| Action Date |
Action |
Description |
DEC Staff |
| 8/2/1988 |
Update or Other Action |
Operable Units' source areas that correspond to RCRA Solid Waste Management Unites (SWMUs) from the RCRA Facility Assessment (RFA). SD24 IS-1 Bldg. 42-400 Floor Drain. This site was used for fuel loading operations. Numerous spills, up to 1,300 gals. Most flowed into drain and to dry well. wells in the area has reported contamination impact of 1,1-dichloroethane, methyl chloride, 1,1,1-trichloroethane.
Recommended Actions for sites IS-1 - IS-8, Building floor drains:
A plan will describe in t he RFI work plan to determine the presence of plume(s) of contamination resulting from the operation of the floor drains and the extent of soil and groundwater (GW) impact from the operations. This study will include a geophysical survey to be conducted in the area surrounding each of the subject bldg. to determine surrounding each of the subject building to determine the location of the dry well. In addition, soil and GW monitoring wells will be sampled and analyzed to delineate the extent of contamination. Field permeability tests must also be performed to determine the chactotistics of the uppermost aquifer. |
Louis Howard |
| 3/13/1989 |
Update or Other Action |
Dept. of Air Force letter to Sue Curtin Black & Veatch.
Per your telephone request with Capt Godsave, we submit the following
information:
1. Storm sewer system maps for SP15, SP5/5A, SP7/10, IS-1: Attached.
2. Jet Fuel Supplier: Jet fuel is supplied per one year contracts. Presently, the majority of fuel is supplied by ARCO. Their contact person is Ms Candy Stallings, 213-486-2824. Other suppliers are Tesoro (Contact - Mr Raymond Measles at 907-561-5521), Chevron (415-944-6250), and Mapco (contact - Ms Bonnie Garner at 907-276-4100).
3. Buildings 42-400, 42-425, 43-550, 42-300, 43-410, 43-450, 32-060 floor drains: Originally, minor spillage and products operations in these facilities were washed into floor drains to dry wells. Present conditions are below. Since as-builts clear, this information may not be totally correct. 21-900, and from cleaning and from there are old and not
a. IS-1, Building 42-400: Floor drains run into two oil-water separators.
b. IS-2, Building 42-425: Sanitary sewer runs along side of building, unclear whether floor drains run into it or not.
c. IS-3, Building 43-550: Sanitary sewer runs along side of building, do not know whether floor drains run into it or not.
d. IS-4, Building 42-300: Floor drains run into an oil-water separator and then into the storm drain on the east and west side of the building.
e. IS-5, Building 43-410: Floor drains are connected to septic tank and leach fields at south side of building.
f. IS-6, Building 43-450: Floor drains probably go to the septic tank and leach pits east of the building and across the railroad track.
g. IS-7, Building 21-900: The floor drains run through sumps to remove sand and grit and dump right into the storm drain on the north side of the building. The floor drains for the mechanical room run out the south side of the building and into a seepage pit. There is also a catch basin on the south side of the building that runs into a seepage pit.
h. IS-8, Building 32-060: Although sanitary sewers run near the building, it appears that floor drains go directly to dry wells.
4. How close can wells be put to the runway? If top cover of wells are flush with the ground surface, there should not be a problem. If above ground surface and within 1000 feet of the runway, the well will require a waiver. If within 500 feet of the runway, well may also be required to be frangible.
5. If well is near the runway, can piping go underground beneath a taxiway to a treatment facility? That should not be a problem if taxiway is tunneled under.
6. What is the frost depth for Elmendorf AFB? The Building Code says 42 inches.
7. Does DRMO recycle fuel? DRMO does have a contract to recycle fuel.
8. At Site D-16, can soil at the site be used for grading? If soil is within acceptable levels for contaminants, yes. However, trees should be left as much as feasible.
9. How much would a contractor be required to pay the government for electricity? The government normally supplies contractors reasonable amounts of electricity at no cost. The government also requests that contractors, in this case, practice conservation.
Signed
Thomas Ritz Major, USAF
Acting Chief, Engineering & Environmental Planning Branch. |
Jennifer Roberts |
| 10/20/1989 |
Update or Other Action |
ADEC Ron Klein, Supervisor, Contaminated Site Investigations, sent letter to Captain Brad Gerken, Dept. of Air Force, 5099th Civil Engineering Operations Squadron (AAC) Subject: Response to September 27, 1989 Letter; Requirements for Temporary Storage of Petroleum Contaminated Soil. Enclosed is a copy of the Southcentral Region Office's interim policy for storage and disposal of waste oil contaminated soil.
The guidance also applies to storage of soils contaminated with clean fuels if they are to be stored off the site where they were generated or stored on-site longer than thirty (30) days. The guidance document will be revised shortly to make that explicit. Petroleum contaminated soils generated on-site and stockpiled onsite for less than thirty (30) days must be placed on a bermed liner and covered. The liner and cover must be at least 6 mil reinforced polyethylene.
Alaska Department of Environmental Conservation Southcentral Region Office - Interim Policy For Storage and Disposal of Waste Oil Contaminated Soil
The Southcentral Regional Office solid waste program has been working on an interim policy for storage and disposal of waste oil contaminated soil. Currently the Region has approved the removal of waste oil contaminated soil to a facility permitted to properly handle the contamination. With the exception of the Municipality of Anchorage (MOA) Landfill and Alaska Pollution Control Palmer Facility (pre-treatment for landfill disposal) all of these
facilities are located in the contiguous United States.
Currently, if the waste oil contaminated soil does not meet MOA Landfill criteria the only disposal option is to send the contaminated soil out of Alaska. Soil disposal under this method is costly due to handling, shipping, and facility fees. In discussions with Responsible Parties (RP) there appears to be a strong move to develop other local disposal methods that would meet with agency approval. Therefore the Regional solid waste program has developed interim storage guidelines for waste oil contaminated soils.
These guidelines include the following:
1. An approved design for a low-maintenance or maintenance free storage liner and cover that will be able to withstand winter conditions and is petroleum resistant. This will include a schedule to monitor the storage facility to verify that the integrity of the liner and cover is maintained throughout the storage period.
2. Obtain a solid waste storage plan approval for onsite storage of waste oil contaminated soil from ADEC prior to storage construction.
3. The Responsible Party may propose to remove the waste oil contaminated soil to an off-site storage location if long term on-site storage is not practical. This location must be approved of by the Department prior to any transfer of the soils. The storage site must meet, ADEC design criteria and the RP must obtain an off-site; solid waste storage plan approval prior to transfer of the soil. All transfer of soil off-site must be done under a Bill of Lading and copies provided to ADEC.
4. The maximum allowable storage time is one (1) year. |
Ron Klein |
| 11/15/1989 |
Document, Report, or Work plan Review - other |
ADEC sent EAFB a comment letter on the Installation Restoration Program, Stage 3 Remedial Investigation/Feasibility Study (RI/FS) Elmendorf Air Force Base, Alaska. ADEC has reviewed the Stage 3, RI/FS prepared by Black & Veatch dated August 1989 & has the following comments. The comments are detailed in 4 areas:
1. characterization contamination, of the nature & extent of contamination, 2. priority ranking of sites, 3. applicable or relevant & appropriate requirements, & 4. selection of remediation alternatives.
CHARACTERIZATION OF THE NATURE & EXTENT OF CONTAMINATION
A. Investigative Methods
1. Paragraph 4.1.2.1 discusses the use of 6 wells to establish background levels for heavy metals. The data presented for the 6 background wells indicates silver in 1 well & mercury in 3 wells. Neither of these elements are common in uncontaminated groundwater; consequently, some of the wells may not represent actual background levels. In addition, the average iron concentration of 23,000 mg/kg is very high. It is suspected carbon steel well casings are in use & the wells were not purged sufficiently prior to sampling. If the wells were not purged sufficiently all of the background data is suspect.
2. Paragraph 4.1.2.2 discusses many reasons why monitoring well data is of questionable validity. However, the questionable data has been used to establish 95% confidence intervals for determining when contamination is present above background. We feel the 95% confidence interval is useless because the data used to develop the confidence interval will probably not withstand a quality assurance review.
3. Ground-penetrating radar may not be successful for locating buried objects in glacial till.
4. Several of the sites were not screened for PCB contamination. Given the past use of PCB containing material by the military it is possible for PCB contamination to be present at any site.
5. Paragraphs 4.2.3.3.2.3 & 4.2.4.3.2.3 state that contamination will not affect well 42 because of a steel well casing in the contaminated zone. This is a poor assumption. Many confined aquifers have been contaminated by contamination migration down the outside of well casings into the saturated zone. The artesian nature of the aquifer may slow down contaminant migration; however, concentration gradients act independently from the pressure gradients which may result in movement of contamination from a low pressure area to a higher pressure area.
6. Paragraph 4.2.13.3.2.3 states that well 16 will not be contaminated for the same reasons already discussed in paragraph 5 of this review. The same concerns stated in paragraph 5 apply.
7. Several references to use of an HNu for soil screening appear in the report. HNu readings of tenths of ppm are frequently cited. The HNu is not accurate to 1/10th of 1ppm & there is no indication regarding what span setting was used. If a 9.8, benzene, span setting was used the response of heavier hydrocarbons would be minimal. In addition, many natural substances can cause a one or two unit response in an HNu. Specifically paragraph 4.2.8.1.3.1 cites a 0.1 ppm HNu reading at site IS-6. Of what significance or use is this information?
Paragraph 4.2.8.3 cites that "organic vapors" were detected with the HNu. The HNu responds to more than just organic vapors & there is no way to verify that organic or inorganic vapors are present.
APPLICABLE OR RELEVANT & APPROPRIATE REQUIREMENTS
Where there is groundwater contamination due to fuel products, EAFB should use the volatile aromatic standards as listed on page 5-14 rather than the visible sheen criteria. The discussion on page 5-22 says EAFB will use the target cleanup levels in Table 5-7. Then the next paragraph says the Air Force will use the visible sheen criteria. EAFB should use the target cleanup levels. Cleanup to Water Quality Standards is required even if an aquifer is not being used for drinking water. As stated above, sites with petroleum contamination in the no further action category have to be re-evaluated with-respect-to the ARAR's. This may move them into the” require further investigation category.”
SELECTION OF REMEDIATION ALTERNATIVES
Sites IS-1 through IS-8, Hangar Floor Drains
Expedited action that would prevent further soil & groundwater contamination is requested. Steps must be taken to identify the discharge locations of floor drains when the discharge locations are unknown. If floor drains are found to be discharging to leachfields or dry wells actions need to be taken to cease the unpermitted discharge & direct it to the sanitary sewer (or storm drains if a sanitary sewer is not available). An oil/water separator will need to be installed & maintained at a point prior to discharge to the sanitary sewer or storm drain. The system must be designed to insure that solvents will partition from the water & be recovered. Please provide details on whether the hangar floor drains meet these requirements. |
Ron Klein |
| 12/29/1989 |
Document, Report, or Work plan Review - other |
ADEC letter to Everett L. Mabry Colonel, Base Civil Engineer, HQ 21st Combat Support Group (AAC) RE: RI/FS Stage 4 Second Draft Work Plan Elmendorf Air Force Base, October 1989.
ADEC Comment letter sent to Air Force Everett L. Mabry, Colonel, USAF Base Civil Engineer on RI/FS Stage 4 Second Draft work plan October 1989. 1. For several sites the disposal method for soil contaminated with high levels of TPH is quoted as "the sanitary landfill". The only area landfill that is permitted to received petroleum contaminated soil is the Municipality of Anchorage (MOA) Landfill. The MOA Landfill will accept soils only if the TPH level is below
1000 mg/kg. In many cases the work plan was referring to soils with TPH in excess of 1000 mg/kg. The issue of proper contaminated soil disposal has been brought up by ADEC several
times (reference letters: Klein to Gerken, October 20, 1989 and Klein to Mabry, November 2, 1989).
The Department requests clarification on the disposal method of soils contaminated with TPH levels over 1000 mg/kg and verification that the proposed sanitary landfill is the MOA Landfill. In addition, the Department requests written notification regarding disposal of all contaminated soils. The notification should include: date of disposal, quantity of soil, location that soil originated, and final disposal method.
2. The Department requests that an expanded seasonal sampling schedule be established for selected monitoring wells. In several sites (for example, well W-18 on site IS-1) there may be floating product. The Department is concerned that accurate data is not being collected based on a once a year sampling schedule. Seasonal water table fluctuations can easily dilute or mask the true concentration level of the contaminate. Determinations on site status and remedial actions are being based on incomplete information.
3. In all the proposed borings/monitoring wells the work plan calls for two soil samples per boring to be taken to determine the extent of vertical contamination. The exact depth of the sample is to be based on field screening results. Field screening techniques to determine the presences of TPH contamination is not reliable and it is not uncommon to miss contaminated zones using field screening in leu of analytical laboratory analysis. Also much of the contamination is from old fuel spills which may now be low in benzene and again would be very difficult to read on any field meter calibrated to benzene. The Department requests that
additional soil samples be taken in soil borings/monitoring wells and recommends that sampling be done on 5 foot or 10 foot intervals depending on the total depth of the boring.
4. Paragraph 2.2.1.2 and many other sections reference HNu readings of less than 1 ppm. Key data such as span setting, ambient HNu reading, and calibration gas used, need to be stated
to interpret HNu data. Ambient levels of greater than 1 ppm at span 9.8 calibrated to benzene are common. Relaying solely on HNu field screening may allow contaminated zones to be missed. Again the Department requests that additional soil samples be taken in soil borings/monitoring wells.
5. In many sites two deep borings/monitoring wells are proposed. The decision to drill the second boring would be based on the results of the first deep boring. The Department is concerned that using only two soils samples per boring to determine if contamination is present will allow layers of contamination to be missed. The Department requests that additional soil samples be taken to determine the vertical location of contamination and that this additional sampling be used to determine the depth of the second deep boring and the other shallow borings.
6. Paragraph 2.2.1.2 and other sections in the RI/FS state that well contamination is not likely because of the Bootlegger Cove aquitard. Stage 3 RI/FS analysis of base well BW-1 shows the presence of chlorinated solvents and TPH, also base well BW-51 had TPH present. This indicates contamination is currently infiltrating into drinking water aquifers. Has a survey of
possible routes through the aquitard been performed? For example, paragraph 3.3.1.5 states that over 400 wells are in the Elmendorf area. Well casings can offer excellent conduits for contamination migration. ADEC requests the following information for each of the base drinking water wells : total depth, wells logs (if available) and how these wells are completed (screened or perforated zones, etc.).
SITE IS-1
In previous work floating free product was noted in W-18. We are concerned that a single sampling will not give an accurate indication of the free product. The Department requests that
additional seasonal monitoring be done to give a more accurate picture of the true product thickness. |
Ron Klein |
| 1/1/1990 |
Update or Other Action |
INSTALLATION RESTORATION PROGRAM STAGE 3 REMEDIAL INVESTIGATION/FEASIBILITY STUDY TECHNICAL DOCUMENT TO SUPPORT A REMEDIAL ACTION ALTERNATIVE ELMENDORF AIR FORCE BASE, ALASKA SITE SP-7/10 PREPARED BY: BLACK & VEATCH, ENGINEERS-ARCHITECTS
Site IS-1 is an active maintenance hangar (Building Number
42-400). Site IS-1 has been used for fuel loading operations. Base
documents indicate that past spills, up to 1,300 gallons, have
occurred at the site (Engineering-Science, 1983). The fuel spills
were primarily JP-4, which is a petroleum product containing high
concentrations of benzene, ethylbenzene, toluene, and xylenes
(collectively referred to as BETX). Other general constituents of
JP-4 include heavy, straight-run naptha; clay-treated petroleum
distillates; the light, aliphatic solvent, naptha; hydrotreated light
distillate; and hydrodesulfurized kerosene.
Laboratory analyses showed soil samples taken at 5- and 31-foot depths to contain 910 and 210 mg/kg of total petroleum hydrocarbons (TPH), respectively. No other organic contaminants were detected in the soil samples at this site.
Well W-18 contained groundwater with high levels of all
benzene, ethylbenzene, toluene, and xylene (BETX) compounds,
2-methylnaphthalene, naphthalene, bis(2-ethylhexyl) phthalate, and
TPH. l,l-Dichloroethane and l,l,l-trichloroethane were detected in
groundwater from well W-19. 1,1-Dichloroethane was also detected in groundwater from well IS1-01. Total BETX concentration in groundwater from well W-18 was 1,795 ug/L, which included 35 ug/L of benzene, a known carcinogen. The sample also included 720 ug/L of another probable carcinogen, bis(2-ethylhexyl) phthalate.
Alternative 3 (Collection, Onsite Air Stripping, Surface Discharge) is the alternative recommended for remediation of Site IS-1. The primary elements of this alternative include containment and
collection of the contaminated groundwater plume by pumping from
extraction wells; recovery of free-floating fuel product, also by
pumping from extraction wells; treatment of the contaminated water by onsite air stripping; discharge of the treated water to local storm drains, and monitoring the groundwater to determine plume migration and performance of the remedial action. |
Ron Klein |
| 4/19/1990 |
Site Added to Database |
Petroleum and chlorinated hydrocarbons. |
Louis Howard |
| 10/31/1991 |
Update or Other Action |
CH2MHILL reviewed previous site investigations that lead to the following recommendations: additional remedial investigations are warranted at source SD24, additional boring/monitor wells should be installed to further define the source characteristics and vertical extent of contaminant plume, water level data should be collected for the existing and newly installed wells and boring to verify groundwater flow direction and gradient.
In situ soil gas survey should be done to better define the horizontal and extent of the contaminant plume, the possibility of alpha-BHC contamination at source being caused by the migration of contaminant from SD26 should be investigated, further discussion of recoverable metals detected in groundwater samples which exceeded federal/state action level MCLs is warranted. |
Louis Howard |
| 11/15/1991 |
Update or Other Action |
Jennifer Roberts Federal Facility Coordinator sent letter to Joe Williamson and Rich Howard pursuant to Section 9.1 of the Elmendorf Air Force Base Federal Facility Agreement (FFA). ADEC designates Jennifer Roberts as the Project Manager and Ron Klein as the Alternate Project Manager for all activities covered under the FFA. |
Jennifer Roberts |
| 12/30/1991 |
Update or Other Action |
EPA sent letter to AF Rich Howard and Joe Williamson. The notification will serve as an addendum to the previous letter of November 4, 1991 which designates the USEPA project managers pursuant to Section 9.1 of the Elmendorf Air Force Base (EAFB) Federal Facilities Agreement (FFA). Marcia Combes will serve a lead remedial project manager (RPM) for Base wide activities, as well as Operable Units (OUs) 2, 3, 5, 6, 7. Michele Poirier-McNeill will serve as lead RPM for OUs 1 and 4. In addition, both RPMs will serve as an alternative RPM on OUs for which they are not the lead. For communication and correspondence purposes, the lead RPM should be the point of contact, and the alternate should be copied. |
Jennifer Roberts |
| 7/17/1992 |
Preliminary Assessment Approved |
Memorandum for a meeting held at CH2MHILL/ANC on July 8, 1992 subject: OU4 IRA Planning. Purpose was to discuss the preliminary results of the OU4 Limited Field Investigation (LFI) field work and reach consensus among the project managers on which OU4 source areas would be appropriate for an Interim Remedial Action (IRA). General criteria for an Interim Remedial Action (IRA):
1) contamination verified above action levels (EPA and ADEC guidance levels);
2) point source contamination defined and accessible;
3) IRA implementable;
4) IRA won't interfere with final remedy; and
5) IRA should prevent further release of contaminants.
SS18 (Building 22-201, Pesticide Storage Building) -consensus: No further Action (based on laboratory analyses results).
SD24 (Building 42-400, Hangar 10): Dry well sludge samples indicated petroleum contamination exceeding action levels; GPR could not confirm pipe connection from dry well to building; SBSD24D sample location is downgradient from previous well sampling locations; Consensus: IRA candidate to prevent continuing release of contamination;
Potential IRA Alternatives: 1. No action; 2. Remove sludge, dry well and associated piping structures, remove any visible obvious "hotspots" contaminated soil, disposal;
3. Remove sludge, dry well and piping, visible "Hotspots", disposal, and construct surface cap over source area.
Preliminary alternatives summary will need to have certain assumptions regarding amount of material to excavate and dispose in order to do cost analysis; amount of soil will be based on a proposed maximum volume and will not be dependent on contaminant concentration levels. Disposal costs for this source and for other sources may be obtained through DRMO. Joe Williamson mentioned that he may have USAF remove sludge from dry well as a Removal Action this summer (1992).
Groundwater contamination results from the source SD24 Building 42-400 floor drains all units in ug/L from Black and Veatch 1990: benzene 35, xylenes 1050, bis-2-ethylhexyl phthalate 720, manganese 27000, TPH (method 418.1) 78000 (floating product observed), oil and grease method 413.2 2,500 ug/L. Soil: TPH Method 418.1 907 mg/kg (Black and Veatch 1990) and oil and grease method 413.2 330 mg/kg (Dames and Moore 1986). |
Jennifer Roberts |
| 9/16/1992 |
Update or Other Action |
USAF letter to Jennifer Roberts regarding "Revisions to Elmendorf AFB Federal Facility Agreement (FFA) Scope of Work for Operable Units (OU) 4 and 7."
1. As a result of this summer's field investigation, we request attachment 1 of the FFA be revised as follows:
a. Move FT23 from OU7 to OU4. Based on the results of the Limited Field Investigation (LFI) it appears FT23 may be a source of contamination observed in past investigations at SD24, SD25,
SD26, and SD27.
b. Move SD31 from OU4 to OU3. Geographically, SD31 is more closely aligned with the sources in OU3.
c. Move SS63 (Classic Owl) from OU4 to OU7. Currently at Classic Owl a building is under construction by the Corps of Engineers. If SS63 remains in OU4, then there could be major
conflicts which several contractors working in the area. Also by moving SS63 into OU7, we would be able to address all of the sources located north of the Elmendorf Moraine in one remedial
investigation.
d. Delete the requirement of an interim remedial action (IRA) at OU4. Based on the LFI, the remedial project managers identified the dry wells at SD24, SD28, and SD31 as potential
IRAs. However, further review of the results of the LFI, indicate only the sludge at the bottom of the dry well at these sources were sampled and no soil samples were obtained. At this
time there is no evidence of soil contamination in the immediate vicinity of the dry wells. Without additional investigation of these wells, it does not appear an IRA is warranted. Instead of an IRA, we will pursue funding to remove the sludge in each dry well.
e. Delete the requirement of an IRA at OU7. In 1988, light non-aqueous phase liquid (LNAPL) contamination was found and an IRA was put into the FFA to remove the LNAPL from this source
area. Based on two rounds of water level measurements that showed no LNAPL and soil samples collected this summer attachment 1), it appears there is no reason to address the LNAPL
and we do not have enough information to address the soil contamination. Without additional investigation of this source, it does not appear an interim action is warranted.
2. Please express your concurrence or non-concurrence to the above request and return this letter within seven days of receipt. |
Jennifer Roberts |
| 11/1/1992 |
Update or Other Action |
FINAL OU4 LFI Report received. The purpose of the OU 4 LFI was to identify and evaluate the drain outfalls at 10 facilities to assess the possible environmental impacts that may have resulted from past operations and disposal practices. The results of this investigation will be used to assess the final disposition of the drain outfalls; to recommend No Further Action (NFA) for drain outfalls, when possible; or to recommend that Remedial Investigation/Feasibility Studies (RI/FS) be performed.
The sampling locations originally recommended to receive IRAs, but will instead be removal actions followed by RI/FS activities include:
SBSD24D-ADEC risk-based criteria for DRO and GRO were exceeded at this grab sample location, which is a wood crib dry well location situated southwest of Hangar 10/Building 42-400.
* SBSD28A-ADEC risk-based criteria for DRO and GRO were exceeded at this grab sample location, which is a dry well located north of Building 43-410.
* SBSD31A-ADEC risk-based criteria for DRO and GRO were exceeded at this grab sample location, which is a dry well location situated near the northeast corner of Hangar 5/Building 32-060.
SBSD24D1: 20 mg/kg Ethylbenzene (6.9 mg/kg), 12 mg/kg toluene (6.5 mg/kg), bis(2-ethylhexyl)phthalate 17 mg/kg (13 mg/kg), 2-Methylnaphthalene 72 mg/kg (6.1 mg/kg), naphthalene 42 mg/kg (20 mg/kg), DRO 30,000 mg/kg (Level B [assumes NO GW contamination, in that case Level "A" applies] 200 mg/kg DRO, 100 mg/kg GRO, 0.5 Benzene, Total BTEX 15 mg/kg), GRO 37,000 mg/kg (100 mg/kg), lead 859 mg/kg (400 mg/kg)
SBSD24D2 bis(2-ethylhexyl)phthalate 30 mg/kg (13 mg/kg), 2-Methylnaphthalene 150 mg/kg (6.1 mg/kg), naphthalene 94 mg/kg (20 mg/kg), DRO 28,000 mg/kg (200 mg/kg), GRO 34,000 mg/kg (100 mg/kg).
In addition to the collection of samples at this location, the pipelines leading either to or away from SBSD24D should be investigated during subsequent RI/FS activities to assess whether Building 42-400 is the only source that has contributed to the contamination identified at SBSD24D.
Groundwater contamination has been identified in the three monitoring wells located near SD24, therefore, other potential sources of contamination in the vicinity of SD24 were identified during the LFI. These other sources of contamination include the fire training pit, reported fuel spills, USTs, and POL lines, as shown in Table 3.4 and Figure 3.2. Petroleum fuel products and chlorinated solvents detected in soil and groundwater samples collected from the fire training pit area have also been identified in downgradient monitoring wells near SD24.
The records search conducted by Engineering-Science (1983) indicated that fuel spills up to 1,300 gallons in size have occurred near Building 42-400, but the exact dates and volumes of each release had not been documented in historical USAF records. There were three USTs identified in the vicinity of SD24. These include two 1000-gallon USTs and one 20,000-gallon UST. The use and status of each tank are summarized in Table 3.4. The USAF UST inventory did not indicate whether these tanks had been tested. Therefore, the soundness of each UST is unknown.
Petroleum, oil, and lubricant lines surround a significant portion of the area around Building 42-400. The closest POL line to the building lies approximately 50 feet to the north and 100 feet to the west of Building 42-400. There is also a low-level point and a drain valve in the POL lines approximately 200 feet upgradient of monitoring well IS1-01.
It appears that the groundwater contamination identified at the SD24 monitoring wells has resulted from the activities conducted at the fire training pit, but this cannot be substantiated until additional RI/FS activities are conducted at OU 7. The other contaminant sources identified during the LFI at SD24, such as POL lines and USTS, may need to be investigated during other RI/FS activities to determine if they have contributed to groundwater contamination at SD24. |
Louis Howard |
| 3/26/1993 |
Update or Other Action |
DOD and ADEC joint Technical Memorandum of understanding signed concerning the Base wide Groundwater (GW) signed by: ADEC Jennifer Roberts RPM and USAF Joseph Williamson Chief Environmental Programs and Restoration. Due to the base wide GW study and the FY92 field work that occurred at Operable Units (OUs) 1, 2, and 5 it appears a large portion of the GW flows into OU5 (Attachment 1-Contour Map). Based on this fact, Elmendorf (EAFB) will move all upgradient GW into the OU5 Feasibility Study, Proposed Plan and Record of Decision (ROD).
This means addressing all GW from upgradient sources (CERCLA (ST20, OUs 3 and 4) and OUs 1 and portions of OU2) and SERA) at OU5 instead of at each individual source area (see Attachment 2-Area Map). Sites with free phased product would be looked at to see if there is an available technology to clean them up in a cost effective way. Soil contamination would be addressed at the source areas. NOTE: addressed at the source areas is interpreted by ADEC as removal through excavation or active treatment systems (e.g. high vacuum extraction, bioventing, etc.).
Also included in the file is the AF memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV.
1) Due to the contamination and commitments to EPA/DEC the use of the shallow aquifer for any purpose on is not allowed. Attached Facilities Board minutes-03/29/1994 0930 Item 9 has Mr. William Hanson, briefing the Board on the policy to not use the shallow aquifer due to contamination. The Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The IRP has RODs for OUs 3 and 6 which require, the aquifer remain unused.
2) Personnel in the review process within CES must be aware of these policies and review them on a recurring basis. It is imperative this restriction be recognized and observed during engineer reviews and operations. |
Jennifer Roberts |
| 1/20/1994 |
Enforcement Agreement or Order |
Janice Adair Regional Administrator Southcentral Regional Office signs the November 29, 1993 Underground Storage Tank Agreement. The Parties enter this Agreement to perform necessary inventory, registration, upgrading or closure, and tightness testing associated with USTs at Elmendorf. All draft final work plans for field work must be submitted to ADEC a minimum of 30 days prior to the start of field work or construction.
Site Assessment draft reports for closures must be submitted to ADEC within 60 days after completion of field work. All reports of confirmed leaking USTs, or the need for further investigation, will be forwarded to 3 SPTG/CEVR (or its) successor organization) for possible inclusion into the SERA*. Initial abatement activities required under 18 AAC 78.230 will be conducted by the Air Force prior to transfer of any site to the SERA.
*SERA=Environmental Restoration Agreement between ADEC and the Air Force dated October 1992.
Discovered USTs-All USTs discovered during the life of this Agreement will be addressed under this Agreement and will be added to Attachment A. The Air Force will notify ADEC by next day mail of any discovery within five days of the discovery of an UST, unless release notification is required under 18 AAC 78 220, in which case those provisions will control.
Installation: Any new USTs installed by the Air Force shall be installed in accordance with 40 CFR 280 and 18 AAC 78.022 through 18 AAC 78.090 and will have leak detection, corrosion protection, overfill protectIon, and spill protection. The Air Force will notify ADEC at least 30 days prior to initiating installation of an UST. UST installation work will be conducted by a certified UST worker as required by 18 AAC 78.030 and 18 AAC 78.400.
Release Detection: The Air Force shall install and perform release detection in accordance with the schedules outlined in Attachment A. If release detection is not installed or the tank not previously permanently closed by the date in Attachment A, the Air Force will close the tank in accordance with the closure requirements in 18 AAC 78. All tightness testing performed to satisfy these requirements will be conducted bv a certified UST worker as required bv 18 AAC 78.030 and 78.400.
Operation and Maintenance of Corrosion Protection: The Air Force shall meet the requirements of 18 AAC 78.045 and 40 CFR 280.31 for any steel USTs, that have corrosion protection systems The testing of the corrosion protection systems shall be done by a certified UST worker as required by 18 AAC 78.400.
Site Assessment or System Tig:htness Test: The Air Force shall either conduct a system tightness test on all regulated USTs located at the Base or permanently close the USTs in accordance with Attachment A. If site assessments or system tests have been conducted, the Air Force shall submit proof of compliance by the deadlines set in Attachment A. All tightness testing work will be conducted by a certified UST worker as required by 18 AAC 78.400.
Release Investigation and Corrective Action: Release investigations, interim corrective action and corrective action on petroleum contamination identified in work conducted pursuant to this Agreement is not within the scope of this Agreement. These activities will be conducted pursuant to the Environmental Restoration Agreement between ADEC and the Air Force dated October 1992. |
Janice Adair |
| 2/9/1994 |
Meeting or Teleconference Held |
Technical review committee meeting held to discuss Proposed Plan and Record of Decision processes. Status update on environmental cleanup activities. Cherry Hill ditch section of Operable Unit 3. Oil in the old power plant (ST20) Possible identification and evaluation of old building sites. Community Relations Plan and photo display. |
Jennifer Roberts |
| 9/2/1994 |
Update or Other Action |
OU4 RI/FS Report received. Ten source areas were included as part of OU 4, including SD24 (Hangar 10), SD25 (Hangar 11), SD26 (Hangar 14), SD27 (Hangar 8), SD28, SD29 (Hangar 15), SD30, SD31 (Hangar 5), SS18, and SS63. Currently, there are six facilities located within OU 4 which may be designated as "source areas", including SD24, SD25, SD28, SD29, FT23, and SS10. SD26 and SD27, while recommended for "No Further Action", are still located within the boundary of OU 4.
The groundwater and soil contamination associated with these two facilities were considered as part of the overall OU 4 contamination. In keeping with the premise of treating the contamination at OU 4 as a whole, previously referenced "source areas", except where discussed historically, will be referred to as buildings or facilities located within the OU.
OU4 West: SD24, SD25, SD26, SD27, FT23. OU4 East: SD28, SD29, SS10. SD30-NFA, SD31 Moved to OU3, SS18 NFA, SS63 Moved to OU7.
The cancer risks for the Average exposure range from 7.0 x 10-8 (ADSA)to 2.2 x 10-4 (Hangar 10/11); the RME risks range from 4.2 x 10- (ADSA) to 3.5 x 10-3 (Hangar 10/11). The majority of the risk from the Asphalt Drum Storage Area comes from benzo(a)pyrene in soil for the Average and RME scenarios. The majority (99%+) of risk for the Hangar 10/11 site for both Average and RME scenarios is from benzene in groundwater.
Future On-site Resident
The hazard indices for the Average exposure are less than one at all sites except one. The hazard index at the remaining site, Hangar 10/11, is 5.8 and is due to exposure to toluene in water which contributes 84% of the hazard index. The hazard indices for the RME exposure ranged from less than one to 9.2. The highest was found at Hangar 10/11 and was due to toluene in water which contributed 69% of this hazard index.
Future On-site worker
The cancer risks for the RME exposure range from 1.5 x 10 6 (ADSA) to 2.1 x 10-4 (Hangar 10/11). The majority (100%) of the risk from the ADSA site comes from soil. Of this, 37% comes from benzo(a)pyrene. The majority (99%+) of risk for the Hangar 10/11 site comes from water. All of this from benzene.
The hazard indices for the RME exposure are less than one at all sites.
Current On-site worker
The cancer risks for the RME exposure range from 8.3 x 10-8 (ADSA) to 1.5 x 10-6 (Hangar 10/11). The majority (37%) of the risk from the ADSA site comes from benzo(a)pyrene in soil. The majority (53%) of risk for the Hangar 10/11 site also comes from benzo(a)pyrene in soil.
The hazard indices for the RME exposure range from less than one at all sites.
The OU was divided during the RI to better characterize the nature and extent of contamination and to better evaluate the risk. This division was made based on both geography and contaminant occurrence. Soil contamination is discussed in terms of six geographic areas, including the Fire Training Area, the Asphalt Drum Storage Area, the Hangar 15/Building 43-410 Area, the Hangar 14 Area, the Hangar 10/11 Area, and the Hangar 8 Area.
Groundwater contamination is discussed based upon the well defined contaminant "plumes" which were delineated during the RI. Five groundwater plume areas were established, including the Fire Training Area Plumes, the Hangar 15/Building 43-410 Area Plume, Hangar 14 Area Plume, the Hangar
11 Area Plume, and the Hangar 8/10 Area Plume. The Asphalt Drum Storage Area, while not having a defined groundwater plume, was also evaluated as a separate groundwater area.
Soil contamination in the Hangar 10/11 area includes low levels of semivolatile organic compounds, VOCs, pesticides, and metals. Contaminant migration into the subsurface at this area of interest is believed to be almost vertical due to the coarse nature of the soils in the Hangar 10/11 vicinity. As represented, groundwater flow is to the southwest. A "smear zone" of contamination was identified resulting from seasonal changes in the water table elevation.
Contaminated soil intervals in the Hangar 10/11 area were defined at six boring locations. Contaminated soil was detected in four surface samples and three subsurface samples. Five constituents, including samples with contamination in the GRO and DRO range, were identified exceeding potential regulatory levels.
Sample SBSD25A10 (OU 4 Limited Field Investigation, CH2M Hill, 1992) exceeded both GRO and DRO standards. Kerosene was detected at sample location SB-33 exceeding the DRO potential regulatory level. With the exception of SBSD25A10, samples were not specifically analyzed for GRO and DRO. The COPC which exceeded potential regulatory levels included benzo(a)pyrene,
dibenz(a,h)anthracene, DRO, GRO and kerosene. All of the regulatory level exceedance locations were adjacent to identified sources, including valve pits, dry wells, and USTs. |
Louis Howard |
| 9/15/1994 |
Risk Assessment Report Approved |
Risk assessment combined with RI/FS final version received and approved. 12 constituents were identified as major contributors to groundwater risk. 8 were identified as contributors to carcinogenic groundwater risk: benzene, chloromethane, dieldrin, 1,1-dichloroethene, 1,2-dichloroethane, chloroform, trichloroethene, and carbon tetrachloride. 4 constituents were principal contributors to non-carcinogenic groundwater risk, including toluene, ethylbenzene, cis-1,2-dichloroethene, and trichloroethene. Three compounds within the plume (benzene, toluene and ethylbenzene) had concentrations exceeding potential regulatory levels. Because of this, groundwater at the Hangar 10/11 Area should also be evaluated in the FS.
Results of the risk evaluation for soils indicated six constituents as primary contributors to the carcinogenic risk in soil, including benzo(a) pyrene, benzo(b)fluoranthene, dibenzo(a,h)anthracene, benzo(a)anthracene, PCB-1260, and benzo(k)fluoranthene. Non-carcinogenic risk in soil did not exceed an HQ of 1.0. Five compounds exceeded potential regulatory levels in the soil, including GRO and DRO thresholds. Since the soils at the Hangar 10/11 Area exceeded risk criteria and potential regulatory levels, they should be evaluated for the feasibility of remedial action in the FS.
The results of the risk assessment indicate that each of the six soil and five of the six groundwater areas of interest have a carcinogenic risk in excess of 1.0 x 10-6 using the most conservative residential estimates. At the Asphalt Drum Storage Area, no groundwater risks were identified.
Ecological risk assessment: Ecological quotients for moose did not exceed 1.0 for moose. EQs of 1.0 were exceeded for copper and lead for meadow voles at OU4. None of these exceedances appear to be highly significant for the following reasons: the overall nature of the methodology used was conservative. In several cases the calculated doses, reference criteria, or measurement endpoints were inappropriate for this site because even normal background concentrations caused exceedances. Finally, the relatively uniform distributions of concentrations of manganese, selenium and thallium across all the sites is not typical of highly contaminated areas. |
John Halverson |
| 9/15/1994 |
Site Characterization Report Approved |
Remedial investigation/feasibility study final version received and approved. |
John Halverson |
| 4/3/1995 |
Update or Other Action |
1995 SERA Phase I Corrective Action Plan: 5557 is within the geographical boundaries of OU-3, in the region defined as the east area, and was included in the remedial investigation (Rl). The only investigation conducted under the OU-3 investigation specifically on S557 was a water sample collected from hydropunch point (HP23), although off-site upgradient soil and groundwater
samples were also analyzed for contamination. Groundwater collected from HP23 was found
to contain low concentrations of halogenated volatile organic compounds (V005), including
chloroform, tetrachloroethylene, 1,1,1-trichloroethane, and perchioroethylene. BTEX constituents were also detected, with benzene present at 8.6 ug/L (2018 Table C is 4.6 ug/L). In general, VOC contamination in groundwater at OU-3 East was found to be widespread and could not be definitively assigned to sources. The RI concluded that contamination impacting SS57 may be associated with pulses of contamination migrating downgradient from OU-4.
Groundwater contamination analysis and local hydrogeologic information at 5557 implicate an upgradient source of the identified groundwater contamination. 5557 is within the geographical boundaries of OU-3 East Area (USAF 1994h). This site was included in the 0U5 model for the entire outwash plain. This model concluded that all sources upgradient from 0U5 (which includes SS57) would remediated via natural attenuation within acceptable risks. It ¡s recommended that further consideration of contamination at SS57 be transferred to OU-3 under the CERCLA program. A risk assessment was conducted as part of the RI for the OU-3 East, which included data from the SERA Phase I Site Assessment. Based on the results of the risk assessment, the East Area (including 5557) was recommended for no further action. |
John Halverson |
| 4/11/1995 |
Proposed Plan |
The proposed plan for Hangar 10 (part of OU4 West) lists fuel contaminants in the deep soil and asphalt-type contaminants in the shallow soils. Groundwater (GW) impacts in the vicinity of Hangar 10 from fuel were detected and the source was attributed to Pumphouse 2. Air Force (AF) tested pumphouse and repairs were made.
Level D is the cleanup standard for shallow and deep soils (1000 mg/kg GRO, 2000 mg/kg DRO and 100 mg/kg kerosene). Benzene was the only contaminant of concern (COC) for GW and a cleanup level of 5 ug/l is the standard that must be met. Bioventing was selected for shallow and deep soils at Hangar 10 with a timeframe to cleanup of 2 years. Institutional controls with intrinsic remediation was selected for GW contamination with a timeframe to cleanup of 13 years (2008). |
Jennifer Roberts |
| 6/15/1995 |
Site Ranked Using the AHRM |
Initial ranking. Action code added because it wasn't when the site was originally ranked. |
Louis Howard |
| 10/10/1995 |
CERCLA ROD Approved |
The Record of Decision specifies for Hangar 10’s contaminated GW will be addressed through intrinsic remediation with ICs.
Deep soils at the FTA, the ADSA, & Hangar 10/11 [SD24/SD25] will be treated with bioventing to accelerate degradation of contaminants in those locations. Deep soils at other source areas will be allowed to degrade through intrinsic remediation. The Air Force will investigate & implement other remedial alternatives should the selected remedies prove to be unsuccessful at meeting the required cleanup levels.
Specific components of the selected remedy consist of the following:
GW
* Institutional controls (ICs) on land use & water use restrictions will restrict access to the contaminated GW throughout OU 4 until cleanup levels have been achieved.
* GW will be monitored & evaluated semi-annually to assess contaminant migration & timely reduction of contaminant levels by intrinsic remediation. This will include five-year reviews to assess the protectiveness of the remedial action, as long as contamination remains above cleanup levels. A monitoring plan will be prepared to address the details involved in sampling.
* All GW is expected to be cleaned up within thirteen years.
Soil
* ICs on land use will restrict access to the contaminated shallow soils throughout OU 4 until cleanup levels have been achieved.
* Deep soils at specified locations & depths at the FTA, the ADSA, & Hangar 11 will be treated with bioventing to accelerate degradation of contaminants in those locations. Deep soils at other source areas will be allowed to degrade through intrinsic remediation.
* Both shallow & deep soils will be monitored & evaluated bi-annually to assess contaminant migration & timely reduction of contaminant levels by intrinsic remediation. This will include five-year reviews to assess the protectiveness of the remedial action, as long as contamination remains above cleanup levels.
* When levels in the bioventing areas are below cleanup levels, bioventing will be discontinued. A monitoring plan will be prepared to address the details involved in sampling.
* All soils are expected to be cleaned up within 11 years.
The remedy will be implemented after the Remedial Design has been completed. A treatability study for bioventing design is currently in progress. Bioventing will be implemented until cleanup levels have been achieved. The actual timeframe for intrinsic remediation at the other source areas is not known, but GW & soil modeling predict cleanup levels will be achieved in 10 to 15 years.
GW & soil will both be monitored to evaluate the progress of intrinsic remediation processes. Further response actions, coordinated with the regulatory agencies, may be considered if monitoring finds unacceptable contaminant migration occurring, or unacceptable reduction in contaminant levels through intrinsic remediation.
NOTE TO FILE: § 300.430 Remedial investigation/feasibility study & selection of remedy.(a) General—(1) Introduction. The purpose of the remedy selection process is to implement remedies that eliminate, reduce, or control risks to human health & the environment. Remedial actions are to be implemented as soon as site data & information make it possible to do so. Accordingly, EPA has established the following program goal, expectations, & program management principles to assist in the identification & implementation of appropriate remedial actions.
(iii) Expectations. EPA generally shall consider the following expectations in developing appropriate remedial alternatives:
(D) EPA expects to use institutional controls such as water use & deed restrictions to supplement engineering controls as appropriate for short- & long-term management to prevent or limit exposure to hazardous substances, pollutants, or contaminants. Institutional controls may be used during the conduct of the remedial investigation/feasibility study (RI/FS) & implementation of the remedial action &, where necessary, as a component of the completed remedy.
The use of ICs shall not substitute for active response measures (e.g., treatment &/or containment of source material, restoration of ground waters to their beneficial* uses) as the sole remedy unless such active measures are determined not to be practicable, based on the balancing of trade-offs among alternatives that is conducted during the selection of remedy.
*“EPA expects to return usable ground waters to their beneficial uses wherever practicable, within a time frame that is reasonable given the particular circumstances of the site. When restoration of ground water to beneficial uses is not practicable, EPA expects to prevent further migration of the plume, prevent exposure to the contaminated ground water, & evaluate further risk reduction” 40 CFR 300.430(a)(1)(iii)(F). |
Louis Howard |
| 10/10/1995 |
Cleanup Level(s) Approved |
Level D is the cleanup standard for shallow and deep soils (1,000 mg/kg GRO, 2000 mg/kg DRO and 100 mg/kg kerosene). Benzene was the only COC for GW and a cleanup level of 5 ug/l is the standard that must be met. |
Jennifer Roberts |
| 10/10/1995 |
Institutional Control Record Established |
ICs established by signing of ROD and subsequent AF base wide planning has implemented these controls on all activities by AF personnel and contractors for soil and GW media.
No current receptors exist for the groundwater at the Base due to the institutional controls (ICs). As a requirement of previously signed RODs for the Base, ICs have been established to restrict the use of the shallow aquifer in the outwash plain on Base. 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. |
Jennifer Roberts |
| 3/13/1997 |
Update or Other Action |
Action 3/13/97 based on Relative Risk Evaluation worksheet dated 8/4/95. Pathway: The soil is gravel with some sand and silt. GW about 30 feet below ground surface. Confining layer between shallow and deep aquifer. Any liquid contaminants that spilled here will go straight down to groundwater. Receptors: Industrial area along flight line. |
Louis Howard |
| 6/16/1997 |
Update or Other Action |
USAF Memorandum to ADEC regarding Clarifications to OU2 ROD. The letter is a follow-up to the discussions regarding institutional controls at OU2. The USAF hopes by this correspondence, to clarify appropriate land use controls at OU2 and setup a land use restriction method consistent with the most recent Elmendorf RODs. The OU2 ROD states that groundwater at ST41 needs remedial action and a part of the selected remedy was to restrict land use by implementing zoning controls. The Summary of the ROD on page 9-2 states that the selected remedy includes "Zoning the affected area for industrial use only, excluding the development of commercial aquaculture."
However, the Declaration of the ROD states "Zoning the affected area for undeveloped outdoor/recreational use only." In light of this contradiction and the use of "restricted use areas" under the RODs for OU3 and OU6 the USAF is providing clarification of the permissible land uses within the area affected by ST41 groundwater. The affected area should include those areas that exceed the groundwater cleanup levels established in the OU2 ROD. A map of the area currently and potentially impacted by the contaminated groundwater from ST41 is at Attachment 1. This map may be revised based upon review of the contamination remaining in place, which will be conducted at least every 5 years. While the affected area remains above cleanup levels, it will be designated as a "restricted use area" in the base Planning Office. This designation provides for recreational use of the parcel (such as cross country skiing, bicycling, etc.) and the construction of unmanned facilities (such as parking lots, storage buildings, etc. ) but prohibits the construction of any manned facilities (such as office buildings or a residence). Construction activities within the affected area of OU2 will be restricted to construction of unmanned facilities. Furthermore no construction will be allowed which comes within five feet of the groundwater. Existing industrial uses within OU2 are allowed as they are unmanned. This description conforms to the current base land use planning terminology and is consistent with the recently signed RODs for OUs 3 and 6. Land use restrictions will be enforced by the following method. When there is a construction project on Base, the project is to be approved by the Base Planning Office. The planner will route all projects through the Environmental Management Office. The project will be disapproved if it conflicts with the above construction restrictions. The USAF believes this will be a reliable and effective means of enforcing the zoning land use restrictions imposed by the various RODs. Signed by Randy E. Honnet Colonel USAF Vice Commander. |
Louis Howard |
| 7/24/1998 |
Update or Other Action |
6/98 remedial action report for OU4 to document the five year review by U.S. EPA, AF and ADEC states that it will take 8 more years for the benzene contaminated groundwater to achieve cleanup levels of 5 ug/l. Latest results show 96 ug/l of benzene exists in GW. |
Louis Howard |
| 11/8/1999 |
Update or Other Action |
The location of a former 500-gallon UST (tank 31-338) that was primarily used to store JP-4 jet fuel waste from fuel truck maintenance activities. The UST was removed in August 92, and replaced with a 1,200-gallon UST (31-338A) in an adjacent location. NOTE TO FILE: Naphthalene is a white solid or a liquid that occurs naturally in fossil fuels such as coal and crude oil and is best known as the primary ingredient of mothballs. It is extracted from these sources for other uses including jet fuel (as 1-3% of the fuel JP-4, JP-8, and commercial aviation gas or AvGas)
The depth to groundwater in well 49WL01 located approximately 150 feet south-southwest of the site, was measured at 13.59 feet below ground surface (bgs). The depth to groundwater in the bioventing vent well was measured at 11.53 feet bgs. Shallow groundwater is not currently used as a drinking water source and is unlikely to be used as one in the future. Contaminant of concerns (COCs) with initial contamination levels are as follows:
Initial Contamination Levels for Soil Water
Diesel Range Organics (DRO) 860 mg/kg 9,700 ug/l
Gasoline Range Organics (GRO) 3,600 mg/kg 9,700 ug/l 9 Benzene .033 mg/kg 740 ug/l
Toluene 1.3 mg/kg 35 ug/l
Ethylbenzene 4.9 mg/kg 95 ug/l
Total xylenes 80 mg/kg 1,300 ug/l
STATEMENT OF BASIS-This decision is based on the following attached references:
a. Site ST71 from SERA Phase I Corrective Action Plan (CAP), Final, Apr 95
b. Alaska Department of Environmental Conservation's (ADEC) 27 Feb 97 Ltr
c. Table 4-17, Basewide Annual Groundwater Report, Final, Mar 98 (49WL01)
d. Site Closure Report for Site ST71, Nov 96 (refer to your copy)
e. Table 5-8, Basewide Annual Groundwater Report, Final, Jun 99 (49WL01)
f. Table 2-4, Basewide Monitoring OU4-Round 1, Aug 99 (49WL01)
DESCRIPTION OF THE SELECTED REMEDY-No further remedial action remedy is based on the field sampling conducted on 28 May 96 pursuant to closure of site ST71 on base. All of the laboratory analytical results for vadose zone soil were below ADEC (1995) Category A soil cleanup levels for all analytical methods. These results indicate that petroleum hydrocarbons in the vadose zone soil at the site have been remediated to the applicable matrix cleanup levels during the operation of the bioventing system.
Monitoring well 49WL01 has been added to the OPERABLE UNIT (OU)4 monitoring program. With the exception of benzene concentrations in groundwater at down gradient well 49WL01 (14.9 ug/l), GRO (930 mg/kg at 49BH07-12 and 500 mg/kg at 49BH08-13), and DRO (1,600 mg/kg at 49BH07-12) concentrations in saturated soil samples, this site meets all applicable state cleanup goals. Contaminated soil below the watertable is not effectively remediated through bioventing.
The vadose zone soil was below ADEC (1995) Category A soil cleanup levels for all analytical methods. This has allowed the bioventing system at this site to be turned off in 1997 and will be removed in the future. The groundwater contamination is under the cleanup levels in Table C using the criteria outlined by 18 AAC 75.345 (b)(2)(A)&(B). In addition, the wetland remediation system constructed on the Ship Creek flood plain prevents ST71 contamination from leaving the base property boundary. Therefore, there is no further requirement for tracking conditions at ST71. Monitoring well 49WL01 has been added to the OPERABLE UNIT (OU)4 (Basewide) monitoring program.
If any information is presented in the future that indicates contamination from this project area is present (above established cleanup levels) and/or poses a risk to the public's health or the environment, then additional assessment and corrective action may be necessary. The location of this monitoring well is useful to track trends of trichloroethene (TCE), dichloroethene (DCE), and chloride concentrations in the outwash plain. The remedy of no further remedial action under the ERP is selected because the contaminant levels at the site present no significant threat to human health or the environment; thus, no treatment is necessary. |
Louis Howard |
| 10/30/2000 |
Update or Other Action |
Base wide Groundwater sampling report received for Round 2. No MTBE was detected in any of the samples during this time as was the case for Round 1. Benzene cleanup level of 5 ug/L was exceeded in wells: FP-56 (13 ug/L), OU4W-04 (57 ug/L), OU4W-08 (150 ug/L), and OU4W-11 (6.3 ug/L).
Trichloroethene (TCE) cleanup level of 5 ug/L was exceeded in these wells: 48-WL-01 (40 ug/L), FP-56 (7.1 ug/L), OU3MW-11 (79 ug/L), and OU4W-11 (69 ug/L). |
Louis Howard |
| 2/21/2002 |
Update or Other Action |
Staff reviewed and commented on the annual base wide groundwater monitoring report.
Regulatory Levels
ADEC requests removing the word “Potential” from the heading “Potential Regulatory Level” in the tables throughout the document. Listing the word “Potential” gives the reader the impression that compliance with the levels listed is optional or not required (e.g. Tables 4-7, 4-11, 4-15, 4-20, 4-25, 4-29, 4-32, and 6-2).
Free Product
Please note 18 AAC 75.325(f) states: A responsible person shall to the maximum extent practicable,
(A) use permanent remedies;
(B) recover free product in a manner that minimizes the spread of contamination into an uncontaminated area by using containment, recovery, and disposal techniques appropriate to site conditions.
ADEC recognizes that in some cases it may not be technically practicable to implement an active or passive recovery system for free product. The Elmendorf Remedial Action Report for Operable Unit (OU) 2 (September 1998) set a precedent for defining what is meant by “technically practicable” for free product recovery. Section 2.4.1 Product Recovery Endpoints at the 1st bullet on page 10 states: “As designed and constructed, the ST41 ground water treatment system cannot recover floating product when there is less than a measurable thickness of 0.1 feet of product. Therefore, as an endpoint for product recovery, if less than 0.1 feet is sustained for one year, recovery at that source can be discontinued. Floating product will be measured monthly. When product thickness falls below 0.1 feet for one year, the recovery of product at that source will not be considered “technically practicable”.
Therefore, where free product is greater than 0.10 feet, ADEC expects corrective action (active or passive) to be implemented for free product recovery. Currently, free product was found to exceed 0.10 feet or more in SERA Phase I well 43-WL-11. This well had the highest level of free product measured at 0.86 feet. The presence of measurable free product is generally not considered conducive for intrinsic (natural) attenuation. ADEC requests the identity of the free product be described in the text at each source area that it is found (e.g. gasoline, diesel, or chlorinated solvents).
3.3.4 Target Analytes Pages 3-10 and 3-11
Benzene and TCE are identified as target analytes to evaluate contaminant of concern (COC) trends in detail and be consistent with the Base wide Groundwater model. ADEC concurs, however, focusing on these two analytes does not accurately reflect whether diesel range organics (DRO) and gasoline range organics (GRO) plumes are migrating, expanding, steady state, or receding (especially for wells noted to have either free product or fuel odor and/or sheen being observed during sampling). Benzene can be at low levels or even non-detectable while concentrations of DRO and GRO remain above cleanup levels (1.5 mg/L and 1.3 mg/L respectively). Please see the following examples below of where benzene was below the 5 ug/L cleanup level, but DRO and GRO are above cleanup levels.
OU 4
Round 1 sampling at well 49-WL-01 detected benzene at 0.11 ug/L and DRO at 2,400 ug/L and well OU4W-11 detected benzene at 4.3 ug/L while GRO was detected at 3,000 ug/L and DRO was detected at 6,100 ug/L.
OU6
Round 1 sampling at well OU6MW67 detected benzene at 2.8 ug/L, GRO at 2,500 ug/L and DRO at 1,700 ug/L during round 1 sampling. During round 2 sampling, well OU6MW-91 detected GRO at 25,000 ug/L and DRO at 9,500 ug/L while benzene was found to be non-detectable.
See site file for additional information. |
Louis Howard |
| 8/28/2002 |
Meeting or Teleconference Held |
STATUS MEETING MINUTE ELMENDORF BASEWIDE MONITORING PROGRAM AUGUST 28, 2002 Attendees: Joe Williamson (USAF), Cindy Hood (AFCEE), Terry Beach (AFCEE), Kevin Oates (EPA), Louis Howard (ADEC), Cory Hinds (URS), Russ Beck(URS)
Agenda: Review of soil gas surveys and new well locations, Recommendation for treatment of TCE at OU5 Seeps 9, 10, and 11 in the existing Wetland Remediation System, Well sampling frequencies for 2003
2003 Monitoring Well Sampling Frequencies
URS presented the new proposed Basewide decision guide for determining sampling frequencies for monitoring wells. Proposed monitoring frequencies are based on position of plumes relative to environmental receptors. Plumes immediately upgradient of a receptor were proposed for annual sampling. Plume not immediately upgradient of a receptor were proposed for sampling every 2 to 5 years.
EPA pointed out that this guide is only appropriate for stable plumes and suggested that we add a box to include a decision for unstable plumes. Unstable plumes should be sampled semi-annually if upgradient of a receptor or within the early warning line in OU 5.
URS presented the new sampling frequency table, which is based on plumes rather than program areas. EPA and ADEC agree that it makes sense to organize on a plume-by-plume basis instead of by program area. The Air Force mentioned that there will be additional wells required for the early warning system at OU5, and that some of the early warning sampling will be conducted using passive diffusion bags. Use of the passive bags may mean that it is feasible to sample in the winter. EPA, ADEC, and URS agreed on modification of sampling frequencies. In general, sampling frequencies were increased when the plumes were close to a receptor (i.e., Ship Creek) or the concentrations of contaminants were increasing. A list of the agreed sampling frequencies is attached.
Additional items discussed:
• WP14: Air Force mentions reducing number of wells. ADEC mentions an early warning system. These will be discussed later.
• Air Force will investigate the floating product at OU4 West. |
Louis Howard |
| 9/25/2003 |
Update or Other Action |
Memorandum to the Site File was signed for OU4. The purpose of this document (Memorandum to the Site File) is to present non-significant or minor changes to the Record of Decision (ROD) signed for OU 4 at EAFB. The minor changes to the OU 4 ROD involve modifying the sampling frequency of groundwater wells. Other components to the OU 4 selected remedy will not be affected by this minor change.
The Record of Decision (ROD) was signed in October 1995 and the major components of the selected remedy include:
Groundwater
• Institutional controls on land use and water use restrictions will restrict access to the contaminated groundwater throughout OU 4 until cleanup levels have been achieved.
• Groundwater will be monitored and evaluated semi-annually to assess contaminant migration and timely reduction of contaminant concentrations by intrinsic remediation.
Soils
• Institutional controls on land use will restrict access to the contaminated shallow soils throughout OU 4 until cleanup levels have been achieved.
• Deep soils at specified locations and depths at the FTA (FT23), the asphalt drum storage area (SS10) and hanger 11 (SD25) will be treated with bioventing to accelerate degradation of contaminants in those locations. Deep soils at other source areas will be allowed to degrade through intrinsic remediation.
• Both shallow (less than 5 feet in depth) and deep soils will be monitored and evaluated bi-annually to assess contaminant migration and timely reduction of contaminant concentrations by bioventing and intrinsic remediation.
The selected remedies for groundwater and soils have been implemented and are currently ongoing. Groundwater monitoring for OU 4 is included as part of the EAFB Basewide Environmental Monitoring Program (Basewide Monitoring Program). The Basewide Monitoring Program was established to integrate the needs of multiple environmental programs and compliance issues included in the FFA, State-Elmendorf Environmental Restoration Agreement (SERA), CERCLA regulations and the Resource Conservation and Recovery Act (RCRA).
This minor revision to the ROD changes the sampling frequency for groundwater monitoring. Data collected semi-annually over the past seven years has provided an understanding of the nature and extent of contaminant migration and the effectiveness of intrinsic (natural) remediation. In many instances continuation of the semi-annual sampling would not provide any useful new data as compared to less frequent monitoring.
Revised Remedy: Sampling changed from semi-annually to a frequency determined by the Decision Guide.
The changes to the sampling frequency will continue to provide sufficient data to assess contaminant migration and timely reduction of contaminant concentrations by intrinsic remediation as required by the ROD. The revised monitoring frequency will also streamline the groundwater reporting process and reduce monitoring costs.
These changes to the sampling frequencies were discussed in the August 28, 2002 meeting between the USAF, Region X of the EPA and the ADEC. Both EPA and ADEC project managers concurred with the proposed changes. This change in the ROD does not significantly change or fundamentally affect the remedy selected in the ROD; therefore, no public comment is required. |
Louis Howard |
| 1/27/2004 |
Update or Other Action |
The second five year review was signed by ADEC. The purpose of this five-year review is to evaluate the implementation and performance of the remedial actions that were selected in the Record of Decision (ROD) for each Operable Unit (OU). For soil there have been numerous newly promulgated state soil cleanup levels that apply to the COPCs identified in the ROD (28 promulgated current alaska cleanup levels which were either new or more stringent than the OU4 ROD levels).
Of these, the only COPCs that had maximum detected levels that exceed the new standard are 1,1,1-trichloroethene (2.9 ug/L), benzene (0.043 ug/L), and methylene chloride (0.092 ug/L). However, the associated calculated risks are within EPA's risk management decision range (i.e. less than 1 x 10-6 for carcinogens and the hazard is less than 1 for the non-cancer chemical).
Note that the risk and hazard quotient estimates presented in Tables B-2 and B-3 in attachment B appear slightly underestimated because they do not include the ingestion pathway; however, because the estimated risks are orders of magnitude below a level of concern, the addition of the ingestion pathway would not affect the conclusions of this evaluation. The new soil inhalation standards are risk-based and, if concentrations were present at the level of the standards in Table B-3, risks would not exceed the ADEC target risk goal of 1 x 10-5 for carcinogens or a hazard quotient of 1 for non-carcinogens. The protectiveness of groundwater clean-up levels presented in Table B-2 for soil are not risk-based levels for direct exposures to soil; they represent soil concentration if the chemicals leach from soil. Therefore, levels above the protection of groundwater cleanup levels do not represent exceedances of target health goals from exposures to soil as shown in Table B-3 in Attachment B.
The original risk assessment identified risks above target health goals if groundwater was used as a drinking water source under either a future residential or a current/future commercial/industrial land use scenario. No risks/hazards from soil exposures exceeded target health goals. LUCs prevent groundwater use as a source of drinking water and no significant land use changes have occurred at the sites. The site use remains commercial/industrial, specifically, military buildings staffed by civilian and military personnel. All exposure assumptions, cleanup levels or RAOs used at the time of the remedy selection remain valid at this time and are still protective according to the current regulatory cleanup levels. |
Louis Howard |
| 7/2/2004 |
Site Number Identifier Changed |
Changed Work plan to reflect the presence of at hazardous substance above cleanup levels, trichloroethene. |
Former Staff |
| 3/6/2006 |
Update or Other Action |
Staff reviewed the draft 2005 Phase I Remedial Process Optimization (RPO) Annual report. The text states if significant downgradient migration were to occur, the contaminants found at SD24 would be detected at downgradient sites. ADEC requests the text include reference to exactly which specific sites are downgradient of SD24 that are monitoring these same contaminants of concern. The OU 4 Record of Decision (ROD) identified benzene as the contaminant of concern (COC) in groundwater at SD24 and it remains as the only COC in groundwater currently. |
Louis Howard |
| 2/23/2007 |
Exposure Tracking Model Ranking |
|
Louis Howard |
| 3/7/2008 |
Update or Other Action |
Zone 2 Remedial Process Optimization Report received. Zone 2 consists of seven sites containing a total of eight groundwater plumes and one site with no apparent groundwater contamination. These sites are spread throughout the central and eastern areas of Elmendorf AFB. The Zone 2 sites are primarily operated under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) and through the OU4 and OU6 Records of Decision (RODs).
Site ST32 was formerly managed under a cooperative agreement with the Alaska Department of Environmental Conservation (ADEC) and the State Environmental Restoration Agreement (SERA). On 21 October 2002, SERA was dissolved by mutual agreement between the USAF and ADEC. The sites and programs formerly addressed by SERA are now addressed in accordance with applicable requirements of 18 Alaska Administrative Code (AAC) 78 (Underground Storage Tanks) and 18 AAC 75 (Oil and Other Hazardous Substances Pollution Control)
(USAF, 2005c).
The selected remedies for SD24 are LUCs and MNA (USAF, 1995a). The monitoring well network in place at SD24 appears to be adequate to track migration of contaminants toward potential human or ecological receptors. LUCs are preventing human and environmental receptors from being exposed to contaminated groundwater.
Monitoring data show that benzene concentrations remain above the ROD-specified cleanup level of 5 µg/L (USAF, 1995a). Monitoring of this site is ongoing in accordance with the ROD, and samples are collected and analyzed in accordance with the 2006 Work Plan, Remedial Action-Operations, Zone 2, Elmendorf AFB, Alaska (USAF, 2006b). ROD-specified LUCs are enforced through the Elmendorf AFB 3rd Wing Dig Permit process. Annual LUC inspections are performed and documented in accordance with the Final Land Use Control Management Plan (USAF, 2003c).
The Hangar 10 area is a Green priority site because the groundwater remedy is on track to reach the specified cleanup level within one year of the expected date in the ROD. In addition, the current management of Site Hangar 10 is protective because land use controls are preventing human and environmental receptors from being exposed to contaminated groundwater and soil.
However, no wells are sampled immediately downgradient to verify the plume is not migrating. Despite this, historical contaminant measurements at OU4W-04, the general success of fuel natural attenuation at Elmendorf AFB, and the location of this site thousands of feet from the base boundary all contribute to a high level of confidence for success of the remedy.
The recommendations for the Hangar 10 plume are as follows:
Short-Term (FY08-FY09)
• Continue monitoring per Figure 1.4. Long-Term (FY10 or Longer)
• Continue monitoring per Figure 1.4.
The following assumes concentrations at Hangar 10 Plume do not continue to show a declining trend.
• Perform field investigation to define the source area and downgradient contamination.
• Update Conceptual Site Model (CSM).
• Reduce source area mass through removal or in-situ treatment.
• Perform RPO evaluation. Perform long-term monitoring optimization study and implement with approval from regulatory agencies.
• Monitor according to optimized monitoring schedule. |
Louis Howard |
| 10/15/2008 |
Update or Other Action |
5 YR Review
Groundwater was monitored annually at FT23 and SD25, and every three years at SD29 and every five years at SD24, in accordance with the Basewide Monitoring Program Well Sampling Frequency Decision Guide (USAF, 2003d; also included in Attachment F, Figure F-1). No wells associated with SD28 were monitored. Groundwater at all other OU4 sites meets cleanup levels, and the sites either require NFA or are closed. Groundwater monitoring results were evaluated four times in the past five years (USAF, 2004b, 2005i, 2006d, 2008a).
Evaluations included trend analysis of COCs and assessment of natural attenuation parameters. Also, a USEPA scoring model (Wiedemeier et al., 1998) assessment for natural attenuation of chlorinated solvents was performed for FT23 (USAF, 2005i). COC concentrations are rapidly decreasing at FT23, SD24 and SD29. Natural attenuation processes appear to be working and trending predicts that cleanup levels will be met by 2009.
Recommendations for changes to the OU4 monitoring program include:
Because groundwater at SD24 and SD29 is expected to meet cleanup levels by 2009, increase monitoring frequency from once every five years to annually in accordance with the monitoring frequency decision guide (Attachment F, Figure F-1). This will document attainment of cleanup levels and expedite closure of these sites.
Site Inspection
OU4 (SD24, SD25, SD28 and SD29). All active monitoring wells were located and were in good condition. There are no active monitoring wells for SD28. There was no evidence of unauthorized wells or site disturbance.
The cleanup levels for 1,2-dichloroethane, PCE, and TCE for FT23 groundwater, and DRO and GRO for SD24 and SD25 soil, as presented in OU4 ROD, are inconsistent with their referenced standards. The cleanup levels for 1,2-dichloroethane, PCE and TCE at FT23 are listed as 6 µg/L instead of the MCL standard of 5 µg/L. The cleanup levels identified for DRO and GRO at SD24 and SD25 are 1,000 and 2,000 mg/kg respectively, which is the reverse of their referenced ACM Level D standard. These inconsistencies appear to be typographical errors because there is no discussion in the ROD about deviation from the referenced standards. The cleanup levels for these COCs should be adjusted in a memorandum to the site file so they are consistent with the standards referenced in the ROD.
Issues
Inconsistent Cleanup Levels: The cleanup levels for 1,2-dichloroethane, PCE, and TCE for FT23 groundwater, and DRO and GRO for SD24 and SD25 soil, as presented in OU4 ROD, are inconsistent with their referenced standards. The cleanup levels for 1,2-dichloroethane, PCE and TCE at FT23 are listed as 6 µg/L instead of the MCL standard of 5 µg/L. The cleanup levels identified for DRO and GRO at SD24 and SD25 are 1,000 and 2,000 mg/kg respectively, which is the reverse of their referenced Alaska Cleanup Matrix Level D standard. These inconsistencies appear to
be typographical errors because there is no discussion in the ROD about deviation from the referenced standards.
Recommendations & Follow-up Actions
Update the ROD-specified cleanup levels for 1,2-dichloroethane, PCE, and TCE for FT23 groundwater, and DRO and GRO for SD24 and SD25 groundwater, so that they are consistent with their referenced standards. Document the updated cleanup levels in a memorandum to the site file.
Increase monitoring frequency of wells OU4MW-04 and IS6-01 to annually to document attainment of cleanup levels and expedite closure of these sites.
The remedy at OU4 is expected to be protective of human health and the environment upon attainment of soil cleanup levels through bioventing at one remaining site (FT23) and attainment of groundwater cleanup levels through natural attenuation at sites FT23, SD24, SD25 and SD29. In the interim, exposure pathways that could result in unacceptable risks are being controlled. |
Louis Howard |
| 3/17/2009 |
CERCLA ROD Periodic Review |
Cover letter to the EPA's Five-Year Review signature sheet sent to Richard J. Walberg, Colonel, US Air Force Vice-Commander from EPA Region 10 Office of Environmental Cleanup Daniel D. Opalski, Director. The Environmental Protection Agency (EPA) has completed their review of the third Five-Year Review report for the United States Air Force (USAF) Elmendorf Superfund site, in Anchorage Alaska.
EPA reviewed this report for technical adequacy, accuracy, and consistency with EPA guidance. In general, EPA agrees with the protectiveness determinations in this report. However, I understand that all parties to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 120 Federal Facility Agreement (FFA) are aware of a potential new source that has not been fully characterized, namely SS-022. It is also my understanding that while the Five-Year Review identifies this potential new source, the USAF has not adequately discussed the interim measures it has already taken to ensure protectiveness as site characterization proceeds, such as Institutional Controls (ICs) at SS-022 and the ongoing Remedial Investigation.
Therefore, we recommend that within ninety (90) days (by June 15, 2009), USAF supplement the Site File and Administrative Record with a Memorandum to document the ICs (e.g., installation of a fence, signage, and notation on the Environmental Restoration Program Atlas) that have been implemented for the protection of human health and the environment at SS-022. The Memorandum should also mention the Installation-wide ICs (including restriction of ground water use) already in place.
In addition, EPA agrees with USAF's recommendation for further action at the OU-l landfill area for the trichloroethylene (TCE) groundwater contamination, and requests that the Program Managers meet to discuss the timeline for completion of the groundwater contamination characterization and establish deadlines and, as appropriate, target dates for subtasks, as required under the FFA.
|
Louis Howard |
| 4/14/2010 |
Update or Other Action |
This annual report includes a qualitative evaluation of the 2009 groundwater analytical data to determine if the current conditions at the Zone 2 potentially warrant changing the 2007 RPO category for each site. The next detailed RPO evaluation is scheduled for 2012.
Field activities performed during 2009 at Zone 2 included water level measurements; groundwater sampling; operation, maintenance, and monitoring (OM&M) of the bioventing system at Sites FT23 and ST32; decommissioning of the FT23 bioventing system; soil, groundwater, and vapor intrusion investigations at FT23; a groundwater investigation at SS43; soil and groundwater investigations at ST32; monitoring well inspections and surveys at ST32; well abandonment; well maintenance; well flagging; land use control (LUC) inspections; and waste management.
The 2008 RPO evaluation identified Site SD24 as a Green priority site because the remedy was on track to reach the site cleanup levels within one year of the expected date in the ROD of 2008 (USAF, 2008). Based on the 2009 groundwater analytical data, the benzene concentration at OU4W-04 has still not reached the specified cleanup level. However, the remaining benzene concentration is only slightly above the cleanup level and the historical benzene concentrations exhibit an overall decreasing trend. Based on this information, the Green priority designation for Site SD24 remains appropriate. |
Louis Howard |
| 11/10/2010 |
Meeting or Teleconference Held |
A meeting of the remedial project managers (RPMs) convened at 0900 on 17 November 10 at
the Joint Base Elmendorf-Richardson (JBER)-Richardson Conference Room in Building 658.
Attendees included:
Mr. Bill Adams - Environmental Protection Agency (EPA); Mr. Louis Howard - Alaska Department of Environmental Conservation (ADEC); Mr. Robert Shirley - Air Force Center for Engineering and Environment (AFCEE) Western Region Environmental Office; Mr. Nick Muszynski - AFCEE Restoration - Program Management Office (R-PMO); Mr. Rafael Vazquez - AFCEE R-PMO; Mr. Jim Klasen - lith Air Force Environmental Attorney; Ms. Renee Wright - Environmental Restoration Community Relations Coordinator; and CEANR personnel - Mr. Gary Fink, Mr. Mark Prieksat, Ms. Donna Bawnler, Mr. Don Aide, Mr. Tim Plucinski, Mr. Dick Nenahlo, and Ms. Cynthia Tomlinson.
Zone 2 - Mr. Don Aide explained that field activities for Summer 2010 were complete and included the following:SD24 - benzene is below cleanup levels for the 1st time ever. |
Louis Howard |
| 1/24/2011 |
Update or Other Action |
Staff received the 2010 Zone 2 Mgt. Area Annual Report. This annual report presents a description of the activities performed in 2010 at the Zone 2 Management Area at Joint Base Elmendorf-Richardson (JBER), Alaska. This document describes field activities and pertinent observations, presents analytical data, and provides recommendations for the Zone 2 Management Area, which now includes Sites ST48 and ST68. Beginning in 2010, Sites ST48 and ST68 have been included in reports related to the Zone 2 Management Area (rather than the Zone 3 Management Area) because the boundary between the Zone 2 and Zone 3 Management Areas was revised during the 2009 field season.
A groundwater sample was collected from well OU4MW-04 on 11 June 2010 and submitted to a fixed-base laboratory for analysis of BTEX. The benzene concentration measured in the sample from OU4MW-04 (4.2 µg/L) in 2010 was below groundwater cleanup level of 5 µg/L (Figure 4.1). The other BTEX compounds analyzed were also well below their respective cleanup levels.
Biogeochemical indicator parameters measured in well OU4MW-04 using field methods indicate a moderately anaerobic and reducing environment (Table 1.3). The range of individual parameter values and the corresponding interpretation of the active electron acceptor processes for 2010 are consistent with findings from previous monitoring events, indicating that the dominant contamination degradation processes have not changed over time. Although the rate of petroleum hydrocarbon degradation under anaerobic conditions is slower than the rate typically observed in an aerobic environment, degradation rates for benzene and other petroleum hydrocarbons are often significant in anaerobic environments.
The 2008 RPO evaluation identified Site SD24 as a Green priority site because the remedy was on track to reach the site cleanup levels within one year of the expected date in the ROD of 2008 (USAF, 2008). Based on the 2010 groundwater analytical data, the benzene concentration at OU4MW-04 (4.2 µg/L) is now below the specified cleanup level (Figure 4.2). Annual measurement of BTEX concentrations at Site SD24 is recommended until three consecutive years of data demonstrate that cleanup levels in groundwater have been achieved. The Green priority designation for Site SD24 remains appropriate.
The southwesterly groundwater flow direction indicated on Figure 4.1 is based on regional flow patterns previously identified for the Zone 2 Management Area. However, the presence of a local groundwater divide associated with the Elmendorf Moraine could cause a local southerly or southeasterly groundwater flow direction under this site. Due to this uncertainty, an assessment of the local groundwater flow direction under Site SD24 is planned for completion during 2011. This assessment should evaluate whether there are seasonal changes in groundwater flow direction using all available wells in the vicinity of the OU4MW-04 Plume. The results of the groundwater flow direction assessment will also be used to determine if a downgradient monitoring well (existing or new) should be added to the monitoring program for this site. |
Louis Howard |
| 1/28/2011 |
Institutional Control Update |
Staff received the 2010 Annual Land Use Control (LUC) Monitoring Letter for DP98 and Operable Units (OUs) 1,2,4,5, and 6. References: (a) DP98 Record of Decision, Section 12.2.3.4, dated May 2004, (b) OU6 Explanation of Significant Differences, Section 4.3.1.3, dated Mar 2007, and (c) Memorandum to the Site File for OUs 1,2,4, and 5, Section 4, dated Jan 2010.
This letter serves as the annual monitoring report on the status of LUCs in place at DP98 and
at OUs 1,2,4,5 and 6.
Groundwater - Restrict access to the contaminated groundwater throughout OU 4 until cleanup levels have been achieved. OU4 is designated "Airfield Use Area" for aircraft operations and maintenance, to include active and inactive runways, taxiways, and parking aprons for aircraft.
Soil- Institutional controls on land use (also called LUCs) will continue to restrict access to the contaminated shallow soils throughout OU 4 until cleanup levels have been achieved.
Evaluation - A land use control inspection was performed and land use controls are in place and continue to be effective at SD24.
The Air Force ensures compliance with LUCs by conducting periodic monitoring and completing site inspections. Separate controls are in place and enforced by the Air Force to prevent inappropriate soil and groundwater exposure at these sites. The Air Force currently requires all proj ects resulting in soil disturbance of greater than four inches below ground surface
to follow 3r Wing Instruction 32-1007, Safeguarding Utilities from Damage, dated 17 Aug 07 and 3rd Wing Instruction 32-7003, Land Use control Management, dated 16 Feb 07.
Both instructions require the proponent to obtain an approved Base Civil Engineer Work Clearance
Request (3 WG Form 3) prior to conducting work on the Base. |
Louis Howard |
| 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).
Currently there are ten active sites within the Zone 2 Management Area: FT23, SD15, SD24, SD25, SD28, SD29, SS43, ST32, ST48, & ST68. The OU4 ROD (USAF, 1995a) specifies the selected remedy for Sites FT23, SD24, SD25, SD28, & SD29. Currently, LUCs are used at all OU4 sites until cleanup levels are met, & GW monitoring is performed at Sites FT23 & SD25. At Site SD15, 149 an ESD; to the OU 6 ROD (USAF, 1997) transitioned the remedy for this site to monitored natural attenuation (MNA). The remedial approach for Site SS43 is described in the State-Elmendorf Environmental Restoration Agreement (SERA) Phase I Corrective Action Plan, & currently consists of natural attenuation with free product removal. The selected remedy for soils with contamination in excess of cleanup levels at Site ST32 is limited hot spot removal with off-site low-temperature thermal desorption.
A final remedy for GW at Sites ST32 & ST48 has not been established. The remedy for ST68 includes MNA & LUCs specified in a DD that was finalized in 2007. Impacted media at the Zone 2 Management Area sites includes soil & GW. COCs identified for Zone 2 sites include trichloroethene (TCE); tetrachloroethene (PCE); 1,1,1-trichloroethane (1,1,1-TCA); 1,1,2-TCA; 1,2-dichloroethane (1,2-DCA); 1,1-dichloroethene (1,1-DCE); 1,2-DCE; 1,1,2,2-tetrachloroethane (1,1,2,2-PCA); benzene, toluene, ethylbenzene, & total xylenes (BTEX); DRO; & gasoline-range organics (GRO).
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 SD24 consists of one groundwater plume (OU4MW-04 Plume) in the central portion of Zone 2 north of the East/West Runway. The OU4MW-04 plume was formerly referred to as the Hangar 10 Plume. Hangar 10 (Building 15455) was used for fuel-loading operations, and potential sources of contamination identified in the RI/ Feasibility Study (FS) included an underground storage tank (UST) and pump house southwest of this building, and a petroleum, oils, and lubricants system near Hangar 10. However, uncertainties regarding the local groundwater flow direction in the vicinity of Site SD24 suggest that there may be a source area for this plume completely unrelated to Hangar 10.
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, as follows (analytes shown exceeded cleanup levels during the most recent monitoring event):
• Site FT23 (2 plumes) - TCE & PCE
• Site SD15 - benzene & TCE
• Site SD24 - benzene
• Site SD25 - toluene & benzene
• Site SD28 - TCE & PCE
• Site SD 29 - TCE & PCE
• Site SS43 - benzene, gasoline range organics (GRO), DRO
• Site ST32 (2 plumes) - benzene, GRO, & DRO
• Site ST48 - GRO
• Site ST68 (2 plumes) - benzene & GRO
|
Louis Howard |
| 2/2/2012 |
Update or Other Action |
Memorandum for 2010 Annual Land Use Control (LUC) Monitoring Letter for DP98 and OUs 1, 2, 4, 5, and 6. References: (a) DP98 Record of Decision, Section 12.2.3.4, dated May 2004 (b) OU6 Explanation of Significant Differences, Section 4.3.1.3, dated Mar 2007 (c) Memorandum to the Site File for OUs 1,2,4, and 5, Section 4, dated Jan 2010 1. This letter serves as the annual monitoring report on the status of LUCs in place at DP98 and at OUs 1,2,4,5 and 6. The specific LUCs in place at each site are provided below. An evaluation of the implementation of these requirements is provided in bold following each specific LUC.
OU4:
Site SD24
Groundwater - Restrict access to the contaminated groundwater throughout OU 4 until cleanup levels have been achieved. OU4 is designated "Airfield Use Area" for aircraft operations and maintenance, to include active and inactive runways, taxiways, and parking aprons for aircraft.
Soil - Institutional controls on land use (also called LUCs) will continue to restrict access
to the contaminated shallow soils throughout OU 4 until cleanup levels have been achieved.
Evaluation - LUCs are in place and continue to be effective at SD24. A land use control inspection was accomplished in Oct 2011. The inspection forms will be presented in Appendix B of the 2011 Zones 1, 2, and 3 Mgt. Area Annual Report
2. The Air Force ensures compliance with LUCs by conducting periodic monitoring and completing site inspections. Separate controls are in place and enforced by the Air Force to prevent inappropriate soil and groundwater exposure at these sites. The Air Force currently requires all projects resulting in soil disturbance of greater than four inches below ground surface to follow 3 Wing Instruction 32-1007, Safeguarding Utilities from Damage, dated 20 Aug 10 and 673d Wing Instruction 32-7003, Land Use control Management, dated 19 May 2011. Both instructions require the proponent to obtain an approved Base Civil Engineer Work Clearance Request (3 WG Form 3) prior to conducting work on the Base. |
Louis Howard |
| 4/10/2012 |
Update or Other Action |
Draft 2011 Zones 1, 2, & 3 Annual Report received.
A groundwater sample was collected from well OU4MW-04 on 22 September 2011 and submitted to a fixed-base laboratory for analysis of BTEX. Table 3.16 provides the field and MNA parameters measured during sampling and Table 3.17 provides a summary of the results of the samples. The benzene concentration measured in the sample from OU4MW-04 (1.4 µg/L) in 2011 was below groundwater cleanup level of 5 µg/L (Figure 3.8 and Table 3.17). The other BTEX compounds analyzed were also well below their respective cleanup levels.
A LUC inspection conducted on 20 October 2011 did not identify any LUC issues at Site SD24.
The 2008 RPO evaluation identified Site SD24 as a Green priority site because the remedy was on track to reach the site cleanup levels for benzene within one year of the expected date (2008) per the ROD (USAF, 2008g). Based on the 2010 (4.2 µg/L) and 2011 (1.4 µg/L) groundwater analytical data, the benzene concentration at OU4MW-04 has now been below the specified cleanup level for two consecutive years (Figure 3.9).
Annual measurement of BTEX concentrations at Site SD24 is recommended until three consecutive years of data demonstrate that cleanup levels in groundwater have been achieved. The Green priority designation for Site SD24 remains appropriate. |
Louis Howard |
| 3/1/2013 |
Institutional Control Update |
2012 Annual LUC IC Monitoring memorandum received.
This letter serves as the annual monitoring report on the status of LUCs in place on JBER- Elmendorf at DP98 and OUs 1, 2, 4, 5 and 6. The specific LUCs in place at each site are provided below. An evaluation of the implementation of these requirements is provided in bold following each specific LUC.
Groundwater - Restrict access to the contaminated groundwater throughout OU 4 until cleanup levels have been achieved. OU4 is designated "Airfield Use Area" for aircraft operations and maintenance, to include active and inactive runways, taxiways, and parking aprons for aircraft.
Soil - Institutional controls on land use (also called LUes) will continue to restrict access to the contaminated shallow soils throughout OU 4 until cleanup levels have been achieved.
Evaluation -Inspection conducted on 26 Sep 12 and LUCs are in place and continue to be effective at SD24. |
Louis Howard |
| 5/30/2013 |
Update or Other Action |
Draft Annual Field Activities report received for review & comment.
This report summarizes the 2012 annual long-term management activities, including remedial action-operation (RA-O) & Record of Decision (ROD) requirements conducted at Joint Base Elmendorf-Richardson (JBER) Comprehensive Environmental Response, Compensation, & Liability Act (CERCLA) sites. The United States Air Force (USAF) has mandated a reduction of long-term environmental liabilities & life-cycle costs through accelerated cleanup of contaminated sites.
As such, the Performance Based Remediation (PBR) initiative has been developed to protect human health & the environment in a cost effective manner while at the same time reducing life-cycle costs. In April 2012, Weston Solutions, Inc. (WESTON) was awarded a PBR contract from the Air Force Civil Engineer Center (AFCEC) (Contract Number FA8903-09-D-8589, Task Order No. 0016) that includes remediation & related activities at several JBER contaminated sites. The contract includes performing RA-O & ROD requirements at those sites. The WESTON Team performing the activities summarized in this report consists of WESTON & CH2M Hill Constructors, Inc. (CH2M HILL). WESTON executed project work on sites located within JBER-Elmendorf (JBER-E) while CH2M HILL executed project work on sites located within JBER-Richardson (JBER-R).
During 2012, groundwater monitoring well OU4MW-04 was sampled for BTEX. All analytical laboratory sample results were below OU4 ROD cleanup criteria. Table 9-1 presents a summary of the results. Historic results are presented on Figure 9-1. A LUC inspection performed at SD024 on 26 September 2012 did not identify any issues at the site.
Site Summary
The 2011 Zones 1,2,3 Annual Report (USAF, 2012a) recommended that annual BTEX monitoring continue until benzene was under the specified cleanup level for three consecutive years. 2012 marked the third year in which benzene was under the cleanup level, demonstrating that cleanup levels in ground water have been achieved. The site has met the OU4 ROD and is recommended for site closure. The SD024 closure process should be initiated to include the preparation of a site closure report and decommissioning of the monitoring well (OU4MW-04) associated with the site.
|
Louis Howard |
| 6/28/2013 |
Document, Report, or Work plan Review - other |
Draft CERCLA Annual Field Activities Report receieved for review and comment.
9.4 SD024 Site Summary
ADEC concurs with the recommendations listed in this section for SD024. Site closure will only partially close Operable Unit 4 which the Record of Decision lists the following source areas: SD24, SD25, SD26* , SD27 *, SD28, SD29, SD30* , SS18 *, FT23, SS10.
*1993 Determination of No Further Action Source SD26, Bldg. 43-550:”Based on the preliminary groundwater directions, it appears that the fire training area [FT023] may be the primary source of groundwater contamination.”
1993 Determination of No Further Action Source SD27, Bldg. 42-300: “Other contamination was detected in soils and groundwater at SD27 during earlier investigations conducted at this source area. It appears that the fire training area may be the primary source of groundwater contamination, based on preliminary groundwater directions estimated for Elmendorf AFB.”
Determination of No Further Action Source SD30, Bldg. 21-900: “Because of the position of Monitoring Well IS7-01 relative to the dry well, sumps, and other potential sources, the contamination detected in the groundwater may not be representative of potential contamination from source SD30. Groundwater contamination has been identified upgradient of SD30. This upgradient contamination near Source SD30 will be investigated during the OU 3 remedial investigations”
1993 Determination of No Further Action Source SS18, Bldg. 22-021: “Any groundwater contamination present will be evaluated as part of the ongoing remedial investigation at OU5." |
Louis Howard |
| 5/14/2014 |
Update or Other Action |
Draft 2013 Annual Field Activities Report received. This report summarizes the 2013 annual long-term management activities, including remedial action-operation (RA-O) and Record of Decision (ROD) requirements, conducted at Joint Base Elmendorf-Richardson (JBER) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites. The United States Air Force (USAF) has mandated a reduction of long-term environmental liabilities and life-cycle costs through accelerated cleanup of contaminated sites. As such, the Performance-Based Remediation (PBR) initiative has been developed to protect human health and the environment in a cost-effective manner, while at the same time reducing life-cycle costs.
In April 2012, Weston Solutions, Inc. (WESTON) was awarded a PBR contract from the Air Force Civil Engineer Center (AFCEC) (Contract Number FA8903-09-D-8589, Task Order No. 0016). The contract includes performing RA-O and ROD requirements at several JBER sites. The WESTON team performing the activities summarized in this report consists of WESTON and CH2M HILL Constructors, Inc. (CH2M HILL). WESTON executed project work on sites located within JBER-Elmendorf, while CH2M HILL executed project work on sites located within JBER-Richardson.
The 2011 Zones 1, 2, and 3 Annual Report (USAF, 2012a) recommended that annual BTEX monitoring continue until benzene was under the specified cleanup level for three consecutive years. The 2012 annual sampling marked the third year in which benzene concentrations were below the cleanup level, demonstrating that cleanup levels in groundwater have been achieved. The site has met the OU4 ROD requirements and is recommended for site closure. Preparation of a site closure report and decommissioning of the monitoring well (OU4MW-04) associated with the site is planned for 2014. |
Louis Howard |
| 6/4/2014 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft CERCLA GW report.
See comments regarding dig permits issued within the last 12 months and ICs adequacy being reported as N/A. The Site Inspection Checklist should refer reader to photo 49 for SD024 in the Comments section as was done for FT023 and DP098 previously. |
Louis Howard |
| 11/5/2014 |
Document, Report, or Work plan Review - other |
EPA provided comments on the draft CERCLA report.
Comment: Three samples below cleanup level doesn't satisfy cleanup goals unless specifically in the ROD, and even then should be discussed prior to closure. |
Louis Howard |
| 5/29/2015 |
Update or Other Action |
Draft Interim Remedial Action Completion Report received for review & comment.
This Interim Remedial Action Completion Report (I-RACR) documents that the United States Air Force (USAF) has completed all required remedial actions (RAs) & has met all remedial action objectives (RAOs), resulting in the protection of human health & the environment at Site SD024.
The only COC identified at Site SD024 was benzene in GW. As specified in the ROD, the cleanup level for benzene in GW is 5 µg/L. The selected remedy for Site SD024 was intrinsic remediation (natural attenuation) for GW.
GW at Site SD024 has been monitored since 1996 using monitoring well OU4MW-04. Benzene concentrations from this well have been reported at concentrations less than the ROD cleanup level of 5 µg/L since 2010. The remediation phase at a monitoring well is typically complete when the data collected demonstrate that the GW has reached the cleanup level for COCs. The EPA recommends evaluating COC concentration levels on an individual well-by-well basis to assess whether aquifer restoration is complete.
Statistical evaluations were conducted to support the non-statistical review of the GW. Both the Mann-Kendall & Theil-Sen trend tests indicated there is a statistically significant decreasing trend for benzene at monitoring well OU4MW-04. In addition, the calculated benzene UCL of 4.42 µg/L for monitoring well OU4MW-04 is below the cleanup level 5 µg/L, indicating that attainment of the monitoring phase is complete in accordance with current EPA requirements (USEPA, 2014).
It is recommended that CERCLA Site SD024 be considered closed, & a letter of agreement is hereby requested from EPA & ADEC. Closure of SD024 does not close the OU 4 ROD, as other OU 4 sites remain open. |
Louis Howard |
| 6/3/2015 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft remedial action completion report. Main comments were on the EPA's use of UCL averaging of contaminant concentrations on a well-by-well basis to determine whether restoration is complete versus ADEC's regulatory requirement to have groundwater meet the maximum concentration detected in groundwater to show compliance with cleanup levels. |
Louis Howard |
| 7/23/2015 |
Update or Other Action |
Draft Annual Field Activities Report received for review and comment.
Five-Year Review
Areas in OU 4 that remain above cleanup goals are required to have CERCLA five-year reviews
conducted until such time as the cleanup goals are achieved. The purpose of the five-year review
is to evaluate the implementation and performance of the remedial actions. There were no
recommendations for SD024 documented during the first five-year review period. Site SD024 groundwater results for benzene indicated intrinsic remediation was occurring. Consistent with the 2002 Annual Report (USAF, 2003e) and OU4 Memorandum to Site File, the second five-year review report recommended decreasing the frequency of sampling at the in-plume monitoring well OU4MW-04 to once every five years.
The third five-year review report recommended increasing the frequency of sampling at monitoring well OU4MW-04 at Site SD024 to document attainment of cleanup levels (USAF, 2008c). The benzene concentrations reported in the 2010, 2011, and 2013 annual groundwater sampling events were less than the cleanup standard of 5 µg/L; therefore the fourth five-year review report recommended no further action for Site SD024.
Recommendations
The RA-Os at SD024 have been met and the site is scheduled to be closed. An I-RACR has been
prepared to document that remedial action at Site SD024 has been completed and the RA-Os in
the ROD have been met. It is recommended that annual LUC inspections continue until site closeout.
Site SD024 is identified as a Green priority since groundwater monitoring was discontinued in
2012 and the site has met the RA-Os as described in the ROD. |
Louis Howard |
| 8/5/2015 |
Cleanup Complete Determination Issued |
ADEC agrees with the conclusions provided by the Air Force to support the Interim Remedial Action
Completion Report including:
1.Groundwater remedies at SD024 have met the remedial action objectives through intrinsic remediation and institutional controls.
2. Monitoring for SD024 groundwater contaminant of concern (COC) benzene has been conducted from 1994 to 2012. Since 2010, benzene concentrations at monitoring well OU4MW-04 have been below the cleanup level of 5 ug/L as established in the 1995 OU4 Record of Decision (ROD) indicating the attainment of cleanup levels.
3. ADEC regulates on the maximum concentrations of a hazardous substance in groundwater throughout the aquifer and not the statistical upper confidence limit (UCL) that was calculated for SD024 in accordance with EPA’s Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities-Unified Guidance (2009).
4. Groundwater monitoring well OU4MW-04 may be decommissioned, pending JBER confirming that the monitoring well is not needed for: Compliance program monitoring, future monitoring for perfluorinated compounds (e.g. perfluorooctane sulfonate and perfluorooctanoic acid) or for 1,4-dioxane groundwater monitoring.
5. The implemented remedies for groundwater achieved the degree of cleanup or protection as specified in the OU4 Record of Decision (ROD) for all pathways of exposure.
6. ADEC has determined that SD024 has been adequately characterized and has achieved the applicable requirements under the site cleanup rules ADEC is issuing this written determination that cleanup is complete, subject to a future department determination that the cleanup is not protective of human health, safety, welfare, or of the environment [18 AAC 75.380(d)].
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Louis Howard |
| 8/6/2015 |
Institutional Control Record Removed |
Institutional Controls have been removed. |
Louis Howard |
