| Action Date |
Action |
Description |
DEC Staff |
| 9/3/1968 |
Update or Other Action |
In 1968, approximately 700 to 800 gallons of diesel fuel seeped into the ground immediately
north of Hangar 3 (Building 11-470). None of the diesel fuel was recovered at the time of the
spill. The site is located in an open area to the north of Hangar 3 and west of the apron for the north-south runway. |
John Halverson |
| 9/1/1983 |
Update or Other Action |
Phase I Records Search documents the 21st Equipment Maintenance Squadron, Bldg. 11-470 (Repair and Reclaimation) and 21st Component Repair Squadron Bldg. 11-470 (Electric Shop) manages waste material such as hydraulic fluid and JP-4, engine oil and PD-680.
NOTE TO FILE: Each item the Govt. orders must have an N.S.N, a National Stock Number, unless the Agency gets special permission to local purchase the item. Each N.S.N. item goes out for bid and has an associated minimum specification. The specification for PD-680, aka. Stoddard Solvent, back in the 1980's and before was for a petroleum based degreaser with a specified flashpoint. No requirement for non-halogenated existed.
Besides that, because Alaska was so far from venders that supplied the Govt., many federal agencies in Alaska purchased solvents locally. There were no qualifications on those solvents and most often halogenated solvents worked with less effort than pure petroleum distillates, so they were preferred.
NSNs ordered through the PD680 specs had some batches with TCE, Methylene chloride, etc; it depended on who the supplier to the Govt.was at the time. So as a result between 1980 and 1983, some PD-680 batches were in fact halogenated. For historical releases it pays to be suspicious of drums that say PD-680 or Stoddard Solvent. |
Louis Howard |
| 6/1/1988 |
Update or Other Action |
Phases 3 and 4 of a Remedial Investigation/Feasibility Study (RI/FS; Black and Veatch) were conducted at site ST48. Site SP-13 [Bldg. 11-490] is located north of Hangar 3 and west of Taxiway 3. Records indicate that Site SP-13 was the site of a 1968 diesel fuel spill above-ground tank when the overflow valve failed. Collection ditches were excavated in the ice and snow to channel spilled fuel to catchment locations where it was removed by pumping into a tanker. Since the ground was frozen at the time of the spill, no appreciable fuel penetrated the subsurface and none of the fuel reached surface water.
The field investigation included the drilling of two hand auger borings 5 feet into silty gravel; samples were collected for laboratory analysis of total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH). Only one of the borings was located in the area of the spill. Contamination was found in both shallow borings. The TPH concentration was 210 mg/kg in one and 38 mg/kg in the other.
In addition, surface soil from boring SP13-02 contained the following polycyclic aromatic hydrocarbons (PAH): benzo(b)fluoranthene (0.40 mg/kg), chrysene (0.71 mg/kg), fluoranthene (0.94 mg/kg), phenanthrene (0.76 mg/kg), and pyrene (1.3 mg/kg).
Further work at this site should include a soil gas survey to better characterize the area of contamination. Results of the soil gas survey should be used to place a boring/monitoring well at Site SP-13. The well should be located southwest and downgradient of the site.
Groundwater from the well should be sampled and tested for TPH purgeable aromatics and polynuclear aromatic hydrocarbons. A minimum of 2 soil samples should be collected form the boring and analyzed for TPH, VOCs, and polynuclear aromatic hydrocarbons. In addition, a
measurement of floating fuel product thickness will be taken if fuel product is observed floating at the surface of the groundwater in the well. |
John Halverson |
| 8/26/1988 |
Site Visit |
An August 1988 Resource Conservation and Recovery Act (RCRA) facility inspection report of
source ST48 by ADEC stated no further investigation was warranted at this source. |
Max Schwenne |
| 4/6/1989 |
Meeting or Teleconference Held |
TELEPHONE MEMORANDUM USAF Elmendorf AFB EDB Levels Detected at Elmendorf AFB B&V Project 13833 B&V File April 6, 1989 To: Max Schewenne Alaska Department of Environmental Conservation (907) 563-6529 Recorded by J.L. Frizzell Vb I talked with Max regarding the levels of EDB detected at Elmendorf AFB. There are no drinking water regulations regarding the level of EDB in drinking water. The State of Alaska requires an excess cancer risk calculation be calculated. If the excess cancer risk is less than 10-6 , it is probable that the EDB concentration is not of concern. If the level is greater than 10-6 , a site by site review will be conducted by the Alaska Department of Environmental Conservation. |
Max Schwenne |
| 4/16/1990 |
Meeting or Teleconference Held |
On 16 February 1990, a meeting was held to discuss Alaska Department of Environmental Conservation (ADEC) Stage 3 RI/FS & Stage 4 Work Plan review comments in their 15 November 1989 & 29 December 1989 letters. ADEC, AF, EPA, Black & Veatch attended.
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 & the Air Force should be aware of these. Both the State & 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 & 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 & wet seasons.
Page 2, GENERAL COMMENTS #3 & #4: The Air Force & the contractor plan to take a minimum of two samples per boring. More will be taken as needed. The State & 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 & 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 & 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 & 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.
For additional information see site file.
|
Jennifer Roberts |
| 4/27/1991 |
Update or Other Action |
On April 27. 1991, a release of JP-4, an aviation fuel, occurred from a puncture of a fuel pipeline. The volume of the release is not known and an estimate of 100-1000 gallons is approximate. MB Contracting excavated about 50 tons of contaminated soils from the area of product release during an attempt to recover the spilled product on April 27, 1991. These soils were transported to the MB Contracting facility at 7lO1 DeBarr Road and stabilized on a 6-mil reinforced plastic sheeting and covered. |
Jennifer Roberts |
| 5/1/1991 |
Update or Other Action |
Pump and treat system plan sent by Shannon and Wilson for ADEC review. The plan is to pump diesel/water mixture from the recovery well at approximately 30 gallons per minute. Effluent water from the well will be pumped into an oil/water separator, gravity fed into a sparge tank and then back to the existing excavation. Objective is to create a cone of depression at the recovery well. The artificial gradient induce onto the surface of groundwater will allow free product to pond or collect into the cone of depression. NOTE to File: “free product” means a concentration of a hazardous substance that is present as a nonaqueous phase liquid; for purposes of this paragraph, a “nonaqueous phase liquid” is a liquid that is not dissolved in water. |
John Halverson |
| 5/3/1991 |
Update or Other Action |
(Old R:Base Action Code = SI - Site Investigation). Shannon and Wilson sent in Contaminant Plume Assessment Plan for site. The purpose of the plan is to evaluate the lateral extent of the JP-4 release at Fuel Station 11-490. The release originally occurred on April 27, 1991 as a result of a punctured 8 inch fuel pipeline. M-B Contracting removed 50 tons of contaminated soils and transported it to their facility on DeBarr Road where the soils were stockpiled and covered. Benzene, an unexpected contaminant, was found at .093 ppm. This suggests another source location is possible or the pipeline stored other materials and had leaked product prior to this incident. Future remediation of soils and groundwater at site is needed. More sampling at bottom of present excavation should be obtained. |
John Halverson |
| 5/6/1991 |
Update or Other Action |
ADEC sent a Notice of Violation (NOV) letter to Joseph Williamson, EAFB stating that proper notification was not done within 5 hrs. of knowledge of discharge (18 AAC 75.080(a)4). 4/27/1991 spill of approximately 1,000 gallons of JP-4 occurred. Violations of AS 46.03.710 and AS 46.03.740 occurred.
There are civil and criminal penalties for discharges of oil which provide meaningful incentives for the safe handling of oil (AS 46.03.758). Captain Godsave was charged with spill notification duties. He was aware of the Trooper reporting number and the home telephone numbers of the ADEC district staff. Consistently, spill notifications and final reports are not appropriately prioritized and addressed. All correspondence should be directed to Jennifer Roberts in the ADEC Southcentral Regional Office and copied to the Anchorage District Office for spill reports at Elmendorf. Please make note of the enclosed notification and final reporting procedures and brief your personnel accordingly. Following these procedures will help alleviate any future conflicts. |
John Halverson |
| 5/23/1991 |
Update or Other Action |
Site Summaries & Conceptual Plans for the Elmendorf AFB, AK IRP, prepared by CH2MHILL, Dated May 23, 1991. This working notebook provides a preliminary overview of the 53 sites identified by the U.S. Air Force in their Installation Restoration Program (IRP). This overview outlines state & federal regulatory authorities that establish guidelines for addressing cleanup & closure of sites under each specific program. The programs outlined in this working document include:
• CERCLA/RCRA Subtitle C
• ADEC POL Spills
• UST/SPCC
• ADEC SW/RCRA Subtitle D
• RCRA Part B Permit
The rationale for including sites in specific programs & a conceptual plan to address cleanup & closure are stated for each program.
The site summaries presented in this document are based on the preliminary review of previous reports prepared for Elmendorf Air Force Base (AFB). Upon completion of a thorough review of all available data, a final program designation will be made for each site. At that time, the conceptual plan for each program will be implemented. The highlights of each conceptual plan will be reflected in the Elmendorf AFB Community Relations Plan.
UST/SPCC Site
SITE ST48 (SP-13), DIESEL FUEL LINE LEAK
• Approximately 700- to 800-gallon spill occurred in 1968.
• Fuel seeped into the ground.
• No fuel was recovered.
• No previous sampling.
• Suspected contaminants: TPH, purgeable aromatics
• Two 5-foot borings installed.
• Surface contamination of TPH & PAHs detected beneath the asphalt parking lot.
• Groundwater not sampled.
• Recommend soil gas & downgradient well.
• EPA recommends additional site characterization with medium priority.
CERCLA/RCRA
Site No. ST20 (S-5)
Underground Waste Storage Tank
SITE ST20 (S•5), UNDERGROUND WASTE STORAGE TANK
HARM Score: not rated
The 338,000-gallon tank is located adjacent to the old power plant, which was demolished in
1987. The tank was used to store waste oils, hydraulic fluid & used solvents, PCBs, & other
waste generated by industrial shops in the flight line area.
• Spent solvents stored in tank after November 8, 1980.
• Tank contained approximately 105,000 gallons of comingled waste until early 1986.
• Tank liquid & sludge sampled in December 1987.
• Detected contaminants in sludge & liquid included: benzene, ethylbenzene, toluene, vinyl chloride, & xylene.
• Use of tank tor hazardous waste storage places site under RCRA Subtitle C regulation.
Removal of Large Ab&oned Under Ground Storage Tank - North end of Bld.11-420.
338,000 gal. tank located adjancent to the old power plant. Used to store waste oils, hydraulic fluid & used solvents, PCB's & other miscellaneous waste produced from the industrial shops in the main flightline area. On occasions the tank was pumped & the waste materials were either used as fuels for fire fighting exercises, used for dust control, or disposed of offbase by a contractor. The tank has not been used for several years, however the tank contained approximately 105,000 gals. of comingled wastes up until early 1986. Testing of materials was done on the waste in the tank & it was found to have a flash point of 50 F.
The facility has admitted to storing spent solvents in the tank after November 8, 1980, & an analysis indicated the presence of solvents (Analytical report, April 15, 1983). This unit was emptied by DRMO in early 1986, however EAFB stated that approximately 12 to 18 inches of water overlay an undermined quantity of semi-solidified substance.
For additional information see site file. |
Louis Howard |
| 5/30/1991 |
Interim Removal Action Approved |
(Old R:Base Action Code = REM - Removal / Excavation). Shannon and Wilson requests to dispose of contaminated soils at Anchorage Sand and Gravel's rotary asphalt kiln. Approximately 33 cubic yards(50 tons) of waste soils were approved by ADEC for disposal based on results sent in (6/13/91). |
John Halverson |
| 6/18/1991 |
Offsite Soil or Groundwater Disposal Approved |
Contaminated soil from the JP-4 release was excavated on June 18 and 19, 1991, from an
excavation 12 feet by 15 feet wide and 24.5 feet deep. The initial 50 tons and an additional 350
tons of contaminated soil from the excavation were hauled off base for thermal treatment on
June 18, 1991. |
John Halverson |
| 6/19/1991 |
Update or Other Action |
(Old R:Base Action Code = REM - Removal / Excavation). Anchorage Sand and Gravel receipts received for 415.38 tons of fuel stained soils from Elmendorf AFB (M-B Contracting). Analysis of the remediated soils were attached of remediated soils. The actual quantity of soil recycled into asphalt at AS&G's Klatt Road facilty total from the spill site was 677 tons. |
John Halverson |
| 6/19/1991 |
Site Characterization Report Approved |
Assessment & cleanup report received. Low levels of JP-4 constituents are present outside the limits of the contaminated soils recovery excavation. Only area where contaminants exceed the federal/state MCLs are at monitoring well B1MW. Benzene is highest at .099 ppm. Free floating product is present in soils & groundwater at a depth of 24' below the point of release. Recommendations are that the recovery efforts at the collection gallery continue until freeze-up as long as product is being recovered & the 4 monitoring wells be sampled in 10/91.
Phase II groundwater assessment & contaminated soil cleanup report received. The Elmendorf AFB Building 11-490 is located on the West side of the north-south apron at the EAFB runway. The property is located at Longitude 149 degrees 47' W & Lattitude 61 degrees 15' N in the NW 1/4 of Section 3, T13N, R3W of the Anchorage (A-8) NE Quadrangle.
0n June 18 & 19, 1991 the visibly impacted soils in the immediate vicinity of the JP-4 discharge were removed from the ground & either transported directly to AS&G or stabilized on site on a 10-mil reinforced polyethylene membrane. Operations for removing the tainted soils, created all excavation with approximate dimensions of 15 feet long, 12 feet wide & 24.5 feet deep.
On June 18 & 19, two collection galleries made of 18 & 24 inch corrugated metal pipe (CMP) were placed in the excavation. The collection gallery was installed by MB Contracting in accordance with the Collection Gallery Details. The lower 5 feet of the pipe was slotted with a cutting torch by MB Contracting. Septic rock was placed around the CMP to the top of groundwater. The excavation was then lined with 10 mil reinforce plastic membrane, & backfilled with clean pit run gravel. The plastic membrane was pulled back over the top of the excavation to prevent excess water from infiltrating the clean grave;. The area of excavation was then paved with an asphalt pavement to restrict further infiltration of surface water into the area of excavation.
Groundwater sample EW-1 collected from standing water in excavation had 6.5 ppm benzene. Indications are that the floating product (1/8 inch thick), identified as JP-4, encountered in the excavation is limited to an area estimated at 30' X 30'. Six samples were collected during excavation activities from the bottom & sidewalls. DRO maximum level was 1,270 mg/kg, GRO was 1,060 mg/kg, TPH 1,770 mg/kg. BTEX was 150 mg/kg (benzene 7.81, toluene 54.2, ethylbenzene 15.3 & total xylenes 72.9).
The water samples from monitoring well B1MW, positioned at the downgradient edge of the excavation had the highest concentrations of total BTEX ranging from 243 ug/L in May to 162 ug/L in July. The most recent sample, B1MWW2, had 99 ug/L of benzene, 50 ug/L of toluene & 13 ug/L of total xylenes. Water Sample B4MWW1 had 3.2 ug/L of the halogenated volatile organic, trichloroethylene (TCE).
For additional information see site file. |
John Halverson |
| 8/20/1991 |
Update or Other Action |
Letter from USAF Donald Creighton, Colonel USAF Commander to Svend Brandt-Erichsen Regional Administrator ADEC. As you know, the Air Force (AF), the Environmental Protection Agency (EPA)-Region 10, & the Alaska Department of Environmental Conservation (ADEC), recently concluded negotiations concerning a Federal Facility Agreement (FFA) for Elmendorf AFB (EAFB). During these negotiations, the parties mutually agreed that certain of the identified contamination sites might be more appropriately addressed outside the FFA.
More specifically, the parties agreed that nonhazardous solid waste disposal sites, releases from petroleum underground storage tanks, & other petroleum contamination not subject to RCRA corrective action, should be investigated &, if necessary, remediated in accordance with regulatory authorities not explicitly integrated into the FFA.
The AF is anxious to begin work at these sites as soon as possible. To that end, the AF believes it would facilitate efforts at these sites if the AF & ADEC were to enter into an agreement outlining the process to be followed at these sites, & containing a tentative schedule for completion of the necessary investigatory work. The AF is prepared to begin negotiating this agreement in mid-August at a time & location of mutual convenience. The AF additionally proposes to invite the EPA's Project Manager under the FFA to participate in these negotiations to further "cement" the team approach that works so well during the FFA negotiations.
Please have your representative contact Mr Joe Williamson (907-552-4157) soon concerning a suggested time & location for this meeting. Any legal questions concerning this proposal may be directed to Captain Richard Myers (907-552-3046).
On behalf of EAFB, I want to express my appreciation for the technical ability & professionalism your representatives brought to the table during the FFA negotiations. Without their assistance & spirit of cooperation- an agreement would not have been concluded so easily. We look forward to reaching a quick agreement concerning the sites identified in this letter so that we can get on with the work necessary to clean up EAFB. |
John Halverson |
| 8/22/1991 |
Site Added to Database |
JP-4 fuel contaminant. |
John Halverson |
| 10/3/1991 |
Update or Other Action |
10/3/1991 letter to Kurt Wilson of MB Construction on the release from the EAFB JP4 Pipeline at Building 11-490. *NOTE to file: JP-4 is a wide-cut fuel. Where prevailing low temperatures warrant a fuel with very low temperature operability, use of JP-4 is recommended. JP-4 is essentially a mixture of heavy naphtha fraction (like gasoline type blending stock) and kerosene. JP-4 is not considered 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). 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.
The company's response actions were rapid and appropriate. The prompt excavation of JP4 contaminated soils has removed the major source of benzene being released to the groundwater. The physical location of the spill site is in the vicinity of 3 contaminated sites which are being addressed under the Federal and State regulations. OU2, ST48 (1968 JP4 spill (located adjacent to Building 11-490 on O street) and SS50 (a 1961 AVGAS spill adjacent to Building 11-680 on 22nd street). All three of these sites are under active investigation or scheduled for investigation in the 1992 field season.
Active ground water treatment at this site (JP4 pipeline leak) would impact the local ground water. Active treatment would alter the ground water gradient of the other sites, which would give incorrect data at these sites.
The FFA project managers from the EPA, ADEC and the Air Force have discussed the MB pipeline spill site and are in agreement that no active ground water remediation will be requested nor 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 TPH by EPA 418.1, and for benzene, toluene, ethylbenzene, and xylenes (BTEX) EPA method 602. At the end of two years the ground water data will be reviewed. Remediation at any one site in the CERCLA/SERA program would impact the other sites which makes a regional approach to ground water remediation a viable option. In a regional ground water remedial action under CERCLA/SERA the minor amount of ground water contamination generated by this spill would in all likelihood be addressed. |
Jennifer Roberts |
| 12/15/1993 |
Update or Other Action |
A 1993 Remedial Investigation (RI) of operable unit 2 Site ST20, located 200 feet southwest of ST48, indicated that groundwater southwest of Site ST48 has concentrations of BTEX compounds exceeding state MCLs. Groundwater monitoring well ST20-01, located 150 ft. southwest of site ST48, had the greatest concentrations of BTEX compounds of the shallow wells sampled during the 1993 investigation. One of the results of the RI at ST20 was the implication of ST48 as the suspected source for groundwater contamination found during the investigation. Based on the results of these investigations, ST48 was selected for a site investigation under the SERA Phase II. Analytes of concern are GRO, DRO, BTEX relating to the potential diesel fuel and JP-4 from the 1991 leak.
Spills during fuel line abandonment may also have occurred. Types and amounts of waste and prior waste disposal practices at the aircraft hangars are unknown. These leaks and spills may also have contributed to the north and east of ST40 are also potential contaminant sources although they have not been investigate to date.
Organic contaminants above maximum contaminant levels (MCLs) include benzene, bis(2-ethylhexyl)phthalate (BEHP), 1,2-diboromoethane, or ethylene dibromide (EDB) and methylene chloride. BEHP is extremely immobile in groundwater with travel times on the order of thousands of years, indicating that it is probably a result of lab contamination. Benzene was detected above MCL both up-gradient and down-gradient of the former ST20 tank. EDB was present above the MCL only at up-gradient (ST48) locations. The groundwater contaminants: benzene and EDB at ST20 appear to have migrated from an up-gradient source (ST48).
Only two subsurface soil samples at ST20 exceeded EPA risk based concentrations (RBC) or ADEC cleanup levels. One exceeded BTEX levels and the other was for arsenic. However, the arsenic concentration was only slightly above the upper tolerance limit for background samples and thus was eliminated as a contaminant of concern.
WATER:ST20-01 TPH 46 mg/L, B3MW 0.060 ug/L EDB, ST20-02 Benzene 440 ug/L |
Jennifer Roberts |
| 1/5/1994 |
Document, Report, or Work plan Review - other |
EPA Review Comments OU2 Draft Final RI/FS. The FS sections of this RI/FS are generally technically sound. The propose NO ACTION alternative with groundwater monitoring for ST20 may be appropriate at this time on the basis of a Base groundwater agreement between Elmendorf Air Force Base, EPA and Alaska Department of Environmental Conservation (ADEC). The long-term monitoring program, however, should include analysis of ALL the contaminants of concern (COC) until the remedial action for the groundwater beneath ST20 is performed at OU5. This analysis may not be required if the analytical results from the final two rounds of samples indicate that some of the contaminant concentrations are considerably below cleanup levels.
AF RESPONSE: Based on additional EPA comments received December 29, 1993, and subsequent communication with Air Force, EPA, and ADEC, the ST20 feasibility sections will be significantly revised. Since benzene, BEHP, and EDB exceeded MCLs (in groundwater), contaminant fate and transport were evaluated for these contaminants. The evaluation concluded that the contaminants originated either at an upgradient source or as a laboratory contaminant and will be incorporated into the existing ST20 risk management section (17.0 of the RI/FS). Since no contaminants detected in the ST20 groundwater pose unacceptable risks that can be attributed to ST20, no further action is warranted at ST20 under CERCLA. The upgradient source area (ST48) will be cleaned up under the State program (i.e. SERA). Based on these conclusions and communication with Air Force, EPA, and ADEC, the FS sections pertaining to ST20 (18.0 through 21.0) were removed from the document and no further action was recommended in the risk management section. These changes include the removal of the long-term monitoring program at ST20 and negate the content of (EPA's) this comment.
Table 21-2 Page 21-7: The LTM program at ST20 includes seven analytes: benzene, bis(2-ethylhexl)phthalate, ethylene dibromide, lead, manganese, nitrate, and phosphorus. In Section 8.4, arsenic is also considered as the contamination of primary concern, but is not included in the monitoring program. This discrepancy should be clarified. RESPONSE: Arsenic is not a COC and will be removed as such in section 8.4. However, sections 18.0 through 21.0 will be removed from the document and the LTM program at ST20 will be no longer part of the FS.
High metals levels were detected in groundwater at both ST20 and ST41. In particular, manganese levels are significantly elevated (by orders of magnitude) and potentially represent an unacceptable risk based on calculated hazard indices both under residential and commercial/industrial scenarios. In addition to high naturally occurring levels, it appears that manganese levels are higher in seep areas and may be attributable to a reducing environment in the areas of fuel spills and leaks. RESPONSE: High manganese levels at seep areas (ST41 only) are being addressed as part of the IRA. All of the seeps at ST41 have been captured by the IRA extraction system. Treated water from the IRA is sent to the AWWU municipal sewage treatment plant, not released into the environment. Manganese is a risk (at ST20) at only one monitoring well, ST20-03, during two sampling rounds (fall 1999 HI=12.7 and spring 1992 HI=12.5) and is only slightly above the highest upgradient well's HI of 11.9. |
Jennifer Roberts |
| 3/15/1994 |
Risk Assessment Report Approved |
As part of the RI/FS the risk assessment was approved. There was no ecological risk assessment done for ST20 since the source area is covered by streets, paved parking lots, lawns, and buildings, therefore there is little exposed surface soil and no sediments or surface water. The assessment for the commercial/industrial scenario identified no contaminants for soils, sediments or surface water at OU2 that exceeded the EPA Region X risk based screening level of 1 x 10-6 excess lifetime cancer risk.
The risk assessement performed for groundwater determined that exposure would result in an UNACCEPTABLE risk to human health. Several COCs posed a risk of greater than 1 in 10,000. Also other COCs had hazard indices greater than one (1). Maximum unacceptable risk occurs at upgradient monitoring well B2MW and B4MW for all the COCs except for benzene.
Benezne is the only organic COC identified at ST20. The maximum concentration in well ST20-02 in the fall of 1991 was 440 ug/L. Three contaminants for groundwater at ST20 exceeded this 1:1,000,000 excess cancer rate and were found at widespread locations were benzene, BEHP and EDB. The residential exposure risks for benzene fall in a range of 1 x 10-6 to 1 x 10-4. The highest risk occur at one upgradient well and one well nearest the original tank location. Residential risks for both EDB and BEHP were found in a range of 1 x 10-6 to 1 x 10-5. The risks for all 3 compounds also exceeded the risk based screening level of 1 x 10-6 under a commercial/industrial scenario.
For non-carcinogenic exposure, 3 metals exceeded the hazard index of 1.0 which was established by EPA for residential land use exposure scenario. One metal exceeded the hazard index for commercial/industrial scenario. These metals include: lead, manganese, and nitrate for residential and only manganese for the commercial/industrial scenario.
In summary, groundwater at ST20 would pose an unacceptable risk/hazard to human health; however, the source of contamination appears to be due to fuel releases upgradient at ST48. ST48 is currently being addressed under the SERA program, and a Corrective Action Plan is due in 1995. |
Jennifer Roberts |
| 6/13/1994 |
CERCLA Proposed Plan |
OU2 ST20's proposed plan states that ST20 storage tank and related contaminated soils have been removed and the soils are being cleaned at the base bioremediation pile (biopile). The groundwater (GW) contamination upgradient and downgradient of the site is from another source. Located 160 yards northeast or upgradient of ST20, is ST48. ST48 has a known history of jet fuel line leaks and diesel spills.
The Base, EPA and ADEC have concluded that the groundwater contamination below ST20 is actually the downgradient extent of ST48 contamination plume. ST20 groundwater contamination are being addressed in the investigation and treatment of ST48. No further action under CERCLA is being proposed for source ST20. However, the ST48 subsurface soil and groundwater contamination are being cleaned up under the State Elmendorf Restoration Agreement (SERA).
Note to File: SERA was abolished in October 21, 2002. it is understood by the Air Force and ADEC 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 the most current versions of: 18 AAC 60 (Solid Waste regulations), 18 AAC 78 (Underground Storage Tank Regulations) and 18 AAC 75 (Oil and Hazardous Substances Pollution Control regulations). |
Jennifer Roberts |
| 4/17/1995 |
CERCLA ROD Approved |
Record of Decision signed by Marianne See Regional Administrator SCRO ADEC. Although contaminated soil & groundwater were found in the vicinity of ST20 & ST41 Sludge Disposal Area, it is attributed to upgradient source areas ST48 & ST41 Tank Spill, respectively. No actual or threatened release of hazardous substances from ST20 or ST41 Sludge Disposal Area were found during the Remedial Investigation/Feasibility Study. The contaminated media in ST20 will be addressed under the State- Elmendorf Environmental Restoration Agreement (SERA) program, & the contaminated media in the ST41 Sludge Disposal Area is being addressed under the ST41 Tank Spill remedial action.
Declaration Statement: The no further action determination for the uncontaminated soil in the vicinity of the ST20 Underground Waste Storage Tank is made based on the RI/FS performed at OU2. No determination for remedial action is being made for the groundwater & the soil at the groundwater interface in the ST20 area since the contamination is from an upgradient source, ST48, that is being addressed under the SERA program.
The RI/FS for OU2 determined that the ST41 Sludge Disposal Area was not a source of contamination to the soil or groundwater in the area. Contaminated soil in this area is attributed to the ST41 Tank Spill, & remedial measures to address this contamination are identified therein.
In 1992, gasoline & diesel were detected in 5 & 4 out of a total of 25 samples, respectively. The maximum concentrations for both (1,000 mg/kg of gasoline & 610 mg/kg of diesel) were found at a depth of 27 feet in borehole ST20-BH03. This borehole is located approximately 200 feet away to the northeast, hydraulically upgradient of ST20 & approximately 100 feet southwest, hydraulically downgradient of ST48.
Benzene was detected in 14 of 40 samples analyzed during the RI. Although the maximum concentration detected was 440 ug/L at well ST20-02 in fall 1991, a concentration of 400 ug/L was detected at well ST20-01, 200 feet upgradient, during the previous sampling event in 1990. The maximum concentration of ethylbenzene, 210 ug/L, was detected in monitoring well ST20-03 in fall 1991; however, a concentration of 200 ug/L was detected in upgradient well ST20-01 in fall 1990. Toluene, xylene, & TPH were all detected at their maximum concentrations in well ST20-01: xylene & TPH in fall 1990, & toluene in fall 1992.
Data collected over time indicates that groundwater quality has been impacted by an upgradient source. Subsurface soil contamination was primarily isolated to the vadose zone suggesting that contamination was transported to this point by flowing groundwater. It appears that contamination underlying source area ST20 is the result of releases that occurred upgradient, at source area ST48.
Because of the extensive removal of surface soil during the excavation of the underground storage tank at ST20 only one surface soil sample was collected & analyzed at the site in the fall 1990. No constituents were identified in surface soil at significant concentrations. This sample was located upgradient of the former UST location. Surface soil, surface water, & sediment contamination were not addressed during RI activities or the Risk Assessment at ST20.
ROD section 9.1: No further action is required for the uncontaminated soil in & around the vicinity of the ST20 source area. This determination does NOT extend to fuel contaminated groundwater & soil at the groundwater interface underlying ST20, since the contamination is attributed to a separate source area, ST48 that is being addressed under SERA program. Any remedial action necessary to address the contamination will be evaluated & implemented under the SERA program.
For additional information see site file.
|
Marianne See |
| 4/21/1995 |
Update or Other Action |
Air Force AF memo: 18 April 1995 Underground Storage Tank (UST) Meeting. Elmendorf AFB will accomplish the following actions regarding UST Projects. These actions are based upon conversation between, John Mahaffey, Larry Opperman and yourself. EAFB will make every effort to accomplish a clean closure of a UST removal site if possible. UST removal locations requiring cleanup action will be transferred into the State-Elmendorf Environmental Restoration Agreement (SERA).
A list of sites requiring cleanup will be coordinated with your office. The presumptive remedy for contaminated UST sites in the outwash plain only will be bioventing technology. Contaminated soils exceeding cleanup levels may be placed back into the excavation only if the site assessment (SA) indicates a need for further cleanup action. Contaminated UST sites not in the outwash plain will require further investigation to determine appropriate cleanup options. We will make every attempt possible to assure new USTs or new aboveground tanks are not installed in any way that would hamper future access for cleanup. The project will first accomplish removal of all of the USTs. SA information will be used to prioritize sites for cleanup using existing project funds.
Additional funding will be requested to complete cleanup if available. Sites not addressed for cleanup due to exhausted funding will be placed into SERA Phase IV. John Halverson signed on April 21, 1995. Memo was signed by Douglas G. Tarbett, Maj, USAF, Chief, Environmental Compliance. CC: 3 WG/JA and 3 SPTG/CE. |
John Halverson |
| 6/16/1995 |
Site Ranked Using the AHRM |
Initial ranking. Action code added because it wasn't when the site was originally ranked. |
John Halverson |
| 7/31/1995 |
Update or Other Action |
SERA II Site Assessment received. This investigation was successful in determining that past releases at site ST48 have contaminated the soil and groundwater at the site located at Hangar 1, 2, and 3 (USAF IRPIMS Site ID 60). Hangar 3 is associated with bldg. 11-470 and ST48.
The objective of determining the horizontal and vertical extent of any impacted soil was successful because the only contaminated soil is in the smear zone associated with contaminated groundwater, which has been delineated. Groundwater results: DRO 9200 ug/L (ST20-02WGN), GRO: 16000 ug/L in both 60WL04WGN and ST20-01WGN, benzene: 200 ug/L (ST20-02WGN) 51 ug/L 60WL04WGN.
The only soil contamination identified with this site assessment was associated with groundwater in the zone of seasonal fluctuation. The source of hydrocarbon contamination appears to be contaminated groundwater and smear zone contamination remaining from the 1991 fuel line rupture. The excavation completed at the time of release appears to have successfully removed all contaminated soil, and vadose zone soils are not acting as an ongoing source of groundwater contamination by hydrocarbons. However, some hydrocarbons may be contained in the smear zone.
Following the investigation of the immediately downgradient ST20, it was concluded that elevated lead concentrations in the groundwater were originating upgradient, likely from Site ST48. Elevated lead concentrations were detected in all ST48 groundwater samples, including the upgradient wells. These data suggest an as yet unidentified upgradient source of lead, which was observed in groundwater samples collected from both sites ST48 and ST20. Additionally, JP-4, the identified contaminant at ST48 does not contain tetraethyl lead or other lead compounds.
Based on the minimal present and future health risks, natural attenuation is the recommended corrective action for ST48. Petroleum contamination in the zone of water table fluctuation will eventually decline through dissolution and degradation. It is recommended that the results of the ST48 SERA II investigation be incorporated along the OU 5 natural attenuation program. Inclusion within the OU 5 natural attenuation program may require including some ST48 wells with the ongoing basewide groundwater monitoring program.
For additional information see site file. |
Louis Howard |
| 9/26/1995 |
Document, Report, or Work plan Review - other |
Letter to C. Mayer Dept. of Air Force 3 SUG/CEVR RE: SERA Phase II Site Assessment Report Final July 1995. Several UST sites within ST32 are recommended for closure or no further action is recommended based on the finding of no soil or groundwater contamination. However, in most cases petroleum constituents were found in soil or groundwater samples. The wording should be changed to state that no soil or groundwater contamination was found above risked based concentrations or regulatory levels defined in 18 AAC 78, unless analyses were detected in any samples from a site.
Section 4.4.5 describes groundwater sampling and anlysis for lead. It refers to preliminary results from filtered and non-filtered results. The report should contain the final results. Information provided in the report does not clarify whether lead found in the groundwater near ST20 and ST48 is from a contaminant source or a natural source. This issue still needs to be resolved.
Section 4.4.6 recommends natural attenuation as the remedial alternative for soil and groundwater contamination at ST48 and that it be incorporated into an OU5 natural attenuation program. ADEC is not aware of a natural attenuation program under OU5. Please clarify this issue.
A risk assessment conducted at ST20, within Operable Unit 2 and immediately downgradient of ST48, showed unacceptable risks/hazards to human health are present as a result of groundwater contamination. However, it concluded that the contamination was the result of ST48 and not related to ST20.
The OU2 Record of Decision (ROD) justified no further action (no called "Conditional Closure") in response to the groundwater impacts based on the fact a corrective action plan was to be submitted under SERA for ST48. At this point, it is not clear that natural attenuation is the preferred remedial alternative for ST48. To complicate this matter, the question of whether lead is a contaminant of concern in the area has not been adequately resolved. |
John Halverson |
| 10/17/1996 |
Update or Other Action |
Air Force memo: Restricted Use of the Shallow Aquifer on Elmendorf Air Force Base (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 regulators the use of the shallow aquifer for any purpose on Elmendorf is not allowed. Please see the attached Facility Board minutes (March 29, 1994 0930-Item 9 of minutes). Mr. William Hanson, Chief of Environmental, briefed to the Facilities Board the policy to not use the shallow water aquifer due to contamination. The Facilities Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The Installation Restoration Program (IRP) has additional Record of Decisions (RODs) for Operable Units 3 and 6 which require, as a stipulation of the agreement with Environmental Protection Agency and Alaska Department of Environmental Conservation, this aquifer remain unused.
2) Our concern is that key personnel in the review process within Civil Engineer Squadron are aware of these policies and that these policies are reviewed on a recurring basis. It is imperative that this restriction be recognized and observed during engineer reviews and operations.
3. If you have questions on this subject, please contact Mr. Joe Williamson at 552-7229. |
Louis Howard |
| 2/27/1997 |
Meeting or Teleconference Held |
Notes from 27 February Meeting. The meeting to discuss the State of Alaska's Department of Environmental Conservation (ADEC) comments on the SOPs for Closing Bioventing Systems on the Glacial Outwash Plain at Elmendorf Air Force Base, AK was conducted at ElmendorfAFB on 27 February 1997. The following people were in attendance: Claude Mayer, John Mahaffey, John Halversen, Tim Stevens, Louis Howard, Skip Koch.
The ADEC comments were covered in the order that they were presented in ADEC' s memorandum dated 31 December 1996, subject: Comments on the technical memorandum titled "Standard Operating Procedures for Closing Bioventing Systems on the Glacial Outwash Plain at Elmendorf Air Force Base, AK" dated November 14, 1996. The agreed upon responses to the comments are covered in the attached Response to Comments.
One additional point discussed was the possibility of reevaluating sites that are currently being biovented using a risk based closure as outlined in the proposed ADEC UST regulations. ADEC agreed that sites could be reevaluated and bioventing operations stopped if they did not present an unacceptable risk to human health or the environment.
Radian will not begin preparing the final version of the SOP until 7 April so that the responses to the comments can be reviewed, and if there are any issues with the proposed changes to the SOP they can be addressed prior to publishing the final SOP.
Claude Mayer will prepare a list of the number of bioventing sites currently operated or proposed on the Elmendorf glacial outwash plain. The list will show sites that are mainly contaminated by GRO, DRO, and RRO. This list will not become a part of the standard operating procedure (SOP). After discussing the limited number of systems currently operating on the outwash plane, ADEC agreed that confirmation soil sampling at a minimum of 10 sites each for GRO, DRO, and RRO was not required. A new paragraph will be added to the SOP as follows:
Test Period-Similar procedures for closing contaminated sites on Elmendorf AFB have not been used in the past. In order to ensure that this SOP is accurate, the first sites to which this SOP is applied will have workplans for closure soil sampling developed for them and reviewed by the Alaska Department of Environmental Conservation ADEC.
After closure samples have been taken at the initial sites recommended for closure, Elmendorf AFB will develop a correlation between the closure sampling and the recommendations of this SOP for sites contaminated by GRO, DRO, and RRO. The base will forward these correlation data to ADEC for approval. Once the correlation of the recommendations in this SOP and closure sampling data have been approved, this SOP can be applied for closure without confirmation soil sampling, or with a percentage of the sites recommended for closure being sampled to confirm that the correlation does not change.
For additional information see site file. |
John Halverson |
| 4/9/1997 |
Meeting or Teleconference Held |
Call from Elmedorf Air Force Base (C. Mayer) to Halverson RE: SERA Phase II Projects' milestones and what to use for the Record of Decision/Corrective Action Plan dates under SERA II, which includes ST32, ST48, SS49, SS50, ST66, ST67, ST68, and ST74. The Air Force proposed natural attenuation for ST48. The assessment showed minimal soil contamination, but significant "smear" zone and groundwater impacts. The site is located close to ST20 in OU2.
One monitoring well was added to the Basewide Groundwater Monitoring Program to help evaluate natural attenuation downgradient from ST48. One well may not be sufficient or it may be the best well to include. Need to look at wells included for both ST48 and ST20 to make sure there is adequate coverage. |
John Halverson |
| 6/30/1997 |
Update or Other Action |
Site Evaluation and Bioventing Studies for SERA Phase V Sites, 1997 Work Plan received. SERA Phase V sites include the following besides ST48 (also known as ST420-AFIDs 39, 40 and 41 located in the footpring of Bldg. 11-490): ST509 - ST526, AST 527, ST528 - ST537.
During the excavation an area of perched water was encountered beneath the northern portion of
AFID 40. The perched water was approximately 25 feet long by 2.5 feet wide. There was a sheen
visible on the surface of this water. A sample of this water was analyzed for VOCs (EPA 8240); BTEX (EPA 8020); GRO (AK 101); DRO (AK 102); RRO (AK 103); arsenic, cadmium, chromium, lead
(EPA 6010 or 6020); and PCBs (EPA 8080). The following elements and compounds were found in the water sample: arsenic (0.0049 mg/l), lead (0.500 mg/l), GRO (1.8 mg/l), DRO (8.2 mg/l), RRO (11.0 mg/l), benzene (0.0049 mg/l), toluene (0.038 mg/l), ethylbenzene (0.0031 mg/l), and xylenes (total 0.058 mg/l).
One soil sample was collected from the base of the tank excavation, approximately 23 feet below
grade. The results of the sampling are shown in Figure 2.12-1. Low levels of GRO (58 mglkg), DRO
(95 mglkg), RRO (230 mglkg), toluene (0.31 mglkg), ethylbenzene (0.091 mglkg), and xylenes
(1.6 mglkg) were found at this site. Because of the high lead level in the perched water, the soil was sampled for lead and lead was detected at (300 mglkg). None of the three tanks were replaced with a new UST. After removal of the tanks, the excavation was backfilled with the excavated soil.
On July 8-17,1996, USTs AFID 39, 40, and 41 were decommissioned, removed, and transported to the Contractor's yard on Elmendorf AFB for temporary storage in a bermed and lined area, Eventual disposal was by Alaska Metals Recycling.
Laboratory results from one water sample collected from the excavation show a concentration oflead in the water that exceeds the MCL for drinking wateL Laboratory results for the soil sample indicate that the lead concentration is above background levels but below the EPM recommended action level. Based on the results offield screening and laboratory analyses of water and soil samples collected in the vicinity of the excavated USTs, corrective action is not required at this site.
Monitoring ofthe nearby |
Louis Howard |
| 7/1/1998 |
CERCLA ROD Periodic Review |
Five year review documented in the remedieal action report for Operable Unit 2. 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 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.
ST41, known as "Four-Million Gallon Hill", is situated approximately one-half mile east of the Knik Arm of the Cook Inlet and at the west end of the Elmendorf Moraine . ST41 occupies about 20 acres. Four 1-million gallon field-constructed USTs, numbered 601 through 604, were installed at ST41 in the early 1940s. These USTs were used to hold aviation gasoline (AVGAS) and JP-4 jet fuel from the fuel terminal. The tanks were interconnected by two concentric rings of piping and gravity-fed without check valves between the tanks. The tanks were taken out of service in 1991. Contaminated soil and groundwater have been detected in the area.
Since the USTs were installed in 1942, there have been two significant spill events that have been consistently documented. In the mid-1960s, 60,000 gallons of AVGAS were spilled in this area. It is unknown how this spill occurred. None of the AVGAS was recovered. On August 30, 1974, an estimated 33,000-gallon spill of JP-4 jet fuel occurred when an UST was filled beyond capacity. Approximately 16,000 gallons of the fuel was recovered. The remaining 17,000 gallons seeped into the ground northwest of the tanks. Cleanup efforts reportedly prevented fuel from reaching surface water. There are additional reports of two large spills, but no records or evidence have been found and these two reports are unconfirmed and believed false.
Operation of the IRA, GW monitoring and remedial action performed in 1996 revealed information that changed our understanding of the sources and pathway of contamination migration. The ST41 conceptual site model was substantially revised as a result of these new data. This model can be found in the Evaluation of ST41 Treatment System, Operable Unit 2. 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.
For additional information see site file. |
Louis Howard |
| 8/12/1998 |
Document, Report, or Work plan Review - other |
Letter to AF regarding Response to Comments on draft work plan SERA Phase II Sites ST36/66, ST74, and ST61 Investigation dated July 1998. ADEC disagrees with contractor's response to comments concerning analytical methods discussed in Items 1(i) and 1(m). UST and CS regulations require cleanup levels for GRO/DRO be based on analyticals using AK methods not 8015M/8100M.
The only exception to the analytical methods are found in 18 AAC 78.090: "If site assessment sampling began before November 3, 1995, and if test results satisfy the water quality criteria and cleanup levels referred to in (i) of this section, the owner or operator may continue to use the analytical methods used before that date to complete the site assessment. If a site assessment is begun on or after November 3, 1995, the owner or operator shall use the analytical methods set out in Table G of 18 AAC 78.800(b)."
ADEC requests the AF cease use of alternative lab methods (8015M/8100M) for DRO and GRO analyses by the end of the calendar year for soil and groundwater analysis or long term monitoring which do not include AK 101 or 102. The alternative methods will no longer be acceptable when the new 18 AAC 78 and 18 AAC 75 regulations become final. It is anticipated that the UST and CS regulations will become finalized by the end of this calendar year. Please make changes to any future contracting or scopes of work to ensure that by March 1, 1999 all analyses for gasoline range organics and diesel range organics utilize AK methods for both soil and groundwater. |
Louis Howard |
| 12/7/1999 |
Institutional Control Record Established |
No current receptors exist for the groundwater at the Base due to the institutional controls (ICs). As a requirement of previously signed RODs for Operable Units (OUs) at the Base, ICs have been established to restrict the use of the shallow aquifer in the outwash plain on Base for both SERA and CERCLA sites. These restrictions are enforced through the Base Comprehensive Plan (BCP).
Projects and other activities are reviewed during the planning stage to ensure compliance with the BCP. In addition, construction projects and other activities also undergo an environmental review. This review helps ensures compliance with groundwater use restrictions. |
Louis Howard |
| 12/7/1999 |
Long Term Monitoring Established |
SERA Round 2 sampling results received. Benzene remains above MCLs at ST20-03 13.3 ug/L and 60 WL-04 at 6.1 ug/L. |
Louis Howard |
| 1/10/2000 |
Update or Other Action |
10/99-12/99 Quarterly report received. Of the 34 wells sampled, 11 wells remain above the MCL for benzene. Groundwater cleanup levels for petroleum constituents are estimated to be met in September 2010. |
Louis Howard |
| 4/24/2000 |
Update or Other Action |
Another site, named "2 Large Fuel Tanks", Reckey 198821X932501, was a duplicate of this site and was deleted. |
Former Staff |
| 2/12/2001 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Basewide Annual Groundwater Report Draft, Elmendorf Air Force Base, AK, dated January 2001.
Figure 3-1 Groundwater Monitoring and Analysis Decision Guide Page 3-4
The assumptions to the figure state in item #3 that there are no regulatory requirements to sample a particular well or utilize a specific analytical method for a mandated period of time. ADEC disagrees. With regards to sampling frequency, 18 AAC 75.345(h) Groundwater and Surface Water Cleanup Levels states:
The department will require long-term monitoring if the department determines that monitoring is necessary to ensure protection of human health, safety, or welfare, or of the environment and if groundwater, surface water, soil, or sediment contains residual concentrations of a hazardous substance that exceed the applicable cleanup levels. If long-term monitoring is required under this subsection, a responsible person shall submit a plan and schedule for monitoring as part of the requirements for cleanup operations under 18 AAC 75.360. Unless otherwise approved by the department, a responsible person shall conduct monitoring quarterly for at least one year to establish the concentration trend. The department will evaluate the monitoring program yearly.
With regards to a specific analytical method being required, 18 AAC 75.355(d) Sampling and Analysis states: Among the analytical methods set out in EPA’s Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (SW-846), as adopted by reference in (c) of this section, if there is more than one analytical method for a hazardous substance, a responsible person may select any of those methods with a practical quantitation limit less than the applicable cleanup level. If only one analytical method has a practical quantitation limit less than the applicable cleanup level, that method must be used. Analysis for petroleum contamination must follow the Alaska methods for petroleum hydrocarbons referred to in Table 1 of the Underground Storage Tanks Procedures Manual, dated December 1, 1999, and adopted by reference.
ADEC requests the Air Force and US EPA discuss redoing the decision matrix for eliminating wells from the sampling program at the next joint meeting later on in the month of February. ADEC questions the validity of using only two sampling events to drop wells from the program if they are below MCLs during that time. See the three examples obtained from the report which casts doubt upon whether two events are long enough to ensure for no rebound of contaminant levels.
- At monitoring well OU6MW-67 the benzene levels were below the MCL during: 1997-1, 1997-2, 1998-1, and 1998-2 sampling events, which would have lead to this well being dropped. However, in 1999-1 and 1999-2 the levels of benzene rose to and remained at 12 ug/L in 1999-1 and 1999-2 time frame.
For additional information see site file.
|
Louis Howard |
| 4/17/2001 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Basewide Groundwater Monitoring plan. 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 |
| 2/21/2002 |
Document, Report, or Work plan Review - other |
Staff commented on the annual basewide groundwater 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 Basewide 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 [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].
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 |
| 10/21/2002 |
Update or Other Action |
Letter sent to 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 your 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. We concur with you 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. |
Jennifer Roberts |
| 5/14/2003 |
Update or Other Action |
Staff reviewed and commented on Elmendorf Air Force Base’s monitoring and optimization work plan base-wide bioventing system. The text states under item 4 that the closure sampling procedures are provided in a site specific SAP (sampling analysis plan) prepared under a separate cover, and are not discussed in this WP (work plan). The Department reserves approval on this work plan until the Air Force submits the site specific sampling analysis plan for review and comment.
The text states that the State Elmendorf Environmental Agreement (SERA) was developed in October 1992 as a cooperative agreement with ADEC. The Department requests that the Air Force insert text in this section stating that the SERA was dissolved in October 21, 2002 by mutual agreement. It is understood that the sites and programs formerly addressed by SERA, underground storage tanks (UST) and oil and other hazardous substance discharges, will be addressed in accordance with 18 AAC 78 and 18 AAC 75.
Since SERA has been dissolved by mutual agreement, the Department requests the Underground Storage Tanks regulations 18 AAC 78, Contaminated Sites regulations 18 AAC 75 (both effective January 30, 2003), and Underground Storage Tank Procedures Manual (effective November 7, 2002) be included in this section as required regulatory framework that the project will follow for those sites formerly covered by SERA. |
Louis Howard |
| 1/27/2004 |
CERCLA ROD Periodic Review |
Second Five Year review signed. The purpose of this five-year review is to evaluate the implementation and performance of the remedial actions that were selected in Record of Decision (ROD) for each Operable Unit (OU). The contaminant sources at Elmendorf Air Force Base (AFB), Alaska are grouped into six areas including OUl,OU2,OU4,0U5,OU6, and SA100. The remedies vary by site and have included contaminated soil and debris removal. institutional controls. monitored natural attenuation of contaminated groundwater, and operation and monitoring of several active remediation systems such as free product recovery, high-vacuum extraction (HVE), constructed wetland and in-situ bioventing. This is the second review for Elmendorf AFB. The trigger for this review was the signing of the first five-year review report on November 4, 1998.
The Five-Year Review Summary Form on the following pages presents the issues that were identified during the review, associated recommendations and follow-up actions, and protectiveness statements for each area.
The assessment of this five-year review found that the remedies were constructed and in general,
are operating and functioning as intended by decision documents. For the source areas within OU1, OU2, OU4, and OU6 that have not met groundwater cleanup levels, the remedies are expected to be protective of human health and the environment upon attainment of groundwater cleanup levels through natural attenuation. At some sites (i.e., OU2, OU4, OU5, OU6) it is expected to take longer to achieve these goals than predicted in the RODS. In addition, a treatability study that includes system optimization efforts is underway to address remaining soil contamination at OU6 and the remedy is expected to be protective upon completion. In the interim, exposure pathways that could result in unacceptable risks are being controlled (i.e., with land use controls).
The remedy at OU5 currently protects human health and the environment in the short-term because, at present, TCE has not exceeded cleanup levels at the point of compliance (i.e., Ship Creek). However, in order for the remedy to be protective in the long-term, Seeps 9, 10, and 11 must be captured and treated, and investigation into the nature and extent of the TCE plume feeding the seeps at OU5 must be continued and evaluated to ensure long-term protectiveness.
The remedy at SA 100, immediate response and removal action, is complete and protective of human health and the environment. Confiation samples show that no contamination above background levels/regulatory cleanup levels remains and SA l00 is acceptable for unlimited use and unrestricted exposure.
OU2 consists of two source areas, ST20 and ST41, located in the central (ST20) and western (ST41) portion of the base. ST20 is the former site of a 338,000 gallon underground storage tank that was used to store Bunker C fuel oil, waste oils, used solvents, and other wastes. Elmendorf removed the tank and contaminated soils at ST20 in 1990, which resulted in a NFA determination in the 1995 OU2 ROD. ST20 is not included in this five-year review.
In 1983, storage of waste liquids in a tank at ST20 in OU2 was prohibited. Then, in 1986
about 105,000 gallons of liquid waste were removed from the tank. The source (tank piping and 1,300 cubic yards of contaminated soil) was removed and the soil treated during 1990. The OU2 ROD (1995) recommended NFA for ST20 because it was demonstrated that soil was cleaned up and the source of groundwater contamination was due to upgradient sources (i.e., ST48 in the State Program). |
John Halverson |
| 3/21/2005 |
Update or Other Action |
2004 Phase I RPO Annual Report (Draft Final) Groundwater Performance Optimization Monitoring Program received. Analytical data from the in-source well at the ST48 Plume (60WL-04) indicates a fluctuating level of GRO that does not display a significant trend. COC concentrations have remained well below the initial concentration of 16,000 µg/L measured in 1994. Because the three most recent sampling rounds have shown an increase in GRO concentration, monitoring near the source area of ST48 should continue to detect any further increase in GRO concentration. Monitoring at well ST20-03 should also continue to verify that GRO concentrations downgradient of the source area are not increasing. To optimize performance monitoring at this plume, it is recommended that the following evaluations be performed for the ST48 Plume:
COC monitoring: COC monitoring for this plume is currently performed at two wells. Monitoring network optimization and sampling frequencies should continue to be determined by using the decision guides presented in Appendix H.
Contaminant mass calculations: Contaminant mass calculations cannot be determined at this plume with any high degree of accuracy because the ST48 Plume is monitored by only two wells. It is recommended that contaminant mass calculations not be performed at the ST48 Plume.
MNA monitoring: MNA monitoring is currently performed at each well that is sampled to ascertain COC levels. MNA samples are also collected at the same frequency as for the COC samples. It is recommended that these two sampling suites be disconnected. Pending identification of a replacement well for 60WL-04, MNA samples should no longer be collected from the ST48 Plume. The benefits of continued MNA sampling at this plume should be determined after this replacement well has been selected. The installation of additional monitoring wells at this plume to perform an accurate MNA assessment is not recommended.
Cleanup date predictions: The CAP associated with ST48 did not specify an estimated cleanup date for this plume. It is recommended that the cleanup date for the ST48 Plume be predicted by using SourceDK Tier 1. One limitation is that SourceDK Tier 1 requires a decreasing trend in COC concentrations, which during recent years, has not been readily apparent at this plume. The expected outcome is that the cleanup date will be far into the future or Tier 1 will be unable to determine the date because of these fluctuations. If the latter occurs, additional investigation activities may be required to predict a cleanup date. Milestones should be calculated manually when a cleanup date has been developed.
Remedy protectiveness summary: MNA is the selected remedy at the ST48 Plume. This remedy should be considered protective of human health and the environment. Although a predicted cleanup date does not exist, COC concentrations are generally decreasing, plume expansion is not occurring, and potential downgradient receptors are not being exposed to groundwater contaminants.
It is recommended that the COC monitoring network be reevaluated with existing decision guides and a revised cleanup date for this plume be developed during summer 2005. These exercises should be performed and the findings should be submitted as a stand-alone report before the 2005 Annual Report is prepared. The results of the reevaluation would not be generated in time to guide field activities during 2005, but would be available to influence recommendations in the 2005 Annual Report.
|
Louis Howard |
| 4/1/2005 |
Document, Report, or Work plan Review - other |
Staff provided comments on the 2004 RPO Report on March 21, 2005.
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.
NOTE: Zone 3 plumes and COCs are: Fairchild Avenue Plume-TCE, OU5MW-02 Plume-TCE, OU3MW-25-TCE, Kenney Avenue Plume-TCE, SP1-02 Plume-TCE, Slammer Avenue Plume (2 plumes)-TCE, ST48 Plume-GRO, ST68 Plumes (2 plumes)-GRO and benzene, and LF59MW-03-TCE. |
Louis Howard |
| 2/27/2007 |
Exposure Tracking Model Ranking |
|
Louis Howard |
| 4/13/2009 |
Update or Other Action |
Staff received for review: 2009 Zone 2 and Zone 3 Management Areas Work Plan. This work plan outlines the 2009 scope of work for four sites in the Zone 3 Management Area: ST37, ST48, ST68, and LF59. Site ST37 includes several discrete plumes including the Fairchild Avenue Plume, Kenney Avenue Plume, Slammer Avenue Plumes, OU3MW-25 Plume, OU5MW-02 Plume, and SP1-02 Plume. In addition to these plumes, Site ST37 includes groundwater seeps and surface water locations near the southern boundary of the base, the Beaver Pond, the Operable Unit (OU) 5 engineered wetland remediation system (WRS), and the early warning and sentry well networks. Zone 3 also includes operation, maintenance, and monitoring (OM&M) of the Restoration Staging Facility, which is also commonly referred to as the “Contractor’s Yard”. The remedy for ST48
groundwater is not yet finalized. A decision document has not been completed for Site ST48, but GRO is expected to be the only COC that will be identified.
ST48 is monitored by two monitoring wells on annual basis with one proposed new monitoring well to be added. However, Semiannual sampling for lead will be conducted at ST48 wells during 2009 only. GRO is assumed to be the sole contaminant of potential concern based on existing groundwater data. Specific project objective: Investigate the nature and extent of lead in groundwater at ST48.
The objectives of the lead investigation at Site ST48 are to:
• Fill data gaps for completion of the DD for ST48.
• Quantify total and dissolved lead concentrations in groundwater using monitoring
wells located upgradient of, within, and downgradient of the ST48 Plume; and
• Determine the source of lead in groundwater (i.e., upgradient or within the plume).
Historically, total lead has been detected in wells associated with Site ST48 at concentrations exceeding the ADEC groundwater cleanup level of 15 µg/L. The maximum total lead concentration (970 µg/L) was detected in upgradient well 60WL-02 in 1994. Total lead was also detected in downgradient wells at concentrations as high as 700 µg/L. The last groundwater sampling event to include testing for total lead was conducted in 1996. Select samples collected through 1992 were also analyzed for dissolved lead. The maximum dissolved lead concentration reported during these earlier events was 13 µg/L at monitoring well ST20-02. The total lead concentration in the same sample was 120 µg/L. Based on these data, the majority of the lead was attributable to
the presence of aquifer matrix particles (i.e., turbidity) in the sample.
Select groundwater wells were sampled for organic lead in 1994 and 1995, and monitoring wells ST20-03 and 60WL-04 were sampled for organic lead in 1998 to 2000. Organic lead was only detected in two of the 26 samples analyzed (in monitoring wells 60WL-04 and ST20-03). Organic lead was not detected above the 30 µg/L reporting level (RL) in the samples containing the highest total lead concentrations (970 µg/L in upgradient well 60WL-02 and 700 µg/L in downgradient well 60WL-01).
In summary, the majority of lead is attributable to solids (total recoverable lead) and is
not dissolved in the groundwater. However, the dissolved lead data are limited to
samples collected from 1990 to 1992. To determine current concentrations of lead in
groundwater, samples will be collected from four Site ST48 monitoring wells during two
sampling events in 2009 and analyzed for total and dissolved lead. |
Louis Howard |
| 4/30/2009 |
Document, Report, or Work plan Review - other |
Staff provided comments on the Draft 2008 Zones 2 and 3 Management Areas Work Plan, March 2009
for Elmendorf Air Force Base, Alaska.
2.11.4 Site ST48 Lead Investigation Page 2-78
The text states samples for total lead will be unfiltered and samples for dissolved lead will be field filtered. Although filtration of water samples in the field has been used to reduce turbidity and estimate the soluble fraction of chemicals in water, existing RAGS guidance (U.S. EPA, 1989) recommends that unfiltered samples be used as the basis for estimating the chemical concentration for calculating the oral dose. The rationale is that particulate-bound chemicals may still be available for absorption across the gastrointestinal tract. To be consistent with existing EPA guidance, it is recommended that unfiltered samples also be used as the basis for estimating a chemical concentration for calculating the dermal dose.
However, it should be noted that particulate-bound chemicals in an aqueous medium (e.g., suspended sediment particles) would be considered to be much less bioavailable for dermal absorption, due to inefficient adsorption of suspended particles onto the skin surface and a slower rate of absorption into the skin. The uncertainty in the estimation of the dermal dose from a water sample with high turbidity is directly proportional to the magnitude of the difference in the concentration between an unfiltered and filtered sample. The actual bioavailable concentration is likely to lie somewhere between the unfiltered and filtered sample concentrations. (EPA Risk Assessment Guidance for Superfund, Volume 1: Human Health Evaluation Manual Part E 2004)
18 AAC 75 Table C groundwater cleanup levels are based on an analysis of unfiltered groundwater samples. ADEC requests the Air Force analyze for total lead and dissolved lead using both filtered and unfiltered samples for comparison purposes.
SOP #13 Groundwater Sampling
Passive Diffusion Bag Sampling Attachment 1-31
ADEC concurs with the tasks and approach outlined in this section. There are some limitations regarding passive diffusion bag (PDB) sampling. Passive samplers do not provide direct or real-time data. PDB samplers cannot be used for all contaminants; metals and other inorganic compounds will not diffuse through the membrane. The general target is non-polar VOCs with a molecule size of less than 10 angstroms. Biofouling can make PDBs less effective. PDB sampling in monitoring wells relies on the presence of an uninhibited horizontal water flow.
Other factors, such as vertical flow, biofilms, or iron fouling may negatively affect the quality of PDB sampling data. Well stratification can be an issue even in wells with small screened intervals. If PDB samplers are used to identify the highest potential concentration in a well, numerous linked samplers may be needed to decide on the optimal placement of the final sampler.
SOP # 14 Subsurface Soil Sampling Attachment 1-34
ADEC requests the Air Force clarify text in the second paragraph regarding VOC/GRO samples collected concurrently will not be emptied into a stainless steel bowl for homogenization prior to filling the sample jars. |
Louis Howard |
| 10/15/2009 |
Meeting or Teleconference Held |
A meeting of the remedial project managers (RPMs) convened at 0900 on 15 October 2009 in the CEAN Conference Room, Building 5312, at Elmendorf Air Force Base (EAFB), Alaska. Attendees included: Mr. Jacques Gusmano (Environmental Protection Agency [EPA]), Mr. Louis Howard (Alaska Department of Environmental Conservation [ADEC]), Mr. Don Aide (CEANR), Ms. Donna Baumler (CEANR), Mr. Gary Fink (CEAN), Ms. Melissa Markell (CEANR), and Ms. Renee Wright (3 WG/PA).
Zones 2 and 3, SS22 Updates (Ms. Markell)
(1) Parsons is changing project managers for the Zones 2 and 3 contracts from Bill Plaehn to Steve Brauner.
(2) CEANR has changed the RPM for Zone 2 from Melissa Markell to Don Aide. The boundary for Zone 2 has been changed to encompass ST48 and ST68 as these are flightline support area sites with fuel contamination similar to other Zone 2 sites.
(3) A map with sample results and proposed sampling areas for ST32 was distributed (Attachment 6). The map represents what was happening in the middle of the 2009 field season, where more extensive contamination than anticipated was found at ST32 and the plan to install permanent monitoring wells was replaced with a plan to collect groundwater grab samples. This map was distributed to provide a preview of what will be discussed in the annual report regarding the field efforts for 2009. More investigation, an updated conceptual site model, and new sampling program recommendations are anticipated for ST32 in the next few years.
(4) A summary of the biovent decommissioning at FT23 was distributed (Attachment 7). Mr. Fink thanked EPA and ADEC for the quick response and concurrence that allowed this decommissioning to occur. Ms. Markell explained that while the soil remediation had concluded at FT23, groundwater was still being monitored and the soil vapor investigation conducted in summer 2009 could lead to more soil vapor work, including installation of more soil vapor monitoring points. Preliminary soil vapor and groundwater monitoring results were not available for this meeting.
(5) A proposal to continue the Wetland Remediation System Optimization Study was distributed (Attachment 8). Analytical results to date were attached, showing that all sample results have been below cleanup levels. Ms. Markell read through the proposal, emphasizing that if the study continued and a need to reactivate pumping was realized during the winter, a temporary pump and conveyance line would be used since the existing system would be unusable until spring 2010. If the study results indicate that cleanup levels are being met using the passive collection and drainage system, use of passive treatment would be proposed for the duration of the remedy. Mr. Gusmano stated that this proposal was acceptable only because a back-up system would be in place; without the ability to reinstate pumping, it would be hard to concur. Mr. Howard agreed.
(6) Updates to the SS22 schedule for the FFA are under review. These proposed new dates will be sent to the agencies for review and concurrence within the next couple of weeks. A Triad meeting to plan the investigation work for 2010 will be scheduled in the 2-23 November timeframe. EPA and ADEC will provide their available dates to assist in scheduling.
(7) The draft memorandum on interim LUCs at SS22 is in internal review. This memo is expected to be sent for agency review within a few weeks. The memo does not fully cover all interim LUCs at SS22 because the possession-only permit is still pending from the Radioactive Isotope Committee (RIC) Secretariat. The current version of the memo includes descriptions of the dig permit process, health physics monitoring, and fencing. Once the permit is received, details on signage requirements and other LUCs will be specified; another memo will be issued to describe these interim LUCs. |
Louis Howard |
| 2/16/2010 |
Update or Other Action |
Staff received the draft 2009 Zone 3 Management Area Annual Report Environmental Restoration Program.
GRO concentrations for duplicate samples collected at 60WL-05 (5,300J/5,000J ug/L) and the single sample collected at 60WL-06 (4,800 J) exceeded the ADEC groundwater cleanup level of 2,200 ug/L. All VOC concentrations were below their respective ADEC groundwater cleanup levels. Geochemical indicator parameters measured in groundwater from 60WL-05 indicate an anaerobic, reducing environment, while the parameters measured at 60WL-02, 60WL-03, and 60WL-06 indicate a weakly reducing to weakly oxidizing environment. Of the four wells, 60WL-05 was the only one where indicator parameters were measured in 2008, but the range of individual parameter values and the corresponding interpretation of the active electron acceptor processes for 2009 at this well for this well are consistent with historic results and with expectations for conditions within a petroleum hydrocarbon plume (i.e., conditions are anaerobic). Petroleum hydrocarbons generally degrade under anaerobic conditions at rates that are significant, but slower than what would typically occur in an aerobic environment.
A LUC inspection conducted on 25 June 2009 identified minor well maintenance issues at Site ST48, but no significant LUC concerns were found.
The 2007 RPO evaluation identified the ST48 plume as a Green priority because concentrations were below ADEC groundwater cleanup levels. Well 60WL-05 was installed in 2008 to improve the existing monitoring well network. Well 60WL-06 was installed in 2009 to replace downgradient well ST20-03, which was abandoned in 2009. GRO concentrations measured in 2009 at both wells exceed ADEC groundwater cleanup levels, although the concentrations in well 60WL-05 are lower than those detected in 2008. Although GRO concentrations exceed current ADEC cleanup levels in groundwater at two wells, there are insufficient data points to develop a trend to estimate a cleanup date for this site. Based on this information, a change in site designation from Green to Yellow is recommended for this site.
All lead concentrations (total and dissolved) measured in groundwater in 2009 were below the cleanup level of 15 µg/L. Based on these results, lead contamination in groundwater is not a concern at Site ST48. No further sampling for lead is recommended. Preparation of a draft DD for groundwater at Site ST48 is recommended. Available data suggests that GRO will be the only COC that exceeds applicable cleanup levels. To support the final DD, annual sampling of 60WL-05 and 60WL-06 in 2010 and 2011 is recommended to develop an estimated time frame for cleanup using an MNA-based approach.
For additional information see site file. |
Louis Howard |
| 2/25/2010 |
Update or Other Action |
For releases where leaded gasoline and aviation gasoline are suspected contaminants of concern, ADEC requires analysis for EDB and 1,2-DCA. EPA 8260 is required for the analysis of 1,2-Dichloroethane (1,2-DCA). EPA 8011 or EPA 504.1 should be used when evaluating ethylene dibromide (EDB). EDB soil samples should be field preserved in hexane. EPA 8260 will quantify EDB in ground water; however, the detection limits do not meet the Table C cleanup level of 0.00005 mg/L.
|
Louis Howard |
| 2/26/2010 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (ADEC) Contaminated Sites Program has received the Draft Zone 3 Management Area Annual Report, February 2010 Elmendorf Air Force Base, Alaska for review & comment on February 16, 2010. The cover letter requested comments by March 12, 2010.
Below are ADEC’s comments regarding the annual report which covers various GW plumes & the following source areas (but is not limited to): LF59 (CS DB Hazard ID 642), ST37 (CS DB Hazard ID 631), ST48 (CS DB Hazard ID 1237) & ST68 (CS DB Hazard ID 2746).
4.4 Summary & Recommendations Page 4-5
The text states: “Preparation of a draft DD for GW at Site ST48 is recommended. Available data suggests that GRO will be the only COC that exceeds applicable cleanup levels. To support the final DD, annual sampling of 60WL-05 & 60WL-06 in 2010 & 2011 is recommended to develop an estimated time frame for cleanup using an MNA-based approach.”
ADEC concurs. However, GRO were not the only COC at ST48, formerly SP-13 (1961 800 gallons diesel fuel release near bldg. 11-490, April 1991 1,000 gallons Jet Fuel JP-4 release from fuel line being penetrated) located near the E/W & N/S runways on Elmendorf AFB. These other COCs will need to be reanalyzed either at the five year review or when GRO is approaching the applicable cleanup level to ensure that they have all achieved final cleanup levels prior to final closure.
From the 1993 OU2 Remedial Investigation:
One of the results of the RI at ST20 was the implication of ST48 as the suspected source for GW contamination found during the investigation. Based on the results of these investigations, ST48 was selected for a site investigation under the SERA Phase II. Analytes of concern are GRO, DRO, BTEX relating to the potential diesel fuel & JP-4 from the 1991 leak. Spills during fuel line abandonment may also have occurred. Types & amounts of waste & prior waste disposal practices at the aircraft hangars are unknown. These leaks & spills may also have contributed to the north & east of ST40 are also potential contaminant sources although they have not been investigate to date.
Organic contaminants above MCLs include benzene, bis(2-ethylhexyl)phthalate (BEHP), 1,2-diboromoethane, or ethylene dibromide (EDB) & methylene chloride. BEHP is extremely immobile in GW with travel times on the order of thousands of years, indicating that it is probably a result of lab contamination. Benzene was detected above MCL both up-gradient & down-gradient of the former ST20 tank. EDB was present above the MCL only at up-gradient (ST48) locations. The GW contaminants: benzene & EDB at ST20 appear to have migrated from an up-gradient source (ST48).
Lead & manganese were also detected at elevated levels at ST20. However, the contaminants were observed at higher levels at the upgradient ST48 wells, indicating that the contaminants are migrating onto ST20 from an upgradient source. Manganese may be the product of a release mechanism produced by the presence of degrading fuel-related products. Therefore, the presence of elevated levels of manganese is a product of the elevated levels of organics, which are migrating from an upgradient source (ST48).
In general, the data for arsenic, lead, & manganese at ST20 are consistent with these metals being transported slowly downgradient, possibly in a pulsed fashion, from a source area located upgradient of ST20, in the vicinity of ST48. These observations are consistent with the statistical summaries that suggest that arsenic, lead, & manganese correlate fairly well with total BTEX, which also appear to have their source upgradient of ST20 in the vicinity of ST48.
The promulgated cleanup level for EDB in GW is 0.00005 mg/L or 0.05 µg/L as listed in 18 AAC 75.345 Table C. Currently, only DRO, GRO, lead & BTEX are being sampled & at ST48. Method 504.1 (Drinking Water method) or Method 8011 are the only two methods recommended for the analysis of 1,2-dibromoethane (EDB) CASRN 106-93-4 in water at Elmendorf. The Air Force would have to confirm with the lab to ensure that the detection limit for the method is below the listed cleanup level. |
Louis Howard |
| 3/10/2010 |
Document, Report, or Work plan Review - other |
The following are EPA comments on the subject [Draft Zone 3 Management Area Annual Report, February 2010 Elmendorf Air Force Base] Report:
In General, the Report does a good job correlating sampling strategy and well maintenance with the findings of the 2007 RPO Report.
Some items less clear, are the last well survey, or screen depths and lengths. Also the use of PDB samplers needs to be consistent and there may be an issue here. All the aforementioned issues effect sample integrity and consistency and determine proper depth of a sample in the
water column.
A brief intro to each section outlining the above well info would help greatly.
It is also hoped that some of the issues raised in the last RPO Report will have been addressed by the next RPO Report; or at least an improved plan implemented so better data can be collected to improve the monitoring program.
4.4 Summary and Recommendations, Page4-5 EPA agrees with this finding but , as does ADEC we believe you should verify the presence/or lack of, for other contaminants historically present at this site. |
Louis Howard |
| 1/24/2011 |
Update or Other Action |
Staff received the 2010 Zone 2 Mgt Area Report.
Water samples were collected from wells 60WL-05 and 60WL-06 on 10 June 2010. Groundwater samples from both wells were submitted to a fixed-base laboratory for analysis of GRO. GRO concentrations for the samples collected at 60WL-05 (7,200 ug/L) and 60WL-06 (2,400 ug/L) exceeded the ADEC groundwater cleanup level of 2,200 ug/L.
Geochemical indicator parameters measured in groundwater from 60WL-05 and 60WL-06 indicate an anaerobic, reducing environment. The range of individual parameter values and the corresponding interpretation of the active electron acceptor processes for 2010 at these wells are consistent with historic results and with expectations for conditions within a petroleum hydrocarbon plume (i.e., conditions are anaerobic). In terms of COC degradation, petroleum hydrocarbons generally degrade under anaerobic conditions at rates that are significant, but slower than rates that typically occur in an aerobic environment.
The 2007 RPO evaluation (USAF, 2008b) identified the ST48 plume as a Green priority because concentrations were below ADEC groundwater cleanup levels. However, wells 60WL-05 and 60WL-06 were installed in 2008 and 2009, respectively, to improve the existing monitoring well network. GRO concentrations measured in 2009 at both wells exceeded ADEC groundwater cleanup levels. Because there were insufficient data points from these two wells to develop trends to estimate a cleanup date for the site, the site designation for ST48 was changed from Green to Yellow (USAF, 2010c).
GRO concentrations in well 60WL-05, the in-plume well, were higher in 2010 (7,200 µg/L) than in 2009 (5,300J / 5,000J µg/L), and there are still too few data points to develop trends to estimate a cleanup date. Therefore, the Yellow designation remains appropriate.
Preparation of a draft DD for groundwater at Site ST48 is recommended. Available data suggests that GRO will be the only COC that exceeds applicable cleanup levels. To support the final DD, continued annual sampling of 60WL-05 and 60WL-06 in 2011 is recommended to develop an estimated time frame for cleanup using an MNA-based approach. |
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).
A final remedy for GW at Sites ST32 & ST48 has not been established. The overall objectives of RA-O activities within the Zone 2 Management Area are to monitor the rate of natural attenuation within GW plumes, determine the effectiveness & protectiveness of the site remedies (currently MNA for all sites), & manage all waste according to state & federal regulations.
Site ST48 is a State Program site along Slammer Avenue, east of Heritage Circle in the southern portion of Zone 2 (Figure 3.1). Prior to 2010, Site ST48 was discussed in documents for the Zone 3 Management Area. Beginning in 2010, this site is being discussed in documents for the Zone 2 Management Area because the boundary between the Zone 2 and Zone 3 Management Areas was revised during the 2009 field season.
The source of the ST48 Plume is a diesel fuel spill that occurred due to a line leak 80 in 1968, and a JP-4 leak caused by a punctured pipeline in 1991 (USAF, 1995b). Two groundwater monitoring wells (60WL-04R and downgradient well ST20-03) were historically used to monitor the contamination levels in this plume. Well 60WL-04R was installed in 2005 to replace 60WL-04, which was destroyed by construction activities after groundwater sampling in 2002. In-source well 60WL-05 was installed in 2008, and downgradient well 60WL-06 was installed in 2009. Well 60WL-06 replaced former downgradient well ST20-03, which was abandoned in 2009 due to safety concerns related to its proximity to a running track.
The Zone 2 Management Area sites are located throughout the central portion of JBER-Elmendorf. The southern boundary of Zone 2 is parallel to the southern edge of the east/west instrument runway. The WP presents the site locations, associated sources, & plumes. Ten sites & 12 GW plumes are located within this management area.
• Site ST48 - GRO
There is no decision document for ST48 groundwater. GRO is assumed to be the sole contaminant of potential concern based on existing groundwater data. There is no decision document for ST48. The cleanup level presented has been updated to match the current groundwater cleanup level for GRO.
For additional information see site file.
|
Louis Howard |
| 4/10/2012 |
Update or Other Action |
2011 Annual Report for Zones 1, 2, & 3 received.
GRO concentrations for the samples collected at 60WL-05 (10,000 J mg/L) and 60WL-06 (5,000 J mg/L) exceeded the ADEC groundwater cleanup level of 2,200 mg/L.
A LUC inspection conducted on 13 October 2011 did not identify any LUC issues at Site ST48.
The 2007 RPO Evaluation Report (USAF, 2008g) identified the ST48 plume as a Green priority because concentrations were below ADEC groundwater cleanup levels. However, wells 60WL-05 and 60WL-06 were installed in 2008 and 2009, respectively, to improve the existing monitoring well network. GRO concentrations measured in 2009 at both wells exceeded ADEC groundwater cleanup levels (Figure 3.22).
Because there were insufficient data points from these two wells to develop trends to estimate a cleanup date for the site, the site designation for ST48 was changed from Green to Yellow (USAF, 2010b). GRO concentrations in well 60WL-05, the in-plume well, were higher in 2011 (10,000 J µg/L) than in 2010 (7,200 µg/L) and in 2009 (5,300J / 5,000J µg/L), and there are still too few data points to develop trends to estimate a cleanup date. Therefore, the Yellow designation remains appropriate. |
Louis Howard |
| 6/6/2012 |
Update or Other Action |
Draft Project Management Plan received for review and comment.
Performance Objective
Site Closure
Performance Indicators
· Prepare an approved Characterization Workplan by December 2012
· Coordinate, mobilize, and execute Characterization Investigation by August 2013
· Prepare an approved Site Characterization Report and Site Closure Report by March 2014
· Conduct final site closure requirements and well abandonment to achieve SC by May 2014
Potential Risk
HRC indicates soil contamination is present exceeding risk levels; HRC indicates groundwater contamination is present exceeding risk levels.
Risk Mitigation
Excavation or treatment (biovent) will be completed for vadose zone soils exceeding risk
levels to eliminate risk, and evaluation of groundwater impacts will be completed and
appropriate treatment (ISCO) will be implemented to remediate groundwater.
Date of Achieving Performance Objective
3rd Quarter FY 2014
Planned Approach
Prepare an approved Site Characterization Workplan with an updated CSM. Coordinate, mobilize, and execute Site Characterization by installing and sampling five soil borings and convert three borings to monitoring wells.
Use HRC to evaluate SC based on risk to future residential receptors for all pathways.
Prepare an approved Site Characterization Report with an updated CSM, documented HRC risk evaluation, and identification of data gaps and strategies to acquire data.
Prepare an approved Site Closure Report requesting Cleanup Complete without ICs.
Receive concurrence from ADEC that site has achieved Cleanup Complete without ICs and provide documentation to AFCEE. |
Louis Howard |
| 6/22/2012 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft Project Mgt. Plan.
Table 6-3 JBER-Elmendorf
General comments
Risk mitigation: In general, vadose zone soils shall not exceed maximum allowable levels for petroleum contamination for soil from 0 – 15’ bgs (i.e. direct contact for BTEX, PAHs & ingestion for DRO, GRO, RRO) regardless of HRC calculated levels. Treatment or excavations deeper than 15’ bgs may be warranted on a site-specific basis to prevent the soil from acting as a continuing source of GW contamination.
In addition, sites with existing GW contamination above Table C cleanup levels will require that migration to GW cleanup levels be used for soil & ICs will be required. Once GW is below Table C for for a period of time (per the latest approved “Basewide Monitoring Program Well Sampling Frequency Decision Guide”), the maximum allowable levels may become the cleanup levels as determined by ADEC on a case by case basis.
7.1.2
Independent QA Oversight on Performance Based Contracts
The site cleanup rules require that “collection, interpretation, & reporting of data, & the required sampling & analysis is conducted or supervised by a qualified, impartial third party”. Depending upon the specific terms in a performance based contract, a contractor may no longer be considered an impartial third party with respect to collecting, interpreting & reporting data.
This should be taken into consideration when preparing scopes of work. ADEC strongly recommends the Air Force provide an on-site Quality Assurance Representative or a third party QA oversight contractor to monitor fieldwork for consistency with approved plans & contract requirements.
ST048 Diesel Fuel Line Leak (IRP) Page 11-14
GW is already impacted at this site with GRO at 7.2 mg/L so the Table B1 migration to GW cleanup level for soil is applicable. Sites with GW contamination above Table C cleanup levels will not receive a “cleanup complete” designation without ICs.
ST066 Leaking Underground Storage Tank – Out of Service (IRP) Page 11-15
GW is already impacted at this site with DRO at 14 mg/L so the Table B1 migration to GW cleanup level for soil is applicable. Sites with GW contamination above Table C cleanup levels will not receive a “cleanup complete” designation without ICs.
SS83 WWII Anti-Aircraft Artillery (IRP) Page 11-16
GW is already impacted at this site with DRO at 3.6 mg/L so the Table B1 migration to GW cleanup level for soil is applicable. Sites with GW contamination above Table C cleanup levels will not receive a “cleanup complete” designation without ICs.
|
Louis Howard |
| 4/18/2013 |
Update or Other Action |
Draft UFP-QAPP WP received for review and comment.
Delineating the source associated with the 1991 release will not conclude the LIF probing, because there may be more than one NAPL contaminated soil source area within the ST048 study area (there could be noncontiguous source areas at the 1991 release location, near 60WL05 and near the ST020 UST). All of the LIF probes will be advanced through the zone of seasonal water table fluctuation (approximately 35 ft bgs).
There are many buried utilities in the area, so some proposed LIF probe locations may have to be adjusted and final probe locations can only be determined following utility locates. If soil conditions limit the ability to advance LIF probes, then conventional drilling approaches will be used to conduct the investigations (but the number and location of borings would be different than the proposed LIF probes).
Once the LIF probes have identified the extent of 1053 contamination, soil borings will be drilled to collect soil samples which will be used to characterize the source area soil concentrations. If the ST048 source area does not extend to the ST020 UST location and a NAPL source area is not identified at the ST020 location, then only the ST048 source area will need characterization.
If there are separate ST048 and ST020 source areas or if the ST048 source appears to comingle with or be superimposed on the ST020 source, then each source area will be characterized separately because the ST048 and possible ST020 releases would have been of relatively different hydrocarbon types and of different ages.
The investigation of each source area will target the collection of a minimum of ten soil samples from the source area for GRO, DRO, RRO, and BTEX analysis and a minimum of about three samples for PAHs, EPH and VPH analysis. If the source area is small enough that it does not allow the collection of 10 samples, then a lesser number of samples will be collected.
Groundwater samples will be collected from existing monitoring wells 60WL-05 and 60WL-06 and analyzed for DRO, RRO, GRO, BTEX, PAHs, EPH, VPH and EDB. Additional monitoring wells to be installed, as needed, to characterize the source area and monitoring well locations will be selected based on the LIF and soil boring results.
Groundwater from these new monitoring wells will also be analyzed for DRO, RRO, GRO, BTEX, PAHs, EPH, VPH and EDB. If the ST048 source area monitoring wells exceed Table C criteria for EDB, then upgradient monitoring wells may also be tested for EDB. |
Louis Howard |
| 4/30/2013 |
Update or Other Action |
Draft Annual Monitoring report received for review and comment.
Historic sampling results for ST048 have indicated fuel constituents present in groundwater above cleanup criteria in 18 AAC 75 Table C and fuel constituents in vadose and smear zone soil above 18 AAC 75 Tables B1 and B2. Although the ADEC cleanup criterion for GRO in groundwater was updated in 2008 to 2,200 µg/L, the numerical standard as defined by the DD for GRO is 1,300 µg/L.
Current monitoring requirements at ST048 include annual groundwater sampling and an annual LUC inspection. Annual groundwater sampling is required for GRO at groundwater monitoring wells 60WL-05, and 60WL-06.
In 2012, monitoring wells 60WL-05 and 60WL-06 were sampled for GRO and VPH. VPH was included for future use in calculating risk at the site using the HRC. Analytical results for GRO exceeded cleanup criterion in both wells.
Additional investigation to characterize soil and groundwater contamination is being proposed for ST048 in 2013 under the new PBR contract. No changes to the annual monitoring are being proposed for this site. |
Louis Howard |
| 5/9/2013 |
Document, Report, or Work plan Review - other |
Staff reviewed & commented on the Draft UFP-QAPP for ST048.
Page ii
2nd Bullet
Whenever referencing the solubility limit of a fuel, please state the basis & actual solubility limit of the fuel referenced. This comment applies to all UFP-QAPPs submitted to ADEC. There is a range of solubility limits for jet fuel & arctic diesel which varies widely.
GRO [was] were not the only COC at ST48, formerly SP-13 (1961 800 gallons diesel fuel release near bldg. 11-490, April 1991 1,000 gallons Jet Fuel JP-4 release from fuel line being penetrated) located near the E/W & N/S runways on Elmendorf AFB. These other COCs will need to be reanalyzed either at the five year review or when GRO is approaching the applicable cleanup level to ensure that they have all achieved final cleanup levels prior to final closure.
From the 1993 OU2 Remedial Investigation:
One of the results of the RI at ST20 was the implication of ST48 as the suspected source for GW contamination found during the investigation. Based on the results of these investigations, ST48 was selected for a site investigation under the SERA Phase II. Analytes of concern are GRO, DRO, BTEX relating to the potential diesel fuel & JP-4 from the 1991 leak. Spills during fuel line abandonment may also have occurred. Types & amounts of waste & prior waste disposal practices at the aircraft hangars are unknown. These leaks & spills may also have contributed to the north & east of ST40 are also potential contaminant sources although they have not been investigate to date.
Organic contaminants above MCLs include benzene, bis(2-ethylhexyl)phthalate (BEHP), 1,2-diboromoethane, or ethylene dibromide (EDB) & methylene chloride. BEHP is extremely immobile in GW with travel times on the order of thousands of years, indicating that it is probably a result of lab contamination. Benzene was detected above MCL both up-gradient & down-gradient of the former ST20 tank. EDB was present above the MCL only at up-gradient (ST48) locations. The GW contaminants: benzene & EDB at ST20 appear to have migrated from an up-gradient source (ST48).
Lead & manganese were also detected at elevated levels at ST20. However, the contaminants were observed at higher levels at the upgradient ST48 wells, indicating that the contaminants are migrating onto ST20 from an upgradient source. Manganese may be the product of a release mechanism produced by the presence of degrading fuel-related products. Therefore, the presence of elevated levels of manganese is a product of the elevated levels of organics, which are migrating from an upgradient source (ST48).
In general, the data for arsenic, lead, & manganese at ST20 are consistent with these metals being transported slowly downgradient, possibly in a pulsed fashion, from a source area located upgradient of ST20, in the vicinity of ST48. These observations are consistent with the statistical summaries that suggest that arsenic, lead, & manganese correlate fairly well with total BTEX, which also appear to have their source upgradient of ST20 in the vicinity of ST48.
The promulgated cleanup level for EDB in GW is 0.00005 mg/L or 0.05 µg/L as listed in 18 AAC 75.345 Table C. Currently, only DRO, GRO, lead & BTEX are being sampled & at ST48. Method 504.1 (Drinking Water method) or Method 8011 are the only two methods recommended for the analysis of 1,2-dibromoethane (EDB) CASRN 106-93-4 in water at Elmendorf. The Air Force would have to confirm with the lab to ensure that the detection limit for the method is below the listed cleanup level.
For additional information see site file. |
Louis Howard |
| 8/13/2013 |
Document, Report, or Work plan Review - other |
ADEC has reviewed JBER's responses to ADEC's review comments/concerns/issues (also see ADEC's previous comments on the Zone 3 Management Area Annual Report dated February 26, 2010 at Comment 4.4) on ST048 SC WP. ADEC accepts the responses as satisfactory within the limitations/confines of the PBR contract. Finalize the document. |
Louis Howard |
| 3/13/2014 |
Update or Other Action |
Draft 2013 Annual report received for review and comment. The overall project objectives included collecting sufficient data to:
• Monitor concentrations of contaminants of concern (COCs) at each site with sufficient precision and accuracy to evaluate their concentrations with respect to cleanup goals.
• Identify potentially toxic and/or mobile transformation products.
• Verify individual plume characteristics, such as downgradient, lateral, or vertical expansion or retraction.
• Evaluate groundwater flow directions and hydraulic gradients to monitor plume migration and assess contaminant sources.
• Evaluate the effectiveness of land use controls/ institutional controls (LUCs/ICs) to protect human health and the environment.
• Identify and repair damaged monitoring wells to protect groundwater.
• Identify monitoring wells that are no longer needed or are damaged beyond repair.
Historic sampling results for ST048 have indicated fuel constituents present in groundwater
above cleanup criteria in 18 AAC 75 Table C and fuel constituents in vadose and smear zone soil
above 18 AAC 75 Tables B1 and B2. Although the 18 AAC 75 table C criteria for GRO in
groundwater was updated in 2008 to 2,200 micrograms per liter (µg/L), the numerical standard
as defined by the DD for GRO is 1,300 µg/L.
During 2013, monitoring wells 60WL-05 (6.8 mg/L) and 60WL-06 (5.7 mg/L) were sampled for GRO. Analytical results for GRO exceeded the ST048 DD cleanup criteria in both wells.
The ADEC site status for ST048 is “Open.” The only remaining COC for ST048 is GRO.
Samples collected from two site wells in 2013 indicate that GRO concentrations at ST048
continue to exceed 18 AAC 75.34575 Table C and the ST048 DD cleanup criteria.
Additional investigation to characterize the current nature and extent of soil and groundwater
contamination at ST048 was also performed during 2013 under the JBER PBR contract. A site
characterization report has been prepared under separate cover. Recommendations for the site,
including any changes to the sampling program are provided in the site characterization report. |
Louis Howard |
| 8/20/2014 |
Update or Other Action |
Work Plan addendum approved. Finalize and implement the work plan addendum for ST048. |
Louis Howard |
| 9/26/2014 |
Update or Other Action |
Draft SC report received for review & comment.
Recommendations
The vapor intrusion pathway should be investigated to evaluate the potential migration to indoor air vapor inhalation risk associated with shallow vadose zone contamination as indicated below:
• Soil gas sample collection will follow the standard operating procedures (SOP-05, SOP-05a, SOP-05b, SOP-05c, SOP-05d, & SOP-05f) developed in response to the June 28, 2013 ADEC-USAF-Weston meeting minutes.
• One soil gas probe should be installed at the location of the highest known vadose zone VOC contamination (13ST048-SB01) to a depth of 7 feet bgs (representative of the soil gas at the bottom of a potential future building with a basement). A sample will be collected for analyses of petroleum-related VOCs & PAHs, as applicable. These proposed locations & sampling methods will be presented in a work plan addendum to be submitted under separate cover.
• Following the receipt of the soil gas results, the soil gas data will be evaluated to determine risk associated with the indoor air vapor intrusion pathway. The findings & additional recommendations will be made in an addendum to this report in order to decide the next course of action for ST048.
Determine the downgradient extent of soil contamination by collecting a clean soil sample from a boring completed in the zone of seasonal GW fluctuation, downgradient of 13ST048-SB28. Analyze the sample for GRO, DRO, RRO & BTEX. The findings, a revised site map figure, conclusions & recommendations will be included in an addendum to this report.
Document the downgradient extent of contaminated GW by constructing a monitoring well into the clean boring & collecting GW samples for analyses of GRO, DRO, RRO & BTEX. The findings, a revised site map figure, conclusions & recommendations will be included in an addendum to this report.
For additional information see site file.
|
Louis Howard |
| 10/2/2014 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft ST048 SC Report.
Risk Evaluation
The text states: “It is known that VOCs (including BTEX) will not persist in GW more than several hundred feet downgradient from the source.”
ADEC disagrees. SS22 is a very well documented source of VOC GW contamination & has a plume of chlorinated solvent contamination that is 1.6 miles long (more than several hundred feet from SS22). Therefore, the text needs to state: “It is known that petroleum-related VOCs (including BTEX)…”
Risk Calculations & Cleanup Level Requirements
The text states: “According to the Contaminated Site Regulations (18 AAC 75), if a site has been adequately characterized & meets these regulatory risk standards under a residential land use scenario (unrestricted use), then the ADEC will issue a written determination that the site has achieved a “Cleanup Complete” status. Thus, the site is considered suitable for UU/UE.”
It is ADEC’s position that ICs would be applied at a JBER site (even where the HRC states there is no risk) when: The GW throughout or under a site or downgradient of a site is contaminated with a hazardous substance (which includes POL) at concentrations exceeding Table C cleanup levels; or
POL contaminants in the soil are above the maximum allowable concentrations (MAC) given in Table B2 of 18 AAC 75 or at concentrations exceeding risk criteria within the 0-15’ interval below ground surface (bgs).
Treatment or excavation of soils deeper than 15’ bgs may be warranted on a site-specific basis to prevent the soil from acting as a continuing source of GW contamination (i.e. exceeding Table C cleanup levels).
Once GW is below 18 AAC 75 Table C GW cleanup levels for a period of time (per the latest approved “Basewide Monitoring Program Well Sampling Frequency Decision Guide (Attachment 1 Memo to the Site File for OUs 4, 5, & 6 September 2003)”, which is currently two rounds of annual GW monitoring), then GW monitoring may cease at the site & ICs for GW use will be removed.
4.0 Site Characterization Results & Findings
The text states: “The Operable Unit 2 Record of Decision determined that the contamination underlying ST020 was associated with adjacent ST048, & that no further action was required for ST020. However, 2013 soil sample results indicate a higher relative RRO concentration within the eastern half of the ST048 NAPL source area adjacent to ST020. There is potential for an unknown release to have occurred at ST020, within the ST048 footprint, as indicated by these higher RRO concentrations.”
ADEC concurs with the recommendations for the Air Force to investigate this unknown release at ST020 associated with the higher relative RRO concentrations within the eastern half of the ST048 NAPL source area. ADEC has no preference on whether this is conducted under the existing PBR contract with WESTON SOLUTIONS or outside the PBR contract with another environmental consultant/company. “No further action” under CERCLA for ST020 does not preclude the State from requiring further action under its current environmental laws & regulations.
For additional information see site file.
|
Louis Howard |
| 11/25/2014 |
Meeting or Teleconference Held |
Soil Gas Sampling JBER Nov. 25, 2014 meeting
Objectives of the meeting were to (1) discuss Alaska Department of Environmental Conservation (ADEC) comments (dated October 13, 2014 and November 18, 2014) on the Draft Site Characterization Addendum for Sites TU075 and TU085 regarding soil gas sampling field documentation and (2) the path forward to achieve ADEC concurrence with Cleanup Complete (Site Closure) for those sites and others where soil gas sampling was conducted during the 2014 field season.
ADEC comments regarding additional documentation of the helium leak check that is conducted prior to soil gas sampling are noted below.
• “ADEC requests the Air Force describe in detail where the documentation that helium underneath the shroud was greater than ten percent (10%). It appears that this section is the only place where this statement is documented. This information must also be documented in field notes and/or soil gas sampling log.
• Without documentation required supporting a helium leak check, ADEC does not have full confidence in the soil gas data to support a closure determination at this time and the report addendum and initial Site Characterization report for TU085 cannot and will not be approved.
• The concentration of helium gas under the shroud is not reported on soil gas sampling logs or in the field notes; ADEC will require that a leak check be conducted again by the Air Force and at least a three day notice provided to ADEC’s project manager so technical staff can be on site and observe the procedure from start to finish.”
ADEC commented that without documentation that the helium concentration beneath the shroud was greater than 10 percent, either on the sampling log or in the field notes, ADEC will not concur with site closure and will require that leak checks be conducted again for all soil gas probes present at one site on each installation (JBER-Elmendorf and JBER-Richardson). ADEC will also require that a representative(s) is on site to observe these additional helium leak checks from start to finish. There was discussion regarding the potential for the soil gas probes to be compromised due to Base operations and weather since initial installation and sampling (dating back to June 2014) and what additional action would be required if a leak check fails.
The path forward was outlined as follows:
• At each site with a site closure objective, inspect soil gas probes for obvious damage that may have compromised the surface seal since the probe was last sampled.
o Sites TU075, TU085, and TU074 at JBER-Richardson
o Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
• Select a site at each installation (JBER-Elmendorf and JBER-Richardson) for additional helium leak checks of all probes at that site.
• Provide ADEC 48 hours advance notice of the helium leak check/shroud measurements, so ADEC staff can observe field procedures, any necessary repairs, and testing and measurements (helium concentrations in the port and under the shroud).
• If a leak test fails at a specific probe, the seal will be repaired, the leak test performed again at that probe, and soil gas resampled for all probes at the site.
• If all leak tests pass for all of the probes at the site, no resampling of the soil gas at the site will be required.
• If ADEC notes a systematic problem (absent noticeable damage, leak checks fail for all probes at a site and multiple attempts to seal/repair the probes fail), then ADEC will require the 2014 soil gas data for those sites to be rejected. Following this occurrence of systemic failure (i.e. failure to get a leak check to pass at multiple sites and multiple soil gas probes even after remedies are attempted), JBER, ADEC, Weston, and CH2MHILL will meet to discuss to remedy the situation. |
Louis Howard |
| 2/3/2015 |
Update or Other Action |
Staff sent Air Force email regarding soil gas sampling.
*Sites TU075, TU085, and TU074 at JBER-Richardson [currently ADEC has received the SC Report addendum for TU074 and will not provide any comments on it until the leak check test is performed at a predetermined site of the contractor's (CH2MHILL) choosing as agreed upon below from the November 25, 2014 meeting notes.]
AND
*Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
*please do not submit any SC reports/SC report addendums to ADEC for review from these sites if there is a "Cleanup Complete" request since they are being held up until such time that ADEC has observed and the leak checks performed by the contractor at the selected site have passed.
If they include a CC with ICs request, they may not be dependent the leak check results. It will have to be determined on a case by case basis.
There will be a helium leak check on JBER-Elmendorf this week (Thursday at 11 a.m. at SO552) which will determine the fate for the 2014 soil gas sites (e.g. CG702, SO552, ST048, SO525, TU091).
The path forward was outlined as follows:
* At each site with a site closure objective, inspect soil gas probes for obvious damage that may have compromised the surface seal since the probe was last sampled.
o Sites TU075, TU085, and TU074 at JBER-Richardson
o Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
* Select a site at each installation (JBER-Elmendorf and JBER-Richardson) for additional helium leak checks of all probes at that site.
* Provide ADEC 48 hours advance notice of the helium leak check/shroud measurements, so ADEC staff can observe field procedures, any necessary repairs, and testing and measurements (helium concentrations in the port and under the shroud).
* If a leak test fails at a specific probe, the seal will be repaired, the leak test performed again at that probe, and soil gas resampled for all probes at the site.
* If all leak tests pass for all of the probes at the site, no resampling of the soil gas at the site will be required.
* If ADEC notes a systematic problem (absent noticeable damage, leak checks fail for all probes at a site and multiple attempts to seal/repair the probes fail), then ADEC will require the 2014 soil gas data for those sites to be rejected. Following this occurrence of systemic failure (i.e. failure to get a leak check to pass at multiple sites and multiple soil gas probes even after remedies are attempted), JBER, ADEC, Weston, and CH2MHILL will meet to discuss to remedy the situation. |
Louis Howard |
| 2/5/2015 |
Site Visit |
WESTON performed a helium leak test demo for the sub-slab soil vapor Site SO552 on Thursday, February 5, 2015 at SO552 (aka Bldg. 8326 ST402). L. Howard (ADEC PM) and Todd Blessing (ADEC) VI technical expert observed WESTON staff performing helium leak check with JBER (D. Baumler & D. Aide) on hand to observe as well. WESTON staff passed helium leak check procedures. Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf are now okayed to proceed with draft submittal to ADEC for review and comment. |
Louis Howard |
| 2/27/2015 |
Document, Report, or Work plan Review - other |
Staff reviewed JBER's RTCs and finds them acceptable. No change to the current site status is recommended pending regulatory resolution at ST048 and sites with similar conditions where risk-criteria have been met and groundwater Table C levels and/or soil maximum allowable concentrations within the 0-15' bgs soil interval have been exceeded. |
Louis Howard |
| 5/19/2015 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the annual groundwater monitoring report (draft) for State Sites which include this site. Main comments were disagreeing with the Air Force wanting to discontinue groundwater monitoring despite gasoline contamination above Table C cleanup levels and maximum allowable concentrations for gasoline contamination within the 0 - 15' interval.
See site file for additional information. |
Louis Howard |
| 4/27/2016 |
Document, Report, or Work plan Review - other |
Staff commented on the Draft Annual Report for Monitoring State Sites (including this one) on JBER.
Site Summary and Recommendations
The text states:” The site priority is Green since the site characterization evaluation concluded that conditions at ST048 meets the ADEC risk standard for human health and the environment, assuming a residential land use scenario (USAF, 2015i). Based on this conclusion, annual groundwater monitoring at Site ST048 was not performed in 2015 and annual sampling has been terminated. In addition, it is recommended that site inspections be discontinued in 2016 since site ST048 does not present an unacceptable risk to human health and the environment.”
ADEC disagrees. The issue regarding Table C exceedances in groundwater has not been resolved, therefore for all sites where the HRC states there is no risk, assuming the residential land use scenario, and where there are exceedances of Table C, groundwater monitoring should continue and not cease. Pending regulatory disputes between the Air Force and ADEC is not just cause for ceasing groundwater monitoring obligations at any site. ADEC expects groundwater monitoring and site inspections to begin again in 2016 for this site.
|
Louis Howard |
| 9/16/2016 |
Update or Other Action |
Supplemental work plan received for review to address the groundwater sampling, institutional controls (IC) inspection, and landfill cap inspection activities associated with the 2016 Long Term Monitoring (LTM) at the Joint Base Elmendorf-Richardson (JBER), Sites PL081, CG551, ST408, CG530, SO510, SS522, SO507, SS418, TS003, CG543, CG529, TU107, ST048, CG509, SO508, SO549, AT035, AT029, SS019, and DP009.
As a requirement of the 2016 Environmental Long Term Monitoring contract, the following work shall be performed at JBER Site ST048:
? Sample wells 60WL-05 and 60WL-06 for gasoline range organics (GRO).
? Perform IC inspection |
Louis Howard |
| 3/22/2017 |
Update or Other Action |
2016 Draft Report for Remedial Action Operation and Land Use/Institutional Control at JBER received for review and comment.
Historical sampling results for TU107 have indicated fuel constituents present in vadose zone
soil above 18 AAC 75 Tables B1 and B2. Current monitoring requirements at TU107 include
annual groundwater sampling for DRO at groundwater monitoring well 534MW-01.
As long as there remains contamination above Table C cleanup levels, institutional controls will
apply restricting access to the groundwater until sample results meet Table C cleanup levels. At
such time that the groundwater monitoring well(s) achieve Table C cleanup levels for two years
in a row, then ADEC may consider alternative cleanup levels (as long as they are below the
MAC) for soil on a case-by-case basis (ADEC 2017).
See site file for additional information. |
Louis Howard |
| 3/22/2017 |
Update or Other Action |
2016 Draft Report for Remedial Action Operation and Land Use/Institutional Control at JBER received for review and comment.
During the ST048 and ST020 studies in the 1990s, lead and EDB were detected in groundwater
samples in the vicinity of ST048. Groundwater sampling for lead in 2009 allowed the ADEC to
conclude that “All lead concentrations (total and dissolved) measured in groundwater in 2009
were below the cleanup level of 15 µg/L. Based on these results, lead contamination in groundwater is not a concern at Site ST048. No further sampling for lead is recommended”
(ADEC Contaminated Sites Data Base entry for ST048, 2-16-2010).
The inspection of Site ST048 revealed no evidence of ground disturbance at this site. Revegetation
appeared to be occurring and the monitoring wells located at the site were observed to be in good condition. Various buildings, pipelines, fencing, and electrical boxes were observed on site. Notification signage was present on site and appeared in good condition and no erosion was observed on the gravel pads located on site. Photographs 1 through 3 in Photograph Log A10 present the general condition of Site ST048.
See site file for additional information. |
Louis Howard |
| 8/24/2017 |
Document, Report, or Work plan Review - other |
Staff commented on the Draft Supplemental Work Plan for JBER-E and JBER-R sites [PL081 N. Jet Pipeline, CG551 Bldg. 4314, ST408 Bldg. 9569, CG530 ST526, SO510 Bldg. 9480, SS522 Hardstand #39, SO507, Bldg. 9669, SS418, ST532, TS003 Skeet Range, CG543 Bldg. 18877, CG529 ST529, ST048 Bldg. 11-490, CG509 Bldg. 4347, SO508 ST508, SO549 Bldg. 4913, AT035 MEB Complex, AT029 Ruff Road FTA, SS019 Bldg. 755, DP009 Bldg. 986 POL Lab, LF002, LF002 OU6 Disposal Site, CG536 ST510, CG539 Bldg. 15380, CG702 Bldg. 31562, SO544 Bldg. 10334, SO547 Bldg. 4913, CG704 Southern Plume, CG527 ST538, SO501 ST427, TU064 Bldg. 740, SS013 MP Barracks, SS014, SS041 Roosevelt Road Transmitter Site, TU107, ST048] which include this one.
ST048 (Bldg. 11-490)
ADEC concurs with the scope of work for the current work outlined in this section with one exception. The March 2015 Site Characterization and Risk Evaluation Report noted ethylbenzene at 0.03 mg/L or 30 ug/L . This level is above the Table C 18 AAC 75 July 1, 2017 cleanup level of 15 ug/L. Naphthalene was detected at 0.0092 mg/L or 9.2 ug/L. This level is above the Table C 18 AAC 75 July 1, 2017 cleanup level of 1.5 ug/L. Therefore, ADEC will require analysis for at least two consecutive rounds for BTEX and petroleum-related VOCs (SW8260D) and PAHs (SW8270E-SIM) at ST048. |
Louis Howard |
| 11/30/2017 |
Update or Other Action |
Draft VI report received for review and comment. The BTEX compounds are considered to be the most volatile, and therefore mobile, of the aromatic hydrocarbons. Naphthalene has a relatively low volatility and is likely to partition to soil or sediment, therefore limiting its mobility in the environment. Based on these characteristics, naphthalene may not be an appropriate indicator for determining VI pathway completeness (as compared to the other COIs). The Building 11568 aircraft fuel pumping station (see Appendix C, Photograph C.23), which is located approximately 675 feet northwest of the northwestern corner of Building 11550 (see Figure 5.12), could be a potential source for ambient air petroleum impacts. Specific characteristics of Building 11568 operations, including the venting of petroleum vapors, are not known.
Regardless of the uncertainties associated with the relationship between indoor and outdoor air
results, the presence of multiple COIs in indoor air and soil gas suggest the presence of a
potentially complete VI pathway at Building 11550.
See site file for additional information. |
Louis Howard |
| 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 |
| 5/18/2024 |
Document, Report, or Work plan Review - other |
DEC submitted comments regarding the 2023 Annual Remedial Action-operations And Long-term Management Report for Select State-regulated Sites Draft, Dated April 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 were recommended to continue for all sites to ensure that conditions remain protective of human health and the environment. The report recommends updating land use controls (LUC) site boundaries at CG534, a ‘Cleanup Complete’ determination without institutional controls (ICs) for SS522, the removal of groundwater LUCs at SS041, and a ‘Cleanup Complete with ICs determination for TU101. |
Ginna Quesada |
| 6/25/2024 |
Document, Report, or Work plan Review - other |
DEC approved the 2023 Annual Remedial Action-operations And Long-term Management Report for Select State-regulated 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 were recommended to continue for all sites to ensure that conditions remain protective of human health and the environment. The report recommends updating land use controls (LUC) boundaries at CG534, a ‘Cleanup Complete’ determination without institutional controls (ICs) for SS522, the removal of groundwater LUCs at SS041, and a Cleanup Complete with ICs determination for TU101. |
Ginna Quesada |
| 4/15/2025 |
Document, Report, or Work plan Review - other |
DEC provided comments for the 2024 Annual Remedial Action-Operations and Long-Term Management Report for Select State-Regulated Sites Draft, dated April 2025.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 were recommended to continue for the majority of the sites to ensure that conditions remain protective of human health and the environment. DEC concurs with the recommendation to close SS522 site without ICs, discontinue groundwater sampling at TU107, and reducing the sampling frequency for some wells at TU103. |
Ginna Quesada |
