| Action Date |
Action |
Description |
DEC Staff |
| 4/18/1988 |
Update or Other Action |
FY 1989 Milcon construction project data for Asphalt Drum Storage Area.
Abandoned Asphalt Drum Dump 50 samples
Disposal of Drums 4,050
Disposal of Wood Structurs & Molten Asphalt Pit
Scrape Spilled Asphalt from Ground
Fill and Grade (as required)
Seed.
Description of Proposed Remedial Action
lhe scope of restoration work includes the following major elements at IRP site D-10: remove all drums and contents, remove contents and wood structures at molten asphalt pit, scrape spilled asphalt from ground surface,-fill and grade disturbed ground surface to local elevations, seed disturbed ground with a grass/willow seed mixture.
Requirement
PROJECT: Analyze, remove and dispose of approximately 4000 drums
containing hardened asphalt and unknowns. Scrape and remove asphalt laden
soil, and demolition of old wooden asphalt plant structure/pit.
REQUIREMENT:
Project: The proposed project is required to remove a potential. source of soil and/or groundwater contamination. The existing site. has been abandoned for approximately 30 years and drums are scattered over a large area of the base (20-25 acres). Many drums have rusted and asphalt contamination of area soils has occured.
CURRENT SITUATION: An abandoned asphalt plant/drum storage area is located on the runway centerline, approximately 2,000 ft from the east threshold and due west of the TACAN (Bldg 44-005). This area was the staging area for much of the asphalt paving on base during the 1940s era. There are approximately 4,000 abandoned asphalt drums scattered in groupings of several hundred over 20-25 acres of land. A 10 ft by 20 ft by 4 ft deep wood-framed pit of soil asphalt apparently served as a wasteage pit. Approximately 70 percent of the drums are full of hardened
asphalt. All of the drums are severely rusted. Several acres cumulative) of soil are covered with liquid asphalt that has leaked from drums.
In addition, other drums with suspect contents have been deposited at the site over the years. There are about 40-50 suspect drums at the site. The wasteage pit has been fenced to prevent accidents.
IMPACT IF NOT PROVIDED: Contaminants from the asphalt will continue to contaminate area soils and groundwater. Due to the age of the drums at this site, additional leakage/spilling caused by corrosion is highly likely. Although the immediate hazard associated with this area is not
great, the area is a significant visual blight and reflects adversely on Elmendorf AFB's IRP initiative.
ADDITIONAL: This is an RA IRP (old phase IVB) project, Priority IC. The scope of this project totally encompasses all requirements associated with Elmendorf AFB site D-10.
Signed Terese D. LeFrancois GS-12 DAF, AAC DERA Program Manager. |
Jennifer Roberts |
| 8/1/1988 |
Update or Other Action |
RCRA Facility Assessment Report: Preliminary Review and Visual Site Inspection ID # AK8570028649 by ADEC August 1988. The VSI, conducted on July 19 - 20, 1988, consisted of collecting additional facility information and obtaining visual evidence/information of releases. Interviews were conducted with various EAFB representatives to obtain site-wide SWMU information. EAFB's Environmental Coordinator is Mr. Mike Drewett.
Site D-10, Abandoned Asphalt Drum Dump
a. Location: This site is located approximately 1500 feet to the north of the storage facility, and approximately 5 acres in size. See photographs #15, #16, #17 of Attachment 2.
b. Operation: Approximately four thousand full and partially full 55-gallon drums of asphalt were stored at this site during the operation of the old asphalt plant on base during the 1940's and 1950's. Approximately 21 drums were reported by EAFB to contain "suspect" contents, possibly POL fuels, gasoline, jet fuel, sludges, waste oils, and possibly solvents.
c. Contaminant Potential: EAFB reported the following about this site: Approximately 4000 drums (scattered in groups of several hundred over approximately 20-25 acres of land) still remain in an area of dense overgrowth, a 10 foot by 12 foot wooden pit containing five to six feet of viscous liquid asphalt isolated with chain link fencing around its perimeter also exists. Most of the asphalt solidified either within the drum or after leaking outside the drum on the
ground surface. A total of several acres of soil are covered with liquid asphalt that has leaked from drums, various areas of viscous asphalt was noted on soil during the VSI. This site has a potential for environmental contamination due to the potential for leakage during viscous stages.
d. Recommended Action: Soil cores must be analyzed to determine the extent of soil contamination. However, this site has minimal contamination potential and is of lower priority than other solid waste management units at the facility. This investigation will be described in a subsequent phase of the RFI workplan.
GROUP 3
Those sites which are low priority sites and will be dealt with on a secondary basis to the high priority sites, they are as follows: S-6, D-10, D-13, and D-15
|
Max Schwenne |
| 8/2/1988 |
Update or Other Action |
Elmendorf Operable Unit source areas that corresponde to RCRA SWMUs from the RCRA RFA (new source number old source number)
SS10 D-10: Abandoned Asphalt Drum Dump. Located approx. 1500 feet north of the storage facility and approx. 20-25 acres. - 4000 full & partially full 55 gal drums of asphalt stored on site .
21 other drums are reported to contain suspect contents, (possibly POL fuels, gasoline, jet fuel, sludges, waste oils, and possibly solvents). A 10 X 12 ft. wooden pit containing five to six feet of viscous liquid. This site has a potentialfor environmental contamination due to the potential for leak during viscous stages. Soil cores must be analyzed to determine the extent of impact. This site is minimal priority.
OT11 D-11: Small Arms AMMO Disposal - North end of Base and adjacent to Ft. Richerson.
approx. 1 acre. Disposal devise " burn bucket" - bulk explosives, signal devices/pyrotechnics, bombs, grenade, dynamite, small ammunition arms, unstable material. Diesel fuel is used
as the ammunition inhibitor. This site is shown on the part A RCRA permit and described as disposaling of 2000 bls. of D003. This unit must be seen as a treatment unit (T04) and is regulated under Subpart X. However EAFB has stated that this unit is used for training purposes, yet it is listed on the part A as a hazardous waste other unit. A determination as to what this unit will be regulated under is to be determined. RCRA closure will be developed for this site. |
Louis Howard |
| 6/1/1989 |
Update or Other Action |
Design Analysis: Defense Environmental Restoration, Restoration of Asphalt Storage Area June 1989 received. This project will provide for the cleanup of asphalt & small amounts of fuel at a storage location on EAFB. This design analysis investigates alternative disposal techniques & recommends preferred methods of disposal.
An abandoned asphalt plant/drum storage area is located on the runway centerline, approximately 2,000’ from the east threshold of the E/W runway & due west of the TACAN (Bldg 44-005). This area was the staging area for much of the asphalt paving on base during the 1940's era. There are approximately 4,000 abandoned asphalt drums scattered in groupings of several hundred over 20-25 acres of land.
Approximately 70% of the drums are full of hardened asphalt. All of the drums are severely rusted. Several acres (cumulative) of soil are inundated with liquid asphalt that has leaked from drums. Other drums with unknown contents have been deposited at the site over the years. A 14’ by 18’ wood frame pit of asphalt apparently served as a vehicle cleaning area or, perhaps, as a cutting pit for diluting asphalt. The pit is chain-link fenced to prevent human & animal access.
Three individual sampling efforts were completed at the asphalt storage area:
1 - Sampling of drums of unknown contents in order to determine presence of hazardous materials. This effort was coordinated through Mr. Mike Drewett of Elmendorf AFB 21 CES/DEEV. 21 individual drums were sampled. These are listed on plan Sheet C-l as Sample 1-21.
Of the 21 drums sampled, 2 contained water & the rest contained petroleum products, primarily diesel fuel. Those containing fuel products also contained small amounts of pesticides including chlordane, aldrin, DDT & Beta BHC.
According to RCRA, when a hazardous waste (HW) is added to a material such as a recyclable waste, the recyclable waste is then classified as a HW.
ADEC has completed a preliminary review of the test results, but has not made a determination as to the hazardous classification of the contaminated fuel. Until such time, the material shall be treated as if it were a HW.
2 - Sampling of asphalt contained in drums & in an asphalt pit & of an unknown sediment found leaking from a drum during on-site inventory. The sediment sample is shown on plan Sheet C-l as Sample 22. The asphalt was sampled in order to determine presence of hazardous compounds that might preclude reuse of the asphalt. Potential contractors indicated a particular interest in ensuring that PCB's & lead did not exceed standards in case material could be used for road oiling.
Testing indicates that, if used as a waste oil for road oiling, the asphalt would exceed criteria for concentrations of total halogenated volatile organics. These standards do not restrict the use of the asphalt for its original intended purpose as an asphaltic paving material. Testing of the sediment sample as part of Testing Effort 2 reveals that it exceeds EPA toxicity limits for lead & chromium. This will require disposal at a certified hazardous waste facility.
3 - Sampling of asphalt contained in drums in order to try to determine its physical characteristics as a road surface mix material.
Sampling indicates that the asphalt material in drums is an AC-20 asphalt. This is a material that is typically used for paving in warmer climates, though it could certainly be used to pave a road in Anchorage. The asphalt would not meet specifications for a State of AK or Municipality of Anchorage road paving project, but would be adequate in an off-spec application.
Asphalt located at the site that is stored in drums is a paving grade asphalt similar to AC-20. The quantity of asphalt in drums is approximately 100,000 gallons in 1,875 drums. Interview of 21st Civil Engineering Equipment Operations personnel revealed no one that could provide a definite identification of the material.
50% of the asphalt is stored in intact drums & drums that have either rusted through or have been opened, exposing the asphalt contents.
The asphalt is not classified as a HW. It does not have any of the characteristics of ignitability, corrosivity, reactivity or EP toxicity listed in 40 CFR Ch. 1, Subpart C. It thus is considered to be a solid waste & must be disposed of accordingly.
Options
1. Use as a Dust Retardant. Would not require meeting stringent specifications.
2. Re-refining. Recycling the asphalt into an asphalt plant is possible.
3. Disposal at a Certified Disposal Facility. The Municipality of Anchorage Solid Waste Services will not allow deposit of the asphalt at the Sanitary Landfill due to the possibility of the material working its way to the surface as has happened in many other locations across the State.
4. Burning. Another option would be burning the asphalt.
5. Use of the Asphalt as a Paving Material.
6. On-Base Paving Applications. |
John Halverson |
| 11/12/1991 |
Update or Other Action |
Jennifer Roberts Federal Facility Coordinator sent letter to Joe Williamson and Rich Howard pursuant to Section 9.1 of the Elmendorf Air Force Base Federal Facility Agreement (FFA). ADEC designates Jennifer Roberts as the Project Manager and Ron Klein as the Alternate Project Manager for all activities covered under the FFA. |
Jennifer Roberts |
| 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 |
| 4/9/1992 |
Update or Other Action |
EPA Memorandum April 9, 1992 Reply to the ATTN of ES-098. Subject Toxicity of Fuels. From Carol Sweeney, Toxicologist Health and Environmental Assessment Section. To Wayne Pierre Federal Facilities Superfuend Branch (HW-124). A response has been provided to the frequently-asked question of whether a reference dose or other toxicity information can be provided for fuel mixtures so that these mixtures can be addressed quantitatively in Superfund risk assessments. The memo from ECAO Cincinnati is attached (last attachment). They have developed reference doses for gasoline, JP-5/kerosene, and JP-4, and a cancer potency factor for gasoline. The memo emphasizes that these are provisional numbers and that considerable uncertainty is involved in this quantitative assessment, because of data limitations, and because inhalation studies were used to calculate oral reference doses.
I typed up a summary table showing the numbers (first attachment) and calculated some risk-based concentrations (second attachment). On the risk-based concentration table, I also
included ordnance compounds, because I hadn't made a table of those before that I can remember. The risk-based concentrations were calculated the same way as table II-1 and II-2 of the Region
10 Supplemental guidance; for soil, the same limitations apply, that the numbers presented do not consider pathways other than soil ingestion.
Toxicity Reference Vaules for Fuel Mixtures EPA Region 10 4/9/1992 Non-cancer effects-Gasoline (unleaded) RfD (mg/kg-day) Oral: 2.0E-1, Uncertainty Factor-Oral:1000, Level of Confidence-Oral: Low. Toxicity Data Source-Oral RfD: Memo 3/92. Carcinogenicity-Cancer Potency/(mg/kg/day): Oral 1.7E-3, Unit Risk (/ug/m3) 4.8E-7, Cancer Weight Of Evidence-C, Toxicity Data Source-Oral SF and Inhal. SF: Memo 3/1992.
Kerosene/JP-5 RfD2.0E-2, UF Oral: 10,000, LOC Oral: low, TDS Oral RfD: Memo 3/92
JP-4 RfD 8.0E-2, UF Oral: 10,000, LOC Oral: low, TDS Oral RfD: memo 3/92.
Screening Values for Water RBCs based on Ingestion, Residential
Gasoline-Risk = 10-6 (ug/L) 50, 10-4=5000 HI=1 (ug/L) 7000
JP-5 Kerosene Risk 10-6 10-4=NA HI = 1 (ug/L) 700
JP-4 Risk 10-6 10-4 = NA, HI = 1 (ug/L) = 3,000
Screening Values for Soils- RBCs Based on Soil Ingestion Residential
Gasoline-Risk = 10-6 (mg/kg) 400, 10-4 (mg/kg) 40,000, HQ = 1 (mg/kg) 50,000
JP-5 Kerosene Risk 10-6 10-4 NA, HQ =1 5,000
JP-4 Risk 10-6 10-4 NA, HQ = 20,000
USEPA Office of Research and Development, Environmental Criteria and Assessment Office Cincinnati, OH Subj: Oral Reference Doses and Oral Slope Factors for JP-4, JP-5; similar to Kerosene (CAS no. 8008-20-6), Diesel Fuel (CAS No. 68334-30-5), and Gasoline (CAS No. 8006-61-9) (AVGAS) [McChord AFB (Wash Rack/Treatment)/Tacoma, WA]. From Joan S. Dollarhide Associate Director, Superfund Health Risk Techncial Support Center, Chemical Mixtures Assessment Branch TO Carol Sweeney USEPA Region X.
This memorandum is in response to your request for oral systemic and carcinogenic toxicity values for JP-4, JP-5, diesel fuel, and gasoline (AVGAS) found to contaminate soil and
groundwater at McChord AFB (Wash Rack/Treatment), Tacoma, WA. We have attempted to derive RfDs and slope factors for the above fuel mixtures. We have derived provisional RfDs for
gasoline, JP-4, JP-5 and diesel fuel; provisional cancer weight-of-evidence classifications of C for gasoline and D for JP-4, JP- 5 and diesel fuel; and a provisional slope factor (adapted from an interim Agency value) for gasoline
Based on the available evidence, unleaded gasoline can be assigned to U.S. EPA (1986) weight-of-evidence Group C: possible human carcinogen. An earlier U.S. EPA document assigned unleaded
gasoline to Group B2 as a probable human carcinogen (u.s. EPA, 1987a), but that document predates the U.S. EPA (1991d) conclusion that the male rat kidney tumors produced by gasoline
are not predictive for humans, and therefore should not contribute to the weight-of-evidence or dose-response assessment of carcinogenicity. IARC concluded that marine diesel fuel is possibly carcinogenic to humans (Group 2B), but light diesel fuels and jet fuels are not classifiable as to their carcinogenicity in humans (Group 3). |
Jennifer Roberts |
| 12/8/1992 |
Update or Other Action |
Jennifer Roberts provided a comment letter on the draft Conceptual Site Model for OU4. ADEC commented on the fact that SS10 and OU4 East are in close proximity, the same hydrogeologic area and geographic area. ADEC recommends the USAF remove SS10 from OU7 to OU4 East. |
Jennifer Roberts |
| 3/26/1993 |
Update or Other Action |
DOD, EPA and ADEC joint Technical Memorandum of understanding signed concerning the Base-wide Groundwater (GW) signed by: EPA Marcia Combes, ADEC Jennifer Roberts RPM and USAF Joseph Williamson Chief Environmental Programs & Restoration. Due to the base-wide GW study and the FY92 field work that occurred at Operable Units (OUs) 1, 2, and 5 it appears a large portion of the GW flows into OU5 (attach. 1-contour map). Based on this fact, Elmendorf (EAFB) will move all upgradient GW into the OU5 Feasibility Study, Proposed Plan and Record of Decision (ROD).
This means addressing all GW from upgradient sources (CERCLA (ST20, OUs 3 and 4) and OUs 1 and portions of OU2) and SERA) at OU5 instead of at each individual source area (see attach. 2-Area Map). Sites with free phased product would be looked at to see if there is an available technology to clean them up in a cost effective way. Soil contamination would be addressed at the source areas. NOTE: addressed at the source areas is interpreted by ADEC as removal through excavation or active treatment systems (e.g. high vacuum extraction, bioventing, etc...). |
Jennifer Roberts |
| 3/17/1994 |
Site Ranked Using the AHRM |
Initial ranking. |
Louis Howard |
| 5/3/1994 |
Site Added to Database |
GRO and DRO contaminants and asphalt are the contaminants of concern. |
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 noncarcinogenic groundwater risk, including toluene, ethylbenzene, cis-1,2-dichloroethene, and trichloroethene. 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. Noncarcinogenic risk in soil did not exceed an HQ of 1.0.
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 |
CERCLA RI Report Approved |
Report approved for work conducted in 1993 by Radian FS submitted with RI in September 1994. RI/FS concluded low levels of soil contamination were resulting from vehicular traffic, road paving, and pesticide application. Solvent contamination at OU4 east was attributed to dry wells or an upgradient leach field by hangar 15. Buried drums near FTA and other USTs/leaking valve pits near hangar 15 also were identified as sources of contamination in the GW. OU4E-1 monitoring well has a 62.4' total depth and 51.0 feet depth to water.
See site file for additional information. |
Louis Howard |
| 4/11/1995 |
Proposed Plan |
Proposed Plan for SS10 (formerly known as D-10) asphalt drum storage area (ASDA) lists soil contamination with diesel, jet fuel, xylenes, and gasoline. GW not impacted with contaminants. Bioventing was picked as the preferred alternative for deep soil contamination as ASDA and institutional controls with intrinsic remediation for the shallow soil contamination. Land use restrictions on the base would prohibit access disturbance within the source areas while natural processes remediate the soil. Time to cleanup shallow soils is estimated to take 4 years. |
Louis Howard |
| 10/4/1995 |
Update or Other Action |
ADEC commented on the Base Bioventing Treatability Study OU4 dated September 1995. ADEC concurs with the treatability design report as presented and the rationale supporting bioventing at the Fire Training Area ( FT23) , hangar 11, and the Asphalt Drum Storage Area (ASDA). |
Louis Howard |
| 10/10/1995 |
Cleanup Level(s) Approved |
Level D criteria for soils (1000 mg/kg GRO, 2000 mg/kg DRO, 2000 mg/kg RRO, 0.5 mg/kg benzene, and 100 mg/kg total BTEX). |
Jennifer Roberts |
| 10/10/1995 |
Update or Other Action |
The selected remedy in the 1995 ROD for OU4 included institutional controls on the land use restrictions to prevent access to contaminated soils throughout OU4 until cleanup levels are achieved. ICs are in place and are being enforced by the Base Planning and Environmental Management office. The contaminated areas and applicable soil use restrictions are documented in the Base General Plan and the Environmental Restoration Program Management Action Plan.
These documents are consulted prior to approval of any changes in land use, siting, work orders, and/or drilling permits. Water use restrictions in the form of a base-wide prohibition on use of the shallow aquifer due to contamination, were established on 03/29/1994 by order of the Base Commander. The site itself does not have contaminated groundwater.
Existing flight line restrictions are being relied upon to protect against unacceptable human contact with residual contamination in shallow soils. Residential development of the area is prohibited by airfield criteria and the General Plan. |
Louis Howard |
| 10/10/1995 |
Record of Decision |
ROD memorializes selected remedy for ASDA soil: 1) Institutional controls on land use will restrict access to the contaminated shallow soils (less than 5' in depth) throughout OU 4 until cleanup levels are achieved.
2) Deep soils (> 5' below ground surface) at the ADSA will be treated with bioventing to accelerate degradation of contaminants. 3) Both shallow and deep soils will be monitored and evaluated bi-annually to assess contaminant migration and timely reduction of contaminants. Groundwater is not contaminated at the ADSA. Soil contamination: DRO (max. 110,000 mg/kg), Jet Fuel (max. 13,000 mg/kg), Xylene (110 mg/kg), GRO (15,600 mg/kg). 18 AAC 78.315 Alaska Cleanup Matrix "D" will be used for cleanup levels: DRO 2,000 mg/kg (for Jet Fuel as well), Xylene 100 mg/kg, and GRO at 1,000 mg/kg.
Specific components of the selected remedy consist of the following:
Groundwater
* 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 concentrations 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 concentrations 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 concentrations 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 eleven 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 groundwater & 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 concentrations 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 institutional controls 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. |
Louis Howard |
| 7/30/1996 |
Update or Other Action |
June 1996 OU4 bioventing/soil intrinsic remediation monitoring report summarized bioventing from the start of program in December 1995 to early June 1996. The most significant conclusion was that respiration rates indicated that biodegradation was occurring much SLOWER than predicted in the RI/FS and ROD. Estimated time to reach remediation goals was as much as 63 years rather than the 2 to 13 years estimated in the ROD. |
Louis Howard |
| 10/17/1996 |
Update or Other Action |
Air Force memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV
1) Due to the contamination and commitments to EPA/DEC the use of the shallow aquifer for any purpose on is not allowed. Attached Facilities Board minutes-03/29/1994 0930 Item 9 has Mr. William Hanson, briefing the Board on the policy to not use the shallow aquifer due to contamination. The Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The IRP has RODs for OUs 3 and 6 which require, the aquifer remain unused.
2) Personnel in the review process within CES must be aware of these policies and review them on a recurring basis. It is imperative this restriction be recognized and observed during engineer reviews and operations. |
Louis Howard |
| 12/31/1996 |
Update or Other Action |
Staff provided comments on the technical memorandum "SOP for Closing Bioventing Systems on the Glacial Outwash Plain at EAFB" dated November 14, 1996. Project managers from ADEC, the EPA, and EAFB agreed that attempting to develop a correlation between monitoring data and closure sampling would be beneficial. If a good correlation is shown to exist, then developing a closure procedure based on monitoring data should be possible. Since there has been extensive site investigation and monitoring work done on EAFB, this appears to be a reasonable alternative. It would reduce sampling costs associated with having to do subsurface soil confirmation sampling at every bioventing site in the outwash plain.
To decide whether this will be a feasible alternative, it will be necessary to identify the number of sites with various types of petroleum contamination; conduct bioventing system monitoring and respiration testing along with confirmation soil sampling at a representative number of the sites; and show a good correlation between the monitoring data and the soil sample results. To do this, ADEC requests a list be prepared showing the number of bioventing sites currently operating or proposed. The site list should be broken down into categories for gasoline range organics (GRO), diesel range organics (DRO), and residual range organics (RRO). ADEC requests 25% of the sites under each category, with a minimum of 10 from each be included in the confirmation soil sampling sites to decide if a good correlation can be developed. If less than 10 sites exist under any category (i.e. RRO) confirmation sampling should be done at each site in that category rather than pursuing an alternative closure process for them.
At Page 3, under "problem definition", it refers to relatively small volumes of contaminated soil commonly treated at the Base through bioventing. It states that once the obviously contaminated soil around an underground storage tank has been removed, the remaining contaminated soil is often in a relatively shallow and even layer. The basis for these statements is not clear. In many cases, when USTs were removed, contaminated soil was placed back into the ground. Since most outwash plain consists of coarse grained soil with a low organic carbon content, most of the releases have resulted in contaminate migration down to the groundwater.
Table #3 Footnote #1 refers to respiration testing between June 15 and September 30. It is likely that some frost may remain in the ground during June. Also, if sufficient biological activity is generated, the soil temperatures would remain elevated later into the year. Therefore, ADEC recommends respiration testing be conducted later in the year (i.e. between July 15 and November 15).
Figure 2 does not include fields for helium injection and monitoring during respiration tests. These should be included to evaluate whether short circuiting may be occurring. Average air flow rates at each venting well should also be reported. This may help indicate whether soil moisture may be a limiting factor due to drying of the soil during bioventing. The depth and screen length of soil implants should be provided on the form to simplify the review process. |
John Halverson |
| 3/13/1997 |
Update or Other Action |
Action added on 3/13/97, based on Relative Risk Evaluation Worksheet dated 8/17/95. Pathway: site is gravelly with some boulders and sand. Groundwater is +65 feet with no contamination. No surface water/sediment nearby. Receptors: Burrowing animals. |
Louis Howard |
| 6/15/1997 |
Update or Other Action |
OU4 bioventing report evaluated data from start 12/95 to 12/96 and soil borings drilled in 4/97. Biodegradation rates calculated from data shows levels are still above ACM level D values for DRO and GRO. |
Louis Howard |
| 6/16/1997 |
Update or Other Action |
USAF Memorandum to ADEC regarding Clarifications to OU2 ROD (which will also apply to all other RODs dealing with ICs). The letter is a follow-up to the discussions regarding institutional controls at OU2. The USAF hopes by this correspondence, to clarify appropriate land use controls at OU2 and setup a land use restriction method consistent with the most recent Elmendorf RODs. The OU2 ROD states that groundwater at ST41 needs remedial action and a part of the selected remedy was to restrict land use by implementing zoning controls. The Summary of the ROD on page 9-2 states that the selected remedy includes "Zoning the affected area for industrial use only, excluding the development of commercial aquaculture."
However, the Declaration of the ROD states "Zoning the affected area for undeveloped outdoor/recreational use only." In light of this contradiction and the use of "restricted use areas" under the RODs for OU3 and OU6 the USAF is providing clarification of the permissible land uses within the area affected by ST41 groundwater. The affected area should include those areas that exceed the groundwater cleanup levels established in the OU2 ROD. A map of the area currently and potentially impacted by the contaminated groundwater from ST41 is at attachment 1. This map may be revised based upon review of the contamination remaining in place, which will be conducted at least every 5 years. While the affected area remains above cleanup levels, it will be designated as a "restricted use area" in the base Planning Office. This designation provides for recreational use of the parcel (such as cross country skiing, bicycling, etc.) and the construction of unmanned facilities (such as parking lots, storage buildings, etc. ) but prohibits the construction of any manned facilities (such as office buildings or a residence).
Construction activities within the affected area of OU2 will be restricted to construction of unmanned facilities. Furthermore no construction will be allowed which comes within five feet of the groundwater. Existing industrial uses within OU2 are allowed as they are unmanned. This description conforms to the current base land use planning terminology and is consistent with the recently signed RODs for OUs 3 and 6. Land use restrictions will be enforced by the following method. When there is a construction project on Base, the project is to be approved by the Base Planning Office. The planner will route all projects through the Environmental Management Office. The project will be disapproved if it conflicts with the above construction restrictions. The USAF believes this will be a reliable and effective means of enforcing the zoning land use restrictions imposed by the various RODs. Signed by Randy E. Honnet Colonel USAF Vice Commander. |
Louis Howard |
| 6/17/1997 |
Update or Other Action |
ADEC commented on the Semi-annual Bioventing Respirometry Report June 1997. The text states that it may be time to consider alternative cleanup levels for the ADSA (asphalt drum storage area) given the results presented in the report. EPA should be a part of such a review process with the ADEC and AF. The OU4 ROD states as a part of the selected remedy: When concentrations in the bioventing area (deep soils) are below cleanup levels, bioventing will be discontinued." If an alternate remedy of dealing with the contaminants is selected (e.g. no further action based on risk based closure), then it may be cause for "an explanation of significant differences-ESD." Suggest that the 3 agencies discuss this issue further at the upcoming project managers' meeting. |
Louis Howard |
| 9/25/1997 |
Update or Other Action |
(Old R:Base Action Code = RA - Remedial Action). Soil Gas Report #3 for OU4 bioventing system received. Soil temp at implants was 47 and 49 degrees F static pressure, 0.01 to 0.03 inches of water. O2 levels were 18 and 21%, and CO2 levels ranged from 0.25 to 3.50% and PID readings 2 to 5 units. |
Louis Howard |
| 1/13/1998 |
Update or Other Action |
ADEC provides comments to USAF regarding the Draft Soil Gas Report Number 4 and Semi-annual Monitoring Report OU4. The report recommends that bioventing operations be discontinued at sites FTA-1, FTA-2 and Hangar 11. ADEC concurs with recommendations and will require a closure plan with accompanying soil boring data showing cleanup has been attained below level "D" standards for each site. Additionally, if the data from the soil borings indicated those concentrations are above Level "D" standards, then additionally bioventing may be necessary. Finally, the report states the bioventing system at the Asphalt Drum Storage Area (SS10) be enhanced to increase biodegradation rates at the site. ADEC concurs. ADEC recommends further discussion among the OU4 RPMs to define what data needs to be collected and where the borings should be located for closing out the sites at FTA-1, FTA-2 and Hangar 11. |
Louis Howard |
| 7/24/1998 |
Update or Other Action |
June 1998 OU4 Remedial Action Report shows remediation will take 7 years. for deep soils (>5') and 1 more year for shallow soils (<5') with bioventing. |
Louis Howard |
| 10/27/1998 |
Update or Other Action |
7/98-9/98 quarterly progress report received. Monitored natural attenuation (MNA) ongoing to attain cleanup levels in shallow aquifer. Institutional controls remain in place prohibiting use of the shallow aquifer to ensure people will not be exposed to contaminated groundwater until cleanup goals are achieved. In-situ bioventing will be used to treat deep soils (>5') contributing to groundwater contamination at FT23, SD 25 and SS10. Shallow (< 5') and deep soils are being monitored bi-annually to evaluate contaminate migration and timely reduction of contaminant levels via bioventing and MNA. |
Louis Howard |
| 1/12/1999 |
Update or Other Action |
10/98-12/98 quarterly progress report received. Five year review document signed by EPA and ADEC that the remedies in place are operational, functional and protective of human health and the environment. 14 groundwater wells sampled, 4 exceed the MCL for benzene and 5 exceed the MCL for trichloroethylene (TCE). |
Louis Howard |
| 1/29/1999 |
Update or Other Action |
Basewide Bioventing Remediation Monitoring Annual Report received. The respiration test data indicate biodegradation rates of zero (0) to 131 mg/Kg/yr. Bioventing monitoring data indicate that the greatest hydrocarbon degradation is occurring at soil implant 6B. Soil implants 6A and 6C have consistently shown little or no indication of biodegradation except for the initial respiration test conducted at soil implant 6A. A maximum biodegradation rate of 372 mg/Kg/yr (0.99 mg/Kg/day) was observed in October 1997 at soil implant 6B.
The biodegradation rates at soil implant 6B have averaged 204 mg/Kg/yr excluding the November 1995 data. Analytical results for this site indicate GRO concentrations of 3,860 mg/Kg and DRO concentrations of 12,950 mg/Kg (Radian, 1997). These soil concentrations are above the Alaska Cleanup Matrix (ACM) level D cleanup standards.
Bristol recommends that bioventing operations be continued at SS10. We also recommend that additional soil data from borings be obtained after an additional year of operation to better determine the progress of biodegradation. If the soil data collected from these borings indicates that the concentrations are below ACM level D cleanup standards, the bioventing operations could be discontinued and the site closed. If the soil data collected indicates concentrations above ACM level D cleanup standards, an implant should be installed in each boring to monitor bioventing operations in the future. |
Louis Howard |
| 4/7/1999 |
Meeting or Teleconference Held |
Restoration Advisory Board meeting held to discuss: Review and poster display on base bioventing systems, discussion of Elmendorf’s role in operation of the Elmendorf Fish Hatchery, ENVVEST update and report on public meetings March 8 and 9, three terms extended and one new member welcomed, review and poster display of Alaska Railroad realignment project, review of plans to close groundwater treatment system at ST41, overview of Groundwater Monitoring program. Other poster displays: ENVVEST, budget, World War II historic sites, groundwater monitoring |
Louis Howard |
| 4/13/1999 |
Update or Other Action |
01/99-03/99 quarterly progress report received. BTEX, diesel, gasoline and Jet Fuel, kerosene contamination remain as soil contamination at the site. BTEX and chlorinated solvents remain as contamination in groundwater above MCLs. |
Louis Howard |
| 7/8/1999 |
Update or Other Action |
04/99-06/99 quarterly progress report received. Bioventing and groundwater monitoring ongoing at Ft23, SD25 and SS10. |
Louis Howard |
| 10/5/1999 |
Update or Other Action |
07/99-09/99 quarterly progress report received. 13 wells sampled, 4 wells exceed MCL for benzene (5 ug/L), but all 4 had lower concentrations when compared to round 1 1998 results. 5 wells exceeded MCL for TCE (5 ug/L) and 2 increased in concentrations when compared to round 1 1998 results. Site closure sampling conducted for sites SD25 and FT23. |
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.
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 |
| 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. NOTE to File: “free product” means a concentration of a hazardous substance that is present as a nonaqueous phase liquid; for purposes of this paragraph, a “nonaqueous phase liquid” is a liquid that is not dissolved in water.
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 |
| 3/7/2002 |
Update or Other Action |
Staff reviewed and commented on the Base wide Bioventing report for 2001.
General Comments
Decommissioning Bioventing Systems
Where the Air Force is recommending bioventing systems be decommissioned, the Department requests additional clarification if the Air Force has looked at other alternatives to treat the "smear zone" (The smear zone is defined as the range of depths within which the groundwater will fluctuate under normal seasonal conditions, and therefore, in which free product would move and “smear” the soil in response to these seasonal changes in the water level elevation. The smear zone soils may therefore be saturated or unsaturated with groundwater at any given time.) contamination and found it was not practicable to implement them. The basis for not being practicable can be due to reasons such as: reliability of the alternative, alternative is not cost effective, site location, logistics in light of overall project purposes. If an analysis of alternatives was conducted, then it should be stated it is not practicable due to the incremental cost of implementing an alternative is substantial and disproportionate to the incremental degree of protection provided by the alternative as compared to another lower cost alternative.
Well Log Submittal
The Department also wishes to inform the Air Force of the well log recording requirement by the Alaska Department of Natural Resources (ADNR), Division of Mining, Land and Water. The requirement is referenced in the Underground Storage Tank (UST) Procedure Manual, Section 4.7.1 Installing groundwater monitoring wells. Alaska statutes: 38.05.020, 38.05.035, 41.08.020, 46.15.020 and regulations 11 AAC 93.140 require a log of the well be submitted to the ADNR within 45 days after installing a well.
The Department concurs with the recommendations in the document for SS10. |
Louis Howard |
| 10/21/2002 |
Update or Other Action |
J. Roberts sent a letter to Joe Williamson dissolving the State Elmendorf Environmental Restoration Agreement. The Alaska Department of Environmental Conservation (DEC) has reviewed the issue of abolishing the State Elmendorf Environmental Restoration Agreement (SERA) per your recommendation. Elmendorf Air Force Base and DEC entered into the SERA in 1992.
The agreement was developed as a tool to bring the Base into compliance with Alaska's regulations addressing underground storage tanks, oil and other hazardous substance releases and solid waste. Since that time, Elmendorf has made significant progress in investigating and cleaning up historic contamination problems. Many of the sites covered by the SERA have been successfully cleaned up and closed. Cleanup is underway at the remaining sites. Additionally, Alaska has amended the regulations addressing fuel storage tanks, oil and other hazardous substance spills and solid waste. We concur with you that the SERA is no longer a necessary or beneficial. This letter serves as notice that DEC will end oversight on environmental work at Elmendorf by using the SERA. Instead, it is understood that the sites and programs formerly addressed by SERA: solid waste, underground storage tanks (UST), and oil and other hazardous substance discharges will be addressed in accordance with 18 AAC 60, 18 AAC 78 and 18 AAC 75. |
Jennifer Roberts |
| 7/28/2003 |
Update or Other Action |
Staff reviewed and approved a field sampling plan for closure sampling at ST43/55, SS10 and ST32. |
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). In-situ respiration testing in 2001 indicated that bioventing continued to enhance hydrocarbon degradation at SS10. |
Louis Howard |
| 7/15/2004 |
Update or Other Action |
2003 Soil Sampling Report received for soil sampling at bioventing systems SS43 (ST43-SERA) and SS10. Concentrations of all analytes sampled for were below cleanup standards at SSIO. The values for jet fuel were obtained by re-integrating the chromatograms and adding the results from the ranges C8-C10 and C-10 to C16 using the GRO and DRO analysis, respectively. It initially seems anomalous that the integration values with the shortened carbon range are higher than originally reported values with a longer range (full GRO plus DRO).
However, the concentrations in GRO and DRO standards are based on a range of peaks, some with larger areas than others. The smaller area peaks, when looked at individually, tend to take up more of the concentration than peaks with larger areas and, thus, "averaging" a disproportionate number of large peaks leads to a larger, more conservative value.
Concentrations of all analytes sampled for were below cleanup standards at SS10. Cleanup standards for SS10: DRO 2000 mg/kg, GRO 1000 mg/kg and total xylenes 100 mg/kg, jet fuel 2000 mg/kg. The soil sampling results at SS10 show the contaminants of concern are all below the soil Cleanup Standard for this site in the OU 4 Record of Decision. Based on these findings, the USAF is requesting from the Agencies a “Site Closure” decision letter for the bioventing site SS10. |
Louis Howard |
| 12/8/2005 |
Update or Other Action |
The Alaska Department of Environmental Conservation (ADEC) received the Pre-Draft Site Closure Report for Site SS10 on November 30, 2005. After reviewing the document, ADEC has the following comments.
ADEC Concurrence for Closure Signature Sheet Page 18
Add a sentence to signature sheet immediately following first sentence. “The decision may be reviewed and modified in the future if new information becomes available that indicates the presence of previously undiscovered contamination or exposures that may cause unacceptable risk to human health, safety or welfare, or the environment.”
5.0 Protectiveness Declaration Page 15
ADEC concurs that SS10 will not require any further remediation or investigation and will be considered closed. ADEC is basing its decision on the most current and complete data provided by the Air Force. ADEC reserves its rights, under: 18 AAC 75 Oil and Other Hazardous Substances Pollution Control regulations and Alaska Statute 46.03 to require the Air Force to perform additional investigation, cleanup, or containment if subsequent information indicates that: 1) previously undiscovered contamination at the site which may present an unacceptable risk to human health, safety, or welfare, or the environment..
|
Louis Howard |
| 2/14/2006 |
Site Closure Approved |
Site Closure report received and approved by ADEC. The purpose of this Site Closure Report is to document that conditions at Site SS10 located at Elmendorf Air Force Base (AFB), Alaska meet statutory and legal requirements for closure. Site SS10 is the former Asphalt Drum Storage Area located in the eastern part of Operable Unit (OU) 4 at Elmendorf AFB.
Conditions at SS10 meet statutory and legal requirements for closure. Under the FFA, the ROD is the legally enforceable decision document for all OU 4 sites, including SS10. Therefore, matrix-specific cleanup levels established in the ROD for identified COCs are the legally binding numeric closure criteria for OU 4 soils. The ROD for OU 4 (USAF, 1995b) establishes the following cleanup goals for COCs detected in Site SS10 soils, based on the 1995 ADEC Cleanup Matrix for non-UST sites (Level D) in effect when the ROD was signed: 1000 mg/kg GRO, 2000 mg/kg DRO, 0.5 mg/kg benzene, and 100 mg/kg total BTEX, 2000 mg/kg RRO, Jet fuel - 2000 mg/kg ("jet fuel" is defined as the sum of C8 through C10 fraction from GRO analyses and C10 through C16 fraction from DRO analyses;
The ROD for OU 4 establishes maximum contaminant levels (MCLs) as the numeric cleanup goals for the BTEX COCs detected in Site SS10 groundwater. None of the ROD-established cleanup levels have been exceeded for COCs detected in groundwater at Site SS10. Based on the existing site conditions, it has been determined that Site SS10 does not pose a significant threat to human health or the environment. Therefore, in accordance with ADEC regulations (18 AAC 75), USEPA and ADEC concurrence with a formal determination of no further action is requested pursuant to formal closure of Site SS10 at Elmendorf AFB.
ADEC concurs that regulatory closure requirements have been met at SS10, the former Asphalt Drum Storage Area, as required by the OU 4 Record of Decision signed by EPA, USAF and ADEC in 1995. The decision may be reviewed and modified in the future if new information becomes available that indicates the presence of previously undiscovered contamination or exposures that may cause [an] unacceptable risk to human health, safety or welfare, or the environment. |
Louis Howard |
| 7/6/2011 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 72777 name: auto-generated pm edit Elmendorf OU4 SS10 Asphalt Drum |
Louis Howard |
