has been working on an interim policy for storage and disposal of waste oil contaminated soil. Currently the Region has approved the removal of waste oil contaminated soil to a facility permitted to properly handle the contamination. With the exception of the Municipality of Anchorage (MOA) Landfill and Alaska Pollution Control Palmer Facility (pre-treatment for landfill disposal) all of these
facilities are located in the contiguous United States.
Currently, if the waste oil contaminated soil does not meet MOA Landfill criteria the only disposal option is to send the contaminated soil out of Alaska. Soil disposal under this method is costly due to handling, shipping, and facility fees. In discussions with Responsible Parties (RP) there appears to be a strong move to develop other local disposal methods that would meet with agency approval. Therefore the Regional solid waste program has developed interim storage guidelines for waste oil contaminated soils.
These guidelines include the following:
1. An approved design for a low-maintenance or maintenance free storage liner and cover that will be able to withstand winter conditions and is petroleum resistant. This will include a schedule to monitor the storage facility to verify that the integrity of the liner and cover is maintained through out the storage period.
2. Obtain a solid waste storage plan approval for onsite storage of waste oil contaminated soil from ADEC prior to storage construction.
3. The Responsible Party may propose to remove the waste oil contaminated soil to an off-site storage location if long term on-site storage is not practical. This location must be approved of by the Department prior to any transfer of the soils. The storage site must meet, ADEC design criteria and the RP must obtain an off-site; solid waste storage plan approval prior to transfer of the soil. All transfer of soil off-site must be done under a Bill of Lading and copies provided to ADEC.
4. The maximum allowable storage time is one (1) year. |
Ron Klein |
| 11/2/1989 |
Update or Other Action |
ADEC Letter to Colonel Mabry (USAF EAFB). Thank you for your 17 October, 1989 response to my September 1989 letter. The following are answers to the questions detailed in
your letter:
1. What State of Alaska regulations cover the treatment of soil contaminated with petroleum product?
The State has no detailed regulations on petroleum contaminated soil treatment. According to the oil pollution regulations (18 AAC 75.140, Cleanup), Immediately upon becoming aware of a discharge of a hazardous substance to the water or land of the state, persons responsible for that discharge shall clean up and dispose of the material collected using methods for which
prior approval, oral or written, has been given by the regional supervisor or his designee.
Under this section the Department reviews soil treatment plans to insure that the treatment method proposed is effective and will not result in the contamination of other sites.
Petroleum contaminated soil is also classified a solid waste uider State solid waste management regulations. See 18 AAC 60.910 (53) for the definition of solid waste. According to the solid waste regulations a permit is required for solid waste facilities. The solid waste regulations also provide guidance in 18 AAC 60.075 for landspreading operations.
Depending upon the petroleum contaminated soil treatment method selected other regulations may apply such as our Air Quality Control (18 AAC 50) and Wastewater Disposal (18 AAC 72)
regulations.
2. What are the State of Alaska cleanup standards for soil contaminated with petroleum products?
According to 18 AAC 75.130 (Disposal of Hazardous Substances) prior approval by the Department is required for the ultimate disposal of a hazardous substance, and soil, cleanup materials, or other substances contaminated with a hazardous substance. Chapter 75 classifies oil as a hazardous substance (see 18 AAC 75.900 (05)).
Ultimate cleanup levels depend upon what the proposed disposal alternative is. At a minimum soil needs to be cleaned up to a level which will not pose a risk to the lands and waters of the disposal site. The beneficial use of petroleum contaminated soils is encouraged. For example, processing petroleum contaminated soil through a hot mix asphalt plant for use as non-spec asphalt base. |
Ron Klein |
| 12/29/1989 |
Update or Other Action |
ADEC letter to Everett L. Mabry Colonel, Base Civil Engineer, HQ 21st Combat Support Group (AAC) RE: RI/FS Stage 4 Second Draft Work Plan Elmendorf Air Force Base, October 1989.
SITE SP-5/5A
The Department again (reference letter Klein to Mabry, November
1989) strongly suggests that the POL tanks be replaced due to the
corrosion problems and the associated distribution lines be tested
or replaced also. The reason for replacing the petroleum, oil and lubricants (POL) tanks is that the construction method allows water to build-up where the bracing attaches, and the water then causes corrosion to the tank.
Paragraph 5.2.2.3 Boring/Monitoring Well Installation states that
installation of deeper boring south of Loop Road will be based on
the results of the first deep boring which is on the northern
portion of the site. This site is complicated by the presence of
the groundwater divide which separates the northern and southern regions of the site. Due to stratigraphy creating the groundwater divide, information gained from the northern area should not be used to determine the installation of borings on the southern section of the site. |
Ron Klein |
| 1/1/1990 |
Update or Other Action |
INSTALLATION RESTORATION PROGRAM STAGE 3 REMEDIAL INVESTIGATION/FEASIBILITY STUDY TECHNICAL DOCUMENT TO SUPPORT A REMEDIAL ACTION ALTERNATIVE ELMENDORF AIR FORCE BASE, ALASKA SITE SP-5/5A PREPARED BY: BLACK & VEATCH, ENGINEERS-ARCHITECTS
Four 1,000,000-gallon bulk fuel storage tanks (nos. 601 through 604) are buried at this site. Extensive underground piping interconnects the tanks. The fuels spilled are petroleum products. The AVGAS and JP-4 contain purgeable aromatics such as benzene, ethylbenzene, toluene, and xylenes, collectively known as BETX compounds. Other general constituents of JP-4 include heavy straight-run naptha, clay-treated petroleum distillates, light aliphatic solvent naptha, hydrotreated light distillate, and hydrodesulfurized kerosene. NOTE TO FILE: Lead scavengers are compounds added to leaded gasoline to prevent buildup of lead deposits that foul internal combustion engines. In this capacity, EDB and EDC are referred to as “lead scavengers”. Even though leaded gasoline has not been used for on-road automobiles for more than a decade, lead compounds (and, therefore, lead scavengers) are still in use in aviation gasoline (Avgas) and in some off-road applications such as racing fuel. Beginning in the 1940s, EDB was partially replaced with EDC as a cost saving measure. In 1981, 83 percent of the EDB produced was used for lead scavengers. The most commonly used lead antiknock packages contain either tetraethyl lead (TEL) or tetramethyl lead (TML), both of which contained EDB and EDC.
Much physical evidence of soil contamination was apparent during installation of the boreholes. Fuel odors, soil stains, floating fuel, and elevated HNu readings were encountered at many of the boring locations. Total petroleum hydrocarbons (TPH), ethylbenzene, toluene, and xylenes contamination was detected. Maximum detectable concentrations of TPH, ethylbenzene, toluene, and xylenes in the soil samples from Site SP-5/5A were 286, 6.2, 6.6, and 27 mg/kg, respectively. TPH contamination in soil samples from well SP5/5A-16 is above the probable cleanup level of 100 mg/kg suggested by interpretation of the Alaska Department of Environmental Conservation (ADEC) Interim Soil and Groundwater Cleanup Guidelines.
One sample contained a small amount of ethanol. Other samples contained methylene chloride. Both are common laboratory contaminants. However, review of laboratory quality assurance and quality control (QA/QC) data does not allow these chemicals to be considered as laboratory contaminants at this site.
Extremely high concentrations of all BETX compounds were observed at the site. Peak concentration of each BETX compound in groundwater samples, all from well SP5/5A-16, are as follows: Benzene - 21,000 ug/L, Ethylbenzene - 2,700 ug/L, Toluene - 26,000 ug/L, Total xylenes - 10,900 ug/L. The maximum concentrations detected are beyond the saturation point
and may represent samples of water supersaturated with contaminants or samples in which free product was inadvertently introduced during collection.
Alternative 3 (Collection, Onsite Air Stripping, Surface Discharge) is the alternative recommended for remediation of Site SP-5/5A. The primary elements of this alternative include containment and collection of the contaminated groundwater plume by pumping from an extraction well and collection trench; recovering free-floating fuel product, also by pumping from the collection trench; treating the contaminated water by onsite air stripping; discharging the treated water to local storm drains; and monitoring the groundwater to determine plume migration and performance of the remedial action. |
Ron Klein |
| 1/22/1990 |
Update or Other Action |
USAF letter from Everett L. Mabry, Colonel, USAF Base Civil Engineer to Ron Klein. This letter is a follow-up to our 25 Sep 89 response concerning the Notice of Violation/Request for Corrective Action for the JP-4 seep at Four Million Gallon Hill on Elmendorf AFB.
Construction of the permanent underflow dam was completed 24 November 1989. Weekly inspection of the seep area and dam will continue, with petroleum, oil and lubricants (POL) products removed from the impoundment surface as they accumulate. |
Ron Klein |
| 2/19/1990 |
Meeting or Teleconference Held |
On 16 February 1990, a meeting was held to discuss Alaska Department of Environmental Conservation (ADEC) Stage 3 RI/FS and Stage 4 Work Plan review comments in their 15 November 1989 and 29 December 1989 letters. Those in attendance were:
Maj Lindsey C. Waterhouse Air Force
Capt Russell K. Godsave (Recorder) Air Force
lLt Walter Migdal Air Force/OEHL
Mr Glenn Brown Air Force
Ms Susan A. Curtin Black & Veatch
Mr Doug Johnson EPA
Mr Ron Klein ADEC
Mr Vernon M. Reid Black & Veatch
Ms Jennifer L. Roberts ADEC
Mr Howard Weaver Air Force
Mr Joseph Williamson Air Force
Page 1, GENERAL COMMENT #1: State mentions "several sites"; we requested in the future that the State identify sites. The 1000 mg/kg TPH level was noted by the State of Alaska (State) to be a Municipality of Anchorage (MOA) landfill requirement only. It was suggested that Mr Mike Blair of the MOA be contacted in relationship to the MOA landfill accepting "mass balance" of soil
to meet turn-in requirements. In relationship to this, Mr Doug Johnson noted that off-site disposal, as in the case of the MOA landfill, may include certain potential liabilities and the Air Force should be aware of these. Both the State and EPA stated that it may be better to treat contaminated soils on base. Mr Williamson reinforced this, stating that pretreatment of
soil will always be considered for each operable unit. The California "LUFT Manual" was noted by Major Waterhouse as guidance the State should consider adopting. In addition, the Air Force requested that State guidance be clear and promulgated. The State added the Air Force should strive for 100 ppm TPH for nongasoline removal or treatment.
Page 1, GENERAL COMMENT #2: The State requested seasonal sampling, they said, to get a better picture of hydrologic data, especially along Ship Creek. The intent is seasonal water level sampling, not full analytical sampling. In addition, the seasonal water sampling is intended to give us a good baseline for the future. The Air Force agreed. Seasonal sampling was
noted to be two periods: our dry and wet seasons.
Page 2, GENERAL COMMENTS #3 AND #4: The Air Force and the contractor plan to take a minimum of two samples per boring. More will be taken as needed. The State and EPA indorsed collecting samples for routine laboratory analysis at every 2 to 5-foot interval of the bore holes in preference to using an HNu to screen the split spoon sample and sampling only those levels where a positive HNu reading was obtained.
Page 2, GENERAL COMMENT #5: Again, the State mentions "many sites"; request in the future that State identify sites. Also, as discussed in the meeting, the contractor has based the location of new wells on logical data. The well locations, however, are general and will be sited more precisely as the study continues.
Page 2, GENERAL COMMENT #6: Although it was agreed upon that a possible route of contamination exists along well casings, at least the Air Force and contractor felt this risk was, at best, minimal. Still, Major Waterhouse pointed out that Bioenvironmental Engineering monitors all deep aquifer potable water wells. To date, no signs of contamination has been noted. Well
#1 is a 16-foot shallow well (cistern) collecting water from the shallow aquifer. The identified volatile organic contaminants in this well are not indicative of the deep water aquifer water quality.
Page 3, GENERAL COMMENT #7: Capt Godsave asked the State what an "approved oil/water separator" was and what regulations are entailed. The State elected to defer their answer. Mr Johnson noted that this was a NPDS or RCRA issue and not a CERCLA issue. Major Waterhouse noted that a team from Occupational and Environmental Health Laboratory (OEHL) are coming to Elmendorf AFB soon to achieve an inventory of floor drains as requested by the State. The State requested that the OEHL team discuss their methodology with the State up front. Major Waterhouse agreed to this.
Page 3, GENERAL COMMENT #8: The State stated this comment was essentially for our information. Both the State and EPA stated that a industrial waste water permit is not required for the storm sewers, but that the Air Force should meet the intent of such a permit.
Page 3, GENERAL COMMENT #9: The Air Force has asked the contractor to better define and consistently use the terms "off-site" and "off-installation," and be more definitive on the potential for contamination migration. Contaminant migration should only be inferred when enough
technical data has been obtained to support such a statement.
Page 4, SITE SP-S/5A: The Air Force feels the suggestion that the POL tanks be replaced is premature. The Air Force further stated that these tanks shall be leak tested under our next RI/FS study. It was agreed that Paragraph 5.2.2.3 could have been written more clearly, and a southern well, not northern well, as discussed, will be the basis of the installation of a deeper boring. |
Jennifer Roberts |
| 4/16/1990 |
Update or Other Action |
USEPA Memorandum Subject: Elmendorf AFB Deliverables and Operable Units (OU) from D. Johnson Environmental Scientist, AOO/A to George Hofer Chief Federal Facility Branch HW-074.
The following is a synopsis of two meetings that were held with staff members of ADEC and EPA. The first meeting was held on April 6, 1990 and the second was held on April 12, 1990. Attendees for the meetings from ADEC were Ron Klein, Max Schwenne, Colleen Burgh, Jennifer Roberts with Mary Siroki and Geoff Kany attending the first meeting.
The following reflects the input from ADEC regarding the document deliverables, determination of operable units, and schedules for inclusion to the Elmendorf AFB Interagency Agreement. This information was discussed with Bob Loiselle during your absence.
Document Deliverables: It was determined by mutual agreement that the same document deliverables now proposed for the Eielson IAG be incorporated into the Elmendorf IAG without change. ADEC agrees that for consistency and simplicity reasons the document deliverables for all Alaska IAG's remain the same.
Operable Units: Operable unit determination was based upon a hierarchy which was derived by either geographic or site characteristic similarities. The listed order was determined by severity of contamination (worst first) based upon common knowledge of the meeting participants.
Operable Unit #1 (Million Gallon Hill Area)-Sites SP-5/5A, OT-1, D-15, D-16, D-17, NS-2.
Operable Unit #2 (Air Force High Priority Sites-Sites S-5, D-4, D-10, FT-1
Operable Unit #3 (Landfills)-Sites D-5, D-6, D-7, D-8, D-9, D-11, D-12, D-13, NS-2
Operable Unit #4 (Hangar Floor Drains)-Sites IS-1, IS-2, IS-3, IS-4, IS-5, IS-6, IS-7, IS-8
Operable Unit #5 (Fuel Spill Sites)-Sites SP-1 thru SP-16, NS-3
Operable Unit #6 (UST/LUST Sites)-Approx. 35 known UST/LUST sites scattered around facility.
Operable Unit #7 (Misc. Sites)-Sites D-1, D-2, D-3, RD-1, S-l, S-3, S-4, S-6, S-7
Please note that of these operable units, the first three are probable definites for inclusion to the IAG. The last four have been included at this stage for discussion purposes and for understanding the perceived universe of sites at Elmendorf AFB.
Further refinement of this list and determination of schedules to be discussed on May 2, 1990 with ADEC. I will continue to discuss this subject with Bob as it develops, and would welcome any input you might have. |
Jennifer Roberts |
| 5/1/1990 |
Update or Other Action |
AK ACTION-SPECIFIC ARARS
18 AAC 72.027. DISCHARGE TO SEWERS.
(a) ADEC will, in its discretion, require that nondomestic wastewater (NDWW) discharged to a sewer, domestic treatment works, or disposal system be treated & equalized to prevent overloading of or damage to the sewer treatment works, or disposal system, or pollution of receiving waters.
(b) No person may
(1) discharge stormwater, silty water from construction dewatering efforts, gutter runoff, or street runoff into sewer designed to handle only sewage or sewage & NDWW flows;
(2) discharge oil, petroleum products, or industrial solvents into a sewer designed to handle only sewage or stormwater;
(3) install a gravity collector sewer unless its diameter is equal to that set out in Table D, it has minimum conduit velocity of 2 ft/sec (0.6 m/sec.), & the receiving sewer has a diameter at least equal to that of the largest sewer line connecting to it; or
(4) cause any connection or additional discharge to a sewer or domestic WW treatment works or disposal system which the ADEC has found to be overloaded or inadequate. (Eff. 12/30/82, Reg. 84)
18 AAC 72.210. RESTRICTIONS.
(a) A person who disposes of NDWW into or onto waters or lands in AK must have a permit issued by ADEC for that disposal.
(b) The deputy commissioner will, in his discretion, issue a project-wide disposal permit as a person who plans to conduct an operation with the same disposal characteristics at various discharge locations. The deputy commissioner will, in his discretion, require the submission of site-specific plans for approval as a condition of the permit. (Eff. 12/30/82, Reg. 84)
18 AAC 72.240. SLUDGE DISPOSAL.
A person may dispose of sludge resulting from a manufacturing or production process or a NDWW treatment works only at a site or facility with a waste permit issued by ADEC for that disposal. The ADEC will require that the sludge be treated before disposal if necessary to protect public health or the environment. (Eff. 12/30/82, Reg. 84)
18 AAC 72.260. SYSTEM PLAN REVIEW.
(a) A person who constructs, alters, installs, modifies, or operates any part of a NDWW treatment works or disposal system must first have written approval from ADEC of engineering plans.
18 AAC 72.270. REPORTS.
ADEC will, in its discretion, require that a person who owns or operates a NDWW treatment works or disposal system routinely submit operational reports on forms provided or approved by ADEC. (Eff. 12/30/82, Reg. 84)
(b) If construction, alteration, installation, modification, or operation has not begun within 2 years after issuance of plan approval, the approval is void, & plans must be resubmitted to ADEC for review & approval.
(c) Engineering plans required (a) of this section must include:
(1) location of proposed or existing improvements, WW treatment works & disposal systems, sewers, DW supply lines, drinking water sources, & waters in the vicinity of the proposed system;
(2) detailed flow diagrams showing the physical & chemical composition & amount of each NDWW disposal;
(3) a statement identifying persons who will own, operate, & maintain the proposed project;
(4) a description & timetable of the proposed construction or other activity;
(5) information on sludge handling & disposal from the proposed treatment works;
(6) a statement identifying persons who will own, operate, & maintain the proposed system; &
(7) other information ADEC requires to assess compliance with this chapter.
(d) ADEC will, in its discretion, attach terms & conditions to submitted plans if needed to ensure compliance with this chapter.
(e) As accurate & complete set of as-built engineering plans for NDWW treatment works & disposal systems with a discharge greater than 10,000 gal/day must be submitted to ADEC within 90 days after the project's startup date. ADEC will, in its discretion, waive this requirement if it has made an on-site inspection & finds that the system was built as approved. (Eff. 12/30/82, Reg. 84)
18 AAC 75.130. DISPOSAL OF HAZARDOUS SUBSTANCES.
(a) Prior approval by ADEC is required for the ultimate disposal of a hazardous substances, and soil, cleanup materials, or other substances contaminated with a hazardous substance. Approval under this section may be granted orally by the regional supervisor or his designee.
(b) As used in this section, "ultimate disposal" includes disposal into or upon the waters or the surface or subsurface land of the state, and open burning. (Eff. 4/23/77, Reg. 62)
18 AAC 75.140. CLEANUP.
(a) Immediately upon becoming aware of a discharge of a hazardous substance to the water or land of the state, persons responsible for that discharge shall cleanup and dispose of the material collected using methods for which prior approval, oral or written, has been given by the regional supervisor or his designee. The discharge must be cleaned up to the satisfaction of the regional supervisor or his designee. |
Louis Howard |
| 9/26/1990 |
Update or Other Action |
INTERIM GUIDANCE FOR SURFACE AND GROUNDWATER CLEANUP LEVELS SEPTEMBER 26, 1990
Interim cleanup guidance for contaminated surface and groundwater remediation is necessary to ensure that consistent cleanup levels are being applied by district and regional program staff. The following guidelines should be implemented under 18 AAC 75.140 which specifies that a "discharge must be cleaned up to the satisfaction of the Regional Supervisor or his designee.
Final cleanup levels shall be determined by the Regional Supervisor or his designee based on site-specific conditions. Staff should be aware that if a facility is regulated under RCRA, that RCRA corrective action and cleanup standards should enter into development of final site cleanup levels.
Groundwater should be cleaned up to levels not exceeding the more stringent of the final State or Federal Maximum Contaminant levels (MCLs) for Organic and Inorganic Chemicals. If final MCLs have not been adopted for a contaminant, then groundwater should be cleaned up to levels not exceeding proposed Federal MCLs. The group of compounds collectively identified as total petroleum hydrocarbons (TPH) should be cleaned, up to non-detectable levels as measured by EPA Method 418.1.
Final State MCLs are specified in 18 AAC 80.050 and final Federal MCLs are specified in 40 CFR 141 and 142. Proposed Federal MCLs are specified in the May 22, 1989, Federal Register Vol. 54, No. 97, pages 22155 - 22157 and the July 25, 1990, Federal Register Vol. 55, No. 143, pages 30408 - 30448. Appendix I provides a summary listing of State and Federal Final and Proposed MCLs for selected organic and inorganic contaminants.
For organic and in organic contaminants that have not been assigned a final or proposed MCL, cleanup levels should be based on criteria cited in EPA's Water Quality Criteria. 1986 using a health risk factor of 10-6. EPA's water quality criteria identify concentrations of elements and compounds which have toxic effects on aquatic organisms or toxic and carcinogenic effects on humans.
If groundwater is being used as a drinking water source and alternative water supplies or point of use water treatment cannot be provided, then final or proposed secondary maximum contaminant levels (SMCLs) may be used as cleanup target levels. SMCLs are based on aesthetic properties such as taste and odor, whereas MCLs are based on human health risks. For compounds such as xylenes, the SMCL maybe several hundred times lower than the MCL.
Surface waters used for drinking water should also be cleaned up to levels not exceeding the final or proposed MCLs for organic and inorganic chemicals, as specified above. Under the authority of 18 AAC 70.020, surface waters important to the growth and propagation of aquatic life should be cleaned up to the listed criteria which includes EPA's Water Quality Criteria. 1986. These criteria identify concentrations of specific elements or compounds which have toxic effects on aquatic organisms. The group of compounds collectively identified as total petroleum hydrocarbons (TPH) should be cleaned up to non-detectable levels as measured by EPA Method 418.1.
Alternative Cleanup Levels (ACLs) may be adopted for a site if a risk assessment approved by the department is performed and cleanup to levels identified above is technically infeasible. Risk assessments will not by themselves establish ACLs. Determination of cleanup levels is a risk management decision that the department must make based on results of a quantitative risk assessment and other pertinent information.
The responsible party (RP) may prepare at its own expense a risk assessment which shall include an assessment of both human health and environmental risks. Specific components of the risk assessment should include an exposure assessment, toxicity assessment, risk characterization, and justification of ACLs. A general description of these risk assessment components is provided in Appendix II.
General technical requirements for risk assessments should be based on EPA risk assessment guidance for superfund sites. A site specific risk assessment procedure must be prepared by the RP and submitted to the department for review and approval prior to conducting a risk assessment. The RP, at the department's discretion, must agree to reimburse the department for expenses incurred by the department if it chooses to contract for a risk assessment review. |
Louis Howard |
| 10/15/1990 |
Meeting or Teleconference Held |
An IRP progress meeting was held at Elmendorf AFB on 15 Oct 1990. The following people were present:Ken Lauzen EPA, Anchorage Office, Jennifer Roberts ADEC, Anchorage Office, Rick Belan MITRE, HSD/YAQ Brooks AFB Texas, Mark Bryant Harking Lawson Associates, Anchorage, Don Dubois Jacobs Engineering Group, Seattle, Rick Prescott Harding Lawson Associates, Anchorage, H. L. Willman Jacobs Engineering Group, Seattle, and H. D. Weaver 21 CSG/DEEV Elmendorf AFB, Alaska.
The following items were discussed and agreement was reached between all the attendees:
A. Deep wells are to be postponed until spring 1991 when we will have more information, from previous testing, to use in deciding where to locate them. Additionally casing will be required to prevent possible cross zone contamination from occuring. A rotary drill rig will be used to drill this well.
B. Clean decontamination rinse water, determined to be clean by
laboratory testing, will be disposed of in the Municipality of Anchorage (MOA) Waste Water Sewage Treatment System if possible. Before any clean decontamination rinse water is disposed of the contractor shall determine what the MOA requires in terms of testing and meet any requirements. If the Anchorage Waste Water Sewage Treatment is unavailable the second choice will be the Eagle River Waste Water Treatment Plant. The Anchorage system might refuse the rinse water because they use a single level treatment process. The Eagle River plant adds a second level of treatment.
C. The sampling location plan was upgraded to include some further sites at the Four Million Gallon Hill (ST41) and the old Power Plant Storage tank site (ST20).
D. A spring with a noticeable odor and a visible sheen has been
discovered north of the Four Million Gallon Hill. It was decided that the surface water needs to be sampled. Our contract called for one surface water sample to be collected from the seep south of the Four Million Gallon Hill, however it was decided to move this sample to the spring. Everyone ageed that the seep has floating petroleum on the surace and a sample to prove this is unnecessary.
E. When petroleum contamination is a possibility, we will use stainless steel screens in all monitoring wells. |
Jennifer Roberts |
| 2/8/1991 |
Public Notice |
Anchorage Daily News public notice regarding leaks discovered from the four 1,000,000 gallon Base fuel tanks. Base officials notified the Alaska Department of Environmental Conservation today that they had discovered leaks from four of the base's fuel tanks. The leaks were discovered during continuing studies of soil and ground waters around several underground storage tanks. The fuel storage area was previously identified as a spill site because of incidents from the late 1960s to mid 1970s.
Col. Donald J. Creighton, 21st Tactical Fighter Wing commander here, said he will take immediate steps to eliminate the problem. "We've already begun transferring fuel from the
affected tanks, and they will be taken out of service entirely," he explained. "It would be environmentally unsafe to continue using them. We'll construct new facilities elsewhere on the
base and take whatever cleanup measures are necessary to restore the old storage site."
The latest information is the result of new technology that allows engineers to add elements to the fuel in the tanks and then test for traces of the vapors in the ground around the tanks.
There are four tanks in the area with a total capacity of over 4 million gallons. Base officials estimate it will take about 4 weeks to drain all the tanks. Three tanks are nearly
full and the fourth is only partially filled. Ground water testing has failed to show any fuel seepage outside the immediate area of the storage tanks. That testing will continue to ensure there is no danger to the public.
Point of contact for this release is TECHNICAL SGT DAVID HAULBROOK, 552-5755. |
Jennifer Roberts |
| 2/14/1991 |
Update or Other Action |
Bill Lamoreaux received a USAF hazardous substance discharge report. Four one-million gallon underground storage tanks near building 31-600 released unknown amount of JP-4 fuel. Four fuel tanks taken out of service. It is estimated that it will take four weeks to drain the tanks completely.
ST41 (formerly SP-5): JP4 Bulk Storage Tank spill. Bulk Fuel Storage Tank Numbers 601 through 604. Located north of Loop Road and west of Brown Road. Numerous spills since their installation in 1942. They are interconnected and gravity fed without any check valves between tanks. A 60,000 gallon avgas spill occurred in the mid-1960s and on 8/30/64 33,000 gallons of JP-4 fuel was recovered. Several million gallons of JP-4 were reported spilled 1973-1974. *Note to file: In 1951, the JP-4 fuel specification was
adopted and became the primary jet fuel
of the U.S. military for the next 30 years.
JP-4 was called a wide-cut fuel rather than a kerosene, because the boiling range
broadly overlapped both gasoline and
kerosene. Again, there was no flash point
requirement, but the Reid vapor pressure
was reduced to the range of 2 to 3 psi,
which produced flash points around 0°F.
The U.S. Navy briefly used JP-4, but rapidly
developed concerns over shipboard
safety with the volatile fuel. JP-5, with a
140°F flash point, was developed for Navy
aircraft and is still used today. JP-4 is the military equivalent of Jet B with the addition of corrosion inhibitor and anti-icing additives; it meets the requirements of the U.S. Military Specification MIL-PRF-5624S Grade JP-4. JP-4 also meets the requirements of the British Specification DEF STAN 91-88 AVTAG/FSII (formerly DERD 2454),where FSII stands for Fuel Systems Icing Inhibitor. NATO Code F-40.
Visible seeps are seen from the hill side into flight line storm drainage ditches. Monitoring wells were installed and reported contamination and contamination migration. This site has been listed on the National Priorities Listing (NPL), further investigation will be determined and performed pending determination of the appropriate authority (CERCLA or RCRA enforcement). Proposed listing on NPL was 07/14/1989 and Final listing on NPL was on 08/30/1990. |
Bill Lamoreaux |
| 4/11/1991 |
Update or Other Action |
Tracer Tight Test report prepared for VRCA Environmental Services for the Air Force of 4 USTs at facility 31600 on 2/7/1991 received by Anchorage Western District Office. Tanks inoculated to 10 ppm equivalent concentration on 11/2/90. Samples collected on 12/16-17/1990. Pass classification = 0.05 gal/hr or Tracer detected at less than 0.1 ug/L at 5' below grade or less than 1.0 ug/L or greater than 0.1 ug/L if concentration below grade decreases with an increase in depth. Fail criteria = leak rate => 0.05 gal/hr or Tracer indicated at greater than 1.0 ug/L with any depth below grade or greater than 1.0 ug/L but less than 1.0 ug/L if concentration sustains or increases with an increase in depth. *Note sustaining concentrations are those concentrations which are within 50% of the concentration detected at the shallower depth. All tanks were determined to "failed" with Tracer DDM. Limitations on the results: Temperature is not a factor because TRACER detection outside the tank does not depend on fuel temperature in the tank. Temperature does not affect the amount of TRACER released. Other limitations by the vendor TRACER Research Corp during testing: After TRACER chemical is added, you must wait at least 14 days to collect samples from the vapor probes. Alternative approaches must be used if top of the tank is under water. These approaches are available through Tracer Research Corp. |
Jennifer Roberts |
| 5/8/1991 |
Document, Report, or Work plan Review - other |
EPA (MJ Nearman Environmental Engineer) sent Joe Williamson 21 CES/DEEV a comment letter on the September 1990 SAP OUs 1 and 2. The field sampling plan (FSP) does not appear to contain the supporting rationale for the proposed location and the number of borings, wells, product probes and ground water field sampling probes. No proposed locations were presented for the screening methods. Much of this information is assumed to be available in the earlier reports (e.g., Stage 4 RI/FS Workplan). If so, the relevant maps, tables, figures, and text should be referenced to support the location and number of sampling points.
If the aquifer is less than 10 feet thick, it is appropriate to have well screening that fully penetrates the entire aquifer. When the aquifer becomes thicker, multiple well screens are necessary to characterize the groundwater flow. Multiple completions at the same location are particularly important in areas of ground water recharge and discharge where flow paths and contaminates will be following flow paths other than horizontal. Significant dilution of the ground water samples will occur if the well screens are too long.
The number of well screens that are necessary both horizontally and vertically is a function of the complexity of the geology and waste disposal history of each unit. The investigation methods have to be consistent with the complexity of the geology and the potential flow paths that contaminants may follow for the waste. It does not appear from reviewing the available data that there is the appropriate number of wells at these units. Further, it does not appear that the appropriate testing has been done to demonstrate that wells are related to each other. Such methods as pump tests and surficial geophysics between wells have not been done to demonstrate that the hydrogeology is understood.
The use of broad arrows to indicate ground water flow directions does not allow for adequate review of the proposed locations of monitoring wells, field sampling points, and product probes. Supporting information to demonstrate the direction of ground water flow should be included. It is not clear what sampling frequency of the monitoring wells is being proposed. It is necessary to collect ground water samples over a period of time in order to evaluate seasonal trends in the chemical data and in the ground water flow directions. Since most monitoring wells have been in place since at least the summer of 1989, there has been ample opportunity to collect at least four to eight quarters of data. Many wells have been in considerably longer. Once it is determined that remedial action will. be necessary, quarterly groundwater sampling is typically continued to provide additional data for remedial design.
In several places, the presence of floating free product is suspected. Wherever found, this floating layer should be analyzed. The results from analyzing the floating layers should be compared with the analyses of the ground water to determine if changes are occurring as the waste dissolves, volatilizes, and ages within the system.
Page 2-28: There is no proposal to sample and analyze the LNAPL layer, if encountered. It is assumed that no sampling of LNAPLs is being proposed because-there is no question about the chemical composition of any LNAPL and that all reactions of weathering, chemical interaction, etc. are known from previous studies. If this is the case, then the supporting data should be at least referenced to support the non-sampling of all LNAPLs. If a LNAPL is detected, it is being proposed that a riser pipe be placed into the wells several feet below the LNAPL/water interface, that the well be purged, and that groundwater be sampled through the riser pipe. It is assumed that part of the intent of using this method is to sample ground water separate from the LNAPL. It is not clear in reading this proposal how smearing of the LNAPL within the aquifer material and filter pack is going to be avoided as the water level is lowered during purging. When the water level recovers, the LNAPL will be coating the aquifer material and the filter pack. This results and may transport contaminants into portions of the aquifer where it has not been before.
More detail is needed regarding: (1) the proposal of using the riser pipe; (2) what controls are to be used to avoid spreading LNAPLs deeper into the aquifer; and (3) the potential for biasing future ground water sampling. It has to be explained what the advantages are of this single wells system over other systems that might be used such as well clusters. Have 2-stage pumps for simultaneous product and ground water sampling been evaluated?
See site file for additional information.
|
Jennifer Roberts |
| 11/12/1991 |
Update or Other Action |
Jennifer Roberts Federal Facility Coordinator sent letter to Joe Williamson and Rich Howard pursuant to Section 9.1 of the Elmendorf Air Force Base Federal Facility Agreement (FFA). ADEC designates Jennifer Roberts as the Project Manager and Ron Klein as the Alternate Project Manager for all activities covered under the FFA. |
Jennifer Roberts |
| 11/12/1991 |
Enforcement Agreement or Order |
Federal Facility Agreement under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) signed for docket # 1089-07-19-120. The agreement ensures that the environmental impacts associated with past and present activities at the Base are thoroughly investigated and appropriate removal and/or remedial action(s) taken as necessary to protect human health and the environment. Elmendorf Federal Facility Agreement signed. The general purposes of this Agreement are to: (a) Ensure that the environmental impact associated with past and present activities at the Site are thoroughly investigated and appropriate removal and/or remedial action(s) taken as necessary to protect the public health, welfare, and the environment.(b) Establish a procedural framework and schedule for developing, implementing, and monitoring appropriate response actions at the Site in accordance with CERCLA, the NCP, Superfund guidance and policy, RCRA, RCRA guidance and policy, and applicable state law.
The FFA divided the CERCLA study source areas at Elmendorf AFB into the following seven operable unites (OUs), on the basis of geographic proximity and similar source characteristics or contaminants:
- OU1 Landfills (LF05, LF07, LF13, LF59, OT56)
- OU2 Tank Spill Sites (ST20, ST41, including the ST41 Sludge Disposal Area)
- OU3 Central Containment Area (SD16, SD31, SD52, SS21)
- OU4 Northern Containment Area (SD24, SD25, SD28, SD29, FT23, SSl0)
- OU5 Southern Containment Area (ST37)
- OU6 Surface Disposal Sites (LF02, LF03, LF04, SD15, SD73, WP14)
- OU7 Limited Field Investigation (SS19)
Proposed listing on NPL was 07/14/1989 and Final listing on NPL was on 08/30/1990.
See site file for additional information. |
Jennifer Roberts |
| 12/2/1991 |
Update or Other Action |
Installation Restoration Program Interim Remedial Action Operable Unit 2 (Source Area ST41) Preliminary Alternatives Summary. This Preliminary Alternatives Summary is for an Interim Remedial Action to address fuel (product) floating on the groundwater near four one-million-gallon fuel storage tanks. The tanks are at Source Area ST41 at Elmendorf Air Force Base, Anchorage, Alaska. Three Alternatives are examined: (1) No Action; (2) Product recovery using the tanks as collection vessels; (3) Product recovery by installing large diameter recovery wells. The alternatives were weighed against evaluation criteria as specified in the NCP. The preferred alternative is Alternative 3.
The IRA objectives are to remove fuel product known to be floating on the groundwater and to contain and treat three groundwater seeps. Accomplishing these objectives will remove a source of contamination at ST41 and will reduce the present flow of fuel product contamination away from the tank area.
The overall risk to human health and the environment will be reduced by implementing the IRA. The three alternatives analyzed for ST41 are 1) no action 2) extraction of product using the existing storage tanks and 3) extraction of product using extraction wells. The second and third alternatives also include collection and treatment of groundwater seeps. The alternatives are evaluated and a preferred alternative is selected.
This document is issued by the U.S. Air Force, the lead agency, in consultation with the U.S. Environmental Protection Agency (USEPA) and the Alaska Department of Environmental Conservation (ADEC). The Federal Facilities Agreement (FFA) is the basis for the interim action.
From Section 2.1 (i) of the FFA: "Interim Actions" or "IAs" are discussed in the Preamble to 40 CFR 300.430 (a) (1), 55 Fed. Reg. 8703-8706 (March 8, 1990), and shall mean all discrete actions implemented under remedial authority that are taken to prevent or minimize the release of hazardous substances, pollutants, or contaminants so that they do not endanger human health or the environment. Interim actions shall neither be inconsistent with nor preclude implementation of the final expected site remedy and shall be undertaken in accordance with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part 300, as amended, and with the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
The preferred alternative for recovering the maximum amount of fuel product at ST41 is Alternative 3 - Product Removal Through Recovery Wells and Seep Containment. Based on information currently available, the preferred alternative provides the best balance of tradeoffs among the alternatives with respect to the
relevant evaluation criteria. Because this action does not constitute the final remedy for OU2, the statutory preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a principal element, although partially addressed in this remedy, will be addressed by the final response action.
Subsequent actions are planned to address fully the threats posed by the conditions at this operable unit. Because this remedy will result in hazardous substances remaining on site above health-based levels, a review will be conducted to ensure that the final remedy continues to provide adequate protection of human health and the environment within five years after commencement of the remedial action. Because this is an interim action, review of this site and of this remedy will be continuing as final remedial alternatives for this operable unit continue to be developed.
A detailed analysis and evaluation of ARARs was not conducted for this alternatives summary due to the scope of the IRA for ST41. For the alternatives considered, regulations directly related to the removal, treatment and disposal of the fuel product and associated groundwater are considered and the intent of the regulations will be met. |
John Halverson |
| 12/6/1991 |
Site Added to Database |
See also 88210932501 "Elmendorf tank farm" |
Louis Howard |
| 12/27/1991 |
Update or Other Action |
Letter from USAF to Jennifer Roberts requesting extension to 12 May 1992 for the submittal of the draft record of decision (ROD) for interim remedial action at OU2. Currently scheduled for submission on 15 January 1991 and due to reformatting of the proposed plan and allowing extended review process for EPA it has resulted in the USAF not being able to meet the ROD deadlines outlined in the FFA. Had the USAF been aware of the EPA's review process for proposed plans during FFA negotiations last summer (1990), they would not be committed to submitting the ROD on the earlier date.
Note to file:
Interim Actions
The purpose of the IA-OUs at the EAFB are to achieve early actio using remedial authority at
those sites which meet the IA deneral principles that are discussed in the NCP. If at anytime the information submitted to suppo-t the IA is found to be equivalent to that obtalned during an Rl/FS and the OU is separable, then he IA may be upgraded to an early final action.
The Preamble of the NCP, 55 Federal Register 8703-8706 (March 8, 1990) states that to Implement
an early action under remedial authority, an operable unit for which an interim action is appropriate is identified. IA decisions are intended for straightforward sites that are limited in scope.
Data sufficient to support the interim action decision is extracted from the ongoing RI/FS or from previous studies and an appropriate set of alternatives is evaluated. Few alternatives and in some cases only one should be developed for interim actions. A completed basellne risk assessment generally will not be available or necessary to justify an interim action. |
Jennifer Roberts |
| 12/30/1991 |
Update or Other Action |
EPA sent letter to AF Rich Howard and Joe Williamson. The notification will serve as an addendum to the previous letter of November 4, 1991 which designates the USEPA project managers pursuant to Section 9.1 of the Elmendorf Air Force Base (EAFB) Federal Facilities Agreement (FFA). Marcia Combes will serve a lead remedial project manager (RPM) for Base-wide activities, as well as Operable Units (OUs) 2, 3, 5, 6, 7. Michele Poirier-McNeill will serve as lead RPM for OUs 1 and 4. In addition both RPMs will serve as an alternative RPM on OUs for which they are not the lead. For communication and correspondence purposes, the lead RPM should be the point of contact, and the alternate should be copied. |
Jennifer Roberts |
| 1/2/1992 |
Update or Other Action |
EPA letter to AF and cc to J. Roberts regarding extension request for OU2 Interim Remedial Action. Wayne Pierre Chief Federal Facility Section states the USAF enclosed schedule with its request proposed April 13, 1992 as the new date for submittal of the draft ROD, based on a thirty (30) day public comment period. This is approximately 3 months beyond the established deadline listed in the FFFA. Although the only reason EPA can see as the cause of the delay is inexperience, the Agreement does provide for extensions when there is mutual agreement between the Parties that an extension is necessary. Although the 12/27/1991 letter did not support a "good cause" demonstration (in EPA's opinion) for the extension, we, like the Air Force, are committed to completing environmental restoration at Elmendorf on or ahead of schedule and understand the difficulties in getting such a complicated remedial action program started. Based on these assumptions, EPA agrees to extend the deadline for he draft ROD until April 13, 1992. A formal form which documents this extension will be forthcoming from EPA. |
Jennifer Roberts |
| 1/10/1992 |
Update or Other Action |
Jennifer Roberts sent to Joe Williamson (USAF) a letter regarding the AF's request for an extension on the draft Record of Decision (ROD) deadline date pursuant to Section XXV of the EAFB Federal Facility Agreement (FFA). One of DEC's prime objectives is to keep the actual cleanup actions on schedule. ADEC recognizes the difficulties EAFB appears to be having in altering their environmental program to meet the FFA requirements. Therefore ADEC is willing to grant EAFB the extension which will allow the draft ROD to be submitted on April 13, 1992 based on the 30 day public comment period. |
Jennifer Roberts |
| 1/30/1992 |
Update or Other Action |
Jennifer Roberts received a USAF request to close out the September 13, 1989 Notice of Violation (NOV) involving petroleum, oil, and lubricant releases to stream from leaking underground storage tanks (USTs). The tanks were taken out of service and an underflow dam was installed. The site will begin remediation under the Defense Environmental Restoration Program (DERP) in FY 1993 (September 92-October 93). Asking ADEC to provide USAF a letter indicating the closure for their records. Roberts drafted letter to USAF and referred it to Anchorage District Office for signature. |
Jennifer Roberts |
| 2/1/1992 |
Long Term Monitoring Established |
Long term monitoring of groundwater and surface water begins at ST41. Fuel and groundwater movement will be monitored using existing observation wells. If necessary, additional recovery wells will be install to increase product recovery. |
Jennifer Roberts |
| 2/17/1992 |
Proposed Plan |
Proposed Plan for Interim Remedial Action at ST41 received. Product removal using recovery wells and seep containment was selected for the interim remedial action (IRA) at ST41. Remedial action objectives are 5.0 ug/l benzene and the Alaska water quality standards of 5.0 ug/l.
This plan, submitted in accordance with Section 117(a) of CERCLA, highlights the IRA preferred by the Agencies The actual remedy selected may be the preferred alternative, a modificatwn of it, a combination of elements from some or all of the alternativcs, or a separate response action. Comments are being solicited on all of the alternatives, not just the preferred
alternative. The alternative to reduce movement of contaminated groundwater will not be selected until the public comment period has ended and all comments have heen received and considered.
The purpose of the IRA is fourfold 1) to prevent the spread of fuel constituents, 2) to facilitate recovery of floating fuel product from the shallow groundwater surface in the vicinity of the fuel tanks, 3) to collect contaminated water at the seeps, and 4) to initiate a
cleanup strategy expected to be consistent with the fmal remedy for ST41.
These actions promote the ultimate goal of protecting potential drinking water for future users by controlling a source of groundwater contamination and reducing further movement of contaminated groundwater. Containment of the seeps will eliminate a pathway of contamination to humans, wildlife, and plants from surface water and groundwater. The final cleanup may he different than this IRA or may include additional measures (e.g., soil cleanup) that are beyond the scope of this action.
Alaska Department of Environmental Conservation has been involved in the preparation of this Proposed Plan and comments received have been incorporated.
The Agencies recommend Alternative 3 - Product Removal Using Recovery Wells and Seep Containment
as the preferred alternative for the IRA at ST 41. This alternative is preferred because it best achieves the goal of the first seven applicable evaluation criteria in comparison to the other alternatives. In addition, community acceptance will be evaluated based on comments received and will be documented in the Record of Decision. Alternative 1 does not reduce the
risk or expedite the total site cleanup. Alternative 3 was selected over Alternative 2, because Alternative 1 uses an unproven technology that reduces the confidence level for an effective cleanup.
Public Notice in Anchorage Times on 2/18/1992 announcing public comment period and public information meeting regarding the Proposed Plan for Interim Remedial Action at Source Area ST41 (Four-million gallon hill). Comment period is from 2/17/92 to 3/17/92. Agencies (AF, DEC, EPA) preferred alternative identified is: product removal using recovery wells and seep contaminant. |
Jennifer Roberts |
| 2/27/1992 |
Meeting or Teleconference Held |
Public meeting held for discussing comments from the public on the Proposed Plan for Interim Remedial Action at ST41. |
Jennifer Roberts |
| 3/19/1992 |
Document, Report, or Work plan Review - other |
Jennifer Roberts sent comments to USAF regarding the OU2 Conceptual Site Model (CSM) and data quality objectives (DQOs) dated February 1992. General comments: It contained extensive information that is unessential. Section 2 (Base Environmental Setting) of the CSM is appropriate in the OU2 management plan (MP), not the CSM and therefore extraneous. ADEC is concerned that the information needed to develop a comprehensive MP will not be available in time to be used in determining data needs for the OU2 MP. For example, the base-wide groundwater study which will not be completed before OU2 field work.
Information generated by the base-wide groundwater study includes onsite and offsite well data which will be a valuable tool in determining additional data needs for OU2. The CSM lacks information on the future use scenario for the risk assessment. This scenario needs to be developed in the CSM to determine what data need must be met. ADEC disagrees that benzene in the water sample is not expected since benzene is not a component of JP-4. *NOTE to file: • JP-4 is essentially a 50:50 mixture of heavy naphtha fraction (like gasoline) and kerosene. This fuel is not considered to be an acceptable substitute/alternate for diesel fuel. JP-4 is interchanged within NATO under NATO Code Number F-40. JP-4 is mainly procured as ASTM D 975 Jet B (or perhaps as CAN/CGSB 3.22). The chief difference between JP-4 and Jet B is that JP-4 contains the three mandatory additives while Jet B does not unless requested during procurement. JP-4 is not a kerosene-type aviation turbine fuel, but instead is approximately a 40:60, 50:50, or 60:40 mixture of kerosene with naphtha (e.g., a gasoline-type blending stock). It is called a "wide-cut fuel". JP-4 is procured under MIL-T-5624 and has been interchanged-within NATO under NATO Code Number F-40. It is not usually considered as an acceptable substitute for diesel-fueled equipment.
Due to presence of benzene Shannon and Wilson contacted the fuel manufacturer (Mapco) and was informed the benzene is a component of Mapco's JP-4. In general fuels used in Alaska tend to have a slightly higher amount of benzene than is common in fuels produced for use in the contiguous United States. |
Jennifer Roberts |
| 4/9/1992 |
Update or Other Action |
EPA Memorandum April 9, 1992 Reply to the ATTN of ES-098. Subject Toxicity of Fuels. From Carol Sweeney, Toxicologist Health and Environmental Assessment Section. To Wayne Pierre Federal Facilities Superfuend Branch (HW-124). A response has been provided to the frequently-asked question of whether a reference dose or other toxicity information can be provided for fuel mixtures so that these mixtures can be addressed quantitatively in Superfund risk assessments. The memo from ECAO Cincinnati is attached (last attachment).
They have developed reference doses for gasoline, JP-5/kerosene, and JP-4, and a cancer potency factor for gasoline. The memo emphasizes that these are provisional numbers and that considerable uncertainty is involved in this quantitative assessment, because of data limitations, and because inhalation studies were used to calculate oral reference doses.
I typed up a summary table showing the numbers (first attachment) and calculated some risk-based concentrations (second attachment). On the risk-based concentration table, I also
included ordnance compounds, because I hadn't made a table of those before that I can remember. The risk-based concentrations were calculated the same way as table II-1 and II-2 of the Region
10 Supplemental guidance; for soil, the same limitations apply, that the numbers presented do not consider pathways other than soil ingestion.
Toxicity Reference Vaules for Fuel Mixtures EPA Region 10 4/9/1992 Non-cancer effects-Gasoline (unleaded) RfD (mg/kg-day) Oral: 2.0E-1, Uncertainty Factor-Oral:1000, Level of Confidence-Oral: Low. Toxicity Data Source-Oral RfD: Memo 3/92. Carcinogenicity-Cancer Potency/(mg/kg/day): Oral 1.7E-3, Unit Risk (/ug/m3) 4.8E-7, Cancer Weight Of Evidence-C, Toxicity Data Source-Oral SF and Inhal. SF: Memo 3/1992.
Kerosene/JP-5 RfD2.0E-2, UF Oral: 10,000, LOC Oral: low, TDS Oral RfD: Memo 3/92
JP-4 RfD 8.0E-2, UF Oral: 10,000, LOC Oral: low, TDS Oral RfD: memo 3/92.
Screening Values for Water RBCs based on Ingestion, Residential
Gasoline-Risk = 10-6 (ug/L) 50, 10-4=5000 HI=1 (ug/L) 7000
JP-5 Kerosene Risk 10-6 10-4=NA HI = 1 (ug/L) 700
JP-4 Risk 10-6 10-4 = NA, HI = 1 (ug/L) = 3,000
Screening Values for Soils- RBCs Based on Soil Ingestion Residential
Gasoline-Risk = 10-6 (mg/kg) 400, 10-4 (mg/kg) 40,000, HQ = 1 (mg/kg) 50,000
JP-5 Kerosene Risk 10-6 10-4 NA, HQ =1 5,000
JP-4 Risk 10-6 10-4 NA, HQ = 20,000
USEPA Office of Research and Development, Environmental Criteria and Assessment Office Cincinnati, OH Subj: Oral Reference Doses and Oral Slope Factors for JP-4, JP-5; similar to Kerosene (CAS no. 8008-20-6), Diesel Fuel (CAS No. 68334-30-5), and Gasoline (CAS No. 8006-61-9) (AVGAS) [McChord AFB (Wash Rack/Treatment)/Tacoma, WA]. From Joan S. Dollarhide Associate Director, Superfund Health Risk Techncial Support Center, Chemical Mixtures Assessment Branch TO Carol Sweeney USEPA Region X.
This memorandum is in response to your request for oral systemic and carcinogenic toxicity values for JP-4, JP-5, diesel fuel, and gasoline (AVGAS) found to contaminate soil and
groundwater at McChord AFB (Wash Rack/Treatment), Tacoma, WA. We have attempted to derive RfDs and slope factors for the above fuel mixtures. We have derived provisional RfDs for
gasoline, JP-4, JP-5 and diesel fuel; provisional cancer weight-of-evidence classifications of C for gasoline and D for JP-4, JP- 5 and diesel fuel; and a provisional slope factor (adapted from an interim Agency value) for gasoline
Based on the available evidence, unleaded gasoline can be assigned to U.S. EPA (1986) weight-of-evidence Group C: possible human carcinogen. An earlier U.S. EPA document assigned unleaded
gasoline to Group B2 as a probable human carcinogen (u.s. EPA, 1987a), but that document predates the U.S. EPA (1991d) conclusion that the male rat kidney tumors produced by gasoline
are not predictive for humans, and therefore should not contribute to the weight-of-evidence or dose-response assessment of carcinogenicity. IARC concluded that marine diesel fuel is possibly carcinogenic to humans (Group 2B), but light diesel fuels and jet fuels are not classifiable as to their carcinogenicity in humans (Group 3). |
Jennifer Roberts |
| 4/21/1992 |
Update or Other Action |
Air Force cuts use of benzene Jet Fuels (Anchorage Times B3)
The U.S. Air Force is switching jet fuels to eliminate hazardous benzene emissions and reduce fuel handling risks, officials said Monday. Starting May 4 [1992] fighter jets at Elmendorf will tank up on JP-5, a kerosene-based fuel that contains no benzene, and in October [1992] will switch to JP-8, another kerosene-based fuel without benzene, said Col. Dennis
Beck, deputy chief of stafllogistics with the 11th Air Force.
The entire Air Force should be converted to JP-8 within two years, he said. Up to now the Air Force fueled its aircraft with JP-4, a naphtha-based fuel that contains low molecular
weight hydrocarbons such as the cancer-causing benzene.
The switch in fuels should decrease benzene vapor emissions in the tank farms, which supply Elmendorfs fuel, by 10 to 12 percent, said Lt. Col. Robert Dreyer, commander of the Defense Fuel Office-
Alaska.
But Dreyer said it could take 12 to 18 months to eliminate the JP-4 stockpile. This year the Air Force signed fuel contracts totaling 52 million gallons, he said.
Although benzene vapor emissions are a consideration, "the prime reason for converting to JP-8 is, it's a much safer fuel with lower volatility," Beck said. "We're moving toward a common battlefield fuel that can be used by aircraft and diesel-powered main battle tanks, plus in the process we're solving environmental problems by doing away with emissions." But JP-8 has several drawbacks, including reduced aircraft mileage, Beck said.
"It normally takes more fuel, but not significantly more," he said. 'The offset, it's a much safer operation in peacetime and combat, because it does not ignite like JP-4." |
Louis Howard |
| 5/4/1992 |
Document, Report, or Work plan Review - other |
Jennifer Roberts sent comments on the OU2 Management Plan to the USAF. ADEC still needs to review the revised conceptual site model, Applicable or Relevant and Appropriate Requirements (ARARs), and Jacobs Engineering's standard operating procedures (SOPs). Requested further information on how the evaluation of the hydraulic connection between the shallow and the artesian aquifer will be performed and how deep the well will be. light non-aqueous phase liquid (LNAPL) should be recycled on Base instead of shipped off for recycling.
The report states that all decisions during field activities will be made jointly by the TPM and the project manager. ADEC requires that all critical decisions be correlated with ADEC and EPA project managers. Organic vapor meter (OVM) or organic vapor analyzer (OVA) shall not be used for field monitoring as a sole means for determining hazardous nature. OVA/OVM cannot be used for contaminants such as metals, therefore all drill cuttings, purge and decontamination fluids be drummed and stored on site until their hazardous nature can be determined. Well screens are stated to have a 0.020 slot screen size. ADEC requires that the screen and annular packing material be determined based on the grain size of the soil in the subsurface.
The report states that due to the depth of each borehole, samples will be collected at ten foot intervals. In order to detect the vertical distribution of the contaminants and contaminant types in the subsurface, it is critical that samples be collected every five (5) feet or at every change of formation, whichever interval is smaller, to the total depth of the hole. |
Jennifer Roberts |
| 5/8/1992 |
Update or Other Action |
EPA Marcia Combes and ADEC Jennifer Roberts sent joint comments regarding the Draft Interim Remedial Action ROD for Source Area ST41 within OU2 to the USAF. Changes and suggestions are noted by double asterisk. An additional recommendation would be to make use of expanded numerical subheadings. With some additions, certain sections have become lengthy and would benefit from being broken down into subheadings. An excellent example of this formatting style is found in the enclosed Naval Air Station Whidbey Island ROD.
Lab detection limits exceed risk based concentrations for a number of compounds. Additional clarification and detail are needed concerning toxicity testing methods and sampling locations for the ecological risk assessment. Selection of toxicity endpoints and locations should be coordinated for all OU investigations. |
Jennifer Roberts |
| 6/23/1992 |
Update or Other Action |
Bill Lamoreaux (ADEC-ADO) sent a letter to the USAF regarding the NOV Closure request for the NOV dated September 13, 1989. The environmental problems at this site will be addressed under the CERCLA FFA. ADEC signed the FFA in 1991 and is involved in approval of all cleanup activities in conjunction with EAFB and EPA under the FFA. ST41 is in the FFA operable unit (OU) 2 and is scheduled for field work this year (1992) with a final RI/FS in 1994. An interim remedial action will abate the ecological risk of seepage of light non-aqueous petroleum liquids (LNAPL). The IRA consisted of seep contaminant using recovery wells and infiltration trenches. Construction and implementation of the IRA will be completed in 1993. The completion of the above actions will correct the contamination releases at ST41. Therefore, ADEC approves the closure on the Four Million Gallon Hill ST41 notice of violation (NOV) dated on September 13, 1989. |
Bill Lamoreaux |
| 8/6/1992 |
Update or Other Action |
OU2 ST 41 Interim Remedial Action Remedial Design/Remedial Action (RD/RA) Scope of Work (SOW) received. Included in the SOW: a description of the remedial approach for design and implementation of the selected interim remedy at ST41, a breakdown of the major tasks associated with this action, and a detailed schedule for submittal of post ROD documents. Remedial approach consists of: seep containment using a French drain system and collection sump, air stripping, groundwater control and sampling. The actual flow rate and quantities of fuel and groundwater expected to be recovered are uncertain at this time. Data collected during the ongoing RI/FS activities will be used to better define the extent of the product plume. The hydrologic characteristics of the moraine are highly variable. Results of four slug tests to be conducted during the summer of 1992 will be used to better define the transmissivity and flow characteristics of the surficial aquifer thereby improving the understanding of the hydrogeologic conditions in the area. The groundwater will be monitored for BTEX, other volatile organic compounds and heavy metals.
Major tasks will not include the conceptual/30% design for the IRA since it was previously covered in the IRA ROD signed by the Air Force on July 13, 1992 and previously approved by the Air Force. The RD/RA will begin with the 60% design and proceed to the 90% design. Construction and startup of the treatment system will be followed by an estimated ten month operation and maintenance period. |
Jennifer Roberts |
| 8/7/1992 |
Update or Other Action |
Joint comment letter by ADEC and EPA sent to USAF regarding the ROD for OU2 Source Area ST41. Letter confirms the USEPA agreement with the USAF and ADEC (the parties) regarding the ROD. To allow limited modification of the ROD, the parties agree that the document submitted by the USAF to EPA on 7/13/1992 shall be considered the "draft final" as defined by Part XX of the 9/19/1991 FFA. In addition the Project Managers for the EPA, AF, ADEC agree to extend by fifteen days the period for finalization of the ROD. Accordingly, pursuant to Part XX(G) and (H) of the FFA, the ROD is scheduled for finalization on 8/27/1992, forty-five days after submittal of the draft final document. EPA recognizes that all schedules and deadlines were met by the USAF during generation of the ROD. The above agreement is simply intended to allow the parties additional time to clarify the identification of applicable or relevant and appropriate requirements (ARARs) for the selected remedy set forth in the ROD. No later than 8/14/1992, USAF will modify the ARARs to the mutual satisfaction of the project managers and submit an unsigned revised draft final version of the ROD to EPA for internal review. |
Jennifer Roberts |
| 8/18/1992 |
Update or Other Action |
Anchorage Daily News Aug. 18, 1992. Section C
State Sets Up "Clean 2000" Plan. Alaska environmental officials have developed a strategy to begin cleaning up by the end of the decade the most health-threatening of 1,300 hazardous-waste sites across the state.
The list includes military and civilian sites in Fairbanks, Galena, Adak, Fort Yukon, Chugiak, Kenai, Big Lake, Skagway, Togiak, Anchorage, Moose Creek, North Pole, Fort Greely, Barrow, Valdez, Northway and Nikolski on Unmak Island.
Four 1-million gallon jet fuel tanks on the northeast side of the main east-west runway have leaked fuel into a drainage ditch on one side and into a wetland on the other, said Jennifer Roberts, Southcentral region coordinator for the DEC's hazardous cleanup effort. The tanks are no longer used, and officials are working on containing the seepage. |
Louis Howard |
| 8/25/1992 |
Interim Removal Action Approved |
ADEC received the ROD for the Interim selected remedy on 7/13/1992. Document is called the Declaration of the Record of Decision (ROD)-decision summary and responsiveness summary for an Interim Remedial Action OU2 ST41 July 1992. ADEC signed on August 25, 1992. The interim remedy is expected to be consistent with the final remedy that will be selected for the Operable Unit 2 following completion of the remedial investigation/feasibility study.
Major components of the selected remedy include:
Containment of the seeps using collection systems and subsequent water treatment and product recycling;
Extraction of fuel product from the groundwater surface in the shallow aquifer to minimize further migration;
Treatment of water collected from seeps and wells by an air stripping process to meet federal, state, and local regulations.
Treatment of emissions from the air stripping process to meet state regulations and existing Base permit.
Disposal of the treated groundwater in accordance with federal, state, and local regulations by discharge to the municipal wastewater system.
Monitoring of the effectiveness of the groundwater containment and treatment process to provide design information for the final remedy. Although this interim remedial action is not intended to fully address the statutory mandate for permanence and treatment to the maximum extent practicable, this interim remedial action does utilize treatment and thus is in furtherance of that statutory mandate. Because this action does not constitute the final remedy for the operable unit, the statutory preference for remedies that employ treatment that reduced toxicity, mobility, or volume as the principal element, although partially addressed this remedy, will be addressed by the final response action. Subsequent actions may be necessary to fully address the risks posed by the conditions at this operable unit.
Because this remedy will result in hazardous substances remaining on site above health based levels, a review will be conducted within five years after commencement of the remedial action to ensure that this action continues to reduce the threat to human health and the environment. Review of this interim action will be conducted under the remedial investigation feasibility study being performed for this operable unit.
Treated water will be discharged to the Anchorage Municipal wastewater system through the Elmendorf collection system. Organics concentration would be well below the AWWU allowable standard for BTEX of 100 ug/L and TPH of 10.0 mg/L. |
Jennifer Roberts |
| 8/25/1992 |
Cleanup Level(s) Approved |
Declaration of the Record of Decision (ROD)-decision summary and responsiveness summary for an Interim Remedial Action OU2 ST41 July 1992. ADEC signed on August 25, 1992. The interim remedy is expected to be consistent with the final remedy that will be selected for the Operable Unit 2 following completion of the remedial investigation/feasibility study.
Major components of the selected remedy include: Containment of the seeps using collection systems and subsequent water treatment and product recycling; Extraction of fuel product from the groundwater surface in the shallow aquifer to minimize further migration; Treatment of water collected from seeps and wells by an air stripping process to meet federal, state, and local regulations.
10.2.1 Action-Specific ARARs states: “To the extent the selected remedies result in the removal of petroleum contaminated soil, the contaminated soil will be handed and treated consistent with the requirements of 18 AAC 78.310.”
18 AAC 78.310. SOIL CLEANUP OPTIONS. (a) If treating contaminated soils, the owner or operator shall clean up the site
(1) to the applicable soil cleanup level determined using Table E at 18 AAC 78.315(a);
(i) Except as provided in (e) and (g) of this section (18 AAC 78.315), soils at a site where groundwater has been impacted by petroleum leachate must meet the soil cleanup levels for category A established in Table E, Part B, unless an alternative cleanup level is approved under 18 AAC 78.310(a)(2)(C). Table E MATRIX SCORE SHEET Category A: gasoline range organics 50 mg/kg, diesel range organics 100 mg/kg, residual range organics 2,000 mg/kg, benzene 0.1 mg/kg, total BTEX 10 mg/kg. |
Jennifer Roberts |
| 1/4/1993 |
Document, Report, or Work plan Review - other |
Jennifer Roberts sent letter to USAF regarding the OU2 interim remedial action (IRA) workplan/35% design dated December 1992. The document does not address the seasonal operation parameters which should include: spring startup, fall shutdown, and how these actions will be carried out. ADEC concurs that floating product levels' differences may be attributed to seasonal rises in water levels which causes the floating product to disperse. However, it is equally likely that the rapid influx of water and rise of the water table may trap the free product in pore spaces and slowly through density differences allow the free product to migrate to the seasonal high water table. The trench design shows a geotextile will be installed. The specifications of the geotextile should be discussed and at a minimum, the specifications and design parameters should include the grain size of native soils to prevent infiltration of fine sediments into the gravel bedding.
It should also demonstrate the ability to allow migration of free product without clogging, durability, and how the filter material will be anchored in place. Only one section discusses heating of water prior to air stripping. If the USAF is to utilize this aspect in its design, then it should be consistently discussed in the report. The report discusses discharge of effluent water to Anchorage Water and Waste Water Utility system. The discharge levels required by AWWU should be clearly stated along with the sampling periods (daily, weekly, monthly). Finally, the report discusses the ROD and Air Force approval of the 35 percent design. All Federal Facility Agreement (FFA) parties (USAF, ADEC and USEPA) are involved in the review and approval documents as required by the FFA. |
Jennifer Roberts |
| 3/5/1993 |
Update or Other Action |
USAF Joe Williamson sent Jennifer Roberts (ADEC) letter regarding the Data Quality Problems study. Elmendorf has concluded its study of the data quality problems that were identified in the Weston SW8010 and SW8020 processes for analysis of some samples from Elmendorf Operable
Units (OUs) 1 and 2. After the laboratory procedures were more closely evaluated during a conference call on 16 Feb 93 with EPA, PRC, AFCEE, MITRE and the Air Force, it was determined that the errors noted in the lab procedures were limited to a small amount of the total data developed.
Additionally, method 8240 procedures had been performed on most of the'samples for OUs 1 and 2 and provide a backup check for those samples. Attached is a letter from Jacobs Engineering which details their analysis of this situation and the procedures they used to generate valid risk information at OU1. OU2 sampling and risk assessment procedures will be addressed in a future letter.
2. Based on the results of the discussions and analyses of the data packages, the Air Force proposes the following:
a. because methods SW8010/8020 and SW8240 have provided enough information on contaminants in groundwater, surface water, soils and sediment to evaluate the risk at OU1, no further sampling
will need to be done there to complete the Remedial Investigation and Feasibility Study. Groundwater monitoring will likely be a major component of the Remedial Action at the area and this will supply additional data for continued source evaluation.
b. Method by method and sample location by sample location procedures will continue to be used to ensure that all source areas are assessed for appropriate risk factors based on the
contaminants of potential concern at each area.
c. The entire OU1 area has been limited to nonresidential uses in the past and will be zoned only for that use in the future. This should reduce the risk factor and the level of cleanup
required for the entire area in the future. Jacobs has advised Elmendorf that they also have SW8240 data for samples from OU2.
Elmendorf will also be developing a method for the use of this data to support decisions for work on OU2. This information should be available for your review by 10 Mar 93. |
Jennifer Roberts |
| 3/26/1993 |
Update or Other Action |
DOD and ADEC joint Technical Memorandum of understanding signed concerning the Base wide Groundwater (GW) signed by: ADEC Jennifer Roberts RPM and USAF Joseph Williamson Chief Environmental Programs and Restoration. Due to the base wide GW study and the FY92 field work that occurred at Operable Units (OUs) 1, 2, and 5 it appears a large portion of the GW flows into OU5 (attach. 1-contour map). Based on this fact, Elmendorf (EAFB) will move all upgradient GW into the OU5 Feasibility Study, Proposed Plan and Record of Decision (ROD). This means addressing all GW from upgradient sources (CERCLA (ST20, OUs 3 and 4) and OUs 1 and portions of OU2) and SERA) at OU5 instead of at each individual source area (see attach. 2-Area Map). Sites with free phased product would be looked at to see if there is an available technology to clean them up in a cost effective way. Soil contamination would be addressed at the source areas. NOTE: addressed at the source areas is interpreted by ADEC as removal through excavation or active treatment systems (e.g. high vacuum extraction, bioventing, etc...). |
Jennifer Roberts |
| 4/2/1993 |
Cleanup Plan Approved |
Jennifer Roberts (ADEC) sent letter to USAF regarding the OU2 Interim Remedial Action Plan 90% Design dated February 1993. The plan does not take advantage of the most current data produced during the 1992 field investigation. It is unlikely the inclusion of this information will cause major modifications to the remedial design, it will, however, serve to update design parameters and ensure that the most up to date and accurate information is utilized. The text misrepresents the Bootlegger Cove Formation as a moraine clay. It is correctly considered to be of marine deposition. Also it is mistakenly referenced that it occurs at depths of 15-30 feet below ST41. It should be correctly referenced in this area that the Bootlegger Cover formation is at a depth of 44 feet. At the 90% design stage, ADEC expects the specific design parameters for iron and biological pretreatment be developed. By this stage it should be known what method of treatment (filters, oxidation/precipitation) will be used. Pretreatment design should be included in the construction plans. The text states disposal of treated water through AWWU via a permit would be a one time discharge. ADEC requests clarification whether or not the treated discharge water meets the requirements for a one time discharge permit. If a one-time permit is incorrect, then a correct permit time should be used. The text incorrectly references that the building where the treatment system is housed will be heated to a temperature of 500 degrees Fahrenheit. This should be corrected in the subsequent revision. The text states that the air emissions will be less than 5 ppb for benzene. The ROD states in section 9.2 page 15, for this site, an established air emission criteria for discharge air of 0.5 ppb benzene. The air emission criteria in the ROD will be the criteria for this project and the text should be changed to reflect the ROD. |
Jennifer Roberts |
| 4/12/1993 |
Update or Other Action |
AF sent Jennifer Roberts a letter regarding the study of data quality problems identified in the Weston SW8010 and SW3020 processes for analysis of remaining samples. Screening procedures for OU2 indicated the need to resample one monitoring well and eight surface water sampling locations at ST41. AF will take additional samples from a few adjacent sampling locations to establish a current benchmark for evaluating the new sampling data. Resampling locations are monitoring wells ST41-MW32, ST41-MW32 and surface water locations ST41-SW01 to SW11. The sampling results from these 13 locations will be incorporated into the OU2 RI/FS prior to EPA/ADEC review of the draft RI/FS. |
Jennifer Roberts |
| 5/15/1993 |
Update or Other Action |
Jennifer Roberts received the final fact sheet for the EAFB ST41 Remedial Design and Construction of the IRA. ST41 is 20 acres in size located near the western edge of the Base approximately 1/2 mile east of the Knik Arm of Cook Inlet and north of Loop Road. The specific interim remedy to be implemented at ST 41 was selected last fall (1992) by the AF and the USEPA with the concurrence of the ADEC following a careful review of the public comments on the several IRA alternatives then under consideration. Construction of the interim remedial facility is scheduled for July through October 1993. Cleanup activities under the IRA will continue until a final remedial action has been selected and implemented at ST41 in late 1995. The treatment system will be installed in building 31-600 on the top of the ridge near the USTs at ST41. Discharge will be into the Base sewer system into manhole 31-125 near Larch Street.
Discharge air from the carbon adsorption unit will be periodically sampled to ensure that the emissions from the air stripper meet all applicable air quality standards. Fuel extracted from the oil/water separator will be delivered to the Base Defense Reutilization and Marketing Office (DRMO) by tanker truck. |
Jennifer Roberts |
| 6/9/1993 |
Site Ranked Using the AHRM |
Site re-ranked by Louis Howard. |
Louis Howard |
| 7/21/1993 |
Update or Other Action |
Jennifer Roberts (ADEC) sent letter to USAF pursuant to the FFA par. 20.13, requesting an extension to complete ADEC's review of the draft secondary document OU2 Remedial Investigation/Risk Assessment. Request made for 20 days which would allow comments to be due on August 14, 1993. |
Jennifer Roberts |
| 8/3/1993 |
Update or Other Action |
Memo for the record-RE: Backfilling [interim remedial action] IRA trenches with POL contaminated soil by Richard Howard.
1. Today I spoke with Jennifer Roberts, DEC, and Marcia Combes, EPA, about levels of contamination that would be allowed in soil to be replaced in excavations at IRA site. They both agreed that any material that exhibited HNU readings up to 50 PPM could be replaced in the excavations, while material with higher readings would have to be stored on protective liners pending disposition as determined by a joint agreement between the [remedial project managers] RPMs.
NOTE TO FILE: Portable instrument that gives rapid analysis of total organic vapor con-centrations in water, soil, and sediment to 100 ug/l benzene equivalent.
METHOD DESCRIPTION: Used to screen water, soil, and sediment samples for total organic vapor concentration. HNU is a portable photoionization detector that requires internal electronic calibration as well as calibration to a known standard.
APPLICATION: Measures total organic vapor concentration. Response to VOC varies with probe used. Insensitive to methane. May detect unsaturated hydrocarbons, chlorinated hydrocarbons, aromatics, nitrogen and sulfur compounds, aldehydes, ketones, alcohols, acids, and others.
LIMITATIONS: [The HNU is] Not able to identify individual compounds or contaminants. Total response reported as benzene equivalent. Adversely affected by electrical power sources
(e.g., power lines and transformers) Methane can depress readings. Unfavorable environmental conditions: High humidity (e.g., 90% causes erratic responses-usually low.),>1% CH4, low O2 (<15%),temperature below 32 degrees Farenheit. |
Jennifer Roberts |
| 8/11/1993 |
Update or Other Action |
Memo for the record by Richard Howard RE: Regulator concurrance on IRA changes. 1. Today, during a meeting with Marcia Combes, EPA, and Jennifer Roberts, ADEC, it was agreed that the following changes would be allowed for work on the Interim Remedial Action at source area ST41:
1. The south extraction well would be reduced in size from a 36 inch to a 6 inch size. Jennifer Roberts said that it would be necessary for the contractor to write a technical memo explaining the reason for the size change, detailing the reduced amount of product available to be pumped from the watertable at the location.
2. The sanitary sewer line could be temporarily eliminated as long as an acceptable substitute method for placing the processed water into the Elmendorf AFB sanitary sewer was devised. The eventual construction of the line might depend on the output of the system after it has been in operation for a while. Also, the line might need to be re-designed if the final remedial action for the source area utilizes the IRA system but requires a different size pipeline.
3. The project changes will be implemented now, so that there
will be no loss of time in the construction of the extraction system. |
Jennifer Roberts |
| 8/11/1993 |
Update or Other Action |
USAF sent a letter regarding schedule extensions for Operable Units (OUs) 1 and 2. Pursuant to part XX of the Elmendorf Federal Facility Agreement (FFA), the Air Force is scheduling a 13 day extension for all future Secondary and Primary documents for OU1 and a 20 day extension for all future Secondary and Primary documents for OU2. The Alaska Department of Environmental Conservation (ADEC) requested a 10 day extension for comments on the draft Remedial Investigation and Baseline Risk Assessment for OU1, but the comments were not received by the Air Force until 13 days after the scheduled comment date. ADEC has also indicated a need to extend the review time for the draft Remedial Investigation and Baseline Risk Assessment for OU2 by up to 20 days.
The Air Force will therefore require schedule extensions for both of these OUs to allow adequate time to evaluate and respond to the ADEC comments and to develop subsequent documents. |
Jennifer Roberts |
| 8/14/1993 |
Document, Report, or Work plan Review - other |
Jennifer Roberts commented on the draft Remedial Investigation (RI). The ecological risk assessment focused on the adult wood frog as a receptor with exposure by contaminant ingestion. While this is appropriate, the report does not address risk to wood frog larval stages. The larval stage is the more sensitive receptor and is more closely associated with surface water and sediments and should be addressed in the ecological risk assessment. Methylene chloride was listed as being eliminated as a chemical of concern even though it was above the risk based concentration (RBC) level. Unless methylene chloride can be eliminated as a lab contaminant it should be evaluated in the risk assessment.
The text states that the feasibility study will evaluate the chemicals of potential concern under the commercial/industrial land use scenario, since it was the most representative scenario for present and future exposure conditions. ADEC concurs with this approach, it must request that the risks determined under residential land use scenario which are reduced or excluded in the commercial land use scenario should be listed to allow for comprehensive evaluation of potential remedial actions based on future land use. |
Jennifer Roberts |
| 8/20/1993 |
Document, Report, or Work plan Review - other |
Michael Lu (ADEC) sent letter to Rich Howard USAF re: Elmendorf Environmental Restoration Program - Sanitary Sewer Hookup ADEC Project No. 9421-WW-218-016. This letter is in response to the materials received in this office regarding the OU2 Interim Remedial Action to be carried out at Contaminant Source Area ST41, Elmendorf Air Force Base, Alaska. The Department has completed its review of the submitted materials and has the following comments regarding approval of the project:
1. Since this facility will be discharging an industrial wastewater that will enter the AWWU wastewater treatment facility, the effluent quality of the discharge from this facility will require monitoring to prevent a violation of acceptable wastewater discharge into the AWWU system. Based upon a review of the plans submitted, as there did not appear to be one in the proposed plans, it is recommended that a control manhole be placed prior to MH-1. The control manhole is recommended in place of the sampling port mentioned in the OU2 Work Plan.
2. Fuel product/groundwater recovery pumps in a potentially hazardous environment should be intrinsically safe.
Subject to the above comments and questions this project meets the concerns of this Department, therefore, in accordance with State Wastewater Disposal Regulations (18 AAC 72) approval to construct is granted. |
Louis Howard |
| 9/14/1993 |
Update or Other Action |
USAF Memo for the Record by Richard Howard Remedial Project Manager Subject: Relocation of South IRA Well. 1. On this date, I spoke to Jennifer Roberts, DEC, and informed her that the contractor had detected another small seep between the 2 south collection trenches. The seep had only been detected after a few rain events had occurred during the ongoing work at the trenches. I told Jennifer the contractor had recommended
that the south extraction well should be relocated to the new
seep location to try to capture the effluent from this new drain
with the cone of depression from this well. In view of the flow
at this new site, it was also felt that the well should be kept
at its original size of 36 inches. Jennifer said this appeared
to be a good idea and said she looked forward to seeing it
detailed in the tech memo for the changes at the site.
2. Marcia Combes, EPA, contacted me later in the day and I gave
her the same information. She said that it was a good idea and
she was pleased that the new seep area had been identified. I
told her that I would send her a copy of the tech memo after it
was completed. |
Jennifer Roberts |
| 10/22/1993 |
Update or Other Action |
Dept. of Army Cold Regions Research and Engineering Laboratory, Corps of Engineers, CECRL-RC Memorandum for Sharon C. Stone, Remedial Project Manager, 3 SPTG/CEVR Subj: Peer Review for Operable Units 1 and 2 Elmendorf AFB.
CRREL review of OU 1 found no conspicuous concerns, This review was limited since no remedial investigation reports were
available for reference. Even with all the limited data, CRREL
feels confident the U.S. Air Force is proceeding in a manner consistent with all applicable federal and state requirements.
Conceptual Site Model Summaries: Suggest the models depict not only the contaminant zone, but also an anlysis trend of benzene over time. This suggestion would enable reviewers (regulators and public) to graphically understand what contaminant concentration changes have occurred, if any over time. This should help illustrate why contaminant migration to the wetland area is not a reasonable concern considering it will take approximately 35 years for contaminated groundwater on the north side of ST41 to migrate 750 feet, not including natural attenuation effects.
Table 1B: This table does not illustrate any of the ecological concerns identified in the RI Report. It states no risks were identified in the ST41 human health risk assessment for surface water or sediment. The RI report indicated that water was being resampled for BTEX. Did the results indicate there are no contaminant concerns?
Was not lead detected above the maximum contaminant level (MCL) in most of the wells at ST41? If so, suggest including this information in Table 1B. Ethylbenzene and xylene were also detected above the MCL. Suggest they also be included.
Remedial Alternatives for ST41: Agree the ecological risks associated with ST41 are in most cases directly related to groundwater contamination, but question how remediating groundwater will eliminate the inorganics and compounds that are relatively insoluble or have high sorption potentials. These contaminants were identified as a specific concern to both wood frogs and masked shrew in the RI report.
Why not use a no action alternative as the basis for comparing alternatives? Suggest this no action alternative be compared against naturall attenuation/long-term monitoring (LTM) program, enhanced natural attentuation/LTM, air sparging, or a collection and treatment action. The no action alternative should only evaluate the site at end of each required 5-year review cycle.
The enhanced natural attentuation/LTM type action could utilize vibratory well points to install numerous small wells. The wells would pump atmospheric air to both the saturated and unsaturated zones. This concept would be particularly effective in the spring since the ambient air temperature is significantly warmer than the soil temperatures. One drawback is that this concept would NOT address any free product concerns.
Air sparging was mentioned in the RI report, but was not addressed in this peer review document. It is assumed air sparging is no longer considered a cost-effective or viable alternative.
Understand the interim remedial action is well along in its design, so a radical change is probably not cost-effective. Do suggest evaluating two alternatives: enhancing natural attenuation upgradient from the trench or extraction wells and recirculating the water extracted on site, thus eliminating the carbon adsorption unit.
A proposed 65K monitoring program may be appropriate depending on what justifications were used to determine analytical methods, frequencies, and if the contractor will produce a quarterly or annual fact sheet or report. Assume the monitoring requirements will be fully explained in the final feasibility study.
Source Control Alternatives: Why are the tanks and piping considered a source if they have been emptied, purged and cleaned? The really continuing source is the smear zone itself.
Recommened Alternatives: Suggest the LTM for ST20 and ST41 be better defined. Assume a better defined LTM program explaining the justification, specific analytical methods, sampling frequencies and reporting mechanism for ST20 and ST41 will be included in the final feasibility study report. Recommend ST20 be analytically monitored only at the conclusion of the 5 year review period. |
Jennifer Roberts |
| 12/15/1993 |
Document, Report, or Work plan Review - other |
Jennifer Roberts, Alaska Department of Environmental Conservation (ADEC) commented on the Remedial Investigation/Feasibility Study (RI/FS) Report dated November 1993. ADEC does not concur that the groundwater is considered non-potable and was incorrectly chosen during the matrix score sheet ranking for ST41. Pursuant to state drinking water regulations (18 AAC 70) all groundwater is considered drinking water with only specific creeks delineated as non-potable. As a result, the score of the matrix becomes 28 which advances the matrix score to level B (15 mg/kg BTEX, 0.5 mg/kg Benzene and 100 mg/kg gasoline). The report does not address the different parameters of the Interim Remedial Action (IRA) in relation to the final action. A status report describing the operation, recovery rates, pumping rates and the effectiveness of the IRA is crucial to evaluating the FS alternatives. Cost sensitivity analysis at ST41 is not addressed during the comparison of alternatives. The following factors should be addressed: effective life of a remedial action, duration of cleanup, volume of contaminated material, uncertainty about site conditions, and depreciation.
Data summary excludes soil samples collected below the water table at the interface of the groundwater and subsurface water. These samples have consistently had benzene and BTEX levels above the State of Alaska cleanup levels. These samples represent the "smear zone" (Smear Zone: the vertical area over which groundwater fluctuates (thereby the contaminated water will smear floating and dissolved contamination into the soils in the zone) and might have been overlooked in subsurface and the groundwater analyses. Their exclusion will under estimate the risks, please explain the reasoning behind this action. ADEC sees no difficulty in granting a waiver of 18 AAC 78.085 (Abandoning In Place), on the basis that greater risk will result to the environment if the tanks were to be removed. As outlined in he general comments section, excavation of soil associated with the piping system will continue until soil contamination is below Level B cleanup levels.
The report establishes natural attenuation as one viable option of cleanup out of three alternatives. However, in examining the alternatives, ADEC does not agree with considering natural attenuation as a different groundwater option than no action. Previous work has not identified parameters that test for natural attenuation and currently there has been no work to verify that natural attenuation is occurring. The process of attenuation could be the result of dilution, dispersion and sorption. Natural attenuation should be considered as a part of the NO ACTION alternative with long term monitoring to verify natural attenuation is occurring. |
Jennifer Roberts |
| 1/11/1994 |
Update or Other Action |
USAF sent to Jennifer Roberts a letter regarding a time extension notification for Operable Unit 2. Pursuant to Section 20.17 of the Elmendorf AFB Federal Facilities Agreement, the Air Force is extending the delivery date for the OU2 Draft Remedial Investigation/Feasibility Study (RI/FS) for 20 days. The extension is required to allow the Air Force adequate time to respond to additional written EPA comments on the Draft RI/FS which were received by Elmendorf on 29 December 1994 and also to subsequent comments proposed by EPA during conference calls on 4 January and 10 January 1994. In the event that the requested document revisions are extensive enough to require additional response time, the Air Force will request additional time as needed to complete the revisions. It will also be necessary to extend the dates for all future OU2 documents to allow ample time for Air Force response on these items. |
Jennifer Roberts |
| 2/17/1994 |
Document, Report, or Work plan Review - other |
Jennifer Roberts sent comment letter to the USAF on the Draft Final Remedial Investigation/Feasibility Study (RI/FS) Report for OU2. Pursuant to Part XX Sect. G par. 20.3 of the FFA, this letter serves to identify major outstanding issues that must be resolved prior to finalization of the document in order to avoid dispute resolution pursuant to Part XXI, par. 21.3 of the FFA. ADEC's comments on the draft RI/FS have not been addressed adequately or incorporated into the draft final document.
By not adequately addressing these comments, there is inadequate information in the RI/FS to develop and present to the public, an OU2 Proposed Plan (PP) which would meet ADEC's approval. The specific comments focus on the remedial alternatives for ST41 groundwater and these comments must be addressed for the RI/FS to be finalized and allow the PP and Record of Decision process to move forward.
1) ADEC has expressed concern (in writing and in meetings) that the interim remedial action (IRA) at ST41 has not been included in the FS. This issue was again brought up at an OU2 PP scoping meeting (12/17/93) between project managers for EAFB, ADEC, and USEPA and Jacobs. Basically, there is a fundamental deficiency within the FS which results by not adequately including the IRA actions in the FS and the possible alternatives. The FS has treated the IRA as a completely separate action, not an integral part of the final action. In all previous discussions regarding the IRA, it is ADEC's understanding that it was to be incorporated into the alternatives presented in the FS. This has not been accomplished in the draft final RI/FS nor in the response to comments.
2. At the OU2 PP scoping meeting, ADEC and EPA identified a combination of limited collection and treatment of the groundwater in conjunction with natural attenuation and long-term monitoring as ADEC's tentative preferred alternative. ADEC and EPA requested that this alternative (III) be developed in the draft final RI/FS. Upon review of the draft final document it appears alternative III has not been adequately developed. In addition, the alternative (IV) which proposes collection and treatment was significantly altered by a reducing the installation of new wells from 17 to 7. This change was not brought to ADEC's attention, or addressed in the response to comments for the draft RI/FS.
2. At the OU2 Proposed Plan (PP) scoping meeting, ADEC and EPA identified a combination of limited collection and treatment of the groundwater in conjunction with natural attenuation and long-term monitoring as ADEC's tentative preferred alternative. ADEC and EPA requested that this alternative (III) be developed in the draft final RI/FS. Upon review of the draft final document it appears alternative III has not been adequately developed. In addition, the alternative (IV) which proposes collection and treatment was significantly altered by a reducing the installation of new wells from 17 to 7. This change was not brought to ADEC's attention, or addressed in the response to comments for the draft RI/FS.
See site file for additional information. |
Jennifer Roberts |
| 2/25/1994 |
Update or Other Action |
Jennifer Roberts received a letter (Action Memorandum) from the Air Force regarding the time extension request for Operable Unit 2. Pursuant to Section 20.18 of the Elmendorf AFB Federal Facilities Agreement (FFA), the Air Force is requesting a 15 day extension for finalization of the OU2 Draft Final Remedial Investigation/Feasibility Study (RI/FS). The extension is required to allow the Air Force adequate time to resolve potential disputes per written comments from the Environmental Protection Agency (dated February 10, 1994) and Alaska Department of Environmental Conservation (ADEC) dated February 16, 1994 on the Draft Final RI/FS dated February 10, 1994. The extension will delay the delivery of the OU2 RI/FS from March 3, 1994 until March 18, 1994. The Air Force understands that the EPA and ADEC consider this extension as the informal dispute resolution period pursuant to Part XXI par. 21.3 of the FFA. |
Jennifer Roberts |
| 3/15/1994 |
Risk Assessment Report Approved |
As part of the RI/FS the risk assessment was approved. At ST41: For the residential and commercial/industrial scenarios, the primary media for exposure to contaminants at ST41 is groundwater. Potential exposures to sediment and surface water are highly unlikely to occur frequently enough to justify chronic risk estimates. Exposures to subsurface soil should occur only during excavation or construction activities. In general two compounds in groundwater are associated with carcinogenic risks that exceeded 1 x 10-6 and are relatively widespread: benzene and arsenic. Benzene risks calculated for one monitoring well are in the 1 x 10-2 to 1 x 10-3 range for residential and commercial/industrial exposures. Risks would be of concern if individuals were being exposed to groundwater from wells. However, no groundwater in the shallow aquifer at ST41 is currently or will be used for drinking water purposes. In addition, most of the benzene contaminated groundwater will be treated by the ST41 Interim Remedial Action (IRA).
Three other carcinogenic compounds are less widespread at ST41 are: EDB, BEHP and methylene chloride. These three compounds will also be contained by the proposed IRA extraction wells and trenches. Non-carcinogenic hazard indices for both the RME and average residential exposure scenarios exceed 1.0 for arsenic and manganese in groundwater. However neither arsenic nor manganese may greatly exceed naturally occurring background levels. The hazard indices for antimony, vanadium, nitrate, and thallium are also above 1.0, but have been dismissed since they were observed at limited locations and may have resulted from laboratory contamination.
Ethylbenzene, toluene, and xylene were also greater than a hazard index of 1.0 at several monitoring well locations. The wells that contained these compounds are included in the proposed ST41 IRA fuel/groundwater extraction system.
ST41 Ecological Risk: Isolated risks were identified at OU2 for terrestrial fauna and flora. In general the wood frog and masked shrew populations appear to be at the greatest risk of adverse effects from ingestion of lead, mercury, and several organic compounds. Because of their small home range, frequency of exposure is expected to be high for individuals living in contaminated areas. Passerine bird populations, such as the black-capped chickadee, may also be at risk of adverse effects from ingestion of contaminants at ST41. However, exposure of these birds is expected to be limited by the small area of hotspots containing elevated contaminant concentrations and by their larger home range that may include areas outside of ST41. The potential risk to peregrine falcon is of concern because of the high exposure to lead and mercury. However, exposure to contaminants at ST41 is expected to be limited because the falcon infrequently visits the base and because of the limited area of hotspots.
Lead is the only contaminant that occurs in concentrations capable of producing toxic effects in plants at ST41. The highest detected lead concentration at ST41 was 118 mg/kg. Effects on plant germination have been demonstrated at 12 mg/kg, and plant senescence has been demonstrated at 20 mg/kg. (*senescence: the growth phase in a plant or plant part (as a leaf) from full maturity to death). |
Jennifer Roberts |
| 3/23/1994 |
Meeting or Teleconference Held |
EPA/DEC verbal comments provided on the Operable Unit (OU) 2 final remedial investigation/feasability study (RI/FS) March 23, 1994. Present worth cost of Alternative II is
grossly underestimated - monitoring costs are too low and the 3-yr monitoring cycle is too optimistic, it should be every year. RESPONSE: The monitoring program for groundwater Alternatives II, III, and IV will be modified to include annual sampling. RI not designed for natural attenuation; Alternative II lacks scientific basis for things like dilution, dispersion, oxygen demand (OD), biota respiration. Monitoring program doesn't do enough - DO,
nutrients, pH, temperature only. Need closure sampling round to verify cleanup. RESPONSE: Scientific sources will be added to the text clarifying attenuation indicators. Nitrite, biological oxygen demand, chemical oxygen demand, and total organic carbon will be added to the monitoring program. Phosphorus and nitrate were (and are) included in the program to verify attenuation. A final sampling round will be added to each alternative to verify cleanup. Clarify the cleanup times (17.3 vs. 21) in Alternative III. RESPONSE: Text will be clarified in Section 23 and 24.
Page 15-1 2nd paragraph, 2nd sentence, add ",although state site data are discussed for ST20." RESPONSE: Text will be changed as noted. Page 15-4 4th paragraph, 1st sentence, delete "and
well EW-1." 4th paragraph, add "Well EW-1 is located between the southwest and southeast plumes to intercept a seep discovered during IRA construction. This well currently collects no floating
product." RESPONSE: Text will be changed as noted. Page 15-5: Clarify 1st Sentence, 4th paragraph. RESPONSE: Sentence will be clarified. Pages 23-27 and 23-32: The pumping rates stated on 23-27 for the new extraction wells don't correlate with 23-32. RESPONSE: Page 23-27 states the sustainable pumping rates for each extraction well and page 23-32 states the total pumping rate for each plume. |
Jennifer Roberts |
| 3/30/1994 |
Update or Other Action |
Potential Cleanup Levels for petroleum in soil: ADEC UST Emergency Regulations 18 AAC 78 1991-benzene 0.1 to 0.5 mg/kg and TPH 50 mg/kg to 200 mg/kg.
The primary organic contaminants in groundwater at ST41 are fuel related BTEX compounds. Benzene was detected in the monitoring wells near the south seep area at concentrations in excess of MCLs. Toluene concentrations exceeding the MCL were detected in two monitoring wells that also contained floating fuel. Concentrations of ethylbenzene in monitoring wells exceeded MCLs. Xylene concentrations exceeded MCLs in one well.
Additional organic compounds detected above MCLs include BEHP, EDB, and methylene chloride. Arsenic and lead were also detected above MCLs in most wells. Chromium, thallium and vanadium exceeded MCLs in some wells.
Soil: Sample ST41-SO-03 contained: 1.9 mg/kg benzene, 2,000 mg/kg TFH-gasoline and 3,600 mg/kg TFH-diesel. Based on matrix scores for ST41, 100 mg/kg TFH-gasoline and 200 mg/kg TFH diesel apply to soils at ST41. (NOTE TO FILE Thallium was detected in 2 out of 2 surface soil samples from 25.6 to 29.4 mg/kg. The 18 AAC 75 Table B1 cleanup level for under 40 inch Zone direct contact level is 8.1 mg/kg and migration to groundwater cleanup level is 1.9 mg/kg).
Sediment: (NOTE TO FILE Thallium was detected in 11 out of 11 samples from 39 mg/kg to 200 mg/kg. The 18 AAC 75 Table B1 cleanup level for under 40 inch Zone direct contact level is 8.1 mg/kg and migration to groundwater cleanup level is 1.9 mg/kg). Subsurface sediment thallium concentrations ranged from 36.2 mg/kg to 97.9 mg/kg.
Water: ST41-29 (1990) thallium 0.33 mg/L (NOTE TO FILE Thallium Table C 18 AAC 75 groundwater cleanup level = 0.002 mg/L, 1994 MCL is also 0.002 mg/L, MCLG was 0.005 mg/L, Ambient water quality criteria was 13 ug/L in 1994 for Thallium. In 1994 ADEC did not have a cleanup level for Thallium in UST or CS regulations nor an MCL promulgated for it).
ST41-W-7 (Fall 1992) thallium 0.18 mg/L (NOTE TO FILE Thallium Table C 18 AAC 75 groundwater cleanup level = 0.002 mg/L).
Thallium is not a known or accidental constituent of motor or aircraft fuels. Also, Section 5.1.5 of the RI/FS presents evidence to suggest that thallium in soil samples collected at
OU2 are a sampling, laboratory, and/or reporting artifact. Based on this information,the presence of thallium in groundwater may also be artifactual. Based on the limited number of wells that may pose an unacceptable human health risk from thallium, the site conditions and the evidence suggesting thallium is artifactual, it is recommended that thallium not be considered a groundwater COC that warrants action at ST41.
ST41-16: Benzene 30,000 ug/L, 6,100 ug/L ethylbenzene, Toluene 20,000 ug/L, and xylenes 21,000 ug/L.
ST41-27: Trichloroethene (TCE) 12 ug/L. TPH 1,100 mg/L.
ST41-28 TPH: 220 mg/L and napthalene 15,000 ug/L, Bis(2-ethylhexyl)phthalate: 150,000 ug/L
ST41-26-GW (fuel): 950,000 mg/L
Surface Water: ST42-SW-04 Thallium 0.44 mg/L (NOTE TO FILE Thallium Table C 18 AAC 75 groundwater cleanup level = 0.002 mg/L)
ST41-SW-01: 3.4 mg/L TPH, ST41-SW-11: 16 ug/L methylene chloride, carbon disulfide 67 ug/L,
ST41-SW-09: 2,900 ug/L benzene, ethylbenzene 1300000 ug/L, toluene 92,000 ug/L, xylenes 360,000 ug/L, DRO 12000 mg/L, [NOTE TO FILE: LNAPL is considered present where analytical data shows DRO concentrations above the theoretical solubility limit for diesel of 3.9 mg/L] 59,000 mg/L gasoline range.
ST41-SW-11 1,2-dichloroethane 10 ug/L |
Jennifer Roberts |
| 3/31/1994 |
CERCLA RI Report Approved |
1994 RI/FS states for ST41 it was originally called SP-5 and SP-5A. SP-5 included areas adjacent ot the USTs and SP5a was a fuel seep on the south side of the moraine, north of Loop Road. In 1990, sites SP-5 and SP-5a were grouped together and are now designated as ST41. A 1 acre tank sludge disposal area appeared on an Elmendorf AFB map as early as 1953. At the suspected sludge disposal area, the remedial action objective was to remove the surface debris to be in compliance with solid waste regulations 18 AAC 60.
The tank sludge disposal area is heavily overgrown with alders and metallic debris is scattered near the surface. A surface geophysical survey was conducted to map an area where sludge derived from fuel tank residues is thought to have been buried. The rationale for surveying was that if the sludge were dumped at, or very near the surface, the influence of the sludge on ground conductivity should be more apparent in the horizontal dipole mode than in the vertical dipole mode. The anomoly along the eastern edge of the site is a buried pipeline. The large anomoly in the center of the northern third of the site is the area in which debris and drums were not visible at the surface. However, the elevated conductivities in this 50 to 70 foot zone suggest that either some disturbance of the ground has occurred or some foreign material has been dumped or leaked.
The westernmost anomoly in the norther third of the area was coincident with an area where metallic trash was evident at the surface. The degree of conductivity elevation may be more than would be expected from the trash alone, and the possibility exists that either some disturbance of the ground has occurred in this area or some foreign material has been dumped or leaked.
Total extractable petroleum hydrocarbons (TEPH) were detected at 54 mg/kg on the north side of the Elmendorf Moraine in the vicinity of the sludge disposal area. Tank sludge could be the source of these compounds. Boring ST41-BH11 is located just north of the suspected boundary of the sludge disposal area. The contamination in this boring is consistent with what would be expected from tank sludge disposal. However, three boreholes were drilled in the sludge disposal area (ST41-BH07, BH08, and ST41-MW38), and no sludge, per se, was encountered.
Groundwater probe sample results in the sludge area had benzene above 5 ug/L in 41-FW-06 at 270 ug/L and 41-FW-14 at 450 ug/L. Borings ST41-BH11 and ST41-BH12 contained toluene and benzo(a)pyrene. These borings were drilled downgradient of the suspsected sludge disposal area. Surficial debris consists of barrels, scrap metal, pipes, and at least one wooden box. The response action is to remove the empty barrels and scrap metal from land surface and shallow surface and transfer of the scrap metal debris to DRMO or a scrap metal recycler in the Anchorage area. The total volum estimated is about 128 cubic yards. |
Jennifer Roberts |
| 3/31/1994 |
Update or Other Action |
OU2 RI/FS Report 10.2.3.1 Organic Contaminants Page 10-115: For surface-soil samples collected in 1992, benzene and TFH were detected in sample ST 41-S0-03 in concentrations above ARARs established by the State of Alaska (1993) for soils contaminated by USTs (see Section 4,1.4 for additional information on this ARAR), Benzene was detected at 1.9 mg/kg, which is above the ARAR of 0.5 mg/kg. Although some 1992 purgeable organic analytical data were not usable for RI/FS purposes, data from the surface-soil sampling were determined acceptable based on gasoline results from the TFHs analytical method, A discussion of project data quality problems, samples affected, and an evaluation of results is presented in Section 2,6,2.3.
Sample ST41-S0-03 contained 2,000 mg/kg of TFH-gasoline and 3,600 mg/kg of TFH-diesel. Based on a matrix score developed for OU2, levels of 100 mg/kg for TFH-gasoline and 200 mg/kg for TFH-diesel apply to petroleum contaminants in soils at ST41.
In 1992, TFH-gasoline (8,000 mg/L) was detected in sample ST41-SW-11, which was collected at the same location as the 1990 and 1991 samples TFH was also present in 1992 surface water samples from three additional locations near seeps on the north and south sides of ST41. ST41-SW-09 had TFH-gasoline (59,000 mg/L) and TFH-diesel (12,000 mg/L). ST41-SW-03 had THF-gasoline (14,000 mg/L).
ARARs for surface water bodies in the State (;)f Alaska for TPH are contained in the Interim Guidance for Surface and Groundwater Cleanup Levels (State of Alaska, 1990). According to this document, TPH concentrations should be remediated to a nondetectable level using EPA Method 41 B.1 as the measuring tool. The detection limit for Method 418.1 ranges from 0.95 to 1.5 mg/L.
TPH and benzene concentrations in the surface water samples suggest that the fuel contaminants in groundwater at ST 41 (Section 10.3) are migrating to the surface through seeps. Additional discussion on the migration of TPH and benzene is contained in Section 11.0 of this report.
During the fall 1991 sampling, methylene chloride was detected in sample ST41-SW-11 at 5.5 ug/l, which is above the MCL of 5.0 ug/L. However, the method blank contained methylene chloride above the reporting limit at a concentration 3.8 ug/L. Because the blank may have been contaminated in the laboratory, any results reported for methylene chloride that are less than 10 times the level found in the method blank may be deemed a laboratory artifact. As a result, this compound will not be retained for further consideration.
Concentrations of 2-methylnaphthalene were present in 1991 and 1992 samples above the laboratory detection limit. These levels could not be evaluated because no ARAR or RBC exists for the compound. Bis(2-ethylhexyl)phthalate was present in three 1992 surface water samples above carcinogenic RBCs. However, these concentrations are flagged by the letters B and J indicating that the contaminant was present in the laboratory blank and present below established detection limits. As a result bis(2-ethylhexyl)phthalate will not be retained for further discussion.
In summary, benzene, TPH, and 2-methylnaphthalene will be evaluated further in Sections 11.0, 12.0, and 13.0. Benzene was reltained based on 1990 and 1991 data that exceed the EPA MCL. TPH was retained Ibased on 1990, 1991, and 1992 data that exceed State of Alaska cleanup levels. Because no ARAR or RBC exists for 2-methylnaphthalene, this compound was also retained. |
Louis Howard |
| 6/2/1994 |
Update or Other Action |
Jennifer Roberts received a letter(action memorandum) from the Air Force regarding the OU2 Proposed Plan. The draft Proposed Plan was submitted on April 13, 1994. Verbal comments were provided by ADEC and USEPA to the Air Force in a meeting on April 28, 1994. A revised proposed plan incorporating the agencies' verbal comments was provided to the agencies. Since no written comments were received by the Air Force during the comment period ending May 13, 1994, no formal response to comments is necessary. |
Jennifer Roberts |
| 6/13/1994 |
Proposed Plan |
The proposed plan for Operable Unit 2 is received. The USAF, EPA & ADEC will not select a cleanup alternative until all public comments have been reviewed & considered. Changes to the preferred alternative or a change from the preferred alternative to another alternative may be made if public comments or additional data show such a change would result in a more appropriate solution. The selection of a cleanup alternative will be documented in a Record of Decision (ROD).
ST41 consists of four one-million gallon underground storage tanks & their associated piping, which were used in aircraft fueling activities. The base constructed the tanks in the 1940s. Base documents show spills of aviation gasoline (AVGAS) & JP-4 jet fuel. Fuel contaminated seeps have been observed on the north & south side of the hill surrounding the tanks & fuel (free product) has been observed floating on the water table in monitoring wells at the site.
Site ST41 also consists of a suspected one-acre tank sludge disposal area located adjacent to the storage tanks. A map dated 1953 suggested this area was used for sludge disposal. The base conducted a historical record search & a field investigation consisting of geophysical surveys & subsurface soil sampling to determine the presence or absence of disposed sludge. During the investigation we did not find any evidence of actual sludge disposal at ST41; however, the base did find metal debris strewn across this area. The base will remove this debris from the area & will recycle or dispose of it in accordance with State of Alaska solid waste regulations.
ST41 Preferred Alternative for Treating Groundwater & Surface Water Seeps-In addition to the continued operation of the IRA, the preferred alternative for groundwater & surface water seeps is Alternative G-11, Natural Attenuation with Institutional Controls & Long Term Monitoring for Groundwater & Surface Water seeps. An additional study has been developed to verify that natural attenuation is occurring at the expected rates. The field work for the additional study is scheduled to begin in June & the report will be completed by November.
This alternative will effectively reduce risk to human health & the environment utilizing all natural technologies. The elements of the preferred alternative for ST41 groundwater are:
* Natural attenuation; Monitoring groundwater for 22 years or until the benzene concentration reaches the MCL (5 ug/L);
* 5-year review to assess the protectiveness of the remedial action; &
*Periodic evaluation of monitoring results to determine if there is need for further remediation.
If the additional study determines: 1) a lack of substantial evidence verifying the potential or current occurrence of natural attenuation at the site or 2), natural attenuation rates are significantly less than anticipated at the site or 3), the data indicates that cleanup levels can not be achieved, the contingency alternative for groundwater, Alternative G-IV (Collection & Treatment), would become the preferred alternative.
(*NOTE to file: Contaminated groundwater could be discharged to the local POTW for processing or treatment in their wastewater system. However, the AWWU has specific requirements for discharge into their POTW, which include allowable standards for total BTEX & TPH of 0.1 mg/L & 10 mg/L, respectively.)
For source control the preferred alternative that has been implemented (summer 1996) is tank abandonment & piping removal.
Elements are listed as follows:
1) cleaning the tanks & filling with inert material (dirt),
2) cleaning & removing the piping system & associated soils, &
3) revegetating the area.
5 year reviews to assess protectiveness of the remedial action & periodic evaluation of monitoring results to determine if there is need for further remediation. If additional study determines, 1) a lack of substantial evidence verifying the potential or current occurrence of NA at the site, or 2) NA rates are significantly less than anticipated at the site, or 3) the data indicates that cleanup levels cannot be achieved, the contingency alternative for GW Collection & treatment would become the preferred alternative.
The elements of the contingent alternative are:
- Extracting groundwater from the shallow aquifer to eliminate further migration;
Treating the extracted water with an air stripping process to meet federal, state & local water quality regulations;
- Treating the air emissions from the air stripping process to meet state & base air emission permit requirements;
- Disposing of the treated groundwater in accordance with federal, state, & local regulations
& permit requirements;
- 5-year review to assess the protectiveness of the remedial action; &
- Monitoring of the effectiveness of the groundwater containment & treatment process until the benzene concentrations reach the MCL or groundwater poses an acceptable risk. |
Jennifer Roberts |
| 6/23/1994 |
Update or Other Action |
Jennifer Roberts received a fax on the weekly activities for ST41 Interim Remedial Action (IRA). Air stripper was reassembled on June 13, after cleaning activities were finished. Approximately 6,200 gallons of water were reprocessed through the stripper. Effluent was sampled and test results showed that it was suitable for discharge to the base sewer system. |
Jennifer Roberts |
| 6/30/1994 |
Update or Other Action |
Jennifer Roberts received a fax on the weekly activities conducted for the ST41 IRA. 8 gallons of product recovered to date and 30,400 gallons of water was processed through the system. |
Jennifer Roberts |
| 7/6/1994 |
Update or Other Action |
Jennifer Roberts received a fax of the weekly activities for ST41 IRA. 18 gallons of product recovered to date and 37,500 gallons of water was processed through the system. |
Jennifer Roberts |
| 7/14/1994 |
Update or Other Action |
Jennifer Roberts received a fax of the weekly activities at ST41 IRA. 25 gallons of product recovered to date and the total gallons of water processed through the system was 39,900 gallons. |
Jennifer Roberts |
| 7/21/1994 |
Update or Other Action |
Jennifer Roberts received a fax of the weekly activities report for ST41 IRA. Product recovered to date 45.5 and water processed through the system: 46,900 gallons to date. Product thickness measurements in the extraction well EW-2 ranged from 0.84' to 1.04' at the beginning of operation to 1.43' to 2.12' at the end of the operation. Product thickness in ST41-28 has stabilized between 0.71 to 0.72 feet and in ST41-16 between 0.62' to 0.63' and in ST41-16 sheen was detected. |
Jennifer Roberts |
| 10/11/1994 |
Update or Other Action |
Jennifer Roberts received fax on the ST41 IRA activities. 126.9 gallons of product recovered and 71,400 gallons of water processed through the system to date. No downtime was reported for the system for maintenance. Effluent sample collected on 10/6/94 indicated that it was suitable for discharge. 10/3 activity report was also sent at the same time. 119.7 gallons of product was recovered to date. 69,000 gallons of water was processed through the system to date. 6,400 gallons of effluent water was discharged on Monday 26 September. The fuel recovery rate seems to be rising due to the pump in extraction well EW-2 operating normally. Effluent sample collected and the water will be discharged but that depends on how much water is processed through the system. If there is enough holding capacity left in the tanks, water will not be discharged until the tanks are full enough to warrant the cost of hauling it to the discharge point. |
Jennifer Roberts |
| 10/17/1994 |
Update or Other Action |
Jennifer Roberts received the ST41 IRA activities report. 133.8 gallons of product recovered. Water processed through system total to date: 73,300 gallons. System was operated with no downtime for maintenance. Effluent water was discharged on 10/12/94. Approximately 6,400 gallons of water were hauled offsite to the discharge point by the staging area. |
Jennifer Roberts |
| 11/7/1994 |
Update or Other Action |
Jennifer Roberts received a fax on the weekly activities for 10/31/94 to 11/7/94 ST41 IRA. IRA operated everyday last week with no downtime for maintenance. An effluent sample was collected last week and the analysis indicated that the effluent was suitable for discharge. In order to dispose of the drums of carbon, the lab subcontract was modified to analyze TCLP samples o the carbon. Samples will be collected as soon as possible and the carbon waste will be characterized and taken to DRMO. Product total to date: 146.1 gallons and Total processed through system 76,800 gallons to date.
Also received on this date, USAF letter regarding Record of Decision (ROD) for Operable Unit 2. In accordance with paragraph 20.17 of the Federal Facility Agreement the Air Force is extending the deadline for submitting the Draft Final ROD for OU2 by 20 days. This decision was made following delays due to lack of contractor support in preparing the OU2 ROD and the recent change in project managers. |
Jennifer Roberts |
| 11/16/1994 |
Update or Other Action |
Jennifer Roberts received fax on weekly activity report. No downtime during November 7 to November 14, 1994. However the system alarm for the effluent transfer tank keeps coming on when the tank fills up. It is probably a problem with safety switches inside the treatment unit control panel. A new unit will be purchased and installed to see if this remedies the situation. Bail tests were conducted in monitoring wells ST41- 16 and St41-28. Product recovered to date: 149.7 gallons and water processed through system: 78,300 gallons. |
Jennifer Roberts |
| 12/21/1994 |
Update or Other Action |
Fax received on ST41 IRA Activities performed and activities to be performed. 12/12-12/19/1994: IRA was operated with no downtime for maintenance. On Thursday 15 December the tanks reached maximum holding capacity. Water was scheduled to be hauled on Friday 16 December. However, snow plows have not cleared the road and in order for the tank truck to get up the hill, the road must be completely plowed. Water hauling was tentatively scheduled to be on Monday 19 December. On 19 December, the road was checked and it appeared partially plowed to allow smaller vehicles up the hill but not the tanker truck. Radian and the AF decided if the road was not plowed by end of 19 December, that the Base CE would plow it and it would not be a problem in the future. Product recovered to date 163.6 gallons and water processed to date 80,000 gallons. |
Jennifer Roberts |
| 12/22/1994 |
Update or Other Action |
Jennifer Roberts received a letter regarding the Record of Decision (ROD) for Operable Unit (OU) 2. The letter is in response to EPA's letter dated December 5, 1994. In accordance with paragraph 25.1 of the Federal Facility Agreement, the Air Force is extending the deadline for submitting the draft final ROD for OU2 until January 30, 1995. This decision was mutually agreed upon by the agencies based on the status of the document submitted on November 28, 1994. Final ROD deadline will be March 1, 1995. |
Jennifer Roberts |
| 1/9/1995 |
Update or Other Action |
OU5 Groundwater Modeling Report received. The objectives of the modeling task were to: Evaluate the movement of contaminants across Elmendorf AFB and within Operable Unit (OU) 5; Predict contaminant migration over the next 30 years; and Determine if selected receptor points along Ship Creek and an unnamed beaver pond will be impacted by contamination. A 3 dimensional finite element model (SALT) developed at the University of Waterloo was selected because of its versatility in handling complex geology and boundary conditions. Radian Corporation modified the model to improve the program's efficiency and to include contaminant decay and site specific boundary conditions along Ship Creek. This modified version called SALT 3, consists of groundwater flow and contaminant transport models. The hydrogeology of the modeled area was evaluated using lithologic data collected from all available boreholes within the modeled area and water level data collected from shallow water table monitoring wells in March and September 1993.
After a review of the groundwater quality data from September 1993 groundwater sampling and available OU 1, 2, and SERA site data, benzene and trichloroethene were selected as representative compounds for this modeling effort. Benzene and TCE were selected due to their potential health impacts. As metals and semivolatile compounds were only sporadically detected at concentrations near maximum contaminant levels (MCLs) they are not constituents of environmental concern in much of the aquifer beneath EAFB and were not modeled.
Concentrations in the recharge over the water table was set to zero except for at source areas. Since improvement in soil quality is expected over time, the sources were assumed to cease contributing benzene and TCE to groundwater after five years. All concentrations in the recharge zone were therefore set to zero at the end of the first five years.
The conclusions of the base case simulations show that benzene and TCE will migrate toward the south. However, the concentrations of these contaminants will decline over time. Because of infiltration, there may be some localized areas that experience a temporary increase in concentration as a "pulse" migrates toward the south. Benzene will be detectable in groundwater for over 20 years, however, the concentrations in groundwater basewide should be below the MCL after 15 years (1993-2008). NOTE: this decrease in benzene has not occurred due to the overly optimistic model or additional sources contributing to the benzene concentrations in groundwater or a combination of both. TCE concentrations will be detectable in groundwater after 30 years (2023) and should be less than the MCL basewide after 20 years (2013).
Benzene and TCE will spread and migrate toward the south from identified source areas. Concentrations in groundwater flowing toward Ship Creek and the unnamed beaver pond should not exceed 1 ug/L over the period modeled. The model predicts that the concentrations of these compounds in groundwater near surface water bodies will be approximately 1 ug/L after 5 years (1998) and will then steadily decline over time. The results of the groundwater modeling effort indicate that the groundwater can be remediated naturally (MNA) in all OUs without any predicted increase impact to sensitive receptors in OU5. The model predicted, that in five years, benzene and TCE concentrations in OU5 from upgradient sources will be above 1 ug/L but less than 10 ug/L. In 10 years (2003), the concentration of these compounds is predicted to be less than 1 ug/L in OU5, indicating a measurable improvement in water quality over time. |
Jennifer Roberts |
| 1/30/1995 |
Update or Other Action |
Jennifer Roberts received an action memorandum letter from the Air Force regarding the Record of Decision (ROD) for Operable Unit (OU) 2. As discussed in our meeting on January 12, 1995, the treatability study report examining the natural attenuation alternative for ST41 is available and should be reviewed prior to moving forward with the draft final ROD for OU2. IN addition, a technical memorandum detailing observations made during operation of the Interim Remedial Action (IRA) at ST41 is forthcoming and should be likewise reviewed. These documents are being provided under a separate cover. The Treatability Study is in preliminary draft from and will be revised before being submitted for your formal comment. The draft final ROD is currently scheduled to be submitted on January 30, 1995. In accordance with paragraph 20.17 of the Federal Facility Agreement the Air Force is extending the deadline for submitting the Draft Final ROD for OU2 by 20 days. The newly available information is not anticipated to significantly affect decisions being made in the ROD; however, it will add clarity to the current situation. The decision to extend was agreed upon by all parties. |
Jennifer Roberts |
| 2/27/1995 |
Update or Other Action |
USAF sent the 30% Draft Remedial Design (RD) for ST41. Certain design assumptions are in the design:
1) contaminated soil is resulting from the UST system specifically the leaking valves, pipe fittings, and cracks in piping;
2) contamination has spread in the vertical, rather than horizontal direction;
3) excavation will be based on a stratigraphy evaluation and will not "chase" stringers of contamination;
4) the action level for soil removed will be determined through leachate testing of the native soil (alternative cleanup level now known as Method 3); and
5) contaminated soil will be remediated thermally treated at approved facility offsite.
Procedures changed from using the Alaska matrix level D, a level using an alternative cleanup level for soil determined through leachate testing will be the revised action level for excavation. |
Jennifer Roberts |
| 3/4/1995 |
Update or Other Action |
ST41 IRA Report #1 (February 1 to March 3 1995). During the month of February 1995, Radian Corp assumed operation of the IRA oil/water separator and water treatment system at ST41. Effluent samples were collected and all results were below Anchorage Water and Wastewater Utilities discharge standards. Approximately 8000 and 4000 gallons of treated water were hauled for discharge of the Anchorage sewer system on February 17 and 18. As of January 10, 1995, 154.7 gallons of product had been recovered with a total processed water volume of 81,700 gallons. |
Jennifer Roberts |
| 3/18/1995 |
Update or Other Action |
ST41 IRA Activity Report #2 (March 6-March 17, 1995). Effluent samples collected and all results were below AWWU discharge standards. 6600 gallons of treated water were hauled for discharge to Anchorage sewer system on March 15. |
Jennifer Roberts |
| 4/5/1995 |
Update or Other Action |
ST41 IRA activity report #3 (March 20 through April 4, 1995). Effluent samples collected and all results were below AWWU discharge standards. Approximately 8,800 gallons of treated water were hauled for discharge to the Anchorage sewer system on March 29, 1995. The inoperative extraction well EW-2 was investigated on March 29 and found that the discharge line was frozen solid. According to Tim Grace of Jacobs Engineering, this pump stopped working late last fall in October. It is likely that the discharge line was frozen all winter. Recommend remove and thaw discharge line and investigate back draining of the line so potential for freezing is eliminated. According to historical information received from Jacobs on April 4, and recent Radian records, the cumulative volumes of floating product recovered was 232.8 gallons and cumulative water collected by the system through March 31 was 126,600 gallons. |
Jennifer Roberts |
| 4/15/1995 |
Update or Other Action |
ST41 IRA activity report #4 (April 5 through April 14, 1995). Discharge line for EW-2 was thawed, PVC lines on the outside product storage tank were repaired. Cumulative volumes of floating product 223.8 gallons and cumulative water collected by the system was 128,522 gallons through April 17, 1995. *NOTE cumulative volume of floating product reported in Activity report #3 of 232.8 gallons was incorrect. Initial gauging of the product holding inside building 31-600 tank failed to detect a layer of water at the bottom of the tank. |
Jennifer Roberts |
| 4/28/1995 |
Document, Report, or Work plan Review - other |
Jennifer Roberts sent comments on the 30% remedial design (RD) for ST41. Request in future design documents explanation on how the process "vapor-freeing" will be done during tank decommissioning and cleaning process and what associated monitoring will be done. The RD has several assumptions that differ from the United States Air Force (USAF) letter dated 2/27/1995 that discusses changes based on the final Record of Decision (ROD).
ADEC agrees with the details in your letter and have not made any comments related to those details since ADEC expects to see these changes in the 60% design. Request that in the 60% design that the USAF be specific about the analysis needed for the sludge and rinsate water. Both these fluids are regulated by RCRA and therefore need to be specifically addressed under the appropriate RCRA regulations. |
Jennifer Roberts |
| 4/29/1995 |
Update or Other Action |
ST41 IRA Activity Report #5 (April 17 through April 28, 1995). The north side of the IRA system (EW-2 and ET-3) was not operated during this period due to the separated discharge line in ET-3. Effluent samples were collected and all results were below AWWU discharge standards. Approximately 8289 gallons of treated water were hauled off for discharge to the Anchorage sewer system on April 25. 224 gallons of floating product and 133,618 gallons of water were collected by the system through April 28, 1995. Air compliance: AFCEE has been given permission by the Base air compliance staff to add ST41 emissions to the base-wide permit. Radian is awaiting the appropriate paperwork before bypassing the carbon canisters. |
Jennifer Roberts |
| 5/3/1995 |
Document, Report, or Work plan Review - other |
John Halverson sent USAF review comments on the SERA Phase I Corrective Action Plan dated April 1995. As noted in comments on the draft workplan, the corrective action plan needs to include
schedules for conducting field work, monitoring and maintaining equipment, and submittal
of interim and/or final corrective action reports. We have previously requested quarterly
reporting of remedial efforts at each site where free product has been identified (ST 43 and
ST36).
The Air Force has proposed changes to the several of the tables that outline groundwater
monitoring plans. Unless specifically noted below, the department does not object to these
changes. The locations of substituted wells need to be shown on figures in the plan, if not
already present.
NFA Candidate Sites: ST69 - Diesel Leak (Building 76-520, UST #525)
Section 2.11.7 - The second sentence states cleanup efforts at the time of the tank removal successfully prevented soil contamination. Based on discussion with other program staff, it is my understanding that when the tank was removed a large volume of soil was excavated (to the depth of the water table) and hauled off-site. Therefore, it would be more appropriate to state that contaminated soil was "removed", rather than "prevented", during excavation of the tank.
Section 2.11.9 - The first paragraph states it appears ST41 OPERABLE UNIT 2 4 MILLION GALLON HILL is the source of groundwater contamination beneath ST69 (HAZARD ID 23398). Based on the information that petroleum contaminated soil was excavated to the depth of the water table at the time the UST was removed, it appears the former UST is the likely source of groundwater impacts rather than CERCLA SOURCE AREA ST41. Assessment work after the tank removal and excavation of soil has not located petroleum contaminated soil above the watertable at this site, however, the elevated concentration of benzene in the groundwater warrants further monitoring (under the BASEWIDE GROUNDWATER MONITORING). Therefore, the department does not object to a no further action decision under SERA for soil at ST69 based on the condition that monitoring well 46WL01 be added to the BASEWIDE groundwater monitoring program. |
John Halverson |
| 5/19/1995 |
Record of Decision |
ROD presents the final remedial action at OU2 for ST20 and ST41. Contaminated media associated with ST20 will be addressed under the State Elmendorf Environmental Restoration Agreement.
**NOTE to File: Oct. 20, 2002 Letter from ADEC-J. Roberts to US Air Force Elmendorf Environmental Chief: Joe Williamson dissolving the State Elmendorf Environmental Restoration Agreement. The Alaska Department of Environmental Conservation (DEC) has reviewed the issue of abolishing the State Elmendorf Environmental Restoration Agreement (SERA) per Air Force's recommendation. Elmendorf Air Force Base and DEC entered into the SERA in 1992. The agreement was developed as a tool to bring the Base into compliance with Alaska's regulations addressing underground storage tanks, oil and other hazardous substance releases and solid waste.
Since that time, Elmendorf has made significant progress in investigating and cleaning up historic contamination problems. Many of the sites covered by the SERA have been successfully cleaned up and closed. Cleanup is underway at the remaining sites.
Additionally, Alaska has amended the regulations addressing fuel storage tanks, oil and other hazardous substance spills and solid waste. ADEC concurred with Air Force that the SERA is no longer a necessary or beneficial. This letter serves as notice that DEC will end oversight on environmental work at Elmendorf by using the SERA. Instead, it is understood that the sites and programs formerly addressed by SERA: solid waste, underground storage tanks (UST), and oil and other hazardous substance discharges will be addressed in accordance with 18 AAC 60, 18 AAC 78 and 18 AAC 75.
Selected remedy incorporates the interim remedial action and includes additional remedies for source control and groundwater remediation.
The selected remedy for source control are:
1) cleaning of the four one million gallon underground storage tanks and filling them with inert material;
2) excavating, removing, cleaning and disposing/recycling of the piping systems; 3) removing contaminated soils that may contribute to groundwater contamination and treating in a preapproved facility; and
4) revegetating the area.
The selected remedy for the ST41 groundwater includes: monitoring the groundwater beneath and adjacent to the site to evaluate contaminant migration and timely reduction of contaminant concentrations by natural attenuation with 21 years. This will include 5 year reviews to assess the protectiveness of the remedial action as long as contamination remains above unacceptable levels.
Maintain institutional controls that restrict access to groundwater and groundwater development at the site as long as hazardous substances remain on the site at levels that preclude unrestricted use. Specific ICs to be implemented and or maintained at OU2 are:
1) Development of a site map showing the areas currently and potentially impacted by groundwater contaminants that will be included in the Base Comprehensive Plan;
2) Zoning the affected area for undeveloped outdoor/recreational use only;
3) Continued enforcement of base policy prohibiting installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2; and
4) Prohibiting unauthorized access to existing water supply and groundwater monitoring wells.
In addition, to ensure long term integrity of the above land use controls, the AF will ensure that, to the extent that groundwater contamination remains above unacceptable levels, deed restrictions or equivalent safeguards will be implemented in the event that the property containing such contamination is transferred by the AF. The measures will include:
Five year review to assess the protectiveness of the remedial action;
Periodic evaluation of monitoring results to determine if there is need for further remedial action.
ST41 also consists of a suspected one acre tank sludge disposal area located adjacent to the storage tanks. A map dated 1953 suggested this area was used for sludge disposal. The base conducted a historical record search and a field investigation consisting of geophysical surveys and susbsurface soil sampling to determine the presence or absence of disposed sludge. The investigation did not find any evidence of actual sludge disposal at ST41 and no contamination was found; therefore, a no further action (NFA) determination was made and the ST41 Sludge Disposal Area is not included in the sections following 5.2.8 of the Record of Decision. |
Jennifer Roberts |
| 5/19/1995 |
Institutional Control Record Established |
Signing of the ROD on this date memorializing the institutional controls (ICs) being placed on the groundwater since it remains contaminated above MCLs.
ICs consist of: A site map was developed showing areas currently & potentially impacted by groundwater contaminants to be included in the Base General Plan (USAF 1998), zoning the affected area for undeveloped outdoor/recreational use only, continued enforcement of the Base policy prohibiting installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2, prohibiting unauthorized access to existing water supply & groundwater monitoring wells. Finally, the selected remedy includes a contingent remedy (groundwater pump & treat) to be implemented if LTM indicates the groundwater treatment system &/or natural attenuation are not providing adequate protection to human health & the environment.
NOTE TO FILE: § 300.430 Remedial investigation/feasibility study & selection of remedy.(a) General—(1) Introduction. The purpose of the remedy selection process is to implement remedies that eliminate, reduce, or control risks to human health & the environment. Remedial actions are to be implemented as soon as site data & information make it possible to do so. Accordingly, EPA has established the following program goal, expectations, & program management principles to assist in the identification & implementation of appropriate remedial actions.
(iii) Expectations. EPA generally shall consider the following expectations in developing appropriate remedial alternatives:
(D) EPA expects to use institutional controls such as water use & deed restrictions to supplement engineering controls as appropriate for short- & long-term management to prevent or limit exposure to hazardous substances, pollutants, or contaminants. Institutional controls may be used during the conduct of the remedial investigation/feasibility study (RI/FS) & implementation of the remedial action &, where necessary, as a component of the completed remedy.
The use of ICs shall not substitute for active response measures (e.g., treatment &/or containment of source material, restoration of ground waters to their beneficial* uses) as the sole remedy unless such active measures are determined not to be practicable, based on the balancing of trade-offs among alternatives that is conducted during the selection of remedy.
*“EPA expects to return usable ground waters to their beneficial uses wherever practicable, within a time frame that is reasonable given the particular circumstances of the site. When restoration of ground water to beneficial uses is not practicable, EPA expects to prevent further migration of the plume, prevent exposure to the contaminated ground water, & evaluate further risk reduction” 40 CFR 300.430(a)(1)(iii)(F). |
Jennifer Roberts |
| 5/19/1995 |
Cleanup Level(s) Approved |
Record of Decision signed memorialized cleanup levels for ST41.
Action-Specific ARARs: To the extent hazardous waste, as defined by the Resource Conservation and Recovery Act, 42 U.S.C. sec. 6901 et. seq., is extracted from the groundwater and to the extent air emissions result from operations of and air stripper, the selected remedies will comply with the requirements of 40 CFR 264 Subparts AA & BB. Spent carbon from the carbon
adsorption unit and filters which may be used in conjunction with the remedies and/or
residual materials from the pretreatment system will be stored and disposed of or recycled
at a RCRA approved facility in accordance with EPA policy for offsite disposal of CERCLA
waste.
Air emissions from the air stripper will meet ambient air quality criteria established by the
State of Alaska Air Quality regulations (18 AAC 50).
Processed wastewater will be discharged into the Anchorage municipal wastewater system in
accordance with 40 CFR 4035 and the Anchorage Water and Wastewater Utility
requirements of 100 ppb for BTEX and 10 ppm for TPH.
To the extent wastewater will be discharged into the waters of the United States, such
discharge will comply with the substantive requirements of 40 CFR Part 125 and the Alaska
Wastewater Disposal regulations set forth in 18 AAC 72 and 18 AAC 70.
To the extent the selected remedies result in the removal of petroleum contaminated soil
the contaminated soil will be handled and treated consistent with the requirements of 18
AAC 78.310.
Chemical-Specific ARARs: Cleanup levels established in document: Primary MCis established under the Safe Drinking Water Act are relevant and appropriate requirements for groundwater that is a potential drinking water source:
Groundwater-benzene (5.0 ug/L), ethylbenzene (700 ug/L), toluene (1,000 ug/L) and xylene (10,000 ug/L). Alaska surface water quality criteria, established under the State of Alaska Water Quality Standards, are relevant and appropriate requirements for surface water: benzene (10 ug/L), ethylbenzene (10 ug/L) and toluene (10 ug/L). The State water quality standards for each constituent are based on the total aromatic hydrocarbon (TAH) concentrations.
The selected remedies will meet Alaska Oil Pollution Regulation 18 AAC 75.310 (1994)
pertaining to surface and groundwater cleanup of petroleum related benzene.
The selected remedy will meet AK UST regulations (1994) 18 AAC 78.315 for cleanup guidelines for UST contaminated soil.
Location-Specific ARARs
Executive Order 11990 and 40 CFR Part 6, Appendix A, require that Federal Agencies conduct
activities to avoid, to the extent possible, the long and short-term adverse impacts associated with the destruction or modification of wetlands.
Note to file: Current 18 AAC 70.020 reg states: Samples to determine concentrations of total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) must be collected in marine and fresh waters below the surface and away from any observable sheen; concentrations of TAqH must be determined and summed using a combination of: (A) EPA Method 602 (plus xylenes) or EPA Method 624 to quantify monoaromatic hydrocarbons and to measure TAH; and (B) EPA Method 610 or EPA Method 625 to quantify polynuclear aromatic hydrocarbons listed in EPA Method 610; use of an alternative method requires department approval; the EPA methods referred to in this note may be found in 40 C.F.R. 136, Appendix A, as revised as of October 23, 2003 and adopted by reference.
Register 24 January 1993 in effect when 1995 ROD was signed states: Total hydrocarbons in the water column shall not exceed 15 ug/l, or 0.01 of the lowest measured continuous flow 96 hour LC50 for life stages of species identified by the department as the most sensitive biologically important species in a particular location, whichever concentration is less. Total aromatic hydrocarbons in the water column shall not exceed 10 ug/l, or 0.01 of the lowest measured continuous flow 96 hour LC50 for life stages of species identified by the department as the most sensitive biologically important species in a particular location, whichever concentration is less. Concentrations of hydrocarbons, animal fats, or vegetable oils in the sediment shall not cause deleterious effects to aquatic life. Shall not cause a film, sheen or discoloration on the surface or floor of the water body or adjoining shorelines. Surface waters shall be virtually free from floating oils. |
Jennifer Roberts |
| 5/27/1995 |
Update or Other Action |
ST41 interim remedial action (IRA) activity report #7 (May 16 through May 26, 1995). The third attempt at gluing the discharge pipe in ET-3 was successful and the connection is holding. ET-3 and EW-2 are now operational. Effluent water samples were collected and all results were below AWWU discharge standards. Approximately 800 gallons of treated water were hauled for discharge to the Anchorage sewer system on May 17. The carbon adsorption system will not be bypassed until the carbon has been sampled. If carbon is not spent, then it will continue to be used until it is spent. 226 gallons of floating product and 138,426 gallons have been collected to date through May 26, 1995. |
Jennifer Roberts |
| 6/9/1995 |
Update or Other Action |
Technical memorandum from Air Force to Jennifer Roberts regarding the EAFB OU2 ST41 treatability study field schedule of activities. 1. Floating product recharge testing in EW-2, 2. Seep flow rate and extraction trench recharge testing, 3. Groundwater and surface water sampling, 4. Sediment sampling. Tasks begin on June 19 to the week of July 10.
60% Draft Remedial Design (RD) for ST41 also received.
Finally, the Remedial Design/Remedial Action Statement of Work (SOW) for OU2 Source Area ST41. The SOW has the following general requirements:
1) develop a work plan that details the specific tasks required to design and construct the remedial action for OU2;
2) review existing design drawings and other reference material; determine design parameters;
3) design all elements of the remedial action including tank abandonment, pipe removal, vaults and structures, and contaminated materials handling components;
4) implement institutional control aspects of the remedial action including rezoning the area for undeveloped outdoor recreational use only, securing all existing groundwater wells, and establishing policies that will prohibit the use of shallow aquifer groundwater near ST41;
5) perform required contracting for construction;
6) implement the remedial action;
7) make adjustments as necessary in the free product recovery and seep mitigation system;
8) continue long term operation (LTO) and maintenance of the remedial system; and
9) continue monitoring groundwater quality to evaluate the effectiveness of natural attenuation at reducing contaminant levels. Schedule of RD/RA activities is shown on Attachment A enclosed with the SOW. |
Jennifer Roberts |
| 6/14/1995 |
Update or Other Action |
ST41 IRA Activity Report #8 (30 May to 9 June 1995) received. IRA operated for 4 hrs/day on all weekdays except for 29 May. All effluent samples collected on June 1 were below AWWU discharge standards. 8660 gallons of treated water were hauled for discharge. Carbon adsorption system will not be bypassed until the carbon has been sampled which is planned for week of June 19. If not spent the carbon will continue to be used. Laboratory work for the leachability study was initiated. Cumulative volumes of floating product and water collected by the system through May 25: 226.7 gallons and cumulative water 146,791 gallons. |
Jennifer Roberts |
| 6/16/1995 |
Update or Other Action |
SERA Phase I Corrective Action Plan (1995) shows the results of the subsurface soil sampling indicate that the subsurface soils have not been affected by the release from the former UST at ST69. No leachate modeling was performed for site ST69 because no analytical data are available regarding the spill source.
Contaminated groundwater was detected in two locations.
The spatial distribution of the contamination suggests the former UST as the source. However, the limited extent of groundwater contamination and apparent spread crossgradient to apparent
groundwater flow contradict the former UST as a source. Additionally, the steep groundwater gradient in the coarse-grained soil of the site suggest that the contamination should have been
dispersed and attenuated naturally by this time if originating from the former UST. These data implicate an upgradient source, likely north of Loop Road.
Groundwater in 46WL01 and 46WL04 contained benzene concentrations greater than established Federal and State MCLs. The high GRO and benzene concentrations combined with low DRO concentrations in the groundwater are not typical for diesel fuel contamination. Contamination detected in the groundwater is more representative of jet fuel, which likely originates from an offsite upgradient source. The most likely source is ST41 of
OU-2. This conclusion is corroborated by groundwater analyses conducted in the OU-2 Remedial Investigation/Feasibility Study (RI/FS) for ST41.
It is recommended that ST69 be closed and further actions be incorporated into decisions for ST41. Decisions about the fate of the monitoring wells installed at ST69 should be included along with ST41 monitoring wells. A plan for continued groundwater monitoring for ST41 was presented in the OU-2 RI/FS, which allowed for flexibility in well inclusion and sampling frequency.
Well 46WL01 should be included in the basewide groundwater monitoring program. |
John Halverson |
| 6/29/1995 |
Update or Other Action |
OU2 ST41 GW well sampling work plan memorandum received. A total of 9 wells will be sampled: 4 on the North side and 5 on the south side. These wells are scheduled to be sampled in late June. The long term monitoring will be conducted to assess groundwater quality with the known contaminant plumes, to evaluate natural attenuation of contaminants, and to monitor groundwater quality at the edge of each plume. This will be done to provide an early warning of increased contaminant levels or migration of contaminant plumes.
Also received on this date was the OU2 ST41 IRA Treatability Study Tasks Memorandum. The purpose of this memorandum is to outline the purpose, detailed approach, and procedures for the OU2 ST41 IRA Treatability Study Tasks. The purpose of the study is to evaluate the efficiency of the existing IRA system and the status of sediment, groundwater, and the surface water contamination at the site. Four tasks are outlined in the memorandum:
1. Floating Product Recovery testing to evaluate whether a more efficient method for recovering the floating product is available;
2. Seep flow rate and trench recharge testing to evaluate the effects of the current seep mitigation components (e.g. operation of extraction trenches) on reducing seep flow rates;
3. Sediment sampling. Analytical results from sediment samples at or near seep locations will be compared to previous analytical results to evaluate trends in toxicity and natural attenuation.
4. Surface and shallow groundwater sampling. Results from shallow groundwater and surface water sampling will be used to evaluate toxicity and natural attenuation. Samples will be collected at seeps, wetlands and the existing oil/water separator.
Finally, the ST41 activity report # 9 (12 June through 23 June 1995) was received. Radian operated the IRA system for 4 hrs/day on all but 2 weekdays from 12 June to 23 June. System was not run on 13 and 14 June due to delays in receiving analytical results for treated water. All effluent samples were below AWWU standards. Approximately 8900 gallons of treated water were hauled for discharge to the Anchorage sewer system on 15 June.; |
Ray Burger |
| 7/11/1995 |
Update or Other Action |
Technical Memorandum ST41 IRA Activity report #10 (26 June through July 7, 1995). As specified in the OU2 ST41 IRA Treatability Study Work plan, the IRA system was not operated during the week of 26 June in order to establish baseline water levels and seep flow rates. The IRA system was not operated on 3 or 4 July to observe Independence Day. IRA system was operated for 4 hours/day on 5-7 June. EW-1, EW-2, ST41-28, and ST41-16 were gauged for the presence of floating product. Effluent samples were collected on 6/27/1995 and all results were below AWWU discharge standards. 7200 gallons of treated water were hauled for discharge to the AWWU sewer system on June 30. Additional sediment and shallow groundwater samples were collected upgradient from SE-09 on the north side of ST41 at a seep location on 27 and 29 June respectively. This location was labeled as the NW Seep in the treatability study report and it had a strong hydrocarbon odor and a sheen was present on the water sample.
Problems encountered and recommendations: Without modification, it is not possible to run the IRA system at flow rates exceeding approximately 6 gpm. Higher flow rates cause the oil/water system to overflow. Recommendation: instead of increasing flow rate, simply run the system for a longer duration until the trenches are dewatered. Preliminary results of the seep flow rate testing indicate that neither normal IRA system operation nor increased IRA system operation significantly reduce seep flow rates. It is likely that the seep flow rates will remain unaffected until the ground underlying the seeps is dewatered. Recommendation: Eliminate the 2nd round of seep flow rate and trench recharge testing under increased IRA system operation. Instead keep one source drawn down for an extended period of time (4-6 hrs) while measuring the seep flow rate and cumulative volume of water collected in the IRA holding tanks. While keeping one source drawn down, attempt to simultaneously draw down water levels in other trenches. The goal will be to determine if it would be possible to keep multiple trenches dewatered at the same time without exceeding the maximum IRA system influent flow rate of approximately 6 GPM. |
Ray Burger |
| 8/4/1995 |
Update or Other Action |
Fax of leachability study results OU 2 received from Lisa Alcorn (EAFB). Column leaching tests indicated that leachate from soils containing 2000 mg/kg product will not exceed cleanup standards at any time. The memorandum further states that the leachate from soils contaminated with 4000 mg/kg of fuel will meet the Alaska cleanup standard. No sheen was observed with leachate from any columns, satisfying the DRO and GRO Alaska cleanup standards for groundwater. The maximum total BTEX levels in the leachates (1,000 ug/L) was well below the 11,700 ug/L Alaska cleanup standard. This is INCORRECT since Alaska does not have a BTEX standard (which is a sum of the constituents), instead each COC must be looked at independently. |
Ray Burger |
| 10/3/1995 |
Document, Report, or Work plan Review - other |
Ray Burger (ADEC) provided comments on the OU2 ST41 Remedial Design 100% draft. ADEC reserves concurrence with the action level of 2000 mg/kg (ppm) pending receipt of the final Treatability Study Report addressing the leachability study. In an effort to keep soil contaminated with as much as 2000 ppm of product from being placed in such close proximity to groundwater, clean backfill should be used "if the excavation is within 1 foot of the seasonal high water table." |
Ray Burger |
| 10/31/1995 |
Update or Other Action |
Ray Burger received ST41 IRA Activity report #18. Radian has been notified by AFCEE and the USAF to discontinue operation of the IRA system for the winter. IRA system operated from 16 October through 24 October 1995. On 10/25/95, the motor for the blower failed and the system was shutdown. Analytical results and field screening correlation on spiked samples used in the leachability study have been received and are being interpreted. These results will be communicated in a separate Technical Memorandum as soon as possible. Final pore volumes of water for the additional ST41 leachability study are being leached through the columns this week. The samples will be sent to the lab for standard 2 week turn around time. Final results to be in a technical memorandum and included in the final draft of the OU2 ST41 IRA Treatability Study Report. |
Ray Burger |
| 12/14/1995 |
Update or Other Action |
Technical memorandum from Larry Underbakke received for IRA leachability study Summary of final results. Radian Corp. recommends that the Air Force use a cleanup criteria of 3000 mg/kg total fuel hydrocarbons (by methods AK 101/102). Based on the results of the leachability study, soils at concentrations less than 3,000 mg/kg TFH will not produce leachate that will exceed state and federal maximum contamination levels (MCLs) for drinking water. Bench scale leachability studies were performed as a part of the OU2 ST41 IRA treatability study to evaluate the desorption behavior of fuel contaminated soils from ST41. The main purpose of the study was to establish [a SITE-SPECIFIC] cleanup criteria for fuel contaminated soils in the vicinity of the POL pipeline at ST41 [Not anywhere else].
Composite samples of uncontaminated soils representative of the shallow subsurface soils (which include the tanks and associated piping) were spiked with weathered (NOT FRESH product) petroleum product recovered from extraction well EW-2. Initial leaching tests show that the soils contaminated with 2,000 mg/kg of recovered product will not exceed the MCL for benzene at 5 ug/l at any time. Soils contaminated with 5,000 mg/kg of recovered product may produce leachate containing benzene above the MCL for at least 77 years. 10 pore volumes used in the simulation were stated to represent 77 years of leaching. This is INCORRECT. 7 pore volumes (11 years/pore volume page 5-9 of the August 1997 ST41 evaluation of the treatment system) X 11 years are required for each pore volume to infiltrate the surface and leach through the soils to groundwater = 77 years. Pore Volume calculations: Porosity 0.35 inches/inch, groundwater depth 20 feet, time per pore volume (PV) = (240 inches soil)/7.47 inches/year (net recharge.) x 0.35 = 11.245 year/PV.
Therefore 10 pore volumes=112.45 years. OVM headspace readings were recommended to not exceed 100 ppmv and tested to determine accurate levels of contamination. [This ASSUMES the organic vapor monitoring device reading of 100 ppm ALWAYS equates to less than 2,000 mg/kg diesel range organics or gasoline range organics, which is debatable on weathered fuel product released to the environment]. |
Ray Burger |
| 12/15/1995 |
Update or Other Action |
Ray Burger received a fact sheet for the "EAFB Cleanup Plan for OU2 is Complete." The Base has finalized the remedial design (RD) for cleanup of the UST area at ST41. It focuses on controlling a possible source of contamination as part of the final remedy for OU2. The four main features of the RD plan are:
1) abandoning the four one-million gallon USTs in place;
2) removing associated piping;
3) removing contaminated soil around the piping; and
4) removing a 1,000 gallon oil/water separator.
Monitoring of the groundwater will continue to confirm that natural attenuation of contaminants is taking place. The free product recovery and treatment system will continue to operate to control possible contaminant migration into the shallow groundwater or surface water. More aggressive cleanup actions, if necessary, will be developed in cooperation with the regulatory agencies. |
Ray Burger |
| 12/19/1995 |
Update or Other Action |
USAF spill report. Spill of about 20 gallons of JP-4 caused by backhoe hitting an abandoned pipeline and breaking it. Pipeline capped on either side of the break, but this was at a low spot in the line at a bleed valve. Soil cleanup pending and any investigation is pending. |
Ray Burger |
| 3/29/1996 |
Update or Other Action |
Basewide Annual Groundwater Report-Final (March 1996) showes analytical results for June and October 1995 sampling events. 45-WL-01 (all analytes below cleanup level), 48-WL-01: TCE 64.6 ug/L and 59.9 ug/L (MCL = 5 ug/L), and 49-WL-01 benzene 42.5 ug/L (October), Ethylbenzene 1,350 ug/L and 2,750 ug/L, Gasoline 6150 ug/L (ND limit for October sampling), Jet Fuel 1,530,000 and 790,000 ug/L, Kerosene 407,000 ug/L and 9,790 ug/L, Toluene 1,810 ug/L and 4,270 ug/L, and Xylenes: 15,100 ug/L (October). |
Louis Howard |
| 4/9/1996 |
Update or Other Action |
USAF faxed request for concurrence on disposition of POL discharge ADEC report # 95239935301. John Mahaffey states: 10-20 gallons of JP-4 was released and covered an approximately 1000 square feet area around the break. Because of the wide dispersal of sprayed product, no area appeared to be impacted with sufficient product to cause significant subsurface leaching nor was there any indication that surface or subsurface water could be impacted. The release occurred in an area where ground water contamination levels are being regularly monitored on a long term basis with monitoring wells directly down gradient from the area of release. In view of the nature of the spill, the low volume of the release, the low probability for groundwater involvement and the ongoing water monitoring in the area, the AF will take no additional action and requests the release be closed. John Halverson concurred on 4/16/96 with modifications as stipulated by PER section Jeff Ginalias letter on 4/16/96. |
John Halverson |
| 4/16/1996 |
Update or Other Action |
Jeff Ginalias Prevention and Emergency Response sent letter to USAF John Mahaffey regarding EAFB Abandoned Pipeline Spill 95239935301. ADEC concurs with the proposal to close out the spill based on the rationale set forth in par.. 2-4 of USAF message April 9, 1996. Please note that the closure of the spill by PER section does not impact your prior obligations or commitments regarding long term remediation of the site. In fact, the information concerning the spill has been shared with ADEC's DOD program to provide them more complete information for oversight of the monitoring wells and restoration in this area (ST41 OU2). As the source of the spill was a leak from an abandoned pipeline, there is an issue that abandoned piping in the facility has properly been removed from service, as required by 18 AAC 75.080(e). Ted Moore has been referred to on this matter in the Terminals and Tank Farm Section. |
Jeff Ginalias |
| 7/30/1996 |
Update or Other Action |
Basewide Support and Groundwater Monitoring Program, Analytical Results for OU2 Round 1 received. The purpose of this document is to provide a summary of analytical data collected at fourteen monitoring wells within Operable Unit 2 (OU 2), Elmendorf Air Force Base (EAFB), Alaska. These wells were sampled as part of the long-term monitoring efforts within the framework of the Basewide Support Program. Operable Unit 2 was added to the Basewide Sampling Program in 1996 and this round of analytical data represents the first sampling event to take place at OU 2 within the Basewide Support Program. Data presented are from the Round 1 sampling event, which took place from 20 May through 24 May, 1996.
The objective of long-term groundwater monitoring at OU 2 is to compare concentrations of
constituents of concern to historic concentrations and available background concentrations (for metals), at each respective well. Changes or trends in concentrations will then be established, and any unsuspected increases in contaminant concentrations can then be identified. When sufficient data are collected, groundwater sampling results will be evaluated statistically to ensure that the assumptions made in the OU 2 Record of Decision (ROD) document are accurate; to validate the groundwater model; and to provide early warning of increased contaminant levels or migration of contaminant plumes. All fourteen OU 2 wells sampled during this event were completed in the shallow aquifer. Well locations were selected on the basis of previous contaminant level detections and proximity to source areas of concern to the base Installation Restoration Program (IRP).
Round 1
Thallium results: 0.00623 mg/L B, 0.0105 mg/L B, 0.0112 mg/L B, 0.00380 mg/L JB, 0.00494 mg/L B, 0.00797 mg/L B, 0.00367 mg/L JB, 0.00418 mg/L JB, 0.00726 mg/L B, 0.00584 mg/L B, 0.0121 mg/L B, 0.00935 mg/L B, 0.00185 mg/L JB, 0.00502 mg/L B, 0.00388 mg/L JB, 0.00356 mg/L JB,
*Flags= if a measured analyte concentration is below the sample specific detection limit (SSDL) but still exceeding a potential regulatory standard in at least one sample. In this case, it will also be included in the applicable table, and the data will be "J" flagged. For samples with "no detect" or "J" flags assigned, the SSDL is also provided. B Reported concentration may be due to laboratory contamination.
Quality Assurance/Quality Control-Sampling and analytical activities were conducted following the procedures and requirements described in the Elmendorf AFB Base-Wide Quality Assurance Project Plan (QAPP). Appendix C of the Basewide Environmental Monitoring Plan (USAF, 1996). Results from laboratory QA/QC are to be included in the Comprehensive Annual Groundwater Report. Overall, QA/QC data associated with this program indicate that measurement data are acceptable and defensible.
Thallium cleanup level in groundwater is 0.002 mg/L or 2 ug/L.
Round 2 (Basewide 1996) sample results for Thallium: 0.00374 mg/L B, 0.00726 mg/L B, 0.00636 mg/L B, 0.0131 mg/L B, 0.00354 mg/L B, 0.00185 mg/L JB, 0.00398 mg/L B, 0.00370 mg/L B, 0.000100 mg/L JB, 0.00598 mg/L B, 0.00695 mg/L B. |
Louis Howard |
| 8/29/1996 |
Offsite Soil or Groundwater Disposal Approved |
John Halverson received a fax from Wilder Construction requesting approval to send 2000 tons of contaminated soil for thermal treatment at Clean Soils of Alaska Soils were recovered from the remediation activities at OU2 ST41 areas adjacent to the tanks and associated piping. Approval granted by ADEC. |
John Halverson |
| 8/30/1996 |
Update or Other Action |
John Halverson sent letter to HQ 3 SUP/CES project manager L. Underbakke. Letter states ADEC has no objection to using the remediated soils as fill in closing out Elmendorf's landfill after it has been shown to meet the cleanup levels for "matrix level A" defined in 18 AAC 78.315. This is consistent with both the underground storage tank regulations and the solid waste regulations (18 AAC 60.025(b)). |
John Halverson |
| 9/9/1996 |
Update or Other Action |
4 one-million gallon USTs cleaned and abandoned in place. Piping system excavated, removed and disposed/recycled. Existing contaminated soil containing leachable concentrations of fuel related contaminants and treated them off site by low thermal treatment. |
John Halverson |
| 9/19/1996 |
Update or Other Action |
John Halverson received a fax from Wilder Construction requesting approval to send 500 tons of contaminated soil for thermal treatment at Clean Soils of Alaska Soils were recovered from the remediation activities at OU2 ST41 areas adjacent to the tanks and associated piping. Approval granted by ADEC. |
John Halverson |
| 9/27/1996 |
Offsite Soil or Groundwater Disposal Approved |
John Halverson received a fax from Wilder Construction requesting approval to send 1500 tons of contaminated soil for thermal treatment at Clean Soils of Alaska Soils were recovered from the remediation activities at OU2 ST41 areas adjacent to the tanks and associated piping. Approval granted by ADEC. Digging a trench near tank closest to the road to intercept the wood stave pipe that runs to the ditch near road. AF plans to cut the pipe and plug it with clay so it no longer acts a conduit for water/fuel to flow into the ditch. ADEC requested AF to pull a couple of soil samples from the limits of the excavation to document what residual concentrations of petroleum remain in area. |
John Halverson |
| 10/17/1996 |
Update or Other Action |
Air Force memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV
1) Due to the contamination and commitments to EPA/DEC the use of the shallow aquifer for any purpose on is not allowed. Attached Facilities Board minutes-03/29/1994 0930 Item 9 has Mr. William Hanson, briefing the Board on the policy to not use the shallow aquifer due to contamination. The Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The IRP has RODs for OUs 3 and 6 which require, the aquifer remain unused.
2) Personnel in the review process within CES must be aware of these policies and review them on a recurring basis. It is imperative this restriction be recognized and observed during engineer reviews and operations. |
Jennifer Roberts |
| 11/4/1996 |
Document, Report, or Work plan Review - other |
SERA Decision documents ST69 and ST72 comment letter sent by ADEC to USAF. Due to circumstances with the projects, the sites were not amenable to the simplest no-further-action decision
process. Each site is addressed separately below.
ST 69-As you are aware, an underground storage tank (UST) and petroleum contaminated soil were removed from this site in the past. Site investigation work following the removal did not identify contaminated soil above the watertable. However, elevated concentrations of BTEX and petroleum hydrocarbons were
found in the shallow groundwater. Monitoring well 46WL01 was added to the basewide groundwater monitoring program. Data from the well shows benzene concentrations have decreased from 240 ppb in 1993 to 27 ppb in March 1996. The well will remain in the monitoring program until the concentrations have decreased to below the MCL, as defined in the monitoring plan. Therefore, the department has no objection with the proposed NFA decision at that site. Please see the attached signed decision document. |
John Halverson |
| 12/6/1996 |
Update or Other Action |
Draft Basewide Support & GW Monitoring Program Analytical Results for OU2 Round 2 report received for review & comment.
The purpose of this document is to provide a summary of analytical data collected at fourteen monitoring wells within Operable Unit 2 (OU 2), Elmendorf Air Force Base (EAFB), Alaska. These wells were sampled as part of the long-term monitoring efforts within the framework of the Basewide Support Program. Operable Unit 2 was added to the Basewide Sampling Program in 1996. Data presented are from the Round 2 sampling event, which took place from 25 September through 7 October, 1996.
The objective of long-term GW monitoring at OU 2 is to compare concentrations of constituents of concern to historic concentrations & available background concentrations (for metals), at each respective well. Changes or trends in concentrations will then be established, & any unsuspected increases in contaminant concentrations can then be identified. When sufficient data are collected, GW sampling results will be evaluated statistically to ensure that the assumptions made in the OU 2 Record of Decision (ROD) document are accurate; to validate the GW model; & to provide early warning of increased contaminant levels or migration of contaminant plumes. All fourteen OU 2 wells sampled during this event were completed in the shallow aquifer. Well locations, Figure 1-1, were selected on the basis of previous contaminant level detections & proximity to source areas of concern to the base Installation Restoration Program (IRP).
Jet Fuel
ST41-16 583 mg/L
SW8015ME – Unidentified organics not related to jet fuel were found in the following wells:
ST41-07 43.1 mg/L, ST41-10R 3.21 mg/L, ST41-25 2.89 mg/L.
SW8015MP – Gasoline range organics (GRO) was found in ST41-16 at 61.2 mg/L.
Benzene 46-WL-01 18.3 ug/L, ST41-07 2.030 mg/L, ST41-10R 261 ug/L, ST41-16 11.7 mg/L, and ST41-25 68.6 ug/L.
Unidentified Organics: ST41-10R 6.21 mg/L, ST41-25 15.4 mg/L ST41-28 2,030 mg/L
|
Louis Howard |
| 1/17/1997 |
Update or Other Action |
This letter is written to officially notify the Air Force of our change in Project Managers for
Elmendorf Air Force Base. Louis Howard is replacing me as our lead project manager. He will now
be handling all operable units as well as basewide activities under the FFA. Please direct future project correspondence to Louis. He can be reached at the same mailing address, phone # 269-7552, or via facsimile at 269-7649. |
Ray Burger |
| 2/10/1997 |
Document, Report, or Work plan Review - other |
Review of the draft Basewide Suport and Groundwater Monitoring Program Draft Annual Report of GW Sampling Activities at Elmendorf AFB January 1997. 3.0 Data Evaluation Procedures
3.5.6 Validate Predictions Made in the Groundwater Modeling Report page 3-14: This section states if the results from the 1994 groundwater model does not correlate with current trends, the model may be recalibrated and ran to update predictionts to year T30. The groundwater data from: Operable Unit (OU) 5 and the State-Elmendorf Enivironmental Restoration Agreement (SERA) Phase I and III sites that had contaminant of concern (COC) with increasing trends which conflicted with the predictions made by the 1994 model. The trichloroethylene (TCE) trend prediction made in the OU 5 Record of Decision (ROD) and the 1994 Model for wells located next to Ship Creek was not consistent with the analytical data collected.
The data showed an increase of TCE in five out of seven locations. SERA. Phase I had six wells
out of eight with increasing trends for benzene and increasing TCE concentrations in wells
where the maximum contaminant level (MCL) was exceeded. SERA Phase III sites, in comparison to the baseline, show increasing trends outnumbering decreasing trends for both benzene and TCE. It is assumed that the 1997 model is to be recalibrated and run to update new predictions since the 1994 model did not predict the trends observed at OU 5, SERA Phase I and II sites.
OU 2 4.2.1 Field Parameters page 4-20: The text states there is some correlation between depleted dissolved oxygen levels and elevated benzene concentrations (Table 4-7). Please elaborate on what is meant by depleted dissolved oxygen levels and "normal" dissolved oxygen (DO) levels as it relates to groundwater aquifers at Elmendorf. Typically at 5 degrees C, the DO solubility in pure water is 12.8 mg/I,. DEC disagrees with the assumption that any significant correlation is present with the data in Table 4-7 for OU 2. It is not apparent in the table that a decrease in DO levels between two sampling rounds corresponds to elevated benzene levels. There is only one monitoring welll (ST41-26) out of sixteen sampled that actually demonstrated DO levels were lower between rounds and an increase in benzene was noted. However, there were four wells out of sixteen which do show a decreasing trend of benzene levels which indicates some attenuation is occurring.
DEC concurs with the recommendation to collect methane, redox potential, sulfate ion and ferric
iron (see comments below regarding ferric iron) data to characterize the natural attenuation
processes in addition to collecting dissolved oxygen data. Other parameters that are collected,
but are not used in support of natural attenuation by the Air Force are: alkalinity and pH.
pH: Microbial activity can change the pH of groundwater. A difference in pH between the
contaminated and uncontaminated groundwater is another indicator of biological activity.
Alkalinity: Alkalinity is a result of the presence of hydroxides, carbonates, and bicarbonates of elements such as calcium, magnesium and sodium. These species result from dissolution of
rock, transfer of C02 from the atmosphere and more importantly, respiration of microorganisms.
An increase in alkalinity across a contaminant plume is an indicator of bioiictivity.
Additional indicators of the natural attenuation process the Air Force shou1d consider collecting are: nitrate (NO,) and ferrous iron.
Nitrate: see comments in section 4.1.5 regarding monitoring for nitrate.
Ferrous iron: While measuring for ferric iron (Fez+) will indicate the presence of an electron
acceptor used during anaerobic biodegradation of petroleum hydrocarbons, the Air Force may
want to analyze for ferrous iron (Fe3+) concentrations. Ferric iron is reduced to the ferrous form which may be soluble in water. Ferrous iron concentrations could be used as an indicator of anaerobic degradation of petroleum hydrocarbons. |
Louis Howard |
| 3/13/1997 |
Update or Other Action |
Action 3/13/97 based on Relative Risk Evaluation worksheet dated 8/16/95. Receptors: Small wetland area north of ST41. No one currently using the contaminated aquifer for drinking water or other purposes. Site is located in a relatively remote portion of base zoned for industrial-outdoor-undeveloped purposes only. |
Louis Howard |
| 4/22/1997 |
Update or Other Action |
Comments on the draft evaluation of ST41 Treatment System 2, March 1997 sent to the USAF. ADEC concurs with the recommendations that product recovery at EW-2 should continue until 2 of the 3 endpoints have been met. ADEC concurs with the recommendation for alternative recovery methods of product (i.e. hand bailing) when the average cost per gallon exceeds $500/yr. |
Louis Howard |
| 5/30/1997 |
Update or Other Action |
May 1997 Basewide Annual Groundwater Report, Final received.
Contaminants of Concern: Eight COCs were identified in the OU2 ROD (USAF, 1995a) at ST41, including: benzene, ethylbenzene, toluene, xylene, arsenic, lead, manganese, and thallium. One of these COCs, thallium, was not detected above MCLs in 1996; therefore it was dropped as a COC from this program area. Trichloroethylene is also included in the list of COCs for ST41 since this constituent is a target analyte.
Observed trends over time for groundwater COCs within OU 2 are generally consistent with
assumptions made in the OU2 ROD (USAF, 1995a). Assumptions in the ROD state that COCs will not
migrate significantly from the site due to the fine-grained (clay and silt) nature of the soils, low groundwater velocity, and low hydraulic conductivity. Although some migration of contaminants will inevitably take place over time, it is assumed that long term operation of the groundwater treatment system at ST41 will reduce free-phase petroleum product in groundwater and that natural attenuation would reduce residual contaminants substantially.
Groundwater flows north and south at ST41, due to the presence of the groundwater divide. To the north, toluene, ethylbenzene, and xylene (BTEX components) levels at the downgradient well, ST41-34, decreased from baseline. Benzene levels increased slightly at this well and is addressed further in Section 4.2.4, Target Analytes. To the south, all BTEX levels at the downgradient well, ST41-MW37A decreased from baseline. These decreasing trends, along with observations supporting the occurrence of natural attenuation in the ST41 IRA Treatability Study Report (USAF, 1996e) indicate that ROD assumptions currently appear to be valid.
Results for four organic COCs exceeded MCLs during the two sampling rounds of 1996, including benzene, ethylbenzene, toluene, and xylene. Organic COCs exceeded MCLs at six well locations. Arsenic was the only inorganic COC which exceeded both the MCL and background concentrations. Arsenic exceeded MCL and background levels at one well location. As more data is collected during follow-on sampling events, those analytes which continue to exceed MCLs will be compared over time to establish trends.
Benzene was detected above the MCL at six well locations. Benzene increased from baseline at the northern upgradient well, ST41-34, although 1996 benzene levels continue to be significantly less than the MCL. TCE was detected above the SSDL at only one location, ST41-28, a well noted to have a history of free-phase petroleum product floating on the water table. TCE at ST41-28 was significantly less than the MCL. All other wells sampled at OU 2 in 1996 had historical and current "no detects" for TCE.
Of the six wells which exceed the MCL for benzene, four show a decreasing trend. These declining levels of target analytes over time at OU 2 are consistent with assumptions made in the 1994 Groundwater Modeling Report (USAF, 1994a). It is apparent that the combination of an
active remedial action and natural attenuation at ST41 are reducing BTEX levels at the site and at locations downgradient from this source.
The following are conclusions derived from intuitive and statistical groundwater data analysis
within OU 2:
* A significant correlation could not be established between dissolved oxygen levels and benzene
concentrations, although natural attenuation does appear to be occurring to some degree;
* Benzene exceeded the MCL at six locations during 1996, however, TCE did not exceed the MCL
historically or during 1996 at the OU 2 wells sampled;
* No statistically significant trend (increasing or decreasing) could be established for either
benzene or TCE;
* The highest benzene concentrations were detected at well ST41-16;
* Six ST20 COCs, identified in the OU 2 ROD, were eliminated from the OU 2 program for 1996
because no wells within ST20 are in the sampling program, including: beryllium, bis(2-
ethylhexyl)phthalate, chromium, nickel, nitrate, and vanadium. In addition, thallium was
dropped as a COC in 1996 as a result of no detects above the MCL at any one location; and
* Continue monitoring for analytes which meet the criteria specified in the Decision Guide (Figure 3-1). At a minimum, sampling should continue for 1996 COCs. In addition, the analyte suite used to evaluate the occurrence of intrinsic remediation (methane, redox potential, sulfate ion, and ferric iron) is a recommended addition to the current list of methods at OU 2. |
Louis Howard |
| 6/16/1997 |
Update or Other Action |
USAF Memorandum to ADEC regarding Clarifications to OU2 ROD. The letter is a follow-up to the discussions regarding institutional controls at OU2. The USAF hopes by this correspondence, to clarify appropriate land use controls at OU2 and setup a land use restriction method consistent with the most recent Elmendorf RODs. The OU2 ROD states that groundwater at ST41 needs remedial action and a part of the selected remedy was to restrict land use by implementing zoning controls. The Summary of the ROD on page 9-2 states that the selected remedy includes "Zoning the affected area for industrial use only, excluding the development of commercial aquaculture."
However, the Declaration of the ROD states "Zoning the affected area for undeveloped outdoor/recreational use only." In light of this contradiction and the use of "restricted use areas" under the RODs for OU3 and OU6 the USAF is providing clarification of the permissible land uses within the area affected by ST41 groundwater. The affected area should include those areas that exceed the groundwater cleanup levels established in the OU2 ROD. A map of the area currently and potentially impacted by the contaminated groundwater from ST41 is at attachment 1. This map may be revised based upon review of the contamination remaining in place, which will be conducted at least every 5 years. While the affected area remains above cleanup levels, it will be designated as a "restricted use area" in the base Planning Office. This designation provides for recreational use of the parcel (such as cross country skiing, bicycling, etc.) and the construction of unmanned facilities (such as parking lots, storage buildings, etc. ) but prohibits the construction of any manned facilities (such as office buildings or a residence). Construction activities within the affected area of OU2 will be restricted to construction of unmanned facilities. Furthermore no construction will be allowed which comes within five feet of the groundwater. Existing industrial uses within OU2 are allowed as they are unmanned. This description conforms to the current base land use planning terminology and is consistent with the recently signed RODs for OUs 3 and 6. Land use restrictions will be enforced by the following method. When there is a construction project on Base, the project is to be approved by the Base Planning Office. The planner will route all projects through the Environmental Management Office. The project will be disapproved if it conflicts with the above construction restrictions. The USAF believes this will be a reliable and effective means of enforcing the zoning land use restrictions imposed by the various RODs. Signed by Randy E. Honnet Colonel USAF Vice Commander. |
Louis Howard |
| 6/26/1997 |
Update or Other Action |
Joint letter from USEPA and ADEC on OU2 draft evaluation of the ST41 Treatment system. Comments: Both agencies are in agreement on the approach taken at OU2. Agencies believe that the initially Treatment System objectives have been met and that the system can and should be shut down so that post-operation monitoring and evaluation can begin sooner rather than later. Agencies disagree with conclusion of the report and suggest an alternative conclusion which would still be protective: discontinue long term operation of the ST41 treatment system and begin post operation monitoring period now.
Given the new conceptual site model and the source control work performed in 1996, it seems likely that natural attenuation would effectively remediate remaining product or dissolved phase constituents and be protective of the surface water and seeps. A decision to discontinue LTO now could be done by defining technically practicable endpoints as "less than 0.1 feet for product thickness" and "less than 4 gallons of product per thousand (1000) gallons of treated water are recovered for the entire system" we could instead conclude for this Site those endpoints should be less than 0.15 feet for product thickness and less than 0.75 gallons of product per 1000 gallons of treated water.
Furthermore, both ADEC and USEPA agree that the draft evaluation report supports the conclusion that the system originally constructed as the OU2 interim action and the overall OU2 remedy are operational and functional (O&F) subject to the required inspection by ADEC and EPA. Finally Colonel Honnet's Letter of June 10, 1997 clarifies to EPA and ADEC the OU2 Institutional controls and how they will be enforced (while EPA and ADEC concurrence on the AF proposal will be needed to complete this item, such concurrence is anticipated shortly). |
Louis Howard |
| 9/11/1997 |
Update or Other Action |
Final copy of the Evaluation of ST41 Treatment System OU2 received. Based on the benzene results, the maximum fuel spike level which will be protective of groundwater was verified to be 2,000 mg/kg of recovered product (equivalent to combined DRO/GRO 3,000 mg/kg). As a result of this study, soil cleanup to Alaska Cleanup Matrix Level "D" was approved (2,000 mg/kg DRO, 2000 mg/kg RRO, 0.5 mg/kg benzene). HOWEVER, groundwater is already contaminated with petroleum constituents above cleanup levels so a leachability study is not going to allow for an alternative cleanup level. Leachability studies are done to show that contaminated soils won't impact groundwater above cleanup levels at the "alternative" cleanup level.
Leachate from soil with higher concentrations of recovered product exceeded the groundwater cleanup level for benzene. Note that soils with the highest level of recovered product (5,000 mg/kg) did not always yield the highest benzene leachate concentration (4,500 mg/kg was highest at 37 ug/L at 2 1/2 PV or after 27 years of leaching).
Conclusion of the report indicates that contaminated soil with a GRO level of 2,500 (therefore DRO levels MUST be at 500 mg/kg) or less should be protective of groundwater quality at ST41. To be conservative, a concentration of 2000 mg/kg GRO (by method 101 modified) was used as an Acton level for removal action at ST41. Note cleanup level for DRO would be 475 mg/kg (est.) but to use 500 mg/kg for simplicity's sake in combination with 2000 mg/kg GRO.
To evaluate field screening methods which could be used to assist in the field implementation of the planned removal action, splits of the spiked soil samples were also analyzed using immunoassay field test kits by the laboratories of Ensys and Ohmicron, headspace readings by Thermal Environmental organic vapor mether 580B PID. Results for both brands of immunoassay test kits showed strong correlation with the total fuel hydrocarbon results. The Ensys test kit overestimated the fuel spike concentration at all levels by approximately 40% except at 500 mg/kg. This finding indicates that a degree of conservatism is built into this method so that the percentage of false negatives results will be kept low. The Ohmicron test kit for JP-4 was quite accurate in the 1,000 to 3,500 mg/kg (fuel spike) range, but underestimated the fuel spike in the 500 and 5,000 mg/kg.
The OVM headspace readings were NOT well correlated with AK101/102 results over the range of soil spiking levels. However, the OVM may be usefuel in providing an initial screen for excavated soils. (500 mg/kg spike=311 ppm PID, 1000 mg/kg spike=273 ppm PID, 2000 mg/kg spike=271 ppm PID, 3500 mg/kg spike=260 ppm PID, 5000 mg/kg spike=268 ppm PID). |
Louis Howard |
| 9/11/1997 |
Update or Other Action |
Analytical Results for OU2 Round 1 received. The purpose of this document is to provide a summary of analytical data collected at fourteen wells within Operable Unit OU 2, Elmendorf Air Force Base (EAFB), Alaska. These wells were sampled as part of the long-term monitoring efforts within the framework of the Basewide Support Program. Data presented are from the 1997 Round 1 sampling event, which took place May 16 - 21, 1997.
The objective of groundwater monitoring at OU 2 is to compare concentrations of contaminants of
concern (COCs) to historic concentrations and available background concentrations, at each respective well.
Changes or trends in concentrations will then be established, and any unsuspected increases in contaminant concentrations can then be identified. When sufficient data are collected, groundwater sampling results will be evaluated statistically to ensure that the assumptions made in the Record of Decision (ROD) are accurate; to validate the groundwater model; and to provide early warning of increased contaminant levels or migration of contaminant plumes towards environmental receptors such as Cook Inlet.
All fourteen wells sampled during this event were completed in the shallow aquifer.
GRO (benzene): ST41-02: 13 mg/L (1600 ug/L), ST41-10R 9 mg/L (240 ug/L), ST41-16 62 mg/L (14000 ug/L), ST41-25 11 mg/L (94 ug/L), ST41-28 41 mg/L (460 ug/L), and 46-WL-01 37 ug/L benzene, (Table 2-3 Results for Organic Constituents Round 1 September 1997). |
Louis Howard |
| 9/30/1997 |
Update or Other Action |
Product Recovery Endpoints-The criteria for shutting the treatment system or components down requires any one of the following conditions:
· As designed and constructed, the ST41 groundwater treatment system cannot recover floating product when there is less than a measurable thickness of 0.1 feet of product. Therefore, as an endpoint for product recovery, if less than 0.1 feet is sustained for one year, recovery at that source can be discontinued. Floating product will be measured monthly. When product thickness falls below 0.1 feet for one year, the recovery of product at that source will not be considered "technically-practicable".
* Another measure of "technically-practicable" will be based upon the ratio of product to water recovered during operation of the treatment system. When less than 0.5 gallons of product per 1,000 gallons of treated water are recovered for the entire system, the recovery will be considered to be at the limit of technical practicability. Similarly, when less that 0.5 gallons of product are recovered per 1,000 gallons of treated water from any system component, recovery well or trench, the recovery from that component, well or trench will be considered at the limit of technical practicality. These criteria must be met for two consecutive years in order to discontinue operation of the treatment system. These endpoints are based upon analysis of product and water production data from 1993 through 1996.
· Operation of the system will no longer be economically feasible when the cost of recovering a gallon of product exceeds $16,000 on average for a one-year period. The $16,000 is based upon the total 1994 O&M cost for the system divided by 2.5 gallons of product per year.
Product Recovery Measurements- The required measurements for indicating. when the criteria have been satisfied for shutting the treatment system down include:
· Product in any system component which has not been eliminated using one of the above criteria will be measured monthly with an oil/water interface probe;
· Product and water recovered will be measured weekly as long as product recovery is occurring;
· Contractor O&M costs will be tabulated monthly according to the categories; and
· Data will be evaluated against the performance criteria quarterly.
Surface Water Endpoints-Before the groundwater treatment system can be discontinued, protectiveness of the surface water at ST41 must be documented through analytical sampling over time. Surface water must be below SWQC at point-of-compliance locations for one year with the system operating and an additional year with the system shut off. The shut-off period is to evaluate the potential for "rebound."
Since the installation of the IRA in 1993, the groundwater recovery system has never collected significant amounts of product, calling into question either the design of the system or the model of the area. While unearthing the tanks during the RA, no evidence was found that the tanks had been compromised. The levels and amounts of contaminated soil were substantially less than anticipated. Old woodstave pipes, apparently served as conduits for transport of contaminated media, from the tanks to the location of the seeps were discovered. These pipes were abandoned where feasible. Also, the OWS near Loop Road was removed, along with surrounding soils and contaminated sediments in the ditch.
The previous assumption that a large volume of fuel product was present at ST41 was modified based upon a thorough literature search, the findings of the remedial action, and the data collected to date from the groundwater treatment system. Based upon these findings, it is now believed that large quantities of fuel product were never present and very little recoverable fuel product remains at ST41. The remaining sources of contamination at ST41 include soil around the tanks and residual fuel product. At least one of the southern seeps has not been observed since 1996. Accordingly, operation of the treatment system will continue until product endpoints described in Section 2.4 are met, after which monitored natural attenuation will be expected to achieve cleanup goals in a timely manner.
In performing this action, we learned that implementation, maintenance and enforcement of institutional controls is more complicated than we originally envisioned. This was true, in part, because there are many different parties involved (USAF, ADEC, EPA, contractors, civilians, etc.), because no single control is completely effective and the base is a dynamic environment. The institutional control implementation plan now in place seems to be implementable and effective and includes some overlapping "layers" of controls to ensure protectiveness. |
Louis Howard |
| 11/25/1997 |
Meeting or Teleconference Held |
November 25, 1997 meeting to discuss 1998 additional basewide modeling effort. Attendees: Paul Templeton (AFCEE), Scott Blount (Radian), Sharon Stone (USAF), and Scott Thompson (Booz-Allen Hamilton, Inc.) No ADEC or EPA attendees were present nor on conference call.
Basewide groundwater modeling report final received. Three spills have occurred on base in 1997. The first spill occurred near Pumphouse 3, and is therefore associated with several other sources and numerous wells. The effects of this spill will be addressed in the 1998 modeling effort through the routine sampling being conducted under the Basewide Monitoring program, specifically via the Fall 1997 sampling round results. The second spill was excavated down to groundwater. Effects of this spill will be addressed through SW8020 data collected in late 1997 from one upgradient and one downgradient well at this location. The most recent spill is associated with dissolved-phase and free-phase contamination. Thirteen wells around this spill will be sampled for SW8020 analysis in late 1997. These results will also be incorporated into the 1998 modeling run.
Data from the Fall 1997 Basewide sampling round will be available by 15 December 1997. Data
from the additional water sampling being conducted to assess dissolved phase contamination at the second and third spill sites will be available on 15 January 1998.
* The model will be run using the Fall 1997 and January 1998 groundwater data. Since the original 1994 model was recalibrated in 1997 against year two groundwater data, a detailed recalibration effort will not be performed. The 1997 recalibration effort involved reestablishing model variables and assumptions so that the output matched actual 1996 contaminant plume data. This effort will not be duplicated.
* The new spills will be added as new sources. These sources will be described based upon the
maximum dissolved benzene detection in the given node. Since active bioventing is occurring at the first spill, the new "source" will be considered active for five years (similar to the assumptions used in the original modeling run in 1994). Contamination associated with the second spill will also be given a duration of five years, since contaminated soils in that area were excavated to groundwater. Contamination associated with the third spill will be considered "active" for 15 years.
* Additional new sources will be added into the model as per comments from the Alaska DEC. These
sources will be associated primarily with SERA sites, and will be considered active for five years.
* A sensitivity analysis will be conducted on the input for the new spills. Benzene concentrations in groundwater and the duration of the sources will be varied. Other input parameters may also be varied. This analysis will be conducted to establish whether the 1998 dissolved-phase data fairly represent the potential for migration of the free-phase component present. Specifically, if effects on Ship Creek are predicted to occur based on increased benzene concentrations or source duration, additional or more frequent modeling efforts may be considered.
* The third spill was associated with JP-8. This constituent has a limited benzene content. If it is determined that there is insufficient benzene present to accurately model the potential threat to Ship Creek from this spill, an alternate target analyte will be considered.
* The Draft 1998 Modeling Report will be submitted by 15 February 1998.
|
Louis Howard |
| 1/12/1998 |
Update or Other Action |
10/98-12/98 quarterly progress report received. 12/23/98 is the date that the shutdown of the long term operation of the groundwater treatment system temporarily since existing contract ran out and later than expected authority of Base to advertise for replacement contractor. Five year remedy review signed by EPA and ADEC that the remedy is operational, functional and remains protective of human health and the environment. 38,621 gallons of water treated and no product. 14 groundwater wells sampled and 6 exceeded the MCL for benzene. All but one well (ST41-16) showed a reduction in benzene levels. |
Louis Howard |
| 3/10/1998 |
Update or Other Action |
GW monitoring results for OU2 Round 2 received.
Table 2-3 Round 2 (Aug-Sept. 1997)
GRO (benzene): ST41-07 15 mg/L (2100 ug/L), ST41-10R 4.1 mg/L (200 ug/L), 46-WL-01 23 ug/L benzene, ST41-16 64 mg/L (16000 ug/L) DRO 9.7 mg/L, ST41-25 13000 mg/L (190 ug/L), ST41-28 36 mg/L (540 ug/L), 250 mg/L DRO. |
Louis Howard |
| 4/9/1998 |
Update or Other Action |
EPA Tim Brincefield and ADEC project manager Louis Howard inspected the institutional controls on April 9, 1998 at the Base and concurred that the controls were in place, and were operational and functional. |
Louis Howard |
| 5/1/1998 |
Update or Other Action |
Basewide groundwater modeling report, Final received. The specific objectives of this modeling task include the following:
* To update the contaminant sources and initial groundwater concentration distributions employed
in the 1996 model based on the most current analytical information, allowing for more realistic
long-term (30-year) simulations to be conducted;
* To rerun the 1996 numerical model as a predictive tool for a period of 30 years simulating the
transport of benzene from previous and newly identified sources in groundwater, and;
* To perform a sensitivity analysis upon the benzene concentrations used as input in the Spill 3 source area.
The ultimate objective of the predictive simulations was to reassess the likelihood of benzene reaching Ship Creek at unacceptable [i.e., above maximum cleanup level (MCL) Standard levels. Included in this report are drawings that illustrate the new source locations, simulated distributions of predicted benzene plumes over a 30-year period using the most recent information, and results from the sensitivity analysis of initial benzene concentrations at Spill 3.
For the initial modeling effort, the same 3-dimensional finite element model (SALT3) developed for the original 1994 task was used (USAF, 1994). The basic assumptions, boundary conditions, dimensions, layout and discretization of the model remained unchanged from those utilized in the 1994 modeling task. The 1996 re-calibrated time step and half-life data for benzene were adopted in the current model.
The second task conducted as a component of this study included a simulation to assess the sensitivity of the model to the initial benzene concentrations assigned to the Spill 3 source area. Uncertainty exists to the actual contribution of benzene from the spill to groundwater due to the size of the spill, the presence of a dissolved-phase and free-phase product, the duration of the free-phase, and the benzene concentration within the fuel (JP-8). As a result of these uncertainties, it was determined that a more conservative estimate of benzene contribution to groundwater should be evaluated than might have been determined by the initial groundwater measurements at the site. A very conservative estimate for the initial benzene concentration was determined using the following assumptions: 1) The jet fuel remains as an unweathered, free-phase product; 2) The fuel contains a benzene concentration of 3% (weight/weight; 0.03 mole fraction), and; 3) The aqueous solubility of benzene is 1780 mg/L (normally at 20° C, in pure water).
The model was run for a simulation time frame of 30 years. Significant attenuation of concentrations is predicted as a result of degradation of benzene. At the end of a two-year simulated time frame, maximum benzene concentrations in the model area are expected to decrease to approximately 288 pg/L, based on the modeling assumptions implemented for this scenario. Maximum concentrations are expected at SERA site ST68 (in the vicinity of well 62-WL-05), which was assigned an initial source concentration of 1,500 ug/L.
At the end of five years, only four areas of benzene contamination are predicted to remain at concentrations exceeding 5 uig/L throughout the model area. The lateral extent of benzene contamination is expected to continue decreasing. Based on the predicted shrinking nature of the plumes over time, it is reasonable to conclude that degradation of benzene appears to be the controlling transport process in the model, preventing significant migration toward Ship Creek through advection and dispersion. While most SERA sites and the three spills are assumed to be active sources for at least five to fifteen years, the model predicts that all three spills will be attenuated to levels below the MCL for benzene after five years. Conceptually, this is explained by the transport mechanisms in the vadose zone. Benzene enters the aquifer as a dissolved component in surface water that has entered the soil column and percolated through fuel-contaminated vadose zone sediment.
Based on the results of this modeling study, it is recommended that benzene contamination in groundwater throughout the model area continue to be monitored over time. If significant downgradient migration was detected in the future, additional adjustments could be made to critical model parameters, such as the half-life of benzene in the groundwater, or the rate at which mass enters the system from a source which is considered to be active. Furthermore, a refined model could be utilized to predict the migration behavior of benzene in the groundwater in critical areas, such as the area of Spill 3. However, at this point the model calibration/validation effort conducted in 1996 appears to be accurately predicting the migration behavior of benzene contamination in groundwater. |
Louis Howard |
| 5/6/1998 |
Meeting or Teleconference Held |
Restoration advisory board meeting held and announced beforehand in the Sourdough Sentinel 4/24/98, Alaska Star 4/30/98 and the Anchorage Daily News 5/2-4/98. |
Louis Howard |
| 8/24/1998 |
Update or Other Action |
Basewide Support & GW Monitoring Program GW Analytical Results for OU2 Round 1 August 1998 received.
GRO (benzene) ST41R 13 mg/L (294 ug/L), ST41-16 105 mg/L (14,700 ug/L), ST41-25 23 mg/L(154 ug/L), ST41-28 19.3 mg/L (393 ug/L), and ST41-07 121 ug/L benzene. |
Louis Howard |
| 9/29/1998 |
Update or Other Action |
Operable Unit (OU) 2 Remedial Action Report Final September 1998 received. The purpose of this report is to document the completion of the remedial action (RA) for Operable Unit 2 (OU2) at Elmendorf Air Force Base (AFB), Alaska. As of April 1998, all remedial actions selected in the March 1995 Record of Decision (ROD) have been completed, inspected and are operational and functional. Operation and maintenance (O&M) of the remedies will continue pursuant to the OU2 ROD until remedial action objectives are met.
No actual or threatened releases of CERCLA-hazardous substances were identified in the vicinity of ST20 during the RI/FS. However, fuel-contaminated soil and groundwater were found in the vicinity of ST20, due to a fuel line leak from an upgradient source (ST48). ST48 was an underground storage tank (UST) associated with a diesel pipeline leak in 1968 and is included in the State-Elmendorf Environmental Restoration Agreement (SERA).
The spill was about 800 gallons that seeped into the ground. No product was recovered. An additional release of JP-4 occurred on April 27, 1991 at ST48. The volume of this release was not determined, but was estimated to be between 100 and 1,000 gallons. As a result of this spill, approximately 650 tons of contaminated soil was excavated and thermally treated. A product recovery system was installed in the shallow aquifer and a total of 20 gallons of free product was recovered.
The OU2 ROD determined no future action for ST20 was necessary under the CERCLA program. Details of this decision are set forth in the OU2 ROD.
Pursuant to the IRA ROD, a fuel product and groundwater recovery/treatment system was designed and constructed in 1993. The system was designed to remove product from the groundwater table and to decrease off-site migration of contaminants from groundwater seeps on the north and south sides of ST41. Floating fuel product has been measured and removed weekly since 1993.
During operations from 1993, the recovery and treatment system has performed as designed; however, far less fuel product was recovered and treated than originally anticipated. Since February 1997, no recoverable quantities of fuel product have been observed. As discussed in the "lessons learned" section of this document, this is apparently due to the presence of less fuel to recover than originally anticipated, not due to a failure of or problems with the treatment system. As a result of the RA and subsequent analyses, the conceptual site model for ST41 has been revised.
The selected remedy in the final OU2 ROD includes continued operation of the groundwater treatment system plus additional remedies for source control and groundwater remediation. The selected remedy also included a contingency for additional groundwater response actions, if necessary, to attain remedial action objectives. The final ROD set forth three conditions, which must be met before the groundwater treatment system can be discontinued, including:
1) Recovery of all technically-practicable product; 2) Protectiveness of surface water (wetlands) or seeps; and 3) assurance that natural attenuation will effectively address any remaining product or dissolved-phase constituents in the groundwater through LTM.
The ROD does not define the performance criteria ("endpoints" and "measurements") which should be used to establish when these conditions are met. Subsequent to the ROD, the USAF, EPA and ADEC performed an evaluation of the treatment system and its effectiveness and developed specific performance criteria for the groundwater treatment system.
The following sections describe the endpoints and measurements being used to determine if the above conditions for each of the groundwater treatment system effluent sources are met.
See site file for additional information. |
Louis Howard |
| 10/20/1998 |
CERCLA ROD Periodic Review |
Five-year Remedy Review conducted by U.S. EPA, USAF, and ADEC staff to ensure that the remedial actions selected in the Record of Decision for the operable unit remains protective of public health, the environment and are functioning as designed. The start of construction of the OU2 Interim Remedial Action (IRA) on August 5, 1993 triggered this review requirement. Response actions at the OU are ongoing, all remedial actions are operational and functional as documented in the OU's remedial action report. All required institutional controls have been established and incorporated into the Base General Plan and the management action plan. Site conditions and land use are consistent with the OU's ROD requirements and remain protective, based on evaluation of current monitoring data and trends, and the most recent joint inspection conducted by the USAF, EPA, and ADEC project managers on April 9, 1998.
Future Five Year reviews are necessary because contamination remains above levels that allow for unrestricted use and/or unlimited exposure at the operable units. The next five year review will be completed by August 2003. |
Louis Howard |
| 10/27/1998 |
Update or Other Action |
07/98-9/98 quarterly progress report received. Free product recovery system is ongoing, monitoring of surface water seeps for AWQC, monitoring of natural attenuation , long term groundwater monitoring, and institutional controls are maintained that restrict access to GW and contaminated surface/subsurface soils. Over 37,000 gallons of water recovered and treated. |
Louis Howard |
| 11/17/1998 |
Update or Other Action |
Groundwater Analytical Results for OU2 Round 2 (November 1998) received.
Benzene ST41-07 18.5 ug/L, 46-WL-01 5.51 ug/L benzene, ST41-10R 152 ug/L, ST41-16 17,600 ug/L benzene and 99.5 mg/L gasoline range organics, ST41-25 118 ug/L, ST41-28 356 ug/L and 23.3 mg/L GRO. |
Louis Howard |
| 12/10/1998 |
Update or Other Action |
Concurrence from ADEC sent to USAF regarding the closure of ST41 Long term operation awaiting new contractor. Memorandum states they are requesting concurrence for winterizing and temporary shutdown of the ST41 LTO as discussed in phone conversation on 24 November 1998. FY99 contract is delayed for operation of the LTO and write the closure report for ST41 due to being funded later than anticipated. Estimated start date for FY99 contract is March 99. Existing contract ends on 12/31/1998 and can not be extended. LTO will be returned to operation as soon as he new contractor can start final testing for the close out report. NO product has been recovered from the LTO in the last 22 months and the unplanned shut down of the system will not affect the final shut down. ADEC concurs on 12/10/98. EPA concurred and sent their letter on 12/15/98. |
Louis Howard |
| 12/22/1998 |
Update or Other Action |
9/98 Remedial Action report received and it estimates groundwater will achieve cleanup goals identified in the ROD by 2016 through natural attenuation. The groundwater plumes at the site correspond to the two areas known to contain product. Wells in the center of the two plumes contain contamination exceeding MCLs.
Wells located outside the two plumes did not exceed MCLs. The plumes have been stationary for several years and no migration of contaminants has been identified. Additional declining trends are anticipated at the remaining ST42 wells as a result of the 1996 removal action and natural attenuation. Based on the compilation of data collected since 1988, the chances that other significant occurrences of groundwater contamination which remain unidentified at ST41 are very unlikely.
The primary ongoing activities include Operations and Maintenance (O&M) of the groundwater treatment system, periodic monitoring, evaluation of groundwater quality, progress toward cleanup goals and maintenance, and enforcement of institutional controls (ICs). The ICs are being administered by the Base Civil Engineer and the Environmental Restoration Program. The base general plan and the management action plan document the applicable land and groundwater use restrictions for the OU2 source areas prior to approval of changes in land use, siting, work orders, and/or drilling permits. These plans are updated annually by the Air Force and reviewed and commented on by the EPA and ADEC.
In addition, groundwater modeling will be performed to predict degradation from natural attenuation over time. Model results will be compared to actual field data to validate the modeling predictions made.
The purpose of this report is to document the completion of the remedial action (RA) for Operable Unit 2 (OU2) at Elmendorf Air Force Base (AFB), Alaska. As of April 1998, all remedial actions selected in the March 1995 Record of Decision (ROD) have been completed, inspected and are operational and functional. Operation and maintenance (O&M) of the remedies will continue pursuant to the OU2 ROD until remedial action objectives are met.
The criterion for shutting the treatment system or components down requires any one of the following conditions:
• As designed and constructed, the ST41 groundwater treatment system cannot recover floating product when there is less than a measurable thickness of 0.1 feet of product. Therefore, as an endpoint for product recovery, if less than 0.1 feet is sustained for one year, recovery at that source can be discontinued. Floating product will be measured monthly. When product thickness falls below 0.1 feet for one year, the recovery of product at that source will not be considered '"technically-practicable".
• Another measure of "technically-practicable" will be based upon the ratio of product to water recovered during operation of the treatment system. When less than 0.5 gallons of product per 1,000 gallons of treated water are recovered for the entire system, the recovery will be considered to be at the limit of technical practicability. Similarly, when less that 0.5 gallons of product (are recovered per 1,000 gallons of treated water from any system component, recovery well or trench, the recovery from that component, well or trench will be considered at the limit of technical practicality. These criteria must be met for two consecutive years in order to discontinue operation of the treatment system. These endpoints are based upon analysis of product and water production data from 1993 through 1996.
See site file for additional information. |
Louis Howard |
| 1/29/1999 |
Update or Other Action |
Letter sent to AF allowing for them to have the free product recovery system shutdown after a period of two years of no free product recovered. The monitoring well system will be closely watched for a period of one year for any free product "rebound" in which free product reappears in the wells. If rebound occurs, then an alternate way of recovering the product will be determined by EPA, AF and ADEC. If no free product returns, then the process of natural attenuation will be allowed to continue until cleanup goals are met. |
Louis Howard |
| 4/13/1999 |
Update or Other Action |
01/99-03/99 quarterly progress report received. BTEX continues to be monitored for in groundwater and surface water. |
Louis Howard |
| 4/22/1999 |
Update or Other Action |
Air Force Memorandum for concurrence to ADEC and USEPA for the close down of the ST41 Groundwater Treatment System. ST41 was shut off on 12/19/1998 due to a delay in funding for the FY99 contract. It was agreed that the one year date to evaluate rebound would be starting on 12/19/1998. ST41 treatment system will not be started for FY99 project year and may not be restarted again depending on the project report. The report will detail the study of the product rebound and modeling/data evaluation. These will be used to determine if the MNA without operation of the GW treatment system will be protective and achieve cleanup goals as specified in the ROD. Other means of product recovery will be discussed in the future if required. Both EPA and ADEC concur with the action. |
Louis Howard |
| 7/8/1999 |
Update or Other Action |
04/99-06/99 quarterly progress report received. Groundwater model for ST41 began in June to see if the October 2015 target date remains as the date for cleanup levels to be achieved. |
Louis Howard |
| 10/4/1999 |
Update or Other Action |
07/99-09/99 quarterly progress report received. 14 wells sampled and 6 exceeded MCL for benzene. Groundwater model continues to be analyzed. |
Louis Howard |
| 11/22/1999 |
Update or Other Action |
OU2 Round 2 sampling results received. Wells that exceeded the MCL for benzene were: 46-WL-01, ST41-07, ST41-10R, ST41-16, ST41-25 and ST41-28. TCE remains below the MCL at this site. Well 46-WL-01 increased from 8.9 to 13 ug/L. |
Louis Howard |
| 1/10/2000 |
Update or Other Action |
10/99-12/99 quarterly progress report received. Computer model run for groundwater model for ST 41 (11/99-2/00). Received round 2 analytical results and of 14 wells sampled, benzene continued to exceed the MCL at 6 wells and TCE levels remain below MCL at all locations sampled (11/99). Target date to meet groundwater cleanup levels is October 2015. |
Louis Howard |
| 4/10/2000 |
Update or Other Action |
1 January - 31 March quarterly progress report received. Bailed product at well ST41-28 amounts to about 5 oz. per week. The Air Force is looking at passive product recovery systems to place at this source area. |
Louis Howard |
| 6/1/2000 |
Update or Other Action |
Environmental Monitoring Plan received. The purpose of the Basewide Environmental Monitoring Program (EMP) is to provide information on surface water and groundwater quality, groundwater flow characteristics, and monitoring well integrity at specified locations throughout Elmendorf AFB. The data assessment portion of the program includes data collection via groundwater and surface water sampling, and groundwater level measurements.
Operable Unit 2 Groundwater samples will be collected biannually from 13 wells as part of the OU 2 Groundwater Sampling Program. The groundwater samples at OU 2 will be analyzed for anions (chloride, sulfate, and nitrate), trace metals, volatile organics, and diesel and gasoline range hydrocarbons. The methods prescribed for this OU are based jointly on the results of the RI/FS program conducted at OU 2 and in accordance with COCs identified in the ROD for OU 2. Like OU 1, the purpose of the groundwater monitoring at OU 2 is to compare newly obtained contaminant concentrations to historic and/or background concentrations, such that changes or trends can be established. The data collected will be used to help establish the long-term monitoring approach for OU 2, and in addition, will be used to help assess the levels of contaminants that might be migrating towards environmental receptors such as Ship Creek.
The data will also help calibrate future groundwater modeling efforts and validate predictions made concerning contaminant fate and transport made in the 1998 Groundwater Model Report.
MTBE will be added to the list of compounds analyzed in the Method SW8260B volatile organics
analysis. This change is made as a result of a request by ADEC to monitor for this compound at all wells in the Basewide Sampling Program for one year. |
Louis Howard |
| 9/5/2000 |
Update or Other Action |
2000 Round 1 Groundwater Monitoring Well results report received. In 2000 methyl tert-butyl ether (MTBE) was added to the analyte list and it was not detected in any of the wells. Benzene is above the MCL in five wells and trichloroethene (TCE) is above the MCL in 2 wells. Benzene increased in well ST41-07 and TCE increased in wells ST41-16 and ST41-25. |
Louis Howard |
| 10/2/2000 |
Update or Other Action |
Quarterly progress report received for the 3rd quarter 1, July 2000-30 September 2000. Round 2 groundwater samples collected in August 2000. Contract for groundwater model for ST41 was erroneously closed out before the project was completed. Contract reopened and no work has been done this quarter due to this error. Five wells exceeded MCL for benzene. |
Louis Howard |
| 11/20/2000 |
Update or Other Action |
Base-wide Monitoring OU2 Round 2 report received. Benzene: 46-WL-01 increased from < 5 ug/L in round 1 to 7.4 ug/L in round 2. ST41-07 increased from 39 ug/L to 780 ug/L in round 2. ST41-16 increased from 13,000 ug/L in round 1 to 16,000 ug/L in round 2. ST41-25 increased from 34 ug/L in round 1 to 110 ug/L in round 2. ST41-28 increased from 270 ug/L in round 1 to 300 ug/L in round 2. Trichloroethene (TCE): all wells below MCL of 5 ug/L in Round 2. |
Louis Howard |
| 3/20/2001 |
Update or Other Action |
Memo on PDBs being used as a "Beta Test" at Elmendorf AFB & Eielson AFB. The “Kick-off” meeting in Seattle, 20 March 2001, is intended to introduce the Remedial Process Optimization (RPO) process & the Passive Diffusion Bag Samplers (PDBS) guidance document “beta test” project at Elmendorf AFB & Eielson AFB, AK. The HQ Air Force Center for Environmental Excellence (AFCEE) is conducting an exhaustive “beta test” of the Guidance Document for Use of Polyethylene-Based Passive Diffusion Bag Samplers to Obtain Volatile Organic Compound Concentrations in Wells, described below, & provide feedback to the PDBS workgroup to update the Interagency PDBS Guidance Document for Installation Restoration Program (IRP) managers. The RPO & PDBS guidance document “beta test” will incorporate remediation programs at Elmendorf AFB & Eielson AFB, AK.
Passive diffusion bag (PDB) samplers are suitable for obtaining representative concentrations of volatile organic compounds in ground water in observation wells. A typical PDB sampler consists of a low-density polyethylene lay-flat tube closed at both ends & containing deionized water. The sampler is positioned at the target horizon by attachment to a weighted line. The PDB samplers equilibrate within approximately 48 hours for several tested volatile organic compounds, however vinyl chloride & some chloroethanes may require between 96 & 168 hours to equilibrate. The samplers should be allowed to remain in the well a minimum of two weeks prior to recovery to allow the well water to restabilize following sampler deployment. Recovery consists of removing the samplers from the well & immediately transferring the enclosed water to 40-milliliter sampling vials for analysis.
The method has both advantages & limitations. Advantages include the potential for PDB samplers to eliminate or substantially reduce the amount of purge water associated with sampling. The samplers are relatively inexpensive & easy to deploy & recover. Because PDB samplers are disposable, there is no downhole equipment to be decontaminated between wells & there is a minimum amount of field equipment required. The samplers also have the potential to delineating contaminant stratification in the open or screened intervals of observation wells where vertical hydraulic gradients are not present.
A possible disadvantage of the samplers is that they integrate concentrations over time. Depending on the compound of interest, this time may range between about 48 to 168 hours. The samplers are not applicable for all compounds. They are not effective for inorganic ions, for highly soluble organics such as methyl-tert¬-butyl ether, or poorly soluble organic compounds. An additional disadvantage is water must be freely flowing through the well screen for the samplers to be effective. VOC concentrations in PDB samplers represent concentrations in the vicinity of the sampler within the well screen or open interval. This may be a limitation if the ground-water contamination is above or below the screen, or not in the interrogated sample intervals. If there are vertical hydraulic gradient in the well, then the concentrations in the sampler represent the concentrations in the water flowing vertically past the sampler rather than in the formation immediately adjacent to the sampler. Multiple PDB samplers may be needed in chemically stratified wells or where flow patterns through the screen change as a result of ground-water pumping or seasonal fluctuations.
|
Louis Howard |
| 4/17/2001 |
Document, Report, or Work plan Review - other |
ADEC reviewed and commented on the document received on March 21, 2001. Overall, ADEC concurs with Elmendorf’s approach to reduce its groundwater monitoring costs while still providing protection to human health, safety, or welfare and the environment. With regards to decreasing the monitoring frequency in Operable Unit (OU) 1 to an annual basis, ADEC concurs. With regards to OU 6, ADEC recommends not discontinuing groundwater monitoring at well 703-WL-02 and to continue to monitor for methyl tert-butyl ether (MTBE). |
Louis Howard |
| 1/2/2002 |
Update or Other Action |
Staff received the seventh Annual Report of Groundwater Sampling Activities developed for the
Elmendorf Air Force Base (AFB) Basewide Environmental Monitoring Program, hereafter referred to
as the Basewide Program. The Basewide Program encompasses two field programs, the Basewide
Groundwater Sampling Program and the Basewide Water Level Monitoring and Well Optimization
Program. This Annual Report of Groundwater Sampling Activities contains a summary of 2001 water
quality data and interpretations from the Basewide Groundwater Sampling Program. The Annual
Technical Memorandum (United States Air Force [USAF], 2002a) developed and distributed as a
separate deliverable report, addresses activities associated with the Basewide Water Level Monitoring and Well Optimization Program.
The Basewide Program was established through the Elmendorf AFB Installation Restoration
Program (IRP) to address the needs of multiple programs on the base. These programs include the
Federal Facilities Agreement (FFA), and the State-Elmendorf Environmental Restoration Agreement
(SERA). Over the following two program years, 2002 and 2003, the focus of the Elmendorf AFB
Basewide Program will be modified to reflect the requirements outlined in appropriate Records of
Decision (RODs), decision documents, corrective action documents, and/or any other binding
agreements. In an effort to optimize the program, several changes may occur in sampling frequency, in the wells sampled, and in groundwater seep sampling.
The following are conclusions derived from intuitive and statistical groundwater data analysis
within OU 2:
* As a result of the 2001 Decision Guide analysis of the OU 2 program area, it is recommended that wells ST41-24, ST41-26, ST41-27, ST41-30, ST41-37A, and T40001 be removed from the 2002
program year. Five wells remain for the 2002 program year. It is also recommended to continue
sampling for only the ROD specified ARARs, benzene, ethylbenze, toluene, and total xylenes.
* For wells in the OU 2 program area, a measurable free product layer was detected at two well
locations during the 2001 field season (ST41-16 and ST41-28). In addition, a sheen and/or fuel
odor was noted at four well locations (46-WL-01, ST41-10R, ST41-25, and T40001).
* Three organic COCs (benzene, ethylbenzene, and toluene) exceeded MCLs in 2001. Benzene
exceeded the MCL at six locations (46-WL-01, ST41-07, ST41-10R, ST41-16, ST41-25, and ST41-28); ethylbenzene exceeded the MCL at two locations (ST41-16, and ST41-28); and toluene exceeded MCL at one location (ST41-16).
* Seven wells at OU 2 contained statistically valid trends using current available data for benzene.
As indicated on Table 4-8, 46-WL-01, ST41-07, ST41-1OR, ST41-16, ST41-25, and ST41-28 exceeded the benzene MCL in 2001. Four of these wells, ST41-07, ST41-10R, ST41-25, and ST41-28 showed statistically significant decreasing trends in benzene. The remaining wells with concentrations above MCLs, 46-WL-01 and ST41-16 had no statistical trend.
* A review of 2001 natural attenuation data from OU 2 indicates a high level of microbial activity in all contaminated wells. Natural attenuation appears to be working well in this program area.
* Well 46-WL-01 was installed as an in-source well in the SERA IA program area but was sampled
in the OU 2 program area from 1996 though 2001 to provide an additional downgradient location
for ST41. 46-WL-01 is, however, an in-source well for the SERA site ST69. The well will be
reclassified into the SERA Miscellaneous grouping for 2002. |
Louis Howard |
| 2/21/2002 |
Update or Other Action |
Staff reviewed and commented on the draft base wide groundwater monitoring report.
Regulatory Levels
ADEC requests removing the word “Potential” from the heading “Potential Regulatory Level” in the tables throughout the document. Listing the word “Potential” gives the reader the impression that compliance with the levels listed is optional or not required (e.g. Tables 4-7, 4-11, 4-15, 4-20, 4-25, 4-29, 4-32, and 6-2).
Free Product
Please note 18 AAC 75.325(f) states: A responsible person shall to the maximum extent practicable,
(A) use permanent remedies;
(B) recover free product in a manner that minimizes the spread of contamination into an uncontaminated area by using containment, recovery, and disposal techniques appropriate to site conditions.
ADEC recognizes that in some cases it may not be technically practicable to implement an active or passive recovery system for free product. The Elmendorf Remedial Action Report for Operable Unit (OU) 2 (September 1998) set a precedent for defining what is meant by “technically practicable” for free product recovery. Section 2.4.1 Product Recovery Endpoints at the 1st bullet on page 10 states: “As designed and constructed, the ST41 ground water treatment system cannot recover floating product when there is less than a measurable thickness of 0.1 feet of product. Therefore, as an endpoint for product recovery, if less than 0.1 feet is sustained for one year, recovery at that source can be discontinued. Floating product will be measured monthly. When product thickness falls below 0.1 feet for one year, the recovery of product at that source will not be considered “technically practicable”.
Therefore, where free product is greater than 0.10 feet, ADEC expects corrective action (active or passive) to be implemented for free product recovery. Currently, free product was found to exceed 0.10 feet or more in SERA Phase I well 43-WL-11. This well had the highest level of free product measured at 0.86 feet. The presence of measurable free product is generally not considered conducive for intrinsic (natural) attenuation. ADEC requests the identity of the free product be described in the text at each source area that it is found (e.g. gasoline, diesel, or chlorinated solvents).
3.3.4 Target Analytes Pages 3-10 and 3-11
Benzene and TCE are identified as target analytes to evaluate contaminant of concern (COC) trends in detail and be consistent with the Base wide Groundwater model. ADEC concurs, however, focusing on these two analytes does not accurately reflect whether diesel range organics (DRO) and gasoline range organics (GRO) plumes are migrating, expanding, steady state, or receding (especially for wells noted to have either free product or fuel odor and/or sheen being observed during sampling). Benzene can be at low levels or even non-detectable while concentrations of DRO and GRO remain above cleanup levels (1.5 mg/L and 1.3 mg/L respectively). Please see the following examples below of where benzene was below the 5 ug/L cleanup level, but DRO and GRO are above cleanup levels.
OU 4
Round 1 sampling at well 49-WL-01 detected benzene at 0.11 ug/L and DRO at 2,400 ug/L and well OU4W-11 detected benzene at 4.3 ug/L while GRO was detected at 3,000 ug/L and DRO was detected at 6,100 ug/L.
OU6
Round 1 sampling at well OU6MW67 detected benzene at 2.8 ug/L, GRO at 2,500 ug/L and DRO at 1,700 ug/L during round 1 sampling. During round 2 sampling, well OU6MW-91 detected GRO at 25,000 ug/L and DRO at 9,500 ug/L while benzene was found to be non-detectable.
See site file for additional information. |
Louis Howard |
| 4/30/2002 |
Update or Other Action |
Basewide Environmental Monitoring Plan received.
2.3.2.2 Program Modifications in 2002
Seven wells will be removed from OU 2 based on criteria in the Basewide Decision Guide
provided on Figure 2-1. Table 2-2 provides the well-by-well rationale for continued monitoring, removal from, or addition to the sampling program. Groundwater monitoring Well 46-WL-01 will be removed from the OU 2 wells and reclassified under SERA Miscellaneous. One seep was added to the ST41 sampling locations in order to assess the possibility of contaminants migrating from groundwater and affecting surface water. For both wells and the seep, laboratory analytical methods will be limited to contaminants established as ARARs in the OU 2 ROD. For groundwater, these include BTEX, and for seeps they include benzene, toluene, and ethylbenzene.
Historically, OU 2 was sampled on a biannual schedule for statistical purposes. In 2002, the frequency will be adjusted to an annual schedule as specified in the OU 2 ROD. In addition, all wells at ST41 will be sampled with passive diffusion bags (PDBs) in 2002. Sampling methods used for PDBs are presented in the FSP Section A4.3.
A4.1.2 Operable Unit 2
Five monitoring wells and one seep location will be sampled as part of the long-term monitoring
efforts at OU 2. The locations of these wells are provided in Figure A4-2. All of the wells will be sampled once in 2002, with events scheduled during the month of June. A detailed field schedule for this program is provided in Section 4 of the EMP. All wells and will be sampled according to the procedures outlined in this FSP Section A4.3. The samples from OU 2 will be collected using a passive diffusion bags. The seep sample will be collected as detailed in Section A4.3.
The samples will be analyzed according to the methods outlined in Table A4-2. Details on the
requirements for sample holding times and preservation, and the applicable QA/QC sample requirements, are provided in Appendix C of the EMP. |
Louis Howard |
| 5/10/2002 |
Document, Report, or Work plan Review - other |
ADEC provided comments on the Draft Basewide Environmental Monitoring Plan, Elmendorf Air Force Base, AK, dated April 2002.
1.4.2 Analytical Methods Added or Removed from the Sampling Program Pages 1-9 and 1-10: The table states that OU 2 will remove diesel range organics (DRO) and gasoline range organics (GRO) from the Basewide Monitoring Program. The rationale is that DRO and GRO are not Applicable, Relevant, and Appropriate Requirements (ARARs) for OU 2 and are not needed to monitor natural attenuation of Benzene, Tolulene, Ethylbenze, and Zylenes (BTEX). The Department agrees that DRO and GRO are not needed for monitoring natural attenuation of BTEX.
However, there are still high levels of GRO and DRO at the site, which are much higher than those found at OU 6 that are currently being monitored. For example, ST41-16 had 110,000 ug/L GRO detected in 2001 Round 1 sampling and 12,000 ug/L DRO detected in Round 2 sampling. At OU 6 monitoring well OU6MW-77, the highest level of GRO at 23,000 ug/L during 2001 Round 1 sampling and at OU 6-MW45 8,000 ug/L of DRO were detected in Round 2 sampling.
The Department requests DRO and GRO be included in future sampling events until cleanup levels are achieved for the following Chemicals of Concern (COCs) in the OU 2 ROD:
Groundwater (ug/L)-benzene 5.0, ethylbenzene 700 ug/L, toluene 1,000, xylene 10,000
Surface water (ug/L)-benzene 10, ethylbenzene 10, toluene 10
The Department requests that seep analyses conducted at OU 2 include polynuclear aromatic hydrocarbons (PAHs) in order to calculate total aqueous hydrocarbons (TAqH) and a calculation of total aromatic hydrocarbons (TAH). The seep areas in the northern portion of ST41 have wetland field indicators that are indicative of a wetlands. See discussion below regarding the wetland status of the ST41 Area (sec. 9.4.4.2) and of the wetlands being fed by the groundwater at ST41 (sec. 9.7) taken from the February 8, 1994 RI/FS.
Table 6-6 from the OU 2 ROD identified various compounds which besides benzene, toluene, and ethylbenzene (BET) which exceeds the Alaska Surface Water Quality Criteria (ASWQC) (refer to table below). It appears monitoring for TAH and TAqH should have been conducted at the site instead of for strictly benzene, ethylbenzene, and toluene (BET). The ASWQC for TAH is for a “total” of the aromatic hydrocarbons detected. Therefore, the Department wishes to inform the Air Force that by meeting the cleanup levels for BET (30 ug/L total) it would still not meet the TAH ASWQC of 10 ug/L.
The Department requests inclusion of the TAH and TAqH analyses in the 2003 sampling program. Sampling of TAH and TAqH would be for one year and the Department requests a review of the data by the EPA, Air Force, and DEC to see if TAH and TAqH are an issue at OU 2.
A4.4 Seep Investigation and Sampling Procedures Page A4-28
The text states seep locations will be chosen based on evidence of staining, sheening, odor and/or flow rate. The Department requests the Air Force consider inclusion of at least one seep sampling point as close to the seeps mentioned in the February 8, 1994 OU 2 RI/FS at section 9.4.2 Seep Areas.
In the utility corridor on the north side of ST41, a distinct perennial spring was observed north of monitoring weIlST41-10, on the north side of the corridor. At the time of the ecological site characterization, the drainage from the spring was observed to flow northwest for 25 yards, past ST 41-30, where it entered a narrow drainage. Sedges were observed in the wettest areas of the seep. The pool at the spring was approximately 3 feet across and several inches deep. A narrow growth of sedges around the perimeter of the pool was surrounded by clover and other forbs. A petroleum-type sheen and a brown sludge floated on the surface of the
pool of standing water. This seep was sampled in 1990, 1991, and 1992 (see Figure 2.2.10-1 and Table 2.2.10-1).
A second distinct seep was observed south of the utility corridor, and flowed to the north into the corridor. The drainage pathway of the seep was 3 to 5 feet wide and appeared to be uncharacteristically denuded of vegetation. A petroleum-type sheen was observed on the water in the seep. The surface water and sediment at this seep were sampled in the fall of 1992, and the surface water was resampled in the spring of 1993. |
Louis Howard |
| 6/13/2002 |
Update or Other Action |
June 13, 2002 Air Force letter response to May 10, 2002 letter from ADEC. Subject-Draft Basewide Environmental Monitoring Plan.
Thank you for your 10 May 02 comments on the draft Basewide Environmental Monitoring Plan. Your letter raised some very important,issues regarding Operable Unit (OU) 2 (ST41) and we would like to provide a response to the following points.
a. Location of seep sampling. We concur with your request to sample the groundwater seep in a location as close as possible to the sampling point in the 1994 Remedial InvestigationlFeasibility Study. We will include this sampling point in this year's sampling
effort.
b. Cleanup Standards for Surface Water. We concur the clean-up standards, which are outlined in the March 1995 Record of Decision (ROD), are based on total aromatic hydrocarbons (T AH) concentrations. It is our understanding the sum of benzene, ethylbenzene, and toluene concentrations would need to be less than 10 ug/L in order to meet the cleanup standards. The other constituents (xylene and chlorobenzenes) that are typically used in the calculation of T AH are not contaminants of concern in the ROD and therefore were not included in the cleanup levels for the site.
c. Inclusion of Diesel Range Organics (DRO), Gasoline Range Organics (GRO) and polynuclear aromatic hydrocarbons (PAHs) in the monitoring program. We disagree that DRO and GRO should be included in the groundwater sampling and that PAHs and the calculation of total aqueous hydrocarbons (T AqH) be included in the groundwater seep (surface water) analyses. None ofthese compounds were identified as contaminants of concern in the OU2 ROD; therefore, no State standards or other applicable or relevant and appropriate requirements (ARARs) were listed in the ROD for these contaminants. Generally speaking, ARARs are normally "frozen" at the time the ROD is signed unless a new or modified requirement calls in to question the protectiveness of the selected remedy. As you are aware, we are beginning the five-year review for Elmendorf AFB with the anticipation of completing the review by September 2003 . The five-year review is the appropriate mechanism to determine the effect of either newly promulgated or revised standards on the protectiveness of the selected remedies. We believe the contaminants of concern at OU2 are properly and completely identified in the ROD and that threats to human health and the
environment are being adequately protected by the remedies currently in place. ADEC
concurred in this protectiveness determination at the time or our last five-year review in 1998.
However, if you believe ADEC's revised Oil and Hazardous Substances Pollution Control
regulations or other considerations call into question the overall protectiveness of the selected remedy at OU2 (or other OUs on Elmendorf), then we request you provide a detailed
explanation for us to evaluate in our upcoming five-year review. In order to make best use of
your information and comments, we request you submit this information within 60 days. |
Louis Howard |
| 6/28/2002 |
Update or Other Action |
Final work plan for Basewide Environmental Monitoring Plan received dated June 2002. 2.3.2.2 Program Area Modifications in 2002: Seven wells will be removed from OU 2 based on criteria in the Basewide Decision Guide provided on Figure 2-1. Table 2-2 provides the well-by-well rationale for continued monitoring, removal from, or addition to the sampling program. Groundwater monitoring Well 46-WL-01 will be removed from the OU 2 wells and reclassified under SERA Miscellaneous. One seep was added to the ST41 sampling locations in order to assess the possibility of contaminants migrating from groundwater and affecting surface water.
For both wells and the seep, laboratory analytical methods will be limited to contaminants established as ARARs in the OU 2 ROD. For groundwater, these include BTEX, and for seeps they include benzene, toluene, and ethylbenzene.
Analytical methods removed from OU2: Trace Metals by ICP Screen, DRO, GRO. Total iron was kept to effectively monitor for natural attenuation of fuels. All other trace metals were removed from this program area. DRO and GRO are NOT ARARS for OU2 [ROD] and are NOT needed to monitor natural attenuation of BTEX. DRO and GRO were removed [from the Basewide Sampling Program].
Historically, OU 2 was sampled on a biannual schedule for statistical purposes. In 2002, the frequency will be adjusted to an annual schedule as specified in the OU 2 ROD. In addition, all wells at ST41 will be sampled with passive diffusion bags (PDBs) in 2002. Sampling methods used for PDBs are presented in the FSP Section A4.3.
A4.1.2 Operable Unit 2: Five monitoring wells and one seep location will be sampled as part of the long-term monitoring efforts at OU 2. The locations of these wells are provided in Figure A4-2. All of the wells will be sampled once in 2002, with events scheduled during the month of June. A detailed field schedule for this program is provided in Section 4 of the EMP.
All wells and will be sampled according to the procedures outlined in this FSP Section A4.3. The samples from OU 2 will be collected using a passive diffusion bags. The seep sample will be collected as detailed in Section A4.3. The samples will be analyzed according to the methods outlined in Table A4-2. Details on the requirements for sample holding times and preservation, and the applicable QA/QC sample requirements, are provided in Appendix C of the EMP.
Passive Diffusion Bag Sampler Procedures: In an effort to optimize the 2002 Basewide Program, 16 wells will be added to the OU 5 source area to help serve as an early warning system for Ship Creek (Figure A4-4). These wells will be sampled for VOCs only, using a PDB.
The typical PDB consists of a low-density polyethylene lay-flat tube closed at both ends and is
filled with analyte-free deionized water. The PBD membrane acts as a semi-permeable membrane to
O certain contaminants, especially specifically chlorinated VOCs. VOCs in the groundwater diffuse across the membrane into the deionized water in the bag until equilibrium is established between the diffusible VOC in the groundwater and in the deionized water.
PDB bags will be placed in the wells approximately 1 foot from the screen and will be attached
with a nylon string to the top of the well casings. The PDBs will be left in the wells for approximately two weeks and at that time will be removed and used to fill VOC sampling bottles. The bottles will then be handled and analyzed as outlined in Section A4.5. Field parameters will not be taken as part of the analysis for PDB samples.
The same methodology used in the 1999 Annual Report was used in the 2000 & 2001 Annual Report & will be carried over to the 2002 Annual Report. Sen's Nonparametric Estimator of Slope will be used to determine an overall trend of historical & "current" data on a well-by-well basis for wells having ten (10) or more valid data points.
This analysis will also confirm or deny conclusions established from the intuitive time series plots (see Section 3.3.1) & will provide statistically sound evidence of any new potential contaminant releases. Mann-Kendall statistical analysis will be used to allow determination of trend for "current" conditions (1999-2002). To focus analysis on current conditions statistical analysis will use only the last five years of data. |
Louis Howard |
| 1/14/2003 |
Meeting or Teleconference Held |
Meeting minutes from January 14, 2003 meeting with Joe Williamson (USAF), Gary Fink (USAF), James Klasen (USAF), Kevin Oates (EPA), Louis Howard (ADEC), Cory Hinds (URS), Paul Dworian (URS), Kristin Paul (URS)
Discuss ADEC’s request to add the analyses of Diesel Range Organics (DRO) and Gasoline Range Organics (GRO) to several Operable Units at Elmendorf.
1. URS summarized recent (year 2000) ADEC risk assessment guidance that shows that DRO and GRO themselves can cause noncarcinogenic human health risks. This information was not known during preparation of the risk assessments and RODs for Elmendorf Operable Units. Therefore, addition of DRO/GRO to the sampling scheme for Elmendorf was recommended.
2. The Air Force agreed to add DRO/GRO, but cannot add funding to cover the additional analysis until 2004.
3. The following was decided on implementation:
A. This decision will be documented in the 5-Year Review. The addition of DRO/GRO to the program should be introduced in the 5-Year Review under mention of new issues affecting protectiveness.
B. The Air Force will NOT add DRO/GRO as a CERCLA ARAR, but will compare DRO/GRO results to ADEC cleanup levels in the annual reports and will discuss in subsequent 5-Year Reviews. The benefit of this is that if CERCLA COCs meet ARARs, the Air Force can achieve a partial delisting.
C. The Air Force will add DRO and GRO to the suite of analyses at monitoring wells associated with fuel plumes starting in 2004.
D. The Air Force will not pursue a decision document with ADEC on DRO/GRO until more data is gathered on the extent of the problem.
E. Until a decision document is signed with ADEC, GRO and DRO concentrations will be compared to ADEC regulations in 18 AAC 75 (Table C, Groundwater Cleanup Levels; 1,500 µg/L for DRO, 1,300 µg/L GRO).
F. Sampling frequency for DRO/GRO will follow the latest Decision Guide for Sampling Frequency (see 2002 Basewide Annual Report). “Immediately upgradient” means within a 2-year warning line, similar to that generated for OU5.
G. ADEC GRO/DRO criteria apply to groundwater, not to seeps which daylight as surface water. Criteria in 18 AAC 70 (TAH, TaqH) apply to surface water. |
Louis Howard |
| 1/31/2003 |
Update or Other Action |
2002 Annual Report Basewide Environmental Monitoring Program Draft January 2003 received. Note to file under:
ARARs
This data-reporting category addresses groundwater constituents for each individual program area
specifically identified as COCs. The original list of cleanup levels for each program area is listed in Table 2-1. These chemical-specific cleanup levels were identified either in decision documents prepared for these sites (FFA program areas) or as contaminants which were found to significantly exceed cleanup levels where groundwater COCs were not specifically identified in previous investigations (SERA and Taxiway “N” program areas). Source documents that listed cleanup levels are referenced in Section 4.
Within the context of the Basewide Program, the list of COCs for each program area can change
as data are continuously evaluated and the quality of data improves with new methods. For instance, as natural attenuation occurs, select constituents will reach cleanup levels and additional monitoring for that constituent will not be required unless mandated by a regulatory agreement. Specifically, if a COC is below cleanup levels for two consecutive sampling rounds, sampling for that COC can be discontinued.
Similarly, if cleanup levels for all COCs in a given analytical method are met across an entire program area, analysis using that method in that program area will no longer be required. An exception to the above guideline is made for OU 5. Because OU 5 serves as the downgradient receptor for most of the other program areas, COCs will not be eliminated from OU 5 unless the COC in question has been similarly eliminated first from all upgradient program areas. |
Louis Howard |
| 6/11/2003 |
Meeting or Teleconference Held |
MEMORANDUM FOR FILE FROM: 3 CES/CEVR SUBJECT: Minutes, Remedial Project Manager Meeting, 11 June 2003
A quarterly meeting of the remedial project managers (RPMs) convened at 1430L on 11 Jun 03 in the Environmental Flight (CEVR) conference room, Building 5312. Mr Louis Howard (Alaska Department of Environmental Conservation (ADEC», Mr Kevin Oates (Environmental Protection Agency (EPA) - Anchorage), Mr Gary Fink (CEVR), Mr Joe Williamson (CEVR), Ms Donna Baumler (CEVR), and Ms Doris Thomas (Public Affairs (3WG/PA» attended. Mr. Claude Mayer (CEVR) joined the meeting via teleconference. Mr Jim Klasen (Legal (11AF/JACE) was attending a training course and was unable to attend.
DP98, Land Use Control Issues (Ms Baumler). Ms Baumler stated that the Land Use Control (LUC} Management Action Plan (MAP) was completed in January. It has been updated to include information for DP98. A signature page for the Environmental Protection Committee (EPC) Chairman also has been added. In the future, we plan to have a wing instruction to assist in the enforcement of the MAP. Ms Baumler provided copies of the DP98 inserts which incorporate Mr. Howard's review comments regarding continuous implementation of institutional controls. The MAP will go to the EPC Chairman for signature and should be ready for distribution by the end of the month.
DP98, 2 Jul Meeting for Proposed Plan (Mr Mayer). Mr Mayer stated that the proposed 2 Jul date
would coincide with the date comments were due from agencies and would provide an opportunity to
meet with the contractor to resolve any issues.
Mr. Oates commented that the date would work with his schedule and reminded us that he would be gone in 31 days. He agreed that the meeting would be beneficial. Mr Oates made a few remarks about the Proposed Plan. He said some new issues have arisen in the last few years, such as groundwater analysis of 1,4-Dioxane. This chemical was sometimes used as a stabilizer for different types of ethenes. Mr Howard stated that detection requires a different method of analysis from the type we currently use.
Mr. Williamson said that we would add the new analysis to the Basewide Groundwater Monitoring Program next year. |
Louis Howard |
| 7/17/2003 |
CERCLA ROD Periodic Review |
Staff reviewed and commented on the second draft five-year review for Elmendorf's Operable Unit (OU) OUs 1, 2, 4, 5, 6. Section 121 of CERCLA, as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), requires that remedial actions which result in any hazardous substances, pollutants, or contaminants remaining at the site be subject to a five-year review. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) further provides that remedial actions which result in any hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure be reviewed every five years to ensure protection of human health and the environment.
The requirement applies to all remedial actions selected under CERCLA §121. Therefore, sites with CERCLA remedial actions may be subject to a five-year review. Consistent with Executive Order (EO) 12580, other Federal agencies are responsible for ensuring that the reviews are conducted at sites where five-year reviews are required or appropriate.
The text makes several recommendations and follow-up actions for various operable units. The Department suggests the Air Force formalize these recommendations or follow-up actions in either a separate technical memorandum or separate formal document, as appropriate, to EPA and ADEC for concurrence or non-concurrence to be placed in the administrative record.
General comment: OU (matrix and units) listings are not consistent with the rest of the document. Operable unit 4 is listed as OU 4 instead of “OU4” as is Operable Unit 5 and 6 which are listed as OU 5 and OU 6 instead of OU5 and OU6. Please correct this to be more consistent within the document. The Department requests clarification on the origin of the OU 4 soils cleanup level for 4, 4-DDT at 34 mg/kg. In 18 AAC 75.341 Table B-1 states that DDT has a cleanup level for ingestion in the Under 40-inch zone of 24 mg/kg. Additionally, for OU 5, Di-n-butyl phthalate and Diethyl phthalate have 2,700 ug/L and 23,000 ug/L listed as groundwater cleanup levels in the table.
In 18 AAC 75.345 Table C, the groundwater cleanup levels listed for Di-n-butyl phthalate is 3.65 mg/L or 3,650 ug/L and for Diethyl phthalate it is listed as 29.0 mg/L or 29,000 ug/L. Please correct Table B-1 to reflect the correct cleanup levels or provide justification as to leaving the cleanup levels unchanged.
General comments: The Department requests changing the column heading for Current Applicable Standard (Table B.1.) to include Table C or drop Table B.1 reference and leave it as Current Applicable Standard. Otherwise, the reader will infer that Table B.1 (Soil Cleanup Levels) applies to groundwater cleanup levels, which is incorrect. Also, see comment above regarding OU labeling within Table B-2 to match rest of the document (e.g. OU1 vs. OU 1). See comments above regarding cleanup levels for: 4, 4-DDT, Di-n-butyl phthalate, Diethyl phthalate.
General comment: Also see comment regarding Operable Unit labeling within the table to match rest of the document (e.g. OU1 vs. OU 1). The Department requests that the origin of the cleanup levels for the three OU 4 contaminants of concern be clarified. The Table B1 soil cleanup inhalation values for: 1,1,2-Tricholorethane is 460 mg/kg not 457 mg/kg, benzene is 9 mg/kg not 8.64 mg/kg, and for methylene chloride it is 180 mg/kg not 457 mg/kg. Please correct text in Table B-3. |
Louis Howard |
| 10/1/2003 |
Update or Other Action |
The Basewide Groundwater Monitoring Plan received. The BW GW Monitoring Program (herein called "the Program") was established through the Elmendorf Air Force Base (herein "the Base") Installation Restoration Program to address the needs of multiple programs on the Base. These programs include the Federal Facilities Agreement (FFA) and the State-Elmendorf Environmental Restoration Agreement (formerly "SERA"; now known as "State Program Sites".)
In response to the findings of the Records of Decisions (RODs) for each program area, the United States Air Force began annual groundwater monitoring. This Basewide Groundwater Monitoring Plan ("the Plan") presents relevant historical direction and methodologies of the Program in addition to background information on individual program areas. A generalized approach to groundwater monitoring practices for the Program is also provided in this Plan. A yearly Program Activities Addenda, detailing specific activities to be performed, will be submitted annually.
ST41 South-This plume is located in a site previously referred to as Four Million Gallon Hill. This was the former location of four 1,000,000-gallon aviation gasoline USTs and associated piping. The USAF has been actively remediating this site since 1976. An IRA was implemented from 1992 until January 1999 to remove and treat dissolved phase fuel constituents and free product floating on the groundwater. The IRA also functioned to intercept contaminated water at seep locations on both the north and south sides of ST41. The four USTs were demolished and the piping was removed from this site in 1996.
Future remedial activities at the ST41 South Plume should focus on monitoring natural
attenuation as specified in the ROD and free product recovery should be performed by hand
bailing wells during sampling events. The compliance of ROD specified COCs should be
determined.
ST41 North is located at the western edge of ST41 and consists of a former one-acre sludge
disposal area. It is a POL plume that is inferred to be about 400-feet by 600-feet. Although free product is present at this location, BTEX results are declining and the plume is compliant with the cleanup timeframes specified in the ROD. Future remedial activities at ST41 North should emphasize attenuation monitoring and surface water sampling, as specified in the ROD and free product recovery should be performed by hand bailing wells during sampling events. |
Louis Howard |
| 1/27/2004 |
Update or Other Action |
Five year review-A site inspection and interviews performed at ST41 on May 16, 2003 revealed LUCs, and monitoring wells at OU2 appear to be adequate. Signs at the entrance gate appeared in good condition, inspection of the monitoring wells revealed all wells were in good condition, properly located and locked, and spare parts were readily available. The wells are routinely sampled, monitoring data is submitted on time and is of acceptable quality.
Recent monitoring results in part of the southern plume at ST41 exceed the concentrations predicted in the Bioplume model completed in 2000. The calibration of the 2000 model may be incorrect and the concentrations of the BTEX at ST41 may not reach cleanup levels by 2016 as predicted. However, data shows that this plume is shrinking and is not migrating from the site.
Toxicity information has changed for three of the COCs: benzene, ethylbenzene and xylenes. Specifically, ethylbenzene is now considered a potential carcinogen by inhalation and an inhalation slope factor has been proposed by EPA, and non-carcinogen by inhalation and an inhalation slope factor has been proposed by EPA, and non-cancer reference doses for oral and inhalation exposures have been revised downwards (more stringent) for benzene and xylenes. The cleanup levels in the ROD are still within EPA's risk management range for these compounds. All other exposure assumptions, toxicity data, cleanup levels or RAOs used at the time of the remedy selection remain valid at this time. The OU2 ROD specified COC cleanup levels are still considered protective.
Levels of benzene in the seep on the north side of ST41 exceeded cleanup levels in 2002; however, the point of compliance established for protectiveness of the wetland (at time of ROD Signature) is downgradient of the current seep sampling location. It is predicted that, at the point of compliance, contaminant concentrations will be below surface water quality criteria (SWQC) as established in the OU2 ROD. This was confirmed as recently as 2001, and will be confirmed annually starting in 2003.
The 2002 annual technical report for base wide monitoring program indicates that the method (hand-bailing) used to remove the remaining free product from the wells has not been effective for groundwater. However, because the ROD requirements for removing all technically practicable free product with the IRA system have been met, remedy protectiveness is not in question.
Surface Water: To ensure compliance of SWQC as established in the OU2 ROD, TAH and TAqH should be added to the sampling suite to ensure protectiveness of the wetlands at the point of compliance. For groundwater: conduct a thorough review of modeling results and evaluate the potential for natural attenuation to achieve cleanup levels in the timeframes specified in the RODs. Revise and/or recalibrate the models if needed. Continue groundwater monitoring according to the guidelines of the Base wide Groundwater Monitoring Program until cleanup levels are achieved. |
Louis Howard |
| 2/3/2005 |
Meeting or Teleconference Held |
Meeting minutes from RPM meeting February 3, 2005, ADEC and EPA agreed to decrease the frequency of quarterly reports to semi-annual or twice a year. Elmendorf FFA XIII. REPORTING 13.1 USAF shall submit to the other Parties quarterly written progress reports. The reports will include, but not be limited to, the following information:
(a) A detailed summary of all of the remedial, removal, and investigation activities during the previous quarter, including any analytical results, any community relations activities, and any community contacts or inquiries related to the hazardous substance contamination at the Site;
(b) An outline of the planned activities for the upcoming quarter;
(c) A detailed statement of the manner and the extent to which the timetables and deadlines are being met;
(d) The status of efforts to obtain rights-of-entry necessary for monitoring and well installation off base; and(e) The status of any other activities proposed or underway that may affect any phase of the activities described in the Attachments.
13.2 The quarterly written progress reports shall be submitted on the tenth (10th) day of each calendar quarter following the effective date of this Agreement.
Groundwater (GW) Remedial Process Optimization (RPO) Recommendations (Mr.Fink). Mr. Fink explained that we asked an outside team to look at the Fairchild and Slammer TCE plumes. Previous modeling efforts left data gaps and too many uncertainties. It was unclear if monitored natural attenuation (MNA) was progressing at the rate required to meet our projected cleanup dates. Additionally, we asked the team to review the recently developed long-term monitoring plan for DP98, to determine if we were taking the correct approach. We also asked the team to look at ST36/66 since we are considering shutting down bioventing systems at these sites. In summary, the team suggested that we would not be able to meet the 2025 proposed cleanup dates for the Fairchild and Slammer plumes. The team suggested more of a risk-based approach, specifically at the seeps. Mr. Fink stated that he was not really comfortable with the
suggested approach.
The team suggested cutting back on sampling within the plume and increasing sampling down gradient. Additionally, they suggested that we use a mass based or I-dimensional model instead of a complex numerical model. We intend to run the simpler models, and we expect that our projected cleanup dates will change. EPA remarked that it doesn't really matter what model we use and emphasized that compliance sampling is really the bottom line. Mr. Williamson agreed but pointed out that we need an accurate prediction of cleanup times so that we can effectively develop our budget for the out-years. He also pointed out that we have leases that may expire,
without the possibility of renewals, and we need to plan accordingly. Mr. Fink discussed
the team's suggestion of changing the allowable limits of contamination into Ship Creek.
EPA stated that this would be a move in the wrong direction since Elmendorf has always taken an aggressive protective stance towards Ship Creek, which has been appreciated and well-received in the local community. As far as DP98 is concerned, the RPO team suggested some sampling well points but no outstanding recommendations.
For ST36/66, the team stated that existing sentry wells seemed sufficient and indicated that nothing was leaving the perched aquifer. They didn't think that revamping the bioventing system in an attempt to reach the contaminated lens was worthwhile. They suggested that a vapor test might provide enough additional information to justify shutting down the bioventing system. The team suggested changing the clean-up goals basewide, but Mr. Mayer stated that he rejected that proposal and would only consider the possibility of cleanup goal changes on a site-by-site basis. EPA asked where steps Elmendorf intended to take in light of the team's suggestions. Mr. Fink stated that we plan to implement mass based modeling, establish "best guess" cleanup dates, focus on the Slammer plume, determine if TCE is leaving the beaver pond, and determine if creating a new mulch barrier is needed for the beaver pond.
Quarterly Progress Reports (QPRs) (USAF). EPA and ADEC confirmed that the information they receive in the report, in its current format, is quite useful to them when they are briefing their higher headquarters. Both agreed that we could reduce submittals to semi-annual reports, which will be submitted in December and May of every year. ADEC requested that we continue to break sites out by Operable Unit since that is the way their database has been designed to track. |
Louis Howard |
| 4/1/2005 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (ADEC) received the 2004 Phase I RPO Annual Report (DRAFT FINAL)Groundwater Performance Optimization Monitoring Program on March 21, 2005. Below are ADEC’s comments on the document.
General Comments-Typically, delineating a plume of contaminated groundwater takes more than one well in the source area. ADEC requests the Air Force redraw boundaries for “plumes” in the following figures where one well is defining a “plume” of contaminated groundwater with a bold line and replace it with a dashed line to show it as being “inferred” or “interpreted” rather than a distinct boundary.
Zone 1 - Figures 3.2-1 and 3.3-1 for wells: OU6MW-46 and OU6MW-63, Figure 3.3-3 for well OU6MW-46, Figures 3.5-1 and 3.6-1 for well ST41-10R, Figure 3.9-1 for wells: OU6MW-46 and OU6MW-63, Figure 3.10-1 for well OU6MW-46
Zone 2 - Figure 4.1-1 for well 59WL-31, Figure 4.3-1 for well SP7/10-04, Figures 4.3-1 and 4.5-1 for well OU4MW-04, Figure 4.6-1 for well OU4MW-08R, Figure 4.7-1 for IS6-01, Figures 4.9-1 and 4.10-1 for wells: SP7/10-04 and W-4
Zone 3 - Figure 5.3-1 for well OU3MW-25, Figure 5.5-1 for wells: 60WL-04 and 64WL-01, Figure 5.6-1 for wells: 64WL-01 and 62WL-05, Figure 5.10-11 for well LF59MW-03
3.2.4 Phase I RPO Conclusions and Recommendations- Verifying that plume expansion is occurring with one monitoring well is nearly impossible to do without additional monitoring wells. The text states that the OU6 ROD mandated 5-year reviews be performed to evaluate the performance of the selected remedy (MNA). However, the recommendation in this section for MNA monitoring states MNA assessments cannot be accurately performed at one-well plumes. Also the text states plume expansion is not occurring and potential downgradient receptors are not being exposed to groundwater contaminants. ADEC requests clarification on how it can be demonstrated with one monitoring well that downgradient receptors are not being exposed to groundwater contaminants and whether or not it can be shown a plume is expanding or shrinking when sampling data is limited to one well.
The comments above apply to: PL81 South Plume (Section 3.3.5), ST41 North Plume (Section 3.5.4), 59WL-31 (Section 4.1.5), Hangar 10 Plume (Section 4.5.4), Hangar 11 Plume (Section 4.6.4), OU4 East Plume (Section 4.7.5), SS43 Plum (Section 4.9.4), W4 Plume (Section 4.10.4), OU3MW-25 Plume (Section 5.3.4), and SP01-2 Plume (Section 5.8.4).
7.0 Phase I RPO Recommendations Summary Page 7-1 - ADEC concurs with updating the conceptual site models for inclusion in the 2005 Program Baseline Calculations Report.
7.1 Plume-Specific Recommendations - ADEC concurs with the plume-specific recommendations listed in this section which are not provided in Table 7.1-1. |
Louis Howard |
| 2/23/2007 |
Exposure Tracking Model Ranking |
|
Louis Howard |
| 4/17/2007 |
Update or Other Action |
2006 Annual Phase I RPO report (Draft) received.
The groundwater monitoring objectives for the ST41 North and ST41 South plumes are as follows: Extract floating product from groundwater, as required, to minimize further migration. Monitor groundwater associated with Site ST41 to verify that COC concentrations continue to approach and, ultimately, recede beneath Operable Unit (OU) 2 ROD-specific cleanup levels.
The surface water monitoring objective for the ST41 North Plume is as follows: Monitor COC concentrations in ST41SP-01, a downgradient seep, to ensure that concentrations decrease to below OU 2 ROD-specified cleanup levels.
Recommendations: Review measure to protect casual vistors from contaminated surface water. Evaluate the ecological risk posed by TAH/TAqH exceedances in surface water at ST41 North. Survey the elevations of the ST41 North seep to facilitate evaluation of the hydraulic gradient across the plume. Measure groundwater levels in all site wells within a 48-hour period to provide a synoptic view of the water table. Sample wells downgradient of each plume to verify plume immobility. Use passive diffusion bag samples (PDBSs) to collect groundwater samples for lab analyses of volatile organic compounds. Substitute Well ST41-16 if ST41-07 is dry during sampling in 2007.
4.5.7 Passive Diffusion Bag Samplers
PDBs, described in Section 10.1.3, will be used to collect all groundwater samples for
laboratory analysis for VOCs. Surface water samples for VOCs will continue to be collected
by conventional means. Field parameters and iron will be measured in the three in-plume
wells (ST41-07 [or ST41-16], ST41-10R, and ST41-25) using the low-flow method. |
Louis Howard |
| 5/14/2007 |
Document, Report, or Work plan Review - other |
Draft 2006 Zone 1 Annual Remedial Process Optimization Report, April 2007 received on April 18, 2007. Based on the data presented in the report and any pending U.S. EPA comments, ADEC will approve the document as submitted. |
Louis Howard |
| 5/23/2007 |
Document, Report, or Work plan Review - other |
EPA comments on the Zone 1 RPO Report to Glen Verplancke 3 CES/CEVR Email message:
Great report. I agree with the changes to sampling frequency, fewer MNA parameters and water level measurements. Also the geometric regression may yield better predictions. I also think the use of the geoprobe for deep samples at DP 98 is a good idea.
This was a well written report, I especially like the site overview figure at the end. There are valuable observations made in this report , together with some changes to technique(PBDS), so it will be IMPORTANT for future work to revisit this info. I noted that at a couple sites they observed that we may need downgradient sentry wells to follow the plume, lets revisit that someday also.
Sorry I was late. Again, a very professional report. |
Louis Howard |
| 11/20/2007 |
Update or Other Action |
2007 Zone 1 Remedial Process Optimization (RPO) Report received for contaminated sites & associated underlying GW for the western portion of EAFB. This area, referred to as Zone 1, includes: DP98, ST36/66, ST41, ST61, ST69, LF04 North, PL81, WP14, & LF02. Presently, GW at ST41 is contaminated in two areas, known as the ST41 North & ST41 South plumes. Contaminated GW at ST41 North has been discharging to the surface environment. ST41 South has no point of discharge, & its downgradient extent is determined by a dynamic equilibrium between contamination dissolution in the contaminated smear zone & downgradient natural attenuation. Ongoing monitoring of both plumes evaluates the effectiveness of natural processes for reducing contaminant concentrations in GW & the seep.
MNA is the only remedy currently active at the site. The efficacy of MNA is evaluated through the historical record of COC concentrations in in-plume monitoring wells. Benzene & ethylbenzene in GW exhibit clear trends of declining concentration from 1999 onward. For the seep, results are available from 2003 onward, but any downward trend is obscured by the magnitude of year-to-year variations. Surface-water trends are similarly obscured. A GW cleanup date can be predicted by geometric regression of benzene results from 1999 onward in ST41-10R. The model predicts that benzene will be consistently less than its cleanup level of 5 µg/L in 2015, beating the ROD-specified target date of 2016 by only 1 year. The correlation coefficient from the regression is high (0.95), indicating that the assumed first-order attenuation process explains nearly all of the observed change in concentration over time. This prediction is essentially the same as the prediction in the 2006 A ctivities Report, of cleanup in 2016. Thus, the 2007 result is in accord with past results.
Well ST41-10R is not a good indicator of ST41 North plume cleanup because this well does not sample the most contaminated GW. Benzene concentrations were higher by a factor of 4 in seep & surface-water samples in 2007, & well ST41-28 was more contaminated than ST41-10R by nearly an order of magnitude when it was last sampled in 2002. Geometric regression of the benzene results from ST41-28 from 1996 to 2002, ignoring the change in analytical protocol after 1998, predicts cleanup in 2024. Continued sampling of the seep & surface water & renewed sampling of ST41-28 are needed in order to develop a current cleanup prediction, but the ST41 plume is unlikely to reach the cleanup goal by 2016.
Recommendations:
• Identify a new surface-water location some distance downstream of the seep (ST41SP-01) & discontinue sampling the present surface-water location (ST41SW-01). The purpose of surface-water sampling is to demonstrate compliance with the RAO requiring no discharge to downgradient wetlands. Recent sampling at ST41SW-01, located within a few feet of the seep standpipe & possibly within the zone of active GW discharge, has found COC concentrations equal to or higher than those in the seep samples. Because volatile contaminants attenuate rapidly in surface water, the presence of contamination adjacent to the seep provides no information about the concentrations of 100 feet downstream of the seep would serve as a meaningful point of compliance.
• Add ST41-28 for ST41 North. This in-plume well, located near the trailing edge of the plume, was routinely sampled between 1996 & 2002 & exhibited BTEX levels similar to those encountered in ST41-10R. This well should be sampled annually until the current contaminant trend can be identified (5 years or less). Measure MNA parameters in 2008 in this well to evaluate the status of the plume conditions.
• Reduce the sampling frequency at ST41-10R in ST41 North to once every 2 or 3 years (sampling next in 2009 & then in 2012, in alignment with the 5-year review schedule). Benzene concentrations in the seep (ST41SP-01) have consistently been larger than those in the well. Continued annual monitoring of the seep will provide the required information about GW contamination at the leading edge of the plume.
• Replace ST41-07 with ST41-16 for ST41 South. The trailing edge of the plume now lies downgradient of ST41-07 but upgradient of ST41-16. A thin layer of free product was present in ST41-16 in 2007. This well should be sampled annually until the current contaminant trend can be identified (5 years or less). Measure MNA parameters in 2008 in this well to evaluate the status of the plume conditions.
See site file for additional information. |
Louis Howard |
| 11/20/2007 |
Update or Other Action |
2007 Zone 1 Remedial Process Optimization (RPO) Report received for contaminated sites and associated underlying groundwater for the western portion of EAFB. This area, referred to as Zone 1, includes: DP98, ST36/66, ST41, ST61, ST69, LF04 North, PL81, WP14, and LF02. Presently, groundwater at ST41 is contaminated in two areas, known as the ST41 North and ST41 South plumes. Contaminated groundwater at ST41 North has been discharging to the surface environment. ST41 South has no point of discharge, and its downgradient extent is determined by a dynamic equilibrium between contamination dissolution in the contaminated smear zone and downgradient natural attenuation. Ongoing monitoring of both plumes evaluates the effectiveness of natural processes for reducing contaminant concentrations in groundwater and the seep.
MNA is the only remedy currently active at the site. The efficacy of MNA is evaluated through the historical record of COC concentrations in in-plume monitoring wells. Benzene and ethylbenzene in groundwater exhibit clear trends of declining concentration from 1999 onward. For the seep, results are available from 2003 onward, but any downward trend is obscured by the magnitude of year-to-year variations. Surface-water trends are similarly obscured. A groundwater cleanup date can be predicted by geometric regression of benzene results from 1999 onward in ST41-10R. The model predicts that benzene will be consistently less than its cleanup level of 5 µg/L in 2015, beating the ROD-specified target date of 2016 by only 1 year. The correlation coefficient from the regression is high (0.95), indicating that the assumed first-order attenuation process explains nearly all of the observed change in concentration over time. This prediction is essentially the same as the prediction in the 2006 A ctivities Report, of cleanup in 2016. Thus, the 2007 result is in accord with past results.
Well ST41-10R is not a good indicator of ST41 North plume cleanup because this well does not sample the most contaminated groundwater. Benzene concentrations were higher by a factor of 4 in seep and surface-water samples in 2007, and well ST41-28 was more contaminated than ST41-10R by nearly an order of magnitude when it was last sampled in 2002. Geometric regression of the benzene results from ST41-28 from 1996 to 2002, ignoring the change in analytical protocol after 1998, predicts cleanup in 2024. Continued sampling of the seep and surface water and renewed sampling of ST41-28 are needed in order to develop a current cleanup prediction, but the ST41 plume is unlikely to reach the cleanup goal by 2016.
Recommendations:
• Identify a new surface-water location some distance downstream of the seep (ST41SP-01) and discontinue sampling the present surface-water location (ST41SW-01). The purpose of surface-water sampling is to demonstrate compliance with the RAO requiring no discharge to downgradient wetlands. Recent sampling at ST41SW-01, located within a few feet of the seep standpipe and possibly within the zone of active groundwater discharge, has found COC concentrations equal to or higher than those in the seep samples. Because volatile contaminants attenuate rapidly in surface water, the presence of contamination adjacent to the seep provides no information about the concentrations of 100 feet downstream of the seep would serve as a meaningful point of compliance.
• Add ST41-28 for ST41 North. This in-plume well, located near the trailing edge of the plume, was routinely sampled between 1996 and 2002 and exhibited BTEX levels similar to those encountered in ST41-10R. This well should be sampled annually until the current contaminant trend can be identified (5 years or less). Measure MNA parameters in 2008 in this well to evaluate the status of the plume conditions.
• Reduce the sampling frequency at ST41-10R in ST41 North to once every 2 or 3 years (sampling next in 2009 and then in 2012, in alignment with the 5-year review schedule). Benzene concentrations in the seep (ST41SP-01) have consistently been larger than those in the well. Continued annual monitoring of the seep will provide the required information about groundwater contamination at the leading edge of the plume.
• Replace ST41-07 with ST41-16 for ST41 South. The trailing edge of the plume now lies downgradient of ST41-07 but upgradient of ST41-16. A thin layer of free product was present in ST41-16 in 2007. This well should be sampled annually until the current contaminant trend can be identified (5 years or less). Measure MNA parameters in 2008 in this well to evaluate the status of the plume conditions. |
Louis Howard |
| 9/30/2008 |
Update or Other Action |
Draft Final Five-Year Review Report, September 2008 for Elmendorf Air Force Base, Alaska comment letter from ADEC to U.S. Air Force. The Alaska Department of Environmental Conservation (ADEC) has received the above document for review and comment on September 18, 2008. Below are our comments.
1.1 Purpose Page 1-1: Section 19.1 of the Federal Facility Agreement (FFA) states: “If a remedial action is selected that results in any hazardous substances, pollutants, or contaminants remaining at the Site, the Parties shall review such remedial action no less often than each five (5) years after the initiation of such remedial action to assure that human health and the environment are being protected by the remedial action being implemented. The U.S. EPA Project Manager and the ADEC Project Manager shall advise the USAF Project Manager of their findings in this regard. If any Party determines that additional action is required, the Agreement may be amended pursuant to Part XXXIII.”
Based on ADEC’s review of the information and data contained in the document, ADEC has found the remedial actions being implemented at the Site are protective of human health and the environment. |
Louis Howard |
| 3/2/2009 |
Update or Other Action |
Final Five Year Review received. The purpose of this five-year review is to evaluate the implementation & performance of the remedial actions that were selected in the record of decision (ROD) for each operable unit (OU) at Elmendorf Air Force Base (AFB). This is the 3rd review for EAFB. The trigger for this review was the date the Air Force signed the 2nd five-year review report, which was December 17, 2003.
Remedial action objectives (RAOs) specified in the OU2 ROD are:
• Prevent ingestion & contact with groundwater (GW) containing contaminants in levels in excess of background or MCLs, whichever is greater;
• Prevent use for aquaculture, or if aquaculture use is proposed in the future, treat water to an acceptable level;
• Prevent contaminated seep water (surface water) from entering wetlands;
• Reduce further migration of contaminants due to free-phase product currently at the water table & of any residual product that may exist in piping & underground tanks;
• Prevent migration of contaminants found in soil that would result in GW contamination in excess of MCLs or health-based levels;
• Attain residual contaminant levels which would restore GW as a potential source of drinking water; &
• Compliance with all action-, chemical-, & location-specific applicable or relevant & appropriate requirements (ARARs).
Final remediation goals for GW include preventing ingestion or direct contact with GW containing contaminants with levels in excess of background levels or federal drinking water standards (primary MCLs, 40 CFR 141).
Final remediation goals for surface water (SW) include compliance with location & chemical specific ARARs. The location specific goal is avoidance of long-term & short-term adverse impacts associated with destruction or modification of the wetlands area. The chemical-specific cleanup levels include compliance with State of Alaska SW quality criteria (SWQC) as established in 18 AAC 70, which are based on Total Aromatic Hydrocarbons (TAH). The chemical-specific cleanup levels for SW COCs benzene, ethylbenzene, & toluene were defined in the ROD based on the TAH cleanup level in 18 AAC 70. During development of the 2002 monitoring plan, ADEC comments, & response from the USAF, resulted in the understanding that the 10 ug/L cleanup standard applies to the sum of the benzene, ethylbenzene, & toluene levels. The 2003 five-year review recommended that OU2 SW at the point of compliance be monitored for TAH & Total Aqueous Hydrocarbons (TAqH). However, the 2003 five-year review did not add TAH & TAqH as COCs for OU2 SW, nor did it establish the SWQC for those parameters as cleanup levels for OU2. The COCs for both GW & SW are fuel-related chemicals that are attributed to past operations &/or spills associated with the USTs.
The OU2 SW point of compliance (SW-13) in the center of the wetland area was not monitored between 2003 & 2007 due to confusion over its location. The location of point of compliance was re-established & SW was sampled in 2008. The 2008 results demonstrate that SW contaminants attenuate between contaminated seep ST41-SP01 & the SW point of compliance. Annual sampling is needed to demonstrate protectiveness.
Monitoring shows that the natural attenuation remedies are generally decreasing contaminants of concern (COC) levels. At several sites in OU2, OU4, OU5, & OU6, the process is slower than anticipated in the ROD. For most of the affected sites, the slower attenuation rates are limited to a few individual wells or just a few additional years until cleanup goals are met.
Recommendations: Monitor the OU2 ST41 SW point of compliance (SW-13) annually & seep ST41-SP01 every five years to assess the natural attenuation remedy for OU2 SW. Document these updates to the OU2 monitoring program in a memo to the site file.
Incorporate wells ST41-28 (North Plume) & ST41-16 (South Plume) back into the monitoring program for OU2 when free product is no longer present in these wells. These wells have historically had some of the highest COC levels & are important for trend analysis estimates for meeting cleanup levels. Reduce sampling frequency or eliminate well ST41-07 because cleanup levels appear to be met at this location. Document sampling frequency of seeps (every 5-years) versus SW point of compliance (annually) in a memo to site file. Document changes to sampling program in a memo to the site file.
For OU1, OU2, OU4 & OU5, update the documentation of LUC implementation in a memorandum to the site file to comply with Air Force's policy.
Protectiveness Statement: The remedy at OU2 is expected to be protective of human health & the environment upon attainment of GW cleanup levels, through natural attenuation, at ST41. In the interim, exposure pathways that could result in unacceptable risks are being controlled. |
Louis Howard |
| 3/17/2009 |
CERCLA ROD Periodic Review |
Cover letter to the EPA's Five-Year Review signature sheet sent to Richard J. Walberg, Colonel, US Air Force Vice-Commander from EPA Region 10 Office of Environmental Cleanup Daniel D. Opalski, Director. The Environmental Protection Agency (EPA) has completed their review of the third Five-Year Review report for the United States Air Force (USAF) Elmendorf Superfund site, in Anchorage Alaska.
EPA reviewed this report for technical adequacy, accuracy, and consistency with EPA guidance. In general, EPA agrees with the protectiveness determinations in this report. However, I understand that all parties to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 120 Federal Facility Agreement (FFA) are aware of a potential new source that has not been fully characterized, namely SS-022. It is also my understanding that while the Five-Year Review identifies this potential new source, the USAF has not adequately discussed the interim measures it has already taken to ensure protectiveness as site characterization proceeds, such as Institutional Controls (ICs) at SS-022 and the ongoing Remedial Investigation.
Therefore, we recommend that within ninety (90) days (by June 15, 2009), USAF supplement the Site File and Administrative Record with a Memorandum to document the ICs (e.g., installation of a fence, signage, and notation on the Environmental Restoration Program Atlas) that have been implemented for the protection of human health and the environment at SS-022. The Memorandum should also mention the Installation-wide ICs (including restriction of ground water use) already in place.
In addition, EPA agrees with USAF's recommendation for further action at the OU-l landfill area for the trichloroethylene (TCE) groundwater contamination, and requests that the Program Managers meet to discuss the timeline for completion of the groundwater contamination characterization and establish deadlines and, as appropriate, target dates for subtasks, as required under the FFA.
|
Louis Howard |
| 4/3/2009 |
Update or Other Action |
Five Year Review for Elmendorf Air Force Base signed by ADEC. By signing the review, it documents the State of Alaska Department of Environmental Conservation's (ADEC's) acceptance of the Third Five-Year Review (next one due in 2013) for Elmendorf Air Force Base. As presented in the report, ADEC looks forward to working with Elmendorf and EPA to address the chlorinated solvent groundwater plumes associated with Operable Unit 1 Landfill (Jennifer Roberts, Federal Facilities Program Manager). |
Jennifer Roberts |
| 11/11/2009 |
Update or Other Action |
Draft MEMORANDUM TO THE SITE FILE Elmendorf Air Force Base Operable Units (OUs) 1,2,4, and 5 received. The minor revisions to the OU 1,2,4 and 5 RODs clarify how LUCs will be implemented and managed for activities within these operable units. In addition, this minor revision will correct inconsistencies to chemical specific ARAR in the Operable Unit 4 ROD. In 2003, the USAF published guidance for active installations entitled Air Force Policy on Performance-Based Records of Decision (RODs) for Land Use Control (LUC) Implementation (SAF/IE Memo, 7 Oct 03) requiring documentation of LUCs in administrative documents such as the ROD. LUCs are part ofthe selected remedies in the RODs for OUs 1,2,4, 5, and 6 and Site DP98. This Memorandum to the Site File uses the 2003 guidance to clarify how the USAF intends to implement the LUCs at OUs 1,2,4 and 5. The ROD for Site DP98 is compliant with USAF Policy. The ROD for OU 6 was updated to be compliant with the policy in an Explanation of Significant Difference dated 15 June 2007. The cleanup for OU3 is complete and no LUCs are in place as part of the remedy.
The OU2 Interim Remedial Action ROD for Source Area ST41 was signed by the USEPA on 1 September 1992, by the ADEC on 29 August 1992, and by USAF on 15 July 1992. The OU2 ROD was signed by the USEPA on 31 March 1995, by the ADEC on 17 April 1995, and by USAF on 19 May 1995. There have been two revisions to the OU2 ROD. The Remedial Action Report, dated September 1998, clarified the performance standards that needed to be met in order for the IRA free-product recovery system to be shut down.
The Remedial Action Report also clarified that as a component of the land use controls the area would be designated for outdoor/recreational and unmanned industrial use. The Environmental Cleanup Plan and Quality Program Plan, Closure of the Long Term Groundwater Treatment System at OU2, ST41, dated November 1999, documented completion ofthe free-product recovery and groundwater treatment system remedy at ST41 and established a point of compliance for natural attenuation of surface water contamination.
Land Use Control Performance Objective for OU2: Restrict access to groundwater and contaminated surface and subsurface soils, Designate the affected area for outdoor/recreational use and
unmanned industrial use, excluding the development of commercial aquaculture; Prohibit installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2; and Prohibit unauthorized access to existing water supply and groundwater monitoring wells.
Proposed minor change: Maintain land use controls that restrict access to groundwater and groundwater development at the site: The specific institutional controls to be implemented
and/or maintained at OU2 are as follows: Designate the affected area for outdoor/recreational use and unmanned industrial use, excluding the development of commercial aquaculture; Continued enforcement of base policy prohibiting installation of groundwater wells (other than for
monitoring purposes) into the shallow aquifer underlying OU2; and Prohibiting unauthorized access to existing water supply and groundwater monitoring wells. Land Use Controls will be managed and implemented in accordance with section 4.1 of this memorandum to site file. |
Louis Howard |
| 12/1/2009 |
Update or Other Action |
Semi-annual progress report received. SUMMARY OF WORK PERFORMED DURING LAST SIX MONTHS-Sampled groundwater at 5 monitoring wells and a surface water point of compliance at ST41 (Jul 09) and Conducted annual LUC site inspection (Jul 09).
PLANNED ACTIVITIES FOR NEXT SIX MONTHS- Award FY10 Zone 1 Remedial Action - Operations contract (Jan 10), Receive final 2009 Zone 1 Field Activities Report (May 10), Receive final OU2 Minor Site Letter (or Memo to the Site File) clarifying sampling frequencies for point of compliance and seeps at ST41 (May 10), Receive final work plan for 2010 summer field work (May 10), and Finalize minor site letter for clarification of land use controls (LUCs) at OUs 1, 2, 4, and 5 (Jan 10). |
Louis Howard |
| 2/22/2010 |
CERCLA ROD Periodic Review |
Final Memorandum to.the Site File for OUs 1,2,4, and 5 received. The purpose of this Memorandum to the Site File is to present non-significant or minor changes to the Record of Decision (ROD) signed for OUs 1,2,4, and 5. The minor changes to the OUs involve clarifying how the US Air Force (USAF) intends to implement the Land Use Control (LUC) at sites LF59 (in OUI), ST41 (in OU2), FT23, SD24, SD25, SD26, SD27, SD28, SD29 (in OU4) and ST37 (in OU5). LUCs are referred to as institutional controls in the RODs.
The minor revisions to the OU 1,2,4 and 5 RODs clarify how LUCs will be implemented and managed for activities withi~ these operable units. In addition, this minor revision will correct inconsistencies to chemical specific ARAR in the Operable Unit 4 ROD. In 2003, the USAF published guidance for active installations entitled Air Force Policy on Performance-Based Records of Decision (RODs) for Land Use Control (LUC) Implementation (SAFflE Memo, 7 Oct 03) requiring documentation of LUCs in administrative documents such as the ROD. LUCs are part of the selected remedies in the RODs for OUs 1, 2, 4, 5, and 6 and Site DP98. This Memorandum to the Site File uses the 2003 guidance to clarify how the USAF intends to implement the LUCs at OUs 1,2,4 and 5.
Land Use Performance Objectives: Restrict access to groundwater and contaminated surface and
subsurface soils, Designate the affected area for outdoor/recreational use and unmanned industrial use, excluding the development of commercial aquaculture; Prohibit installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2; and Prohibit unauthorized access to existing water supply and groundwater monitoring wells.
|
Louis Howard |
| 3/3/2010 |
Update or Other Action |
Zone 1 Field Activities Report received. Zone 1 is one of three zones established on EAFB for management of environmental restoration. Eight sites are managed under Zone 1: LF02, LF04, WP14, ST36/66, ST41, ST61, ST69, and DP98. Groundwater contamination is monitored at 10 plumes in Zone 1, and exposed landfill debris is removed annually at LF04.
Five sites (LF02, LF04, WP14, ST41, and DP98) are administered under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) with U.S. Environmental Protection Agency (EPA) oversight and are governed by Records of Decision (ROD). The three remaining sites (ST36/66, ST61, and ST69) are regulated according to State of Alaska cleanup requirements.
Analytical results for the ST41 North plume showed that benzene exceeded its groundwater cleanup level of 5 µg/L in in-plume monitoring wells ST41-10R and ST41-28. Monitoring well ST41-08 was confirmed to remain outside the plume boundary, being ND for all COCs. No COCs were detected in the surface water point of compliance (ST41SW-13). In the ST41 South plume, benzene exceeded its groundwater cleanup level of 5 µg/L in both of the in-plume monitoring wells (ST41-25 and ST41-16). Well ST41-16 also exceeded the cleanup levels for ethylbenzene and toluene.
Fuel product (0.15 feet) was found in monitoring well ST41-16 (Table 7-5) and removed with a bailer. Approximately 0.25 gallons of water mixed with product was segregated for disposal. The same well contained 0.08 feet of product in 2007. No product was found in monitoring well ST41-28, where 0.02 feet of product was encountered in 2007.
At ST41 North, BTEX concentrations in monitoring well ST41-10R exhibited an overall decline since 1996 but were higher in 2009. This well likely reflects the effects of natural flushing, but the higher seep concentrations indicate that the well is not intercepting the core of the remaining plume. Continued monitoring of the seep and in-plume monitoring wells will provide more information and help refine the range of predicted cleanup dates for this plume.
Geochemical conditions at ST41 South are similar to those at ST41 North, limiting significant biodegradation to the fringes of the plume. Only benzene continues to exceed the cleanup level in monitoring well ST41-25, but the scatter in the data results in a predicted cleanup date for this plume of 2051. As previously predicted (USAF 2008b), the scatter likely reflects the sporadic occurrence of LNAPL droplets or emulsion in the water samples from this well combined with variations in groundwater flow patterns. Because the prediction model does not account for multiple modes of contamination, its simple approach is unrealistically conservative in this case. Although groundwater contamination will persist until residual LNAPL in the smear zone is depleted, cleanup will probably occur much sooner than 2051 but later than the goal of 2016.
Recommendations for future monitoring at ST41 are as follows:
Discontinue sampling at ST41-08. The 2009 one-time sample confirmed that contaminants are not reaching this monitoring well, verifying the 1992 results.
Collect samples from ST41-25 and -28 using PDB on the same 2- or 3-year schedule as ST41-10R. These monitoring wells are in-plume but concentrations are decreasing. Annual monitoring is not needed because the plume is not migrating; however, moving to a 5-year schedule may miss the predicted decline in concentrations when residual LNAPL is depleted. The next sample would be scheduled in 2012.
Reduce sampling frequency at ST41-16 to every 5 years based on the decision tree (USAF 2003b). This monitoring well is clearly an in-plume well and is not poised for a rapid decline in concentrations. The next sample would be collected in 2014. For consistency within the ST41 site and in preparation of a five-year review, the next sample event could be scheduled in 2012, if desired. |
Louis Howard |
| 3/12/2010 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (ADEC) has received the draft monitoring report for review & comment on March 3, 2010. Below are ADEC’s comments regarding the report which covers eight sites: LF02 (CS DB Hazard ID 2770), LF04 (CS DB Hazard ID 1804), WP14 (CS DB Hazard ID 639), ST36/66 (CS DB Hazard ID 1793), ST41 (CS DB Hazard ID 429), ST61 (CS DB Hazard ID (2747), ST69 (CS DB Hazard ID 1795), DP98 (CS DB Hazard ID 2595) & ten GW plumes in Zone 1.
6.2 ST41 Monitoring Objectives Page 6-1: The text states: “The OU2 ROD identified only benzene, toluene, and ethylbenzene as the surface water monitoring COCs.” To ensure compliance of SWQC as established in the OU2 ROD, TAH and TAqH should be added to the sampling suite to ensure protectiveness of the wetlands at the point of compliance. During development of the 2002 monitoring plan, ADEC comments (ADEC, 2002), and response from the USAF (USAF, 2002b), resulted in the understanding that the 10 µg/L cleanup standard applies to the sum of the benzene, ethylbenzene, and toluene concentrations (see the 2008 Five Year Review Section 4.2 Operable Unit 2 Page 4-7).
Table 6-1
Contaminants of Concern and Cleanup Levels in Groundwater and Surface Water at ST41 Page 6-2: See comments above for Table 3-3 regarding discussion of use of multiple PDB samplers installed vertically across the screened or open interval to determine the zone of highest concentration and whether contaminant stratification is present. The chemical-specific cleanup levels for surface water COCs: benzene, ethylbenzene, and toluene were defined in the ROD based on the TAH cleanup level in 18 AAC 70. During development of the 2002 monitoring plan, ADEC comments (ADEC, 2002), and response from the USAF (USAF, 2002b), resulted in the understanding that the 10 µg/L cleanup standard applies to the sum of the benzene, ethylbenzene, and toluene concentrations (see the 2008 Five Year Review Section 4.2 Operable Unit 2 Page 4-7).
Table 6-4
Results for Contaminants of Concern in ST41 Monitoring Wells and Seeps Page 6-7: The table incorrectly identifies ST41-SW13 as having Table C Groundwater cleanup levels instead of the applicable surface water quality criteria of 10 µg/L (the sum of the benzene, ethylbenzene, and toluene concentrations, see the 2008 Five Year Review Section 4.2 Operable Unit 2 Page 4-7).
6.6 Summary and Recommendations for ST41 Page 6-15: The text states: “Collect samples from ST41-25 and -28 using PDB on the same 2- or 3-year schedule as ST41-10R.” ADEC concurs. See comments above at Table 3-3 regarding the use of PDBs and whether or not these wells merit deployment of multiple PDBs or if the top of the well screen is below the water table and the COCs being monitored are petroleum (e.g. BTEX). |
Louis Howard |
| 3/24/2010 |
Document, Report, or Work plan Review - other |
EPA has reviewed the Draft Zone 1 Field Activities Report, February 2010, Elmendorf A.F.B., Alaska and has the following comments:
General: There appear to be several significant issues that need further discussion among the RPMs as a result of interpretations and conclusions made in this Report or practices described in this Report. The proper use of PDBs and the rationale for their use seems to be unclear. There also could be an issue with the consistency of their use. The purpose of a Base-wide Monitoring Program should be to integrate all info on all contaminants and not deal with CERCLA COCs, alone. This Report seems to take" liberties" with the interpretation of the OU6 ESD; EPA agrees with the ADEC clarification of the purpose of the ESD in their comments on the above Report. The QA Lab reports, as an Appendix to this Report outline flagged issues dealing with sample temperature and volatile organic analysis (VOA) collection discrepancies that compromise the data in this Report and cast doubt on adherence to Management Plan SOPs.
Specific:
1.1 2009 Zone 1 Project Objectives Page 1-1 EPA agrees with the comments made by ADEC . The Zone or "Basewide Monitoring Plan" should deal with all programs, otherwise we would have only OU Monitoring Plans.
1.3.1 Ground Water and Surface Water Sampling Page 1-7 Since technique and consistency of sampling appears to be an issue, EPA agrees with ADEC suggestions to include SOPs as an appendix to work plans. This section calls into question the value and use of PDB sampling. This is a topic for FFA discussion and possibly consultant briefing.
6.2 ST41 Monitoring Objectives Page 6-1: To assure protectiveness of the wetland ADEC comments on TAH and TAqH should be considered.
Table 6-1 Contaminants of Concern and Cleanup Levels in Groundwater and Surface Water at ST41 Page 6-2: Same comment on the use of PDBs.
6.6 Summary and Recommendations for ST41: Page 6-15 EPA agrees with the recommendation. |
Louis Howard |
| 4/28/2010 |
Update or Other Action |
Memorandum for ADEC. SUBJECT: Response to ADEC Comment on Draft 2009 Zone 1 Field Activities Report (Ref: ADEC Memo, 12.Mar 10)
1. This memorandum is in response to ADEC's concern as to why diesel-range organics (DRO) and gasoline-range organics (GRO) at select groundwater plumes were not sampled in 2009 as
previously agreed in a January 14, 2003 meeting. Specifically, ADEC's comment (Attachment 1) is in reference to Section 3.7.1 Implications of Contaminant and Geochemical Monitoring, Page 3-17 of the draft 2009 Zone 1 Field Activities Report, which stated: "The text states: When these parameters were monitored from 1999 to 2007, GRO concentrations in this monitoring well exceeded cleanup levels while DRO concentrations hovered near the cleanup level. ADEC requests the Air Force provide an explanation or a memorandum to the site file as an appendix to the document on why DRO and GRO were eliminated from the monitoring program as previously agreed to in a January 14, 2003 meeting with ADEC, USAF and EPA."
2. The analytes in question were not included in the Zone 1 groundwater monitoring program
for FY09 due to an administrative oversight. The agreement to monitor for DRO and GRO was
captured in meeting minutes (Attachlnent 2), not in a more formal mechanism such as a decision
document or memorandum to the·site file. In preparation for programming of project
requirements, we reviewed the governing documents for the Zone 1 sites. None of the governing
documents for Zone 1 sites identified GROIDRO as a contaminant ofconcem (COC); therefore,
GRO/DRO sampling was not programmed or conducted in 2009.
3. The U.S Air Force agrees with ADEC's request to continue sampling for diesel-range organics (DRO) and gasoline-range organics (GRO) for CERCLA sites with fuel-related plumes. Minutes of a 14 Jan 03 meeting with EPA, ADEC and DRS, provided with the above referenced ADEC memo, documents that the Air Force agreed to add DRO/GRO into the sampling program under the following conditions:
a. The decision will be documented in the 5-Year Review. The addition of DRO/GRO to the program should be introduced in the 5-Year Review under· mention of new issues affecting protectiveness.
b. The Air Force will NOT add DRO/GRO as a CERCLA ARAR, but will compare DRO/GRO results to ADEC cleanu levels in the annual re orts and will discuss in subsequent 5-Year Reviews. The benefit ofthis is that if CERCLA COCs meet ARARs, the Air Force can achieve a partial delisting.
c. The Air Force will add DRO and GRO to the suite of analyses at monitoring wells associated with fuel plumes starting in 2004.
d. The Air Force will not pursue a decision document with ADEC on DRO/GRO until more data is gathered on the extent of the problem.
e. Until a decision document is signed with ADEC, GRO and DRO concentrations will be compared to ADEC regulations in 18 AAC 75 (Table C, Groundwater Cleanup Levels; 1,500 ug/L for DRO, 1,300 ug/L GRO).
f. Sampling frequency for DRO/GRO will follow the latest Decision Guide for Sampling Frequency (see 2002 Basewide Annual Report). "Immediately up gradient" means within a 2-year warning line, similar to that generated for OU5.
g. ADEC GRO/DRO criteria apply to groundwater, not to seeps which daylight as surface water. Criteria in 18 AAC 70 (TAR, TAqH) apply to surface water.
4. The fact that these analytes were not included in the Zone 1 groundwater monitoring program
for FY09 is attributed to an oversight. The USAF will add DRO/GRO into the suite of analyses
at monitoring wells associated with fuel-related plumes for Zone 1 (LF04 South and WP14) and
will prepare a memo to the site file to prevent this type of oversight from occurring in the future.
The USAF strategy will be to compare DRO/GRO and total aromatic hydrocarbon (TAH)/total
aqueous hydrocarbon (TAqH) sample results as contaminants of interest with current ADEC
regulations in 18 AAC 75 - Table C - Groundwater Cleanup Levels and 18 AAC 70 for surface
water. Should you have any questions, please feel free to contact me at (907) 552-2875.
Signed Gary Fink YF-02 Chief, Environmental Restoration. |
Louis Howard |
| 9/9/2010 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 71408 name: Underground tank |
Louis Howard |
| 1/28/2011 |
Update or Other Action |
Staff received the 2010 Annual Land Use Control (LUC) Monitoring Letter for DP98 and Operable
Units (OUs) 1,2,4,5, and 6. References: (a) DP98 Record of Decision, Section 12.2.3.4, dated May 2004, (b) OU6 Explanation of Significant Differences, Section 4.3.1.3, dated Mar 2007, and
(c) Memorandum to the Site File for OUs 1,2,4, and 5, Section 4, dated Jan 2010.
This letter serves as the annual monitoring report on the status of LUCs in place at DP98 and
at OUs 1,2,4,5 and 6.
Groundwater - Restrict access to groundwater and groundwater development at the site. Designate the affected area for outdoor/recreational use and unmanned industrial use, excluding the development of commercial aquaculture. Continue enforcement of base policy prohibiting installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2. Prohibit unauthorized access to existing water supply and groundwater monitoring wells.
Evaluation - A land use control inspection was performed and land use controls are in place and continue to be effective at ST41.
The Air Force ensures compliance with LUCs by conducting periodic monitoring and completing site inspections. Separate controls are in place and enforced by the Air Force to prevent inappropriate soil and groundwater exposure at these sites. The Air Force currently requires all proj ects resulting in soil disturbance of greater than four inches below ground surface
to follow 3r Wing Instruction 32-1007, Safeguarding Utilities from Damage, dated 17 Aug 07
and 3rd Wing Instruction 32-7003, Land Use control Management, dated 16 Feb 07. Both instructions require the proponent to obtain an approved Base Civil Engineer Work Clearance
Request (3 WG Form 3) prior to conducting work on the Base. |
Louis Howard |
| 2/10/2011 |
Update or Other Action |
Zone 1 Draft Field Activities Report received. Field parameters in the ST41 South plume (monitoring wells ST41-16 & ST41-25) are similar to previous years. Both wells contained substantial ferrous iron (>3.3 mg/L), very elevated conductivity (714 to 1,156 µS/cm), negligible DO (0.17 to 0.21 mg/L), & reducing ORP (-74.4 to -82.3 mV) (Table 6-3). In the ST41 North plume, monitoring well (ST41-28) showed similar results. Monitoring wells in both plumes had fuel odors, & the well in ST41 North also exhibited sheen.
Analytical results for the ST41 North plume showed that benzene exceeded its groundwater
cleanup level in in-plume monitoring well ST41-28. COCs did not exceed the cleanup level at the surface water point of compliance (ST41SW-13).
In the ST41 South plume, benzene exceeded its groundwater cleanup level in both of the inplume
monitoring wells (ST41-16 & ST41-25). Well ST41-16 also exceeded the cleanup
levels for ethylbenzene & toluene.
Conditions & trends in the ST41 North plume are as follows:
Upgradient. No longer monitored; the source was removed.
In-plume. Since 1999, benzene concentrations have been declining in monitoring well ST41-10R & are predicted to reach cleanup levels in 2020. COC concentrations measured in the trailing edge of the plume (ST41-28) are high, & cleanup of benzene is not predicted until 2046.
Downgradient. The core of the ST41 North plume is likely discharging at ST41SP-01. No contaminants are reaching the downgradient monitoring wells or the point of compliance (ST41SW-13).
At ST41 North, the trailing edge of the plume is showing declining rates of benzene contamination. The last time monitoring well ST41-10R was sampled in 2009, BTEX exhibited a small increase but overall decline since 1996. This well likely reflects the effects of natural flushing, but the higher seep concentrations indicate that the well is not intercepting the core of the remaining plume. Continued monitoring of the seep & in-plume monitoring wells will provide more information & help refine the range of predicted cleanup dates for this plume.
Conditions & trends in the ST41 South plume are as follows:
Upgradient. The trailing edge of the plume has passed the former location of monitoring well ST41-07.
In-plume. Since 1997, the body of the plume has been attenuating, but erratic results preclude a meaningful cleanup prediction. ST41-16 did not contain free product in 2010, but BTEX contamination remains well above the cleanup levels.
Downgradient. No downgradient monitoring wells or seeps exist, but mature plumes such as this are stable because free product long ago spread until it reached residual saturation & became immobilized. The leading edge of the ST41 South plume consists only of dissolved contaminants & is presumed to attenuate in the subsurface several hundred feet downgradient of ST41-25, never reaching the surface.
Geochemical conditions at ST41 South are similar to those at ST41 North, limiting significant
biodegradation to the fringes of the plume. Only benzene continues to exceed the cleanup
level in monitoring well ST41-25, but the scatter in the data results in a predicted cleanup date for this plume of 2037. As discussed elsewhere (USAF 2010b), the scatter likely reflects the sporadic occurrence of product droplets or emulsion in the water samples from this well
combined with variations in groundwater flow patterns.
Because the prediction model does not account for multiple modes of contamination, its simple approach is unrealistically conservative in this case. Although groundwater contamination will persist until residual product in the smear zone is depleted, cleanup will probably occur much sooner than 2037 but later than the goal of 2016.
Recommendations for future monitoring at ST41 are as follows:
Continue with the 2010 groundwater monitoring program as outlined in Table 6-2. |
Louis Howard |
| 2/24/2011 |
Document, Report, or Work plan Review - other |
Staff reviewed and approved the recommendations in the draft field activities report for this source area in Operable Unit 2. |
Louis Howard |
| 7/15/2011 |
Update or Other Action |
Draft Work Plan Environmental Remedial Action-Operations & LTM & Maintenance received.
The purpose of this project is to perform RA-O & LTM activities for several JBER Programs. These programs include sites distributed across both JBER-Elmendorf & JBER-Richardson. This Work Plan addresses remedial activities in JBER-Elmendorf Zone 1, Zone 2, & Zone 3 Management Areas, JBER-Elmendorf Compliance Restoration Program (CRP) sites, the JBER Elmendorf Operable Unit (OU) 1 Landfill, JBER-Richardson Multiple Installation Restoration Program (IRP) Sites, & JBER-Richardson Poleline Road & OUE Armored Vehicle Maintenance Area (AVMA).
Environmental Restoration Program Zone 1 Management Area covers the comparatively sparsely developed portions of JBER-Elmendorf to the west, north, & east of the airfield & administrative core of the base. Eleven sites are now managed under Zone 1: LF02, LF03, LF04, WP14, ST36/66, ST41, ST61, ST69, SS83, & DP98. LF02 & LF03 are located in the southeastern portion of the base, near the Boniface gate, whereas the remaining nine sites are distributed throughout the northwestern portion of the base, between the airfield & Knik Arm. GW contamination is tracked in nine plumes at these sites, & exposed landfill debris is of concern at LF04.
Six sites (LF02, LF03, LF04, WP14, ST41, & DP98) are administered under the Comprehensive Environmental Response, Compensation, & Liability Act (CERCLA), with USEPA oversight, & are governed by ROD. The five remaining sites (ST36/66, ST61, ST69, & SS83) are regulated according to State of Alaska requirements. GW COCs for most of the sites (WP14, ST36/66, ST41, ST61, & SS83) are fuel constituents (one or more of benzene, toluene, ethylbenzene, xylenes, or diesel-range organics [DRO]). These sites were contaminated by pipeline & storage tank leaks & past practices. The primary sources have been removed, leaving secondary sources comprised of residual fuel distributed in contaminated smear zones at the water table. Two sites have chlorinated-solvent GW COCs: LF04 (1,2-dichloroethane & methylene chloride, as well as fuel constituents), & DP98 (chlorinated solvents). The chlorinated solvents occur in shallow GW as dissolved contaminants at LF04 & in conjunction with a DRO contaminated smear zone at DP98.
ST41, informally known as Four-Million Gallon Hill, is an approximately 20-acre site that is located east of the Knik Arm & north of Fairchild Avenue (Figure 2.6). Four one-million gallon USTs, installed at this location in 1942 & taken out of service in 1991, stored aviation fuel for flightline operations. Spills are reported to have occurred in the mid-1960s (60,000 gallons of aviation gasoline) & on 30 August 1974 (33,000 gallons of JP-4 when UST was overfilled). No fuel was recovered from the gasoline spill, but 16,000 gallons was recovered
from the JP-4 spill; the remainder infiltrated into the ground northwest of the tanks.
The Zone 1 Management Area sites are located throughout the western, northern, & eastern portions of JBER-Elmendorf. Nine sites on JBER are managed under Zone 1: LF02, LF04, WP14, ST36/66, ST41, ST69, SS83, & DP98. COC are tracked in all nine GW plumes at these sites, & are listed below. LF04 also contains an inactive landfill where debris is monitored & fallen debris removed.
• Site LF02 - 1,1,2,2-tetrachloroethane (PCA)
• Site LF04 - Benzene, ethylbenzene, toluene, methylene chloride, 1,2-dichloroethane
(DCA)
• Site WP14 - Benzene, ethylbenzene, toluene
• Site ST36/66 - diesel range organics (DRO)
• Site ST41 - benzene, toluene, ethylbenzene, & xylenes (BTEX)
• Site ST69 - Benzene
• Site SS83 - DRO
• Site DP98 - tetrachloroethene (PCE), Trichloroethene (TCE), 1,1-dichloroethene, cis-1,2-
dichloroethene, vinyl chloride (VC)
Seep & surface water samples include samples from LF02, LF04 South, ST41, & DP98. The overall objectives of RA-O activities within the Zone 1 Management Area are to monitor the COCs & geochemical parameters affecting natural attenuation in GW plumes, & to detect contaminant migration patterns & provide early indication of unforeseen environmental or human health risks. Data quality objectives directly linked to Zone 1 project objectives are defined in the FSP & UFP-QAPP, within the SAP (Appendix A). Additional Zone 1 Management Area project objectives in 2011 include:
Evaluate & maintain the integrity of monitoring wells;
Evaluate GW flow characteristics while continuing to study trends in GW level with the monitoring wells; &
Evaluate erosion rates & characteristics of the LF04 bluff.
The activities to be performed under this TO include:
Collect & analyze GW & surface water samples;
Conduct GW level survey;
Perform maintenance of existing wells, as needed;
Install a maximum of 2 new/replacement GW wells;
Decommission a maximum of 5 damaged/redundant wells; &
Conduct LF04 erosion survey & debris removal. |
Louis Howard |
| 2/2/2012 |
Update or Other Action |
Memorandum for 2010 Annual Land Use Control (LUC) Monitoring Letter for DP98 and OUs 1, 2, 4, 5, and 6.
References:
(a) DP98 Record of Decision, Section 12.2.3.4, dated May 2004
(b) OU6 Explanation of Significant Differences, Section 4.3.1.3, dated Mar 2007
(c) Memorandum to the Site File for OUs 1,2,4, and 5, Section 4, dated Jan 2010
1. This letter serves as the annual monitoring report on the status of LUCs in place at DP98 and
at OUs 1,2,4,5 and 6. The specific LUCs in place at each site are provided below. An
evaluation of the implementation of these requirements is provided in bold following each
specific LUC.
OU2:
Site ST41
Groundwater - Restrict access to groundwater and groundwater development at the site.
Designate the affected area for outdoor/recreational use and unmanned industrial use,
excluding the development of commercial aquaculture. Continue enforcement ofbase
policy prohibiting installation of groundwater wells (other than for monitoring purposes)
into the shallow aquifer underlying OU2. Prohibit unauthorized access to existing water
supply and groundwater monitoring wells.
Evaluation - LUCs are in place and continue to be effective at ST41. A land use control inspection was accomplished in Oct 2011. The inspection forms will be presented in Appendix B of the 2011 Zones 1, 2, and 3 Mgt. Area Annual Report.
2. The Air Force ensures compliance with LUCs by conducting periodic monitoring and completing site inspections. Separate controls are in place and enforced by the Air Force to prevent inappropriate soil and groundwater exposure at these sites. The Air Force currently requires all projects resulting in soil disturbance of greater than four inches below ground surface to follow 3 Wing Instruction 32-1007, Safeguarding Utilities from Damage, dated 20 Aug 10 and 673d Wing Instruction 32-7003, Land Use control Management, dated 19 May 2011. Both instructions require the proponent to obtain an approved Base Civil Engineer Work Clearance Request (3 WG Form 3) prior to conducting work on the Base. |
Louis Howard |
| 4/10/2012 |
Update or Other Action |
Draft Annual Report received for Zones 1, 2, 3.
Analytical results for the ST41 North plume showed that benzene exceeded its groundwater cleanup level in in-plume monitoring well ST41-28 (Table 2.27). COCs did not exceed the cleanup level at the surface water point of compliance (ST41SW-13). In the ST41 South plume, benzene exceeded its groundwater cleanup level in both of the in plume monitoring wells (ST41-16 and ST41-25). Well ST41-16 also exceeded the cleanup levels for ethylbenzene and toluene.
At ST41 North, COC concentrations are generally declining. Although ethylbenzene hovers around the cleanup level and was less than the cleanup level from 2009 to 2011, the cleanup of the site is driven by benzene at ST41-28. Since 1998, concentrations of toluene and xylenes have been less than the cleanup levels (1,000 and 10,000 µg/L, respectively) in monitoring well ST41-28 and for the entire monitoring period in Well ST41-10R. The downgradient point of compliance (ST41SW-13) remains free of contamination.
Contamination levels at monitoring well ST41-28 continue to decline. Geometric regression of the benzene results for ST41-28 predicts cleanup in 2091 (Figure 2.15A). The correlation coefficient was 0.86 in 2011, allows for better predictive confidence, but does still represent some variability. The time it will take for the site to reach cleanup is likely a function of magnitude of the COC concentrations in samples collected to date, rather than the variability of the dataset.
Concentrations of ethylbenzene have been decreasing steadily since 1999 and have been below cleanup levels during the last three rounds of sampling from 2009 through 2011. Even with the relatively high variability and lower predictive ability (R2 2303 of 0.48), levels were predicted below the cleanup level in 2009. Monitoring results collected since 2009 confirm this prediction. Overall, cleanup predictions for the monitoring wells at ST41 North plume vary, but the COCs are exhibiting a decreasing trend.
Conditions and trends in the ST41 North plume are as follows:
• Upgradient. No longer monitored; the source was removed.
• In-plume. Between 1999 to 2007, benzene concentrations declined 2371 in monitoring well ST41-10R and are predicted to reach cleanup levels in 2020. COC concentrations measured in the trailing edge of the plume (ST41-28) are high, and cleanup of benzene is not predicted until after 2043.
• Downgradient. The core of the ST41 North plume is likely discharging at ST41SP-01. No contaminants are reaching the downgradient monitoring wells or the point of compliance (ST41SW-13).
Conditions and trends in the ST41 South plume are as follows:
• Upgradient. The trailing edge of the plume has passed the former location of monitoring
well ST41-07.
• In-plume. Since 1997, the body of the plume has been attenuating, but erratic results preclude a meaningful cleanup prediction. ST41-16 did not contain free product in 2011, but BTEX contamination remains well above the cleanup levels.
• Downgradient. No downgradient monitoring wells or seeps exist, but mature plumes such as this are stable because free product long ago spread until it reached residual saturation and became immobilized. The leading edge of the ST41 South plume consists only of dissolved contaminants and is presumed to attenuate in the subsurface several hundred feet downgradient of ST41-25, never reaching the surface.
Recommendations for future monitoring at ST41 are as follows:
• No changes to the groundwater monitoring program as outlined in Table 2.25 |
Louis Howard |
| 9/21/2012 |
Update or Other Action |
Draft Basewide UFP-QAPP received. This UFP-QAPP encompasses activities at 141 sites on JBER during the 8 year contract POP. The project approach is to advance sites to site closeout utilizing Optimized Exit Strategies (OES). Activities will include investigations/characterizations, remedial actions, active and passive remediation, long term monitoring/management and the use of the Hydrocarbon Risk Calculator (HRC), where applicable. |
Louis Howard |
| 12/20/2012 |
Meeting or Teleconference Held |
A meeting to discuss the response to comments (RTCs) on the Draft JBER Basewide UFP-QAPP was held on 20 December 2012 at the EPA's office in the Federal Building in Anchorage, AK. On-site & teleconference attendees included representatives from the Joint Base Elmendorf Richardson (JBER), Air Force Civil Engineer Center Technology Transfer Office (AFCEC TDV), the ADEC, the EPA, Weston Solutions, Inc. (WESTON), & CH2M HILL Constructors, Inc. (CH2M HILL).
Ms. Grepo-Grove suggested grouping several sites by OU & then flushing out the QAPPs by OU to ease the process. Ms. Halstead said that there are 10 OUs on base, many already part of monitoring programs that have been in place for years; WESTON is just a new contractor. Mr. Blei said the sites are in a wide range of states, & data objectives may be very different from site to site.
Ms. Tomlinson pointed out that some sites are state led while some sites are CERCLA led. When OUs were addressed later, Mr. Blei added that some of the OUs overlap, many sites within an OU are at different stages, & a benefit would not be gained by grouping them.
The difference between CERCLA & ADEC closure requirements was discussed. Ms. Grepo-Grove mentioned that there are differences between what EPA requires & what ADEC requires for the method of sampling for VOCs in soil. VOCs collected using methanol as a preservative (ADEC Method) yield a higher reporting limit than the CERCLA cleanup level for some VOCs. Ms. Grepo-Grove reminded the group to pay careful attention to lab SOPs regarding VOCs. Mr. Blei concluded that for many sites, soil samples for VOCs will have to be run with both the methanol preserved & multiple ways to satisfy both agencies requirements.
Mr. Larsen brought up Specific Comment #3, regarding the signatures required on the
worksheets. Ms. Halstead asked if Ms. Grepo-Grove is required to sign off on every
UFP-QAPP for the EPA, & more specifically if once the Basewide QAPP is approved
will Ms. Grepo-Grove have to review every site specific plan for sites under CERCLA?
Ms. Grepo-Grove thinks Ms. Halstead can review the specific site QAPPS.
If anything comes up in a site specific QAPP that is not in the Basewide QAPP, then it needs to be reviewed by Ms. Grepo-Grove, or delegated & then reviewed. She said EPA QA approval (by signature) is required on CERCLA sites. Signatures on the Basewide QAPP will be: Ms. Grepo-Grove with the EPA, Mr. Fink with the Air Force, Mr. Howard with ADEC, & a WESTON QA representative. Mr. Fink asked Mr. Jurena if he would like to review all of the QAPPs, & Mr. Jurena answered that he would like to do a QA/QC review of all QAPPs.
Specific Comment #28 from the EPA was discussed, regarding where & for how long the project files will be stored. Mr. Fink said the Air Force would keep all data on base. Ms. Grepo-Grove wanted to know how accessible these files would be. Mr. Blei said all analytical data will also be in ERPIMS. Ms. Grepo-Grove said to include in the Basewide QAPP a summary of where the data will go, as well as where the raw data including specific instrument readouts will go. Ms. Grepo-Grove wants to know who will have the authority & ability to go back & look at the data. She also wanted to know at which point do the EPA & ADEC review the data, & in which form the data will be
delivered.
The form in which the data will be reported & included on ERPIMS was also discussed (Excel, Access, etc). Ms. Grepo-Grove asked if Test America was the lab that would be used. Mr. Larsen answered that it would, & Mr. Blei added that other labs may also be used for any kind of specialty analysis. Ms. Grepo-Grove said to make sure the labs are using the same procedures & to carefully compare the SOPs, as the results can’t be reported together without note unless the procedures used are identical. Mrs. Grepo-Grove asked who was doing the 3rd party data validation. Mr. Larsen said the chemist has yet to be determined.
The Comment & Response worksheet from ADEC was discussed next. Specific Comment #9 was discussed, regarding the definition of the source of contamination. The Basewide QAPP will read “the source &/or point of release.” The definition is site specific & the appropriate wording will be used in site-specific QAPPs.
Mr. Larsen said he expected a discussion over “clean up levels” versus “screening levels” (also from ADEC comment #9). Mr. Schwabenlander explained that when using the HRC, referring to screening levels made more sense, as they weren’t being used as simply as just meeting or exceeding cleanup levels. Mr. Howard said for the HRC the clean up level is the maximum allowable level, so it was just a question of semantics & either was fine. |
Louis Howard |
| 3/1/2013 |
Institutional Control Update |
2012 Annual LUC IC Monitoring memorandum received.
This letter serves as the annual monitoring report on the status of LUCs in place on JBER Elmendorf at DP98 and OUs 1, 2, 4, 5 and 6. The specific LUCs in place at each site are
provided below. An evaluation of the implementation of these requirements is provided in bold
following each specific LUC.
Groundwater - Restrict access to groundwater and groundwater development at the site. Designate the affected area for outdoor/recreational use and unmanned industrial use, excluding the development of commercial aquaculture. Continue enforcement of base policy prohibiting installation of groundwater wells (other than for monitoring purposes) into the shallow aquifer underlying OU2. Prohibit unauthorized access to existing water supply and groundwater monitoring wells.
Evaluation -Inspection conducted on 29 Aug 12 and LUCs are in place aind continue to be effective at ST41. |
Louis Howard |
| 5/30/2013 |
Update or Other Action |
Draft Annual Field Activities report received for review & comment.
This report summarizes the 2012 annual long-term management activities, including remedial action-operation (RA-O) & Record of Decision (ROD) requirements conducted at Joint Base Elmendorf-Richardson (JBER) CERCLA sites. The United States Air Force (USAF) has mandated a reduction of long-term environmental liabilities & life-cycle costs through accelerated cleanup of contaminated sites.
Acceptance criteria for this project are specified in the Draft Basewide UFP-QAPP, criteria specified in the analytical lab standard operating procedures (SOPs), & accepted analytical methods. Overall, the data have met the quality control acceptance criteria specified for this project. Nonconformances of data are identified, discussed, & qualified in this report. When possible, direction of potential bias is assigned.
During 2012, five GW monitoring wells from the North Plume; ST041-10R, ST41-20, ST41-28, ST41-30 & ST41-34 were sampled for VOCs. In addition, one surface water sample (ST41SW-13) & one seep sample (ST41SP-01) were collected & sampled for BTEX compounds. The South Plume containing two ground water wells, ST41-25 & ST41-16, were also sampled for BTEX compounds.
Benzene exceeded the OU2 ROD cleanup criterion for GW monitoring wells ST41-10R (54 µg/L), ST41-20 (12 µg/L), ST41-28 (80 µg/L), ST41-16 (5300 µg/L) & for the seep ST41SP-01 (140 µg/L). GW well ST41-16 exceeded the OU2 ROD cleanup criteria for ethylbenzene (1400 µg/L) & toluene (7800 µg/L). No contaminants exceeded cleanup criteria in the remaining wells. COCs did not exceed the cleanup level at the surface water point of compliance (ST41SW-13).
A LUC inspection performed for ST041 on 29 August 2012 did not identify any issues.
Site Summary
Conditions in the ST41 North plume are as follows:
• Upgradient. No longer monitored; the source was removed.
• In-plume. Between 1999 & 2007, benzene declined in monitoring well ST41-10R; however, the last 2 rounds of sampling, in 2009 & 2012, showed an increase in benzene. COCs measured in the trailing edge of the plume (ST41-28) show a decreasing trend since 2001; however, concentrations are still above clean-up levels. Cleanup of benzene was not predicted until after 2043.
• Downgradient. The core of the ST041 North plume is likely discharging at ST41SP-01. No contaminants are reaching the downgradient monitoring wells or the point of compliance (ST41SW-13).
At ST41 North, the trailing edge of the plume is showing declining rates of benzene. For the last two monitoring events at well ST41-10R in 2009 & 2012, BTEX exhibited a small increase but an overall decline since 1996. This well likely reflects the effects of natural flushing, but the higher seep concentrations indicate that the well is not intercepting the core of the remaining plume. Continued monitoring of the seep & in-plume monitoring wells will provide more information & help refine the range of predicted cleanup dates for this plume.
Conditions & trends in the ST41 South plume are as follows:
• Upgradient. The leading edge of the plume has passed the location of abandoned monitoring well ST41-07.
• In-plume. Since 1997, the body of the plume has been attenuating, but erratic results preclude a meaningful cleanup prediction. ST41-16 did not contain free product in 2011 or 2012, but BTEX contamination remains well above the cleanup levels.
• Downgradient. No downgradient monitoring wells or seeps exist, but mature plumes such as this are generally stable because free product has likely spread until reaching residual saturation & has become immobilized. The leading edge of the ST041 South plume consists only of dissolved contaminants & is presumed to attenuate in the subsurface several hundred feet downgradient of ST41-25, & likely does not reach the surface.
Geochemical conditions at ST041 South are similar to those at ST041 North, limiting significant biodegradation to the fringes of the plume. Only benzene continues to exceed the cleanup level in monitoring well ST41-25, but the scatter in the data results in a confidence interval that does not support prediction of a cleanup date. As discussed in the 2010 Zone 1 Field Activities Report (USAF, 2011a), the scatter likely reflects the sporadic occurrence of product droplets or emulsion in the water samples from this well combined with variations in GW flow patterns. GW contamination is expected to persist until residual product in the smear zone is depleted.
Additional investigation is planned to be conducted under the new PBR contract at ST041. No changes to the remedial activities are being proposed for this site. |
Louis Howard |
| 11/4/2013 |
Update or Other Action |
Fourth Five-Year Review (draft) received for review & comment.
This Five-Year Review found that the selected remedy at OU2 is currently protective, but may not be protective in the future. Although the implemented remedial process is functioning as intended, the cleanup date predicted in the OU2 ROD is unlikely to be met. The ROD stipulates that the contingency remedy will be implemented should the USAF, in consultation with the U.S. Environmental Protection Agency and the Alaska Department of Environmental Conservation, determine that the selected remedy is not expected to meet cleanup goals within a reasonable time frame, which in this case is 2016.
The remedy at OU2 is expected to be protective of human health & the environment upon attainment of GW cleanup levels through natural attenuation at ST41. In the interim, exposure pathways that could result in unacceptable risks are being controlled.
Benzene, ethylbenzene, toluene, & TAH persist above their respective RAOs in groundwater &/or surface water (seep ST41SP-01). All other COCs met cleanup levels at locations sampled in 2012. Although concentrations of benzene are decreasing in all groundwater wells, the ROD-specified time for meeting RAOs with natural attenuation (2016) will not be met across the site.
A geometric regression of benzene results for well ST41-25 shows a decreasing trend in benzene concentrations. Although the best-fit regression line of the data shows a slight decrease from 1999 to the present, the high degree of variability about the best-fit line (r2 of 0.28) does not allow for confident predictions of future concentrations of benzene or when cleanup levels might be reached. No data were collected between 2002 & 2006, which increases the difficulty in predicting cleanup for this dataset. The samples collected in 2010 & 2011 confirm the observed decreasing trend, but remain well above the cleanup level. The shallow slope of the upper confidence interval does not allow for prediction of cleanup. The scatter in the data likely reflects the sporadic occurrence of product droplets or emulsion in the water samples from this monitoring well. Relatively immobile droplets of residual product are likely present in the smear zone near upgradient monitoring well ST41-16.
The OU2 ROD identifies a contingency remedy, removal & treatment of groundwater, if natural attenuation will not meet RAOs by 2016. The 2011 memorandum to the site file (USAF, 2011e) clarified that the contingency remedy would be implemented only if the USAF, EPA, & ADEC determined that natural attenuation was not occurring at an acceptable rate. Benzene is not anticipated to meet the RAO specified in the ROD; however it appears to be slowly decreasing in concentration.
Maximum drinking water contaminant levels defined in 40 CFR 141 Subpart G have not been updated during the review period. ADEC Oil & Other Hazardous Substances Pollution Control (18 AAC 75) & Water Quality Standards (18 AAC 70) were updated April 8, 2012.
GW COPCs were compared to current federal & state standards. Newly promulgated cleanup levels &/or MCLs (not addressed in the ROD or previous Five-Year Reviews) that were more stringent than at the time of the ROD or during the previous review period were identified for 2-methylnaphthalene, 4-methylphenol, chloroform, & trichlorofluoromethane (Appendix B, Table B-1). However, concentrations of 2-methylnaphthalene, 4-methylphenol, chloroform, & trichlorofluoromethane in the GW were below the newly established cleanup levels either at the time of the ROD or during subsequent sampling events (Table B-2); therefore, the newly promulgated cleanup levels for these contaminants do not call into question the protectiveness of the remedy.
Recommendation & Follow-up: Determine whether the attenuation is occurring at an acceptable rate.
Protectiveness statement: The remedy at OU2 currently protects human health & the environment in the short-term because LUCs are controlling exposure pathways to contaminated groundwater & soil. However, in order for the remedy to be protective in the long-term, the remedial process selected in the ROD will need to be optimized if the current rate of benzene attenuation is not considered acceptable.
Future Five-Year Reviews for OUs 1, 2, 4, 5 & 6 & Site DP98 are necessary because contamination remains above levels that allow for UU/UE in these areas. The next Five-Year Review is due on or before January 27, 2019. |
Louis Howard |
| 12/20/2013 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft 4th 5 Year Review report.
S-2, S-3, S-4, S-5 & S-6 Issues & Recommendations Identified in the Five-Year Review: OU2 Remedy Performance Recommendation - ADEC requests Air Force determine: the attenuation rate & an estimated date that cleanup levels will be achieved under the current remedy & whether a revised remedy is necessary.
7-8 7.2 Changes in Toxicity & Other Contaminant Characteristics Operable Unit 2 - The EPA 2001 Five-Year Review Guidance states at 4.2.3: “If there have been changes in the understanding or in our knowledge of these physical/chemical characteristics, you may need to recalculate risk using the original cleanup level or using the current concentration if it has not been identified as a contaminant of concern.”
Notably absent is any discussion regarding updated toxicity information & calculations for toluene which has updated toxicity information in IRIS as of 9/23/2005. The Air Force should apply the updated chemical-specific toxicity information & calculate the hazard quotient & cancer risk at the RAO concentration. Then an assessment using the ADEC Risk Assessment Procedure Manual (2000) should be conducted to determine whether or not the toluene RAO concentration continues to be protective of human health under a residential exposure assumption
Page 207
Operable Unit 2
Arsenic in GW is listed as having a current Alaska Cleanup Level of 50 ug/L. However, Table C of 18 AAC 75 lists a cleanup level of 10 ug/L for arsenic. Please correct table.
TPH (total petroleum hydrocarbons) is listed in the table but not listed with a cleanup level.
Gasoline range organics (GRO) or any other fuel range hydrocarbons are not considered ROD chemicals of concern (COCs) but were recognized as an ADEC concern/issue in accordance with the January 14, 2003 meeting minutes for the Elmendorf Basewide Monitoring Program (summarized briefly below):
The Air Force will NOT add DRO/GRO as a CERCLA ARAR, but will compare DRO/GRO results to ADEC cleanup levels in the annual reports & will discuss in subsequent 5-Year Reviews. The benefit of this is that if CERCLA COCs meet ARARs, the Air Force can achieve a partial delisting.
The Air Force will add DRO & GRO to the suite of analyses at monitoring wells associated with fuel plumes starting in 2004.
The Air Force will not pursue a decision document with ADEC on DRO/GRO until more data is gathered on the extent of the problem.
Until a decision document is signed with ADEC, GRO & DRO concentrations will be compared to ADEC regulations in 18 AAC 75 (Table C, GW Cleanup Levels; 1,500 µg/L for DRO, 1,300 µg/L GRO).
An April 28, 2010 memorandum (Response to ADEC Comment on Draft 2009 Zone 1 Field Activities Report (Ref: ADEC Memo, 12.Mar 10) from the Air Force clarified its position on DRO/GRO monitoring in accordance with the 2003 memorandum.
GRO, DRO & RRO are State concerns at OU2 since they have been detected in one form or another in earlier monitoring but as of 2002 only ROD-specified COCs have been analyzed for at wells located at OU2 (2002 Annual Report Basewide Environmental Monitoring Program). Also see Basewide Environmental Monitoring Plan June 2002, Table 1-2: “DRO & GRO are not ARARs for OU2 & are not needed to monitor natural attenuation of BTEX. DRO & GRO were removed.”
This may be true for monitoring of natural attenuation, however, when ARARs have been met for all fuel related releases, ADEC will require that DRO, GRO, RRO be analyzed for at those source areas previously monitored for individual constituents (e.g. BTEX/PAHs). Monitoring under State regulations for fuel range hydrocarbons will occur even though CERCLA requirements in the ROD have been met.
This comment is applicable to all OUs where DRO/GRO is not currently being monitored at those source areas with GW monitoring for benzene, toluene, ethylbenzene or total xylenes or they were removed due to these contaminants “…not necessary to monitor natural attenuation of BTEX or chlorinated solvents…” (e.g. OU2 & OU6). Two consecutive rounds of GW monitoring for fuel range (DRO, GRO, RRO) will need to take place in order to demonstrate that cleanup levels have been met.
1996 results from OU2 GW monitoring detected various fuel range organics & “unidentified” per SW8015ME & SW8015MP:
SW8015ME
Jet Fuel
ST41-16: 583 mg/L (Table 2 All results of organic analyses for water samples Site OU2 Round 2 Basewide 1996 Page 289 of the PDF report).
Jet Fuel
ST41-28: 754 mg/L (Table 2-3 Continued Page 2-5)
Unidentified organics not related to jet fuel were found in the following wells:
ST41-07: 43.1 mg/L Y, ST41-10R: 3.21 Y mg/L, ST41-25: 2.89 V mg/L (Page 2-4)
SW8015MP
Gasoline range organics (GRO)
ST41-16: 61.2 mg/L (Page 2-4).
|
Louis Howard |
| 1/3/2014 |
Document, Report, or Work plan Review - other |
EPA comments on the draft 4th 5 Year-Review report.
Summary Form OU2 Page S-2 Comment: The issue for this OU is captured correctly, however the recommendation should be to determine the attenuation rate and decide if conditions warrant implementation of the contingent remedy as a part of this Five Year Review. The followup actions from the 2008 Five Year Review were to incorporate additional wells (ST41-28 North Plume and ST41-16 South Plume) to assist in MNA trend analysis. The data was incorporated during this Fourth Five Year Review (2014) and Mann-Kendall analysis predicted a statistical decreasing trend for both wells for all BTE compounds, however the timeframe for groundwater to achieve RAOs was not calculated.
Please determine the attenuation rate for groundwater contaminants at ST41 and propose implementation of the contingent remedy if MNA is not occurring at an acceptable rate.
|
Louis Howard |
| 3/17/2014 |
Document, Report, or Work plan Review - other |
EPA Letter to Air Force regarding the 4th Five Year Review for JBER-Elmendorf.
The U. S. Environmental Protection Agency Region 10 has reviewed the Fourth CERCLA Five-Year Review report for Superfund sites, specifically for Operable Units (OU) 1, 2, 4, 5, 6 and DP98 associated with Elmendorf Air Force Base on Joint Base Elmendorf-Richardson, Alaska. The conclusions in this letter are based on the draft report from November 2013 and revised Response to Comments, Summary Form, and Sections 8 and 9 which were received by the EPA on March 12, 2014.
The EPA reviewed the report for technical adequacy, accuracy, and consistency with the National Contingency Plan and EPA guidance. The document provides a summary of the status and protectiveness for OUs for which Records of Decisions (RODs) have been completed and are not determined as No Further Action. It also identifies actions to be taken that ensure protectiveness of the selected remedies and on-going remedial actions and documents a schedule for completion of the recommended actions.
The following are the EPA’s protectiveness determinations for these OUs and the overall Site protectiveness that will be reported to Congress in the EPA’s annual report. Also included are additional recommendations and follow-up actions necessary to address issues raised in the Five-Year Review that affect or could affect protectiveness. In general, the EPA concurs with the protectiveness determinations in this Air Force report. Each OU is discussed individually below.
OU 2
The EPA concurs that the remedy for OU 2 is currently short-term protective of human health and the environment because Land Use Controls are preventing exposure to contaminated groundwater and soil. Groundwater contaminants at site ST41 (4 Million Gallon Hill) are showing decreasing trends, but the levels will not meet cleanup goals within the 21 year timeframe (by 2016) as specified in the ROD for OU2. In order for the remedy of to be protective in the long term, EPA agrees alternative remedies should be evaluated through the process established in the Federal Facilities Agreement (FFA), including the contingent remedy that was developed in the ROD.
|
Louis Howard |
| 3/20/2014 |
CERCLA ROD Periodic Review |
ADEC appreciates the opportunity to review the fourth Five Year Review report for the Elmendorf Air Force Base (now JBER-E) Superfund site, in Anchorage Alaska. ADEC reviewed this report for technical adequacy, accuracy, and consistency with EPA guidance and the Elmendorf Air Force Base Federal Facility Agreement. Also included are additional recommendations and follow-up actions necessary to address issues raised in the Five Year Review that affect or could affect protectiveness. ADEC has reviewed the report which includes: Operable Units (OU) 1, 2, 4, 5, 6 and DP98, associated with Elmendorf Air Force Base on Joint Base Elmendorf-Richardson, Alaska. In general, ADEC agrees with the protectiveness determinations in this report.
General Comments
ADEC has commented on the matter of sampling for Perfluorinated compounds (PFCs) in this Five-Year Review at various fire-training areas/pits where Aqueous Film Forming Foam (AFFF) fire-fighting agents containing PFCs were used to extinguish fires. The Air Force’s response to ADEC’s comments was the following: “USAF guidance (Interim Guidance on Perfluorinated Compounds, 17 Sep 2012) will be followed to address potential release of perfluorinated compounds (PFCs). A centrally-funded project to conduct initial sampling has been authorized and programmed.” ADEC expects JBER to sample all of its former fire training areas/pits for PFCs [e.g. perfluorooctane sulfonate (PFOS), and perfluorooctoanoic acid (PFOA)] prior to the Fifth Five-Year Review to determine whether or not these compounds are contaminants of concern and require remedial action to protect human health, welfare, safety or the environment.
OU2
ADEC concurs that the remedy for OU2 is currently protective of human health and the environment in the short term through LUCs and long-term groundwater and surface water monitoring. Groundwater contaminants at site ST41 (4 Million Gallon Hill) will not meet cleanup goals within the 21 year timeframe (by 2016) as specified in the ROD for OU2. In order for the remedy to be protective in the long-term, further responses actions (e.g. alternative remedies) should be evaluated through the process established in the Elmendorf Air Force Base Federal Facility Agreement which includes the contingent remedy which was developed and specified in the OU2 Record of Decision (ROD).
Additionally, gasoline range organics (GRO) and diesel range organics (DRO) will need to be either monitored as part of the basewide groundwater monitoring program at OU2 or be monitored under State regulations as soon as possible since there is no longer a Two-Party Agreement for petroleum and the Air Force agreed that petroleum contamination would be addressed under current State regulations. Petroleum contamination was detected in groundwater at levels that exceed current regulatory requirements during the 1994 RI, but did not have established a cleanup level at the time the 1995 ROD was signed. DRO and GRO continued to exceed groundwater cleanup levels in 1996 and 1998, but monitoring for DRO and GRO has ceased after this time period at OU2. |
John Halverson |
| 5/14/2014 |
Update or Other Action |
Draft 2013 Annual Field Activities Report received. This report summarizes the 2013 annual long-term management activities, including remedial action-operation (RA-O) and Record of Decision (ROD) requirements, conducted at Joint Base Elmendorf-Richardson (JBER) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites. The United States Air Force (USAF) has mandated a reduction of long-term environmental liabilities and life-cycle costs through accelerated cleanup of contaminated sites. As such, the Performance-Based Remediation (PBR) initiative has been developed to protect human health and the environment in a cost-effective manner, while at the same time reducing life-cycle costs.
In April 2012, Weston Solutions, Inc. (WESTON) was awarded a PBR contract from the Air Force Civil Engineer Center (AFCEC) (Contract Number FA8903-09-D-8589, Task Order No. 0016). The contract includes performing RA-O and ROD requirements at several JBER sites. The WESTON team performing the activities summarized in this report consists of WESTON and CH2M HILL Constructors, Inc. (CH2M HILL). WESTON executed project work on sites located within JBER-Elmendorf, while CH2M HILL executed project work on sites located within JBER-Richardson.
During 2013, all three of the groundwater monitoring wells sampled had concentrations of contaminants that exceeded cleanup levels cited in the OU2 ROD.
Conditions in the ST041 North plume are as follows:
• Upgradient. No longer monitored; the source was removed.
• In-plume. Benzene concentrations continue to exceed cleanup levels cited in the OU2 ROD in wells ST41-10R and ST41-28. Benzene concentration trends in these two wells are shown on Figures 13-2 and 13-3. Mann-Kendall trend tests show that there is a statistically significant decreasing trend at the 95% level of significance for benzene in both wells.
• Downgradient. The core of the ST041 North plume is likely discharging at ST41SP-01.
No contaminants are reaching the downgradient monitoring wells or the point of compliance (ST41SW-13) at concentrations exceeding cleanup levels cited in the OU2 ROD.
Conditions and trends in the ST041 South plume are as follows:
• Upgradient. The trailing edge of the plume has passed the location of abandoned monitoring well ST41-07.
• In-plume. Benzene, ethylbenzene, and toluene concentration continue to exceed cleanup levels cited in the OU2 ROD in wells ST41-16 at the trailing edge of the plume. Only benzene concentrations continue to exceed cleanup levels in well ST41-25 at the leading edge of the plume. Concentration trends in these two wells are shown on Figure 13-4 and 13-5. Mann-Kendall trend tests show that there is a statistically significant decreasing trend of the contaminants at the 95% level of significance in both wells.
• Downgradient. No downgradient monitoring wells or seeps exist, but mature plumes such
as this are generally stable because free product has likely spread until reaching residual
saturation and has become immobilized. The leading edge of the ST041 South plume
consists only of dissolved contaminants and is presumed to attenuate in the subsurface
several hundred feet downgradient of ST41-25, and likely does not reach the surface.
Additional investigation is planned to be conducted under the PBR contract at ST041 in 2014.
No changes to the monitoring program are proposed for this site. |
Louis Howard |
| 5/16/2014 |
Update or Other Action |
Letter Work Plan Addendum Remedial Action-Operations and Monitoring received for review and comment.
This Letter Work Plan serves as an Addendum to the current version of the Joint Base Elmendorf-Richardson (JBER) Basewide Uniform Federal Policy – Quality Assurance Project Plan (UFP-QAPP) (United States Air Force [USAF], 2014a) for annual field activities associated with remedial action-operations (RA-O) at Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and State-regulated sites.
This Letter Work Plan includes four Tables which list the sites, sampling locations, and constituents to be collected and analyzed during 2014. Tables 1 and 2 are for CERCLA and State sites respectively, on JBER-Elmendorf, while Tables 3 and 4 are for CERCLA and State sites respectively, on JBER-Richardson. Any changes to the Tables in this Letter Work Plan addendum from the 2013 Plan are footnoted to explain the reason for the change.
This Letter Work Plan Addendum also includes six Figures showing all of the sites and sample locations for 2014. Samples will be collected in accordance with the procedures outlined in the Basewide UFP-QAPP (USAF, 2014a). Data validation, Quality Assurance/Quality Control (QA/QC) methods, and other data quality aspects outlined in the Basewide UFP-QAPP will be followed and documented in the Annual Reports.
During 2014, LUC inspections will be performed at the following CERCLA sites:
· CG039 · SD015
· DA089 · SD024
· DP098 · SD025
· FT023 · SD029
· LF002 · ST037
· LF003 · ST041
· LF004 · WP014
· LF059
Air Force Identification (AFID) Numbers were recently assigned to Army sites that are now
being managed by the United States Air Force. |
Louis Howard |
| 5/22/2014 |
Document, Report, or Work plan Review - other |
Staff provided comments on the letter work plan addendum.
QA/QC samples will be collected at the required minimum number to satisfy quality control requirements on a site-specific basis. This requirement will supercede any “JBER Project” field QC samples listed on WS#20 of the Basewide UFP-QAPP. The pooling of duplicates and MS/MSD samples from other sites on a “Program” or “JBER Project” basis is not acceptable to ADEC to satisfy QA/QC requirements for any site.
Please amend all site-specific work plans from this point forward to reflect this. NOTE: this comment applies to PBR sites: JBER-Elmendorf (WESTON) and JBER-Richardson (CH2MHILL).
LUC Inspections
CERCLA Sites
Add OU and site designation for each site as applicable e.g. CG039 (OUB PRDA), DA089 (OUE AVMA), FT023 (OU6 FTA), etc.
ST037 Early Warning Wells and Sentry Wells
ADEC is requesting that the early warning wells be sampled for diesel range organics and gasoline range organics in addition to VOCs. Other constituents that are to be considered for monitoring at these wells are 1,4-Dioxane, PFOS and PFOA (PFCs). ADEC has raised the issue with the Air Force numerous times for monitoring of 1-4 Dioxane and PFCs. The issue remains unresolved at this time.
The purpose of the early warning and sentry wells are not just for OU 5 ROD COCs, but from upgradient contaminant plumes not found in OU 5 and source areas not listed in the OU 5 ROD including identified and unidentified petroleum source areas.
1994 RI/FS E.2 Feasibility Study Page 18 COCs for OU5: “Remedial actions considered for groundwater and surface seeps in OU 5 must also accommodate contaminants that may migrate in groundwater from all upgradient sources.
Therefore, the list of COCs may be expanded in the future, if new COCs are identified during groundwater characterization investigations in areas upgradient from OU 5.”
March 26, 1993 Basewide Groundwater memorandum of agreement between USAF, USEPA and ADEC indicated that any groundwater contamination from upgradient of OU5 would be dealt by OU5 regardless of CERCLA or POL source areas and not be limited to COCs identified specifically in OU5 Record of Decision.
“As a result of the basewide groundwater study and the FY92 field work that occurred at Operable Units (OUs) 1, 2, and 5 it appears that a large portion of the groundwater flows into OU5 (Atch 1). Based on this information Elmendorf AFB would like to move all upgradient groundwater into the OU5 Feasibility Study, Proposed Plan and Record of Decison. This means we would address all
groundwater from upgradient sources (CERCLA (ST20, OU3, & OU4) and SERA) at OU5 instead of at each individual source area (Atch 2).”
Use of Passive Diffusion bags (PDBs) are acceptable for LTM and many VOCs, but not for closure monitoring and not for GRO, DRO, metals, and PAHs. Use of PDBs shall not be accepted for the required 2 year closure groundwater monitoring. Use of PDB data from any groundwater well shall not be used for comparison to Table C with respect to discontinuing GW monitoring.
|
Louis Howard |
| 6/10/2014 |
Document, Report, or Work plan Review - other |
Staff provided comments on the Basewide UFP-QAPP (draft) which is a revision to the 1st UFP-QAPP.
Staff provided comments on the 2nd basewide UFP-QAPP (Draft).
WS #12 Page 12-19
Measurement Performance Criteria Table (PCBs)
PCBs by SW8082A
Representativeness/Usability
Measurement Performance Criteria
The text states: “Samples must be extracted & analyzed within holding times
(Soil:& Water: 40 days to extraction & analysis)”
EPA Method 8082A states at Sample Collection, Preservation, & Storage 8.2: “Extracts should be stored under refrigeration in the dark & should be analyzed within 40 days of extraction.
NOTE: The holding time above is a recommendation. PCBs are very stable in a variety of matrices, & holding times under the conditions listed above may be as long as a year.”
Page 12-22
Measurement Performance Criteria Table (Metals)
Analytical Group or Method
Metals (excluding Hg) by SW6010B/C & SW6020/A
SW6020 should be used if SW6010 cannot meet required reporting limits .
WS #15 Project Action Limits & Laboratory-Specific Detection/Quantitation Limits
Target Analyte Lists
As a general rule for the development of Worksheet #15 for site-specific UFP-QAPPs, project action limits for individual analytes will be set at the most conservative of the applicable cleanup levels. If ADEC cleanup levels are not promlugated for a COC, the EPA RSLs shall be referenced.
Add text back into document: “In the future, 1,4-dioxane & emerging contaminants such as perfluorinated fire retardants; 1,2,3-trichloropropane; & perchlorate may become COPCs at JBER.”
These specific contaminants will either get addressed as subsequent amendments or revisions to the Basewide UFP-QAPP or in site-specific UFP-QAPPs or outside the PBR contract by another contractor for the Air Force on JBER-Elmendorf & JBER-Richardson.
WS #17 Sampling Design & Rationale
Multi-Increment (MI) Sampling
A multi increment (MI) approach, if systematically planned & implemented, can accurately determine an average concentration representative of the soil contained within a defined area, i.e. the “decision unit.” ADEC will evaluate the MI sampling results, including the 95% UCL & calculated Relative Standard Deviation (RSD) of triplicate samples, for contaminated site status determinations. ADEC has determined that an MI approach is acceptable when supported by the project-specific data quality objectives & if applied according to this guidance & an approved work plan. ADEC has further determined that an MI approach, if applied according to this guidance, fulfills the intent of the regulations to protect human health & the environment. The MI soil sampling approach shall follow ADEC’s draft guidance on Multi Increment Soil Sampling (March 2009).
WS #19 & 30 Sample Containers, Preservation, & Hold Times
TestAmerica-West Sacramento
VOC (low-level analysis)
EPA no longer accepts NaHSO4 preserved samples for low-level VOC analysis. See EPA Sampler’s Guide: CLP Guidance for Field Samplers, Appendix B: CLP Sample Collection Guidelines for VOAs in Soil by SW-846 Method 5035A OSWER 9240.0-47 EPA 540-R-09-03 January 2011). Delete NaHSO4 from table for VOC analysis.
Comment applies to all laboratories in this UFP-QAPP (e.g. TestAmerica-Seattle, TestAmerica-Denver, SGS North America Inc., CH2MHill Applied Science Laboratory).
Total Metals (Soil & Water)
Analytical method 6010B may be used for high contaminant level screening. These results can be used for closure only if laboratory reporting limits meet the site-specific cleanup levels. Analytical method 6020A is acceptable for closure. Comment applies to all laboratories in this UFP-QAPP (e.g. TestAmerica-Seattle, TestAmerica-Denver, CH2MHill Applied Science Laboratory).
----------------------------------------------------------------------------------------------------
TestAmerica-Denver
Page 19-11
Water
EDB/DBCP
Preservation states: Cool to 4±2°C, Na2S2O3.
&
CH2MHill Applied Sciences Laboratory
Page 19-18
Water
EDB
Preservation states: No headspace, HCl to pH < 2, 4 ±2ºC
----------------------------------------------------------------------------------------------------
According to SW846, for Method 8011 water samples, aqueous samples with residual chlorine present are preserved by:
• collecting sample in a 125-mL container which has been pre-preserved with 4 drops of 10% sodium thiosulfate (Na2S2O3) solution gently swirling to mix sample
• transferring to a 40-mL VOA vial.
• Cooling to <6 °C
• adjust pH to less than 2 with H2SO4, HCl, or solid NaHSO4
Please ensure that analysis of water samples for EDB via Method 8011 follows SW-846 requirements. It appears that TestAmerica-Denver is not adjusting pH to less than 2 for aqueous (water) samples.
|
Louis Howard |
| 7/23/2015 |
Update or Other Action |
Draft Field Activities Report received for review and comment.
During 2014, all three of the groundwater monitoring wells sampled had concentrations of
contaminants that exceeded cleanup levels cited in the OU2 ROD. The Mann-Kendall trend tests
for benzene in wells ST41-10R, ST41-16, ST41-25 and ST-28, ethylbenzene in wells ST41-16,
ST41-25 and ST41-28, toluene in wells ST41-10R, ST41-16 and ST41-28 and xylene in well
ST41-25 indicated statistically significant decreasing trends at the 95% confidence level. No
statistically significant trends were identified for benzene, ethylbenzene, toluene, xylene or TAH
in the surface water location ST41SW-13, toluene in well ST41-25 or xylene in wells ST21-10R,
ST41-16, or ST41-28.
Five-Year Review
Areas in OU 2 that remain above cleanup goals are required to have CERCLA five-year reviews
conducted until such time as the cleanup goals are achieved. The purpose of the five-year review
is to evaluate the implementation and performance of the remedial actions. There were no recommendations for ST41 documented during the first or second five-year review period. The third five-year review report recommended that surface water point of compliance (SW-13) be monitored annually and seep ST41SP01 every five years to assess the natural attenuation remedy for OU2 surface water. It was also recommended that wells ST41-28 (North Plume) and ST41-16 (South Plume) were incorporated back into the monitoring program for OU2 when free product is no longer present in these wells and reduce the sampling frequency or eliminate well ST41-07 because cleanup levels appear to be met at this location.
The fourth five-year review report recommended that maintenance be performed on monitoring well ST41-25, which showed signs of frost heaving during site inspection activities and reevaluate the sampling frequency for monitoring well ST41-10R based on the decision guide for monitoring well sampling frequency at OU2 provided in the 2011 Memorandum to the Site File: Operable Unit 2 (USAF, 2014e).
NOTE to file: Future five-year reviews for OUs 1, 2, 4, 5 and 6 and DP098 are necessary because contamination remains above levels that allow for UU/UE in these areas. The next five-year review is due on or before March 17, 2019.
Recommendations
Site ST041 is identified as a Yellow priority since contaminant concentrations continue to
exceed ROD cleanup levels but do not show an increasing trend. |
Louis Howard |
| 1/13/2017 |
Update or Other Action |
ADEC received a GW monitoring report for several JBER sites which summarizes the 2015 annual long-term management (LTM) activities, including remedial action-operation (RA-O) & ROD requirements conducted at JBER CERCLA sites.
It is recommended to keep sample frequency consistent for 2016 and continue LUC inspections.
A treatability should be conducted to evaluate a chosen remedial technology for the reduction of
dissolved phase benzene as applicable. A modeled natural attenuation rate and time to reach ROD
cleanup levels (as modeled in Source DK) should be evaluated and presented to ADEC and EPA
to for discussion of whether the natural attenuation rates of benzene for the North and South
Plumes are acceptable. In addition, it is also recommended that the information and the Plexiglas
of the kiosk be replaced
See site file for additional information. |
Louis Howard |
| 5/22/2017 |
Update or Other Action |
Draft Treatability Study received for review and comment.
Treatability study activities will include the following:
• Collect baseline groundwater samples from the two monitoring wells (ST41-16 and ST41-25) in the South Plume prior to injection.
• Install ten direct-push technology (DPT) injection points in the vicinity of well ST41-16 and inject a calculated volume of ISCO/ORC at each target interval.
• Perform monitoring of field water quality and oxidation-reduction parameters during and after initial injection.
• Perform groundwater monitoring after initial injection to evaluate area of distribution and
effectiveness of treatability. Groundwater samples will be collected six months, 12 months, and 18 months after initial injection
See site file for additional information. |
Louis Howard |
| 5/22/2017 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft Treatability Work Plan. Main comments were regarding updating the guidance documents which are out of date in the 2014 Final Basewide UFP-QAPP. Chemicals of concern were listed as BTEX from the 1995 OU2 ROD. However, a request was made to analyze for PAHs since the RI/FS showed exceedances in groundwater and for TAqH in surface water using the data from the RI/FS. This information would be helpful in future five-year reviews for remedy protectiveness determinations.
See site file for additional information. |
Louis Howard |
| 11/7/2017 |
Update or Other Action |
Letter report received for CY2016 [January 1, 2016 - December 31, 2016] Annual Land Use Control (LUC) and Institutional Control (IC) Monitoring at Joint Base Elmendorf-Richardson (JBER). This letter serves as the annual monitoring report on the status of LUCs/ICs in place on JBER-Elmendorf (JBER-E) and JBER-Richardson (JBER-R). The Air Force ensures compliance with LUCs by conducting periodic monitoring and site inspections. Formal LUC/IC inspections occur annually on JBER during late spring through early fall and are typically conducted by contract. A total of 55 sites were formally inspected. Random site inspections are also conducted throughout the year by JBER Restoration staff.
Discrepancies: Kiosk is still intact, but still needs some repairs. The inner PVC casing of well ST041-1 OR was cut down so that the outer casing lid could be secured. It was confirmed that well ST41-ES02 no longer exists. All other monitoring wells were in good condition and secured. Well ST41SW-30 cannot be located due to marshy area and overgrown groundcover.
See site file for additional information. |
Louis Howard |
| 2/9/2018 |
Document, Report, or Work plan Review - other |
Staff commented on the Annual Report for CERCLA sites. Main comments on the contaminants benzene and ethylbenzene which were listed in the 1995 ROD and now have more stringent groundwater cleanup levels in 18 AAC 75 Table C (November 7, 2017). Staff requested an evaluation of these contaminants and if there are changes to cumulative risk as a result of this more conservative cleanup level and any impacts to remedy protectiveness during the next Five Year Review. This comment applies to all source areas with this contaminant in groundwater above current cleanup levels
Based on toxicity information for 2-methylnaphthalene, ADEC requests analysis for 2-Methylnapthalene be conducted and to use the no effect level of 330 µg/L for screening purposes during the Five-Year Review. Currently, EPA Region 5, 6 and 3 provide values in surface water they tend to range from 4.7ug/L to 330 µg/L (RAIS database for 2-methylnaphthalene in surface water). Los Alamos National laboratory value in surface water (Aquatic community organisms – water) = no effect = 330ug/L to low effect = 3300ug/L
Additionally, there is historical results for PAHs such as naphthalene and others which were detected at ST041. ADEC has since promulgated cleanup levels for PAHs in groundwater, but since we are not analyzing for PAHs at OU2 ST041, there is no way to tell if there are exceedances or not for PAHs or if there is a risk to human health or the environment.
See site file for additional information. |
Louis Howard |
| 6/22/2018 |
Update or Other Action |
Supplemental Site Characterization Report received for review and comment. The soil analytical data from the smear and saturated zones in the vicinity of ST41-16 reported concentrations of GRO, DRO, and BTEX above ADEC clean-up levels with the highest concentrations in the saturated zone soils. Data also indicate that contaminant concentrations decrease to the east and west of ST41-16. Groundwater concentrations of benzene and ethylbenzene in ST041-38, north of ST41-16
were lower than those in ST41-16 but exceeded ROD cleanup levels. This is consistent with data presented in the 1994 RI. Soil oxidant demand (SOD) results indicate that the ST041 South Plume would be a good candidate for subsurface soil amendment to decrease contaminant concentrations in the groundwater and treat residual petroleum hydrocarbons in the smear and saturated zone soils.
See site file for additional information. |
Louis Howard |
| 6/26/2018 |
Document, Report, or Work plan Review - other |
Staff commented on the draft supplemental site characterization report. Staff concurred with the conclusions of the report within the confines of the OU2 Record of Decision. However, staff made comments on requiring additional analyses for gasoline, diesel, residual range organics, polynuclear aromatic hydrocarbons, petroleum related volatile organic compounds after the ROD contaminants of concern have achieved the remedial action objectives under State authority and current regulations in effect.
See site file for additional information. |
Louis Howard |
| 1/15/2019 |
Update or Other Action |
Draft 5 Year Review received for comment which include Operable Unit 2 Source Area ST041. Issue: Groundwater (GW) COCs have not achieved RAOs in the timeframe specified by the ROD (2016). Recommendation: The contingent remedy should be re-evaluated & determined if appropriate for implementation. Issue: Cancer risks exceed 1 x 10-4 or have an HQ greater than 1 for the following non-COC chemicals (in GW): 2-methylnaphthalene, naphthalene, thallium, & vanadium. Additionally, no soil COC s are identified at the site, & the following chemicals in soil also exceed acceptable thresholds: mercury (Hg), pentachlorophenol (PCP), & 2-methylnaphthalene. Recommendation: Investigate, by conducting a sampling event, the following chemicals for potential inclusion as remedy COCs: (in GW) 2-methylnaphthalene, naphthalene, thallium, & vanadium, & (in soil) Hg, PCP, & 2-methylnaphthalene. Document any changes to COCs in a decision document.
Issue: Cancer risks exceed 1 x 10-4 or have an HQ greater than 1 for chemicals in soil, & no soil LUC is in place. Recommendation: Implement LUC restricting soil excavation or use at the site. Document this in a decision document
See site file for additional information. |
Louis Howard |
| 2/27/2020 |
Update or Other Action |
Jennifer Roberts (ADEC) sent a letter regarding ADEC's position on the 4/27/1991 JP-4 pipeline leak at Bldg. 11-490. The prompt excavation of JP4 contaminated soils has removed the major source of benzene being released to the GW. Passive removal of JP4 product on the GW surface by rope mop remediation has also decreased the benzene source of GW contamination. It is estimated that the maximum residual quantity of JP4 is less than 50 gallons, which is responsible for the low levels of benzene contamination (56 to 110 parts per billion benzene) in the GW.
Due to the presence of the FFA & SEERA sites active GW treatment at this location would impact the local GW. Active treatment would alter the GW gradient of the other sites, which would give an incorrect data at these sites. In addition, active GW treatment would in all likelihood draw contaminates from the FFA & SEERA sites onto the area undergoing remediation. This is of particular concern regarding the contamination from OU2. CERCLA contamination must be handled in specifically approved methods. Any inclusion of contamination from OU2 in a GW treatment of the pipeline spill contamination may cause the CERCLA site boundaries of OU2 be extended & include this site.
The FFA project managers from EPA, ADEC, & the Air Force have discussed the MB pipeline spill site & are in agreement that no active GW remediation will be requested or allowed at this time. The project managers agree with ADEC's request that MB Construction sample the monitoring wells quarterly for two calendar years. The monitoring wells will be analyzed for Total Petroleum Hydrocarbon by EPA method 418.1 & for Benzene, Toluene, Ethyl Benzene, & Xylene (BTEX) EPA method 602. At the end of two years the GW data will be reviewed.
It is possible that future remediation of this spill may be included in cleanup activities at the CERCLA or SEERA sites. Remediation at any one of these sites will impact the other sites which makes a regional approach to GW remediation a viable option. In a regional GW remedial action under CERCLA or SEERA the minor amount of GW contamination generated by this spill would, in all likelihood, be addressed. |
Jennifer Roberts |
| 4/12/2021 |
Document, Report, or Work plan Review - other |
DEC submitted comments on Draft JBER Basewide UFP-QAPP dated February 2021. |
William Schmaltz |
| 5/19/2021 |
Document, Report, or Work plan Review - other |
DEC Reviewed and approved of Basewide Uniform Federal Policy - Quality Assurance Project Plan. QAPP summarizes general activities for a 5 year period on JBER. |
William Schmaltz |
| 2/16/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed and provided comments regarding the 2023 Letter Work Plan Remedial Action Operations and Long-Term Management, Draft, dated January 2023.The work plan describes the site inspections, maintenance activities, and groundwater, seep, and surface water monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. The scope of work briefly summarizes the site locations, sampling/monitoring schedules, and activities such as free-product removal from monitoring wells and monitoring/maintenance activities at the Operable Unit 5 wetlands. The details regarding the procedures for the remedial action operations and long-term management activities will remain consistent with the 2021 Uniform Federal Policy Quality Assurance Project Plan (UFP-QAPP). |
Ginna Quesada |
| 4/20/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed and provided comments for the 2021 Annual Remedial Action-Operations and Long-Term Management Report for Select CERCLA Sites, Draft, dated December 2023. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections and sampling were recommended to continue for all applicable sites to ensure that conditions remain protective of human health and the environment. |
Ginna Quesada |
| 1/29/2024 |
Document, Report, or Work plan Review - other |
DEC reviewed the 2022 Annual Remedial Action-Operations and Long-Term Management Report for Select CERCLA Sites, Draft, dated October 2023. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections and sampling were recommended to continue for all applicable sites to ensure that conditions remain protective of human health and the environment. |
Ginna Quesada |
| 7/2/2024 |
Document, Report, or Work plan Review - other |
DEC approved the 2022 Annual Remedial Action-Operations and Long-Term Management Report for Select CERCLA Sites, Final, dated June 2024. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections and sampling were recommended to continue for all applicable sites to ensure that conditions remain protective of human health and the environment. |
Ginna Quesada |
| 11/12/2024 |
Document, Report, or Work plan Review - other |
DEC approved the 2023 Annual Remedial Action-Operations and Long-Term Management Report for Select CERCLA Sites, Final, dated October 2024. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections and sampling were recommended to continue for all applicable sites to ensure that conditions remain protective of human health and the environment. |
Ginna Quesada |
