| Action Date |
Action |
Description |
DEC Staff |
| 11/30/1982 |
Update or Other Action |
In November 1982, the United States Air Force (USAF) conducted inspections of the twenty (29) underground storage tanks (USTs) that were interconnected by a pipeline and delivered fuel to the flight line by gravity flow. Tanks 1, 5, 9, 12, 17, 19, 22, 26, 27, 28, 29 failed tank tightness testing. The 29 USTs have been empty and out of service since the 1982 inspection.
The tanks originally stored aviation gasoline (avgas) before conversion to jet fuel (JP-4) between the mid-1950s and 1975. |
Louis Howard |
| 8/1/1988 |
Update or Other Action |
RCRA Facility Assessment Report: Preliminary Review and Visual Site Inspection conducted by ADEC during July 19 and 20, 1988. Site OT-1: This site is located north of Burns Road, between Ridge and Loop Roads, and encompasses an area approximately 2,800 feet long and 800 feet wide.
This is the location of twenty-nine 50,000 gallon underground JP-4 Fuel tanks abandoned in early 1980's. Contamination Potential: Significant scaling, pitting and corrosion failures occurred in several tanks. Further Study Proposed: Area ground-water modeling and monitoring are required, to define the extent of
contamination and to accomplish a feasibility study and
remedial action plan for this site. However, since this site may include the Underground Storage Tank program, coordination with this program will be involved. |
Max Schwenne |
| 8/2/1988 |
Update or Other Action |
CERCLA Source Areas and their corresponding RCRA SWMUs from the RCRA RFA ST32 OT-1 Location is North of Burns Road, between Ridge and Loop Roads, and encompasses an area approx. 2800 ft. long and 800 ft. wide. This is the location of twenty-nine (29) 50,000 gal JP-4 Fuel tanks abandoned in early 1980's. Degragation of tanks and release of residue product. Further invesigation is needed. This could be handled under the UST/LUST program.
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) |
Louis Howard |
| 12/30/1988 |
Update or Other Action |
In 1988, twelve monitoring wells (9 shallow and 3 deeper) were installed in the areas surrounding the 11 tanks that failed the 1982 inspection and testing. Nine groundwater samples and 16 soil samples were collected and analyzed for gasoline range organics (GRO), diesel range organics (DRO), and kerosene. No soil samples exceeded cleanup levels. Groundwater was found to be contaminated in wells associated with tanks 12, 17, and 28 (T40905, T41709 and T42810 respectively). |
John Halverson |
| 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 |
| 5/15/1992 |
Update or Other Action |
Pipeline segment summary (term "abandoned" refers to "out-of-service" designation and should not be confused with documented decommissioning of pipeline segments: Area of Concern (AOC) 92-Segment B Segment B was constructed in 1942, formerly contained diesel fuel, and was operated until approximately 1993. It was abandoned when the switch from JP-4 to JP-8 took place on Elmendorf AFB. Pigging of the line was attempted in 1992; the pig was lost because of an increased pipeline diameter at the power plant. According to PEMCO, the pig was introduced at the Defense Energy Supply Office (DESO) and made it through Line B until it reached the power plant. Immediately east of the T to the power plant, the pipeline diameter increased from 4 to 6 inches and the pig lost the pressure needed to continue down the pipe. The pig was not retrieved, and it is assumed that the p ig is still located at the T.
AOC 94 Segment J-Segment J was constructed in 1955, formerly contained JP-4 and deicing fluid, and was abandoned in the early 1990s. LFM indicated that the feeder line to this segment was reported to still be connected to active fuel lines and would therefore "pressure up" with the presence of fuel. LFM has since reported that Segment J was isolated from the active line and drained in September 1999.
Deicing fluid was present in the segment from the mid-1970s to the early 1990s. When the deicing fluid was removed, the pumps in the segment were discovered to be corroded after an extended period of nonuse and additional pumps were necessary to drain the line. This segment was formerly associated with Farm 2, which was removed around 1996. An environmental investigation was completed in 1991 when the still-pressured line was punctured and released a quantity of JP-4. |
John Halverson |
| 10/2/1992 |
Update or Other Action |
State Elmendorf Environmental Restoration Agreement (SERA) signed. The agreement is designed to remedy environmental contamination due to past practices at the Base and avoid the expense of formal enforcement proceedings. The Air Force will perform any necessary assessment, monitoring, remediation, and closure of the sites. The agreement addresses the following program areas: solid waste, underground storage tanks (USTs), and petroleum oil and lubricants (POL) spills.
LUST sites will be remediated pursuant to 18 AAC 78, POL sites will be remediated pursuant to 18 AAC 75 (non-LUST petroleum); the interim soil guidance for non-UST soil cleanup levels dated July 17, 1991; the guidance for storage, remediation and disposal of non-UST petroleum contaminated soils date July 29, 1991; and for water, the applicable water standards set out in 18 AAC 70; and the applicable federal regulatory requirements for Maximum Contaminant Levels for drinking water; and interim guidance for surface and groundwater cleanups, dated September 26, 1990. ADEC and USAF agree to review new ADEC guidance within sixty (60) days of its formal adoption. The parties agree to incorporate new guidance into future remediation actions.
If the Air Force wishes to reduce soil and water contamination levels to those which exceed the previous mentioned regulations/criteria, it may prepare a risk assessment which sets forth justification for the proposed elevated cleanup levels. Solid waste sites will be remediated pursuant to the levels identified in 18 AAC 60.315 and 18 AAC 60.035(4). |
Jennifer Roberts |
| 3/3/1993 |
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 & 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 |
| 6/1/1993 |
Update or Other Action |
In 1993, soil contamination was encountered in the vicinity of tank 8 during a subsurface
geotechnical investigation for a proposed sewer line. |
John Halverson |
| 11/30/1993 |
Update or Other Action |
In 1993, 28 of the USTs were removed, cut up, and disposed of. Tank 7 was left in place for confined space entry and operational procedures training. Six soil samples were collected from preselected locations from each tank excavation. Soil contamination was encountered in the vicinity of Tank 8 during a subsurface geotechnical investigation for a proposed sewer line. |
Louis Howard |
| 1/18/1994 |
Update or Other Action |
UST Compliance Agreement signed to perform necessary inventory, registration, upgrading or closure and tightness testing associated with USTs at Elmendorf. This is a companion agreement for the Environmental Restoration Agreement signed in October 1992 (SERA) for compliance with release investigation and corrective action |
Louis Howard |
| 6/24/1994 |
Document, Report, or Work plan Review - other |
ADEC Letter to Dept.of Air Force James Spell Jr. 3 SPTG/CEVR RE: SERA Phase II Site Assessment Work Plan June 6, 1994. Based on ADEC review of the document, the department has no objection to implementing the work as proposed. Please note, the plan contained a health and safety plan which is beneficial for informational purposes. However, the department does not comment on or approve health and safety plans. Please contact ADEC when the contractor is ready to begin field work, as ADEC would like to inspect the sites during the project. |
John Halverson |
| 2/4/1995 |
Update or Other Action |
Patrick Coullahan Lt. Col Air Force sent letter to John Halverson re: Closure reports for the underground storage tank removal at ST32. The tanks were abandoned in place in 1984 and this past summer they contracted Integrated Waste Special Services (IWSS) to remove them from the ground. 28 of 29 tanks have been removed and the remaining tank was left in place for training purposes. (*e.g. confined space entry and other training purposes). Dec. 14, 1994 they received sample reports from the contractor and the reports did not meet minimum requirements for a site assessment as required by state regulations. They do not have a firm date as to when the reports will be delivered. |
John Halverson |
| 4/21/1995 |
Update or Other Action |
AF memo: 18 April 1995 UST Meeting. Elmendorf AFB will accomplish the following actions regarding UST Projects. These actions are based upon conversation between, John Mahaffey, Larry Opperman and yourself. EAFB will make every effort to accomplish a clean closure of a UST removal site if possible.
UST removal locations requiring cleanup action will be transferred into the State-Elmendorf Environmental Restoration Agreement (SERA). A list of sites requiring cleanup will be coordinated with your office. The presumptive remedy for contaminated UST sites in the outwash plain only will be bioventing technology. Contaminated soils exceeding cleanup levels may be placed back into the excavation only if the site assessment (SA) indicates a need for further cleanup action.
Contaminated UST sites not in the outwash plain will require further investigation to determine appropriate cleanup options. We will make every attempt possible to assure new USTs or new aboveground tanks are not installed in any way that would hamper future access for cleanup. The project will first accomplish removal of all of the USTs. SA information will be used to prioritize sites for cleanup using existing project funds. Additional funding will be requested to complete cleanup if available. Sites not addressed for cleanup due to exhausted funding will be placed into SERA Phase IV. John Halverson signed on April 21, 1995. Memo was signed by Douglas G. Tarbett, Maj, USAF, Chief, Environmental Compliance. CC: 3 WG/JA and 3 SPTG/CE. |
John Halverson |
| 5/5/1995 |
Document, Report, or Work plan Review - other |
ADEC letter to Joseph Williamson and Claude Mayer RE: review comments SERA Phase II Draft Site Assessment Report March 1995. At all of the sites where residual free product was observed or groundwater contaminant concentrations are indicative of residual free product (e.g. ST32 tanks: 1, 3, 11, 17 and ST68), the monitoring wells need to be checked for measurable amounts of product. If free product is present, then product recovery methods need to be evaluated and implemented. This should reduce the time required for overall remediation and monitoring to verify whether natural attenuation will work.
1.4.1 The report states natural attenuation is the top ranked alternative for both POL contaminated soil and groundwater at EAFB. Based on our previous discussions, it is ADEC's understanding natural attenuation was not being pursued as a primary remedial alternative for petroleum in soil.
ST32: The majority of petroleum contaminants at the site appear to be gasoline range organics and BTEX, therefore, soil vapor extraction followed by bioventing may significantly reduce the time necessary for active remediation. Depending on what may be required for treatment of air emissions, this could be more cost effective than bioventing and longer term natural attenuation (with the associated monitoring). Please add a table or a diagram identifying specific UST sites proposed for no further action, natural attenuation, and active remediation.
Additional monitoring wells may need to be placed along the piping system espicially near valve boxes and juncitons in the lines. This should be included in a larger scale groundwater monitoring program to determine the sources and full extent of groundwater impacts, to evaluate product recovery options, and to monitor the attentuation of groundwater contaminants. The report should include a recommendation to properly abandon monitoring wells that are no longer necessary for groundwater monitoring.
Tank 3-The report recommends no further action associated with the former tank based on a lack of soil contamination being found during the assessment. However, 62,000 micrograms/liter (ug/L) gasoline range organics (GRO) and 1,400 ug/L benzene were measured in a groundwater sample collected from monitoring well 59WL18 at the site. Therefore, the department cannot concur with a recommendation for no further action. The groundwater impacts need to be addressed. The site should be moved to the active remediation or natural attenuation sections.
Tanks 14: The report recommends no further action based on a finding of no soil or groundwater impacts. It should be re-worded to state no significant levels of soil or groundwater contamination. This comment also applies to the recommendation sections for tanks 18 and 23.
See site file for additional information. |
John Halverson |
| 7/31/1995 |
Update or Other Action |
SERA Phase II Site Assessment Report Final Volume 1 of 2 received. Nov. 1982, USAF conducted inspections of the 29 USTs; tanks 1, 5, 9, 12, 17, 19, 22, 26, 27, 29 failed testing. The 29 USTs have been empty & out of service since the 1982 inspection. (page 60 of document stopped here). 1. No further action is recommended for 12 of the former tank sites. 2. Active remediation was recommended for eight of the former tank sites. 3. Natural attenuation was selected for portions of ST32 as a whole, including nine of the former tank sites & locations identified through the regional wells.
Tank 3: No soil contamination was found at the site. It is possible source of the GW contamination may be from an upgradient source or that the pipeline interconnecting the tanks may be or has been the source of GW contamination. LNAPL observed in 50WL18 should be evaluated for the feasibility of free product removal.
Tank 10: GW contamination: GRO 16,000 ug/L & 310 ug/L benzene were detected. 560 mg/kg DRO & 310 mg/kg GRO were detected in soil samples. Given the spatial distribution of the identified soil contamination, the pipeline servicing the tank is implicated as the probable source.
Tank 11: Seven of the soil samples collected exceeded level “A” criteria. DRO 1,200 mg/kg, GRO 1,800 mg/kg, benzene 5.5 mg/kg was detected in soil GW: 27,000 ug/L DRO, 52,000 ug/L GRO & 9,700 ug/L benzene. Free product was noted in some instances in 59WL04. The LNAPL persistence & feasibility of free product removal at 59WL04 & 59WL11 be evaluated if the recommended natural attenuation is implemented.
Tank 12: GW contamination was identified at the site & level “A” cleanup standard is required & benzene was found to exceed the level “A” standard of 0.1 mg/kg at three locations (0.41, 0.17, 0.34 mg/kg). GW results: GRO 15000 ug/L & benzene 1,000 ug/L.
Tank 15: One sample collected near the GW table exceeded level "A" cleanup standards in the boring for well 59WL23. This contamination appears to be related to GW contamination in the smear zone. GRO: 34 ft. bgs 1,100 mg/kg 33.5 ft. bgs 1,200 mg/kg. Water sample 59WL23WGN: DRO 11000 ug/L, GRO 20000 ug/L & benzene at 41 ug/L. Free product recovery should be evaluated for 59WL23. The upgradient extent of GW contamination identified in 59WL23 should be determined.
Tank 16: One sample collected 13.5 ft. bgs contained 3.7 mg/kg benzene which exceeds the level "C" benzene standard of 0.5 mg/kg. This contamination is likely representative of residual hydrocarbons from tank 16 or the associated piping retarded by silt lenses.
Tank 17: GW contamination: DRO 4,900 ug/L, GRO 64,000 ug/L, benzene 4,700 ug/L is indicative of residual free product. Tank 17 is implicated as the source of the contamination along with the associated piping. Soil contamination: GRO 240 mg/kg & benzene 4.8 mg/kg. Active remediation system: bioventing is recommended for the site.
Tank 20: only sample collected from 11 ft. bgs at 1,600 mg/kg GRO exceeded level "C" standards near the pipe exiting tank 20 & may represent a pipe leak rather than a tank leak.
Tank 25: GW contamination was identified at this site & level "A" cleanup is required. Only the sample collected 54 ft. bgs at 0.15 mg/kg benzene exceeded level "A" standards. This is likely representative of smear zone contamination from the GW.
Tank 28: only soil contamination exceeding level C was reported in a sample collected 46 ft. bgs in boring 59BH48 for GRO (140 mg/kg), benzene (4.1 mg/kg) & total BTEX (170 mg/kg).
General recommendation for the tank sites were to incorporate them into the proposed ST32 natural attenuation program based on the soil & GW contamination identified.
See site file for additional information. |
Louis Howard |
| 9/26/1995 |
Document, Report, or Work plan Review - other |
Letter to C. Mayer Dept. of Air Force 3 SUG/CEVR RE: SERA Phase II Site Assessment Report Final July 1995. Several UST sites within ST32 are recommended for closure or no further action is recommended based on the finding of no soil or groundwater contamination. However, in most cases petroleum constituents were found in soil or groundwater samples. The wording should be changed to state that no soil or groundwater contamination was found above risked based concentrations or regulatory levels defined in 18 AAC 78, unless analyses were detected in any samples from a site.
Natural attenuation is recommended for soil and groundwater contamination at a number of the former tank sites. This may be an option, however, sufficient modeling, monitoring, justification and future funding are all necessary to implement a natural attenuation program and none of these have been adequately provided yet. If these items are not all adequately addressed, active remediation may be requested as the preferred alternative at some of these sites.
No further action for Tank 9 was based on a reported finding of no soil or groundwater contamination. However, benzene was measured at 6.9 micrograms per liter, which is above the drinking water MCL, in a groundwater sample from the site. Thus, the statement about no contamination needs to be amended and the groundwater impacts need to be addressed.
Section 3.4 states soil contamination at sites recommeded for natural attenuation presents limited potential risk to receptors and that soil which was accessible for ex-situ remediation was removed, along with the tanks by AGI. No groundwater modeling or risk assessment has been completed for ST32, so the statement that there is limited potential risk is not substantiated. The source of groundwater contamination in several areas has not been defined and may be the piping which remains in place. Future soil excavation may be necessary to identify and address contaminant source areas along the piping and other areas with fine grained soil or complex geology and high concentrations of petroleum contamination.
In the draft report, Tank 15 was recommended for active remediation and in the latest version it is recommended for natural attenuation. No additional assessment work has been done at this site and it is not clear why the change was made. |
John Halverson |
| 12/1/1995 |
Update or Other Action |
SERA Phase II Site Assessment Report Appendix E SERA Phase II Bioventing Treatability Study received.
Conclusions
Tank 2: The initially depressed soil O2 and elevated CO2 levels indicate microbial degradation of petroleum hydrocarbons is occurring at the former Tank 2 site and O2 is a limiting variable. The air permeability test indicates it is possible to supply air to the zone of contamination via injection at 59WL02. The O2 depletion observed through the respiration test confirms the existence of microbial activity; however, O2 consumption rates are lower than has been reported for other Alaskan sites. This suggests variables in addition to soil O2 levels are limiting petroleum degrading microbial populations. One possibility is the low soil temperatures observed during the test.
Tank 5: The initially depleted soil O2 and increased CO2 levels indicate O2 is limiting microbial activity at the site. The air permeability test and post-aeration soil gas levels confirm injecting air in 59WL30 will supply O2 to most of the contaminated soiL However, these data also indicate sufficient anisotropy to severely limit O2 transmission to the upper layers of 59BH82 and 59BH83. These data were anticipated during the system installation, and the upper monitoring points were constructed of 2-inch PVC well screen and can be used as injection/extraction wells as part of the final bioventing system.
The O2 consumption rates observed were below those encountered at typical Alaskan bioventing treatability tests and indicate factors other than O2 may also limit microbial metabolic activity at former Tank 5. One possibility is low soil temperatures. Low soil temperatures were observed at the site during the respiration test. Low soil temperatures were also noted at adjacent tank sites 7 and 8.
Tank 7: The initially depleted soil O2 and elevated CO2 levels observed at Tank 7 indicate the O2 is a limiting factor for microbial activity. The air permeability and post-injection soil gas levels indicate sufficient air can be injected via 59WL29 to influence the zone of contamination. However, O2 was not depleted in most points throughout the duration of the respiration test. Additionally, fluctuations in soil gas levels in some of the points elude interpretation. It is likely factors in addition to O2 are limiting microbial metabolic rates. The high VOC levels at Tank 7 may be toxic to microbes.
Tank 8: The initially depleted O2 levels and elevated CO2 levels indicate O2 is a limiting factor for microbial degradation of petroleum hydrocarbons. The air permeability data indicate the single injection well 59WL20 may be used to adequately aerate the zone of non-smear zone vadose contamination and the site is anisotropic. The post-injection soil gas levels indicate vertical air permeability is not homogeneous. O2 depletion was identified at some of the monitoring points; however, depletion rates suggest other factors in addition to O2 levels are limiting biodegradation of petroleum hydrocarbons. Low soil temperatures is one possibility.
Tank 10: A respiration test was not conducted at Tank 10 due to the inability to inject or extract air from the soil. Based on the low soil air permeability observed at Tank 10, this site is NOT suitable for bioventing.
Tank 11: A respiration test of Tank 11 for bioventing applicability was not conducted after completing the air permeability test due to the low observed permeability, high injection pressures required, and low air flow volumes possible. The low air permeability prevents extracting soil gas for analysis and supplying oxygen through the injection wells. For these reasons, Tank 11 is NOT recommended for bioventing.
Additionally, the pressure drop with time indicates the high injection pressures are likely creating preferential flow pathways, leading to a poor distribution of O2 throughout the contaminated zone. Under these conditions, O2 movement would continue to be limited to movement through diffusion.
See site file for additional information.
|
Louis Howard |
| 12/11/1995 |
Update or Other Action |
Memo from Dept. of AIr Force, 3 SPTG/CEVR for ADEC John Halverson Subject: SERA Phase II Site Assessment Report Final, July 1995.
1. Our response to the Air Force action items identified in your September 26, 1995 letter are:
a) Ref. item 1 and 2). Our understanding is additional release investigation and removal of the pipelines and valve pits within ST32 is required. This effort would have to be programmed as a future project. Our estimate in getting this work done is complete Remedial Design in FY 97 with the Remedial Action accompished in FY 98. Also, it should be noted that a MCP project FXSB 963013, West Ramp Hydrant Fueling System will impact ST32. Our review comments on this project have requested the removal of pipelines and valve pits within the construction area of this project.
b. Ref. item 3). The groundwater monitoring program was changed to include the SERA Phase II sites. The wells included are listed: 62WL05, 62WL06, 49WL01, ST20-03, 62WL07, 64WL01, 59WL31, 59WL36, 59WL37, 59WL38, 59WL30, 59WL29, 59WL35, 59WL42, 59WL43, 59WL39, 59WL40, 59WL41, 48WL01, 62WL02
C. Ref. item 4). We will prepare separate closure document for SS50. Our goal is to have closure documents completed by March 1996.
d. Ref. item 5) Compliance section is aware of the UST identified at site SS49. Tank is being incorporated into a future project. Mr. Larry Opperman is working this action item.
e. Ref. item 6) The pump for BW50 was removed after it was discovered to be screened in the shallow aquifer during the OU6 RI/FS. Reference section 7.0 of the OU6 RI/FS Draft/Final. On page 7-48 under recommendations it stated Media (soil & GW) Recommended No Further Action. Therefore, there are no contaminate sources present which could threaten the supply well.
f. Ref. item 7) Radian is under contract to evaluate passive fuel recovery at ST68. The ST32 monitoring wells will be added to Radian's contract. Our request for additional dollars for Radian's efforts at ST32 is being coordinated.
g. Ref. item 8) The data gaps have been addressed in bioventing basewide project for SERA Phase II sites. The new wells are: ST68-62WL05, 62WL06, 62WL07. These are downgradient wells for ST68. ST32-59WL36, 59WL37, 59WL38, 59WL35, 59WL42, 59WL43, 59WL39, 59WL40, and 59WL41. These are compliance wells on the edge of the moraine.
h. Ref. item 9) The outline on pursuing corrective action at each SERA Phase II Source area:
ST32-NFA tanks: 9, 13, 14, 18, 19, 21, 22, 23, 26, 27, 29. MNA Tanks 1, 3, 10, 11, 12, 15, 16, 20, 24, 25 and 28.
Request being worked for additional dollars to accomplish/look into free product recovery at 59WL01 (Tank 1), 50WL18 (Tank 3), 59WL04 (tank 11), 59WL11 (tank 11) and 59WL23 (tank 15).
Recommend bioventing Tanks 2, 4, 5, 6, 7, 8 and 17. Systems scheduled to be running late December 1995/January 1996.
Request being worked for additional dollars to accomplish/look into free product recovery for 59WL10 (tank 17).
See site file for additional information. |
John Halverson |
| 12/21/1995 |
Document, Report, or Work plan Review - other |
John Halverson commented on the 90% design submittal for the ST32 site. Work plan includes tank #10 at ST32. The final Phase II Site Assessment report recommends natural attenuation instead of bioventing at tank#10. The recommendation was based on a finding that there is limited soil contamination at the site and the results of a bioventing treatability study done by ENSR, which indicated that bioventing is not a feasible technology for the site.
Section 2.1 describing ST32 should note that the pipelines associated with the former tanks have not been removed or assessed for releases. Section 2.1.4 describes the tank 6 site at ST32. It notes a truck filling station is located about 400 feet south of the tank. It is unclear whether the filling station is/was connected to the fuel distribution system at ST32; whether there are USTs at the filling station; and whether site assessment work has been conducted at the filling station. More information on this is necessary.
Table 2.1-8 shows data from tank site #17 at ST32. It shows the maximum level of benzene in groundwater at 47,000 ug/L. The site assessment report states the maximum in groundwater at 4,700 ug/L. Please verify the correct value in the final design. |
John Halverson |
| 3/29/1996 |
Leaking Underground Storage Tank Corrective Action Underway |
Six bioventing systems were installed at tanks 2, 4, 5, 6, 7, and 8. These systems are configured to inject air into the subsurface vadose zone through the use of blowers located on the surface. SERA Phase II bioventing test report. The test included turning off the systems and measuring the oxygen in the soil gas at all implants immediately after the systems were turned off and at 6, 24, 48 and 72 hr thereafter. The oxygen levels should decrease as the oxygen content is utilized by the microbes. The test did not show a dramatic decrease in oxygen as anticipated. The cold weather may be inhibiting the microbes and the lack of snow cover has caused the top ten feet of soil to freeze. The subsurface temperature may be too cold for the microbes to flourish. After being operational for only a few weeks, the microbes may require more time to adjust to an aerobic environment as opposed to a mainly anaerobic environment. Thirdly, the microbes require a moist environment and dry air blown in may cause the soil to dry out. |
John Halverson |
| 7/2/1996 |
Update or Other Action |
Staff received the ST-32 Pipeline Investigation Final Report received.
The effectiveness of field screening as a means to segregate clean & contaminated soil was evaluated by comparing the OVM data & laboratory GRO & DRO results. OVM headspace readings greater than 50 ppm were compared to laboratory results to measure the effectiveness of the preliminary assumptions. The effectiveness of field screening was evaluated by determining the number of false negative & false positive results. False negatives were samples which the OVM identified as clean but laboratory analysis identified as contaminated.
False positives results were OVM concentrations which indicated the soil was contaminated while the corresponding laboratory test results indicated that the soil was actually clean. An abundance of false positives could result in larger than necessary volumes of clean soil being excavated, stockpiled, & tested. False positive field screening results would increase the need to re-segregate stockpiled material & complete additional testing so that clean soil is not removed from the site.
The ST32 demolition program field screening must quantify GRO & DRO compounds during pipeline removal activities. For this reason, GRO & DRO laboratory results were compared to OVM readings to evaluate if a sample was a false negative or false positive. An OVM reading was considered a false positive when the OVM indicated a concentration greater than 50 ppm & GRO & DRO laboratory concentrations were less than 100 mg/kg & 200 mg/kg, respectively.
Based on a comparison of OVM readings & corresponding laboratory results, 30 field screened samples accurately identified contaminated or non-contaminated soil. One false negative field screening result occurred. Fifteen soil samples were measured as false positives. The samples measured as false positives were collected at the following locations: SB-5, SB-6, SB-10, SB-16, SB-18, SB-21, SB-25, SB-27, SB-29, SB-31, SB-33, SB-34, & SB-42, SB-43, SB-44. The number of false positive OVM readings at the 50 ppm screening level represented approximately 33 percent of the 46 samples tested.
Assuming that field procedures were consistent for each field screened sample, false positives could be the result of variations in soil type, moisture content, or the type & degree of fuel weathering.
The false positive percentage drops to approximately 20 percent when the field screening value is increased from 50 ppm to 100 ppm. Further increases in the OVM screening level result in an undesirable increase in false negatives. Based on the above discussion, 100 ppm may be considered a more appropriate field screening level with which to evaluate soil as either clean or contaminated, provided that the field methods & equipment remain consistent with the methods used during this investigation.
Re-sampling & field observations of sheens or soil odors during field screening should also help to minimize the number of false positive OVM readings. (NOTE regulations will not allow for field screening to substitute for lab samples to confirm cleanup levels are met).
See site file for additional information.
|
John Halverson |
| 10/17/1996 |
Update or Other Action |
Air Force memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV
1) Due to the contamination and commitments to EPA/DEC the use of the shallow aquifer for any purpose on is not allowed. Attached Facilities Board minutes-03/29/1994 0930 Item 9 has Mr. William Hanson, briefing the Board on the policy to not use the shallow aquifer due to contamination. The Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The IRP has RODs for OUs 3 and 6 which require, the aquifer remain unused.
2) Personnel in the review process within CES must be aware of these policies and review them on a recurring basis. It is imperative this restriction be recognized and observed during engineer reviews and operations. |
Louis Howard |
| 12/31/1996 |
Document, Report, or Work plan Review - other |
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 |
| 2/26/1997 |
Document, Report, or Work plan Review - other |
Staff approved the ST32 pipeline demolition field sampling plan. Approximately 13,900 linear feet of fuel pipeline leading from the 29 tank sites and associated vaults and valve pits will be cleaned, excavated and removed. |
Louis Howard |
| 3/21/1997 |
Document, Report, or Work plan Review - other |
Letter sent to Larry Underbakke in response to phone call on 3/19/1997 regarding the disposition of excavated contaminated soils encountered during upcoming summer's PL81 (inactive 10-inch) pipeline project in the vicinity of the Port of Anchorage but on the northern portion of PL81. All contaminated soils removed from the ground during the closure or decommissioning of the PL81 project must be done in accordance with 18 AAC 78.311 Soil Storage and Disposal. The rationale for the need to excavate all excavated petroleum contaminated soil is based on previous experience with EAFB at sites where follow-up work was not conducted.
Specifically, Tank #805 at building 24-805, UST failed a tightness test in 1994 and was removed from the ground. Tanks 96-104 associated with building 22-013 were also removed from the ground in 1994. Petroleum contaminated soil was excavated during removal of the tanks. The Air Force requested approval to place contaminated soil back in the ground for both of these sites and subsequently numerous others. DEC approval was granted on the condition corrective action would be started at each site soon thereafter. The Air Force had committed to doing this work under Phase IV of the SERA.
However, DEC has been informed that work plans for risk assessment or corrective action at each site had not been developed. This is a violation of the corrective action requirements outlined in the UST regulations and our prior agreements with the Air Force. Based on the above example, and the fact that funding for DOD environmental cleanups is being reduced, DEC is no longer in a position to allow contaminated soil to be placed back in the ground with the hope it will be remediated in a timely manner. |
Louis Howard |
| 6/6/1997 |
Document, Report, or Work plan Review - other |
Staff approved work plan to install one soil boring to determine the current level of soil contamination and sample at one monitoring well to determine the current level of groundwater contamination. Tank 2 at source area ST32 is located approximately 450 feet north of Burns Rd. and 250 feet west of Loop Rd. in the western portion of the Base. A former 50,000 gallon UST was used to store AVGAS and JP-4 fuels. The UST was excavated and removed in 1993 and the soil contamination was observed beneath the tank.
In 1994 SERA Phase II Site Assessment was conducted and results indicated that remediation of the contaminated soil was required at Tank 2. GRO (12,000 mg/kg), DRO (3,000 mg/kg), benzene (37 mg/kg), toluene (400 mg/kg), ethylbenzene (200 mg/kg), xylenes (530 mg/kg) were detected at 16.5 feet bgs. Groundwater ranged from depths at 12.9 feet to 19 feet bgs in the northern portion of the site. 59WL-02 installed in the center of the excavation detected GRO (14 mg/L), DRO (2.6 mg/L), benzene (.14 mg/L).
NOTE TO FILE:
*Avgas has a lower volatility than mogas. The particular mixtures in use today are the same as when they were first developed in the 1950s & 1960s, & therefore the high-octane ratings are achieved by the addition of tetra-ethyl lead (TEL), a fairly toxic substance that was phased out for car use in most countries in the 1980s. Antiknock Additive-The most important avgas additive is TEL. It is added as part of a mixture that also contains ethylene dibromide (EDB) & dye. EDB acts as a scavenger for lead.
When avgas is burned in an engine, the lead in TEL is converted to lead oxide. Without a scavenger, lead oxide deposits would quickly collect on the valves & spark plugs. EDB reacts with the lead oxide as it forms & converts it to a mixture of lead bromide & lead oxybromides. Because these compounds are volatile, they are exhausted from the engine along with the rest of the combustion products. Just enough EDB is added to react with all of the lead.
Avgas is currently available in several grades with differing maximum lead concentrations. Since TEL is a rather expensive additive, a minimum amount of it is typically added to the fuel to bring it up to the required octane rating so actual concentrations are often lower than the maximum. Avgas 80/87 (dyed red) has the lowest lead content at a maximum of 0.5 gram lead per US gallon, & is only used in very low compression ratio engines. Avgas 100/130 (dyed green) is a higher octane grade aviation gasoline, containing a maximum of 4 gram of lead per US gallon, maximum 1.12 gram/liter. Grade 100 has a maximum 1.12 grams of lead per liter & is dyed green. 100LL "low lead" was designed to replace avgas 100/130. Avgas 100LL (dyed blue) contains a maximum of 2 gram of lead per US gallon, or maximum 0.56 gram/liter, & is the most commonly available & used aviation gasoline.
In 1973, EPA initiated a “phasedown” program for leaded gasoline. This program was designed to reduce lead content from 2.0 grams per gallon to 0.5 gram per gallon in large refineries by 1980 & in small refineries by 1982 (Ref. 2-14). The program allowed refineries to average their total (both leaded & unleaded) gasoline output to achieve the 0.5-gram per gallon standard.
In 1982, EPA lowered the standard for lead in fuel to 1.10 grams per gallon & eliminated the provision that allowed refineries to average their total leaded & unleaded gasoline output to meet the standard. In 1986, the standard was further reduced to 0.10 gram per gallon. By 1995, sales of leaded gasoline were reduced to 0.6 percent of total gasoline sales. Effective January 1, 1996, the Clean Air Act banned the sale of leaded fuel for May 2006 on-road vehicles. However, certain blends of automobile racing fuel continue to use alkyl lead compounds as a component of the fuel & EDB continues to be used as a lead scavenger in aviation gasoline (Avgas).
|
Louis Howard |
| 6/7/1997 |
Document, Report, or Work plan Review - other |
Staff commented on the proposed pipeline demolition Vaults 17A to 18. The terrain is so steep in this area for removal of the section of pipeline, therefore the Air Force wishes to close the pipeline in place. The Department concurs with this recommendation provided the following conditions are implemented.
If the Air Force wishes to close the pipeline in place at this particular stretch, then it must adequately: identify, segregate, stockpile, and characterize the soils remaining near the pipeline for petroleum contamination.
The Department requests field screening of soils be conducted at 20 foot intervals along the pipeline section (17A to 18) that is to remain in place and at any elbows, unions, valve pits present. In areas where field screening indicates presence of contamination (or at intervals no more than 40 feet), DEC requests sampling of soils to determine the levels of contamination present.
If a clean closure can be reached by excavating contaminated soil from around the pipeline, then all contaminated soil shall be removed, sampled, analyzed and taken for remediation to an off-site treatment facility. If clean closure is not feasible in the vicinity of pipeline (vaults 17a to 18), i.e. it is obvious that the contamination goes well beyond the excavation, then backfill excavation with clean fill and treat excavated soils at an off-site treatment facility. All contaminated soil removed from the ground during closure or decommissioning of the ST32 pipeline project must be completely contained in accordance with 18 AAC 78.311 "Soil Storage and Disposal". |
Louis Howard |
| 7/27/1997 |
Update or Other Action |
Spill report from ST32 SERA Site Vault 22 diesel fuel release of approximately 150 gallons. Old pipeline area JP-4 was discovered approximately six inches below bottom of vault 22. Contractor pumped 150 gallons from small depression at bottom of vault 22. Hole still had free product in it when contractor backfilled it and the plan is to go back and reopen hole and remove product. 1996 Awarded Project FXSB96-7110. ST32 POL Abandoned pipeline demolition. Contractor emptying, cleaning, and removing pipeline at this site. |
Jeff Ginalias |
| 9/30/1997 |
Update or Other Action |
SERA Phase II Analytical Results Round 1: GRO: 59-WL-31 22 mg/L, 8.4 mg/L, Ethylbenzene: 220 ug/L (15 ug/L), 1.4 mg/L xylenes (190 ug/L) Toluene (1.1 mg/L) & 59-WL-36 3.4 mg/L (2.2 mg/L).
See site file for additional information. |
John Halverson |
| 10/2/1997 |
Cleanup Plan Approved |
Staff approved Air Force's request to move contaminated soils to Alaska Soil Recycling from CleanSoil's facility. Approximately 3,200 tons of JP4 contaminated soil from ST32 pipeline demolition that was completed last month on Base. Approximately 13,900 linear feet of the fuel pipeline leading from the 29 tank sites and associated vaults and valve pits were cleaned, excavated and removed. Original approval from ADEC was to transfer the material to CleanSoils until the NOV's for the facility were sent.
Request is now for ASR as an alternate contaminated soil processing facility from this project.
Material is currently under cover at a stockpile on Base. All of it will be hauled by trucks keeping loads low to prevent spilling and covered with tarps to prevent contamination from spreading. All material will be sampled per ADEC requirements with copies of analytical data provided to ADEC. All weigh tickets will be confirmed and sent to ADEC. |
Louis Howard |
| 3/16/1998 |
Document, Report, or Work plan Review - other |
ADEC sent comment letter to USAF RE: SERA Phase II Bioventing Remediation Monitoring Annual Report. Source Area ST32 page 4-6
The recommendations state that bioventing should continue and DEC concurs. DEC reserves the right to comment on the SERA risk assessment and its appropriateness for use at this site. |
Louis Howard |
| 3/24/1998 |
Document, Report, or Work plan Review - other |
Staff commented on the project summary report ST32 Pipeline demolition project EA61038.01. The text states the vertical and perpendicular extent of fuel impact was beyond the scope of the project. DEC requests a follow-up site investigation to fully characterize the extent of contamination and implement corrective action for the 19 areas of the former pipeline which exceeded Level "B" criteria (100 mg/kg GRO, 200 mg/kg DRO, 2000 mg/kg RRO, benzene 0.5 mg/kg, total BTEX 15 mg/kg). Please provide additional information on when a more comprehensive site investigation will be conducted in the areas of contamination exceeding cleanup criteria and any corrective action being considered. |
Louis Howard |
| 5/1/1998 |
Update or Other Action |
Air Force sent a response to Department letter. The Air Force stated the first step is to agree on the level of contamination at this site. Once the level of contamination at subject site has been agreed upon, then a review of any area remaining above this level of contamination can be addressed as appropriate. The need to do additional corrective action will depend on the outcome of cleanup levels required.
Air Force stated to keep in mind of the following: Compliance wells surround the site and included in the base wide groundwater monitoring program. The pipeline has been removed and residue fuel disposed of. MCP project to install hydrant fuel system (west ramp) has impacted some sites identified as contaminated. The pipeline project removed contaminated soil from locations also identified as contaminated. Draft 18 AAC 75 Oil and Hazardous Pollution Control Regulations allow for higher levels of contamination than the ACM in 18 AAC 78. (NOTE to file: at this time the regulations are DRAFT and are not promulgated nor do they carry the force of law until that time they are promulgated, therefore the ACM in 18 AAC 78 applies unless a risk assessment is conducted). |
Louis Howard |
| 6/2/1998 |
Document, Report, or Work plan Review - other |
Letter to Air Force from ADEC RE: Draft SERA Phase II Bioventing Remediation Monitoring Annual Report, EAFB May 1998. The text recommends bioventing systems at ST32 Tanks: 2,4, and 8, ST61 and ST68 continue to be operated for another year. ADEC concurs. For sites ST32 Tanks: 5, 6, 7, a closure plan was recommended with soil borings to confirm the concentrations present at the site are below cleanup levels. ADEC concurs. |
Louis Howard |
| 6/3/1998 |
Document, Report, or Work plan Review - other |
Letter to Air Force re: project summary report ST32 pipeline demolition response to comments May 1, 1998. The Department of Environmental Conservation (DEC) concurs with the approach to coming to an agreement on what the cleanup level is for the site (ST32). It is imperative that the Air Force determine the total extent of the vertical and horizontal extent of the fuel impacts from this source area.
DEC requests a follow-up investigation to fully characterize the extent of contamination and implement corrective action for the 19 areas of the former pipeline that have not been characterized through a release investigation to determine the remaining contamination's vertical and horizontal extent that remains using the procedures outlined in 18 AAC 75.335 Site Characterization.
Your letter does not state that the level "B" ACM criteria will not be used for addressing whether a site is "clean" or requires further remedial efforts. At sites deemed appropriate in consultation with the DoD Section Manager (Jennifer Roberts), the Contaminated Sites Remediation Program will accept cleanup plans based on Methods 2, 3 in the May 4, 1998 Draft of the "Oil and Other Hazardous Substances Pollution Control Regulations Cleanup Standards". Note to file: The Air Force does not get to choose whether it is appropriate to use Draft regulations vs. promulgated regulations in effect at this time.
Until these [draft] regulations become final, cleanups conducted [by responsible parties] under these methods will be considered alternative cleanup levels (ACLs) and will therefore require Contaminated Sites Program Manager approval (Lynn Kent). Sites undergoing Method 4 cleanups are already covered by existing program policy related to establishing ACLs through risk assessment [also covered by the SERA between ADEC and the AF]. Method three sites will require an additional peer review by ADEC staff before concurrence by the Program Manager.
Alternative soil cleanup standards developed under method three or four may NOT be used from one site to the another without prior department approval and opportunity for public comment. The Department will, in its discretion, approve the use of alternative cleanup standards developed for one site within a facility with multiple similarly contaminated sites.
Another issue the Department is addressing is the use of aliphatic and aromatic compounds for determining cleanup levels. The Department is NOT considering closure requests or review of work using aliphatic or aromatic analyses since there is not a standard acceptable method yet approved by DEC.
The Department will NOT consider closure requests based on the use of equations to back calculated aromatics or aliphatics from petroleum ranges such as DRO, GRO, and RRO. Only cleanup requests that use AK 101, 102, 103 methodologies will be acceptable for use of Table B2. Use of alternate lab methods: 8020, 8100, 8015, 418.1 will NOT be acceptable for determining cleanup under Table B2 of the draft regulations for petroleum contaminated sites. |
Louis Howard |
| 9/30/1998 |
Update or Other Action |
In September 1998, Tank 7 and associated piping were removed. Laboratory analytical results for the seven primary samples collected from the UST excavation were above ADEC Level "B" cleanup criteria for DRO, GRO, benzene and total xylenes. Work was performed under project FXSB19957110 RD SERA Phase II LUST. |
Louis Howard |
| 1/29/1999 |
Update or Other Action |
Basewide Bioventing Annual Report received. Bioventing monitoring data indicate that hydrocarbons are still present in the soil gas at all five of the ST32 sites, and that hydrocarbons are being degraded at Tanks 4 and 8. The respiration test data indicate biodegradation rates of zero (0) to 296 mg/Kg/yr for Tanks 4 and 8. Tank 6 did have an increase in microbial activity. Biodegradation rates increased at soil implants BV-06-1A and BV-06-1B. Historically, the implants at Tank 6 have had low or no microbial activity.
The implants at Tanks 5 and 7 showed no indication of microbial activity. The explanation for the lack of microbial activity, as measured by hydrocarbon biodegradation, involves several possibilities. Most of the implants at Tank 5 and several at Tank 7 appear to have been installed in relatively uncontaminated soil based on the analytical results for soil and
corresponding boring logs (ENSR, 1995).
Due to the similarities between the tank sites at ST32, it is most likely that hydrocarbon
biodegradation is occurring at all of the sites even though some of the implants do not permit
the monitoring of biodegradation. However, biodegradation will continue, at a diminishing
rate, even after the contamination levels drops below the established clean-up levels. Other
possible explanations for these low respiration rates are discussed in Section 6.4.
Bristol recommends that bioventing be continued for a period of one year at Tanks 4, 6, and
8. Tanks 4 and 8 show measureable biodegredation activity, and Tank 6 has activity this
year, although it has not in the past. At the end of the year, the performance of the bioventing system should be evaluated through soil borings and respirometry testing. Bioventing should be discontinued at Tanks 5 and 7, and site closure should be pursued. |
Louis Howard |
| 11/1/1999 |
Document, Report, or Work plan Review - other |
Notice of Release-Facility ID 1525, Tank # AFID 707 (ADEC # 206): On June 10, 1999, the Alaska Department of Environmental Conservation (ADEC) received the final site assessment report documenting the closure of AFID 707 (ADEC # 206 SERA ST32-29 Tanks). The report summarizes the field data and results of the confirmation samples collected during the September 8, 1998, decommissioning of a 50,000-gallon, JP-4 underground storage tank (UST), located near Building 41-659 on Elmendorf AFB. Information presented in the report indicates a significant petroleum release (350,000-ppm GRO) has occurred. In accordance to 18AAC78.235, ADEC is requesting the Air Force to conduct a release investigation of the former UST excavation to determine the full extent of the contamination associated with the UST. As an interim step to conducting the release investigation, ADEC is requesting the Air Force to submit the following information:
A map showing the location of existing monitoring wells within 1000 feet of the UST site, and analytical results of water samples collected from the monitoring wells during the last two years.
A map showing the locations of any bioventing wells in close proximity of the UST site, and any soil or vapor testing results of the bioventing system(s). |
Tim Stevens |
| 6/1/2000 |
Update or Other Action |
Environmental Monitoring Plan received. The purpose of the Basewide Environmental Monitoring Program (EMP) is to provide information on surface water and groundwater quality, groundwater flow characteristics, and monitoring well integrity at specified locations throughout Elmendorf AFB. The data assessment portion of the program includes data collection via groundwater and surface water sampling, and groundwater level measurements.
SERA Phase II Sites (ST32, ST48, and ST68)-Groundwater samples will be collected from 19 wells at SERA Phase II locations. These wells will be sampled biannually. Groundwater samples from SERA Phase II monitoring wells will be analyzed for the same constituents as for SERA Phase I, and includes anions, organolead, diesel and gasoline range hydrocarbons, and total iron. Like SERA Phase I, the primary purpose of long-term monitoring at SERA Phase II locations is to compare concentrations of these and other constituents in the samples collected to historic concentrations and/or background concentrations, such that changes or trends in concentrations can be established and to provide early warning of increased contaminant levels or migration of contaminant plumes.
MTBE will be added to the list of compounds analyzed in the Method EPA 8021B analysis. This
change is made as a result of a request by ADEC to monitor for this compound at all wells in the Basewide Sampling Program for one year. |
Louis Howard |
| 9/28/2000 |
Offsite Soil or Groundwater Disposal Approved |
Staff approved request to thermally treat twelve 55-gallon drums of POL contaminated soil from the closure drilling efforts at ST32 tanks: 4, 5, 6, ST61 and ST68. September 1998: tank 7 at ST32 and associated piping were removed. Laboratory analytical results for the seven primary soil samples were above level "B" criteria for DRO, GRO, benzene and total xylenes.
Soil will be bulked up and transported to ASR for thermal treatment and disposal of the treated soil.
Closure sampling conducted in 2000 found that continued operation of the bioventing systems was unlikely to reduce the contaminant levels below cleanup criteria at tank locations 4, 5, and 6. Sample results reportedly suggest that the subsurface soils are non-homogenous, and the contamination is only present in isolated areas, and rapidly dissipates with distance from these localized areas. Two areas along the pipeline at Stations 123+80 and 301+40 were identified as being contaminated above applicable cleanup levels. |
Louis Howard |
| 12/1/2000 |
Update or Other Action |
Closure sampling was conducted in 2000 and found that continued operation of the biovent systems was unlikely to reduce contamination levels below cleanup criteria at tank locations 4, 5, and 6. Sample results reportedly suggested that the subsurface soils are nonhomogenous and that contamination is only present in isolated areas and rapidly dissipates with distance from these localized areas. Additionally, during the 2000 bioventing closure effort, two areas along the pipeline, at Stations 123+80 and 301+40, were identified as being contaminated above applicable cleanup levels. Removal actions were conducted during the 2004 field season as a result of these findings. |
Louis Howard |
| 1/3/2001 |
Document, Report, or Work plan Review - other |
Staff reviewed & commented on the draft 2000 Bioventing Closure Effort dated November 30, 2000. ADEC requests including a map of each source area in relation to the specific section's monitoring wells. For example, Site Plan & Sample Locations ST 68 Figure 3-9 lists wells: 62WL01, 64WL02, 64WL01 & 64WL03. It does not list: 64WL04 (reportedly in the ST 68 source area), ST20-03, or 62WL02 identified in the text. Use of Figure 3-2 is not sufficient since it does not include any source areas on it.
ADEC concurs with the recommendations that the bioventing system be shut down since it does not appear to be adequately remediating the soils at ST 32 Tank 4. However, before ADEC can concur with monitored natural attenuation at the site for soils or GW, it will require the following:
* Soils at the site (near 59BH96 & 59BH94) need to be resampled once every three years (at a minimum) through soil borings for petroleum contaminants to assess the degradation of soil contamination which remains above site closure criterion (currently Alaska Cleanup Matrix Level "D" for GRO & benzene);
* Monitoring well 59WL-19 be reactivated & included in all future GW monitoring events. If for some reason 59WL-19 cannot be activated, ADEC will require a well in the source area (former Tank 4) as near as possible to 59BH96.
Sampling of GW will continue until two years (four events) of GW monitoring have shown that all applicable cleanup levels (18 AAC 75 Table C) have been met. Additionally, soil borings will have to be have met cleanup levels in the vicinity of 59GBH96 & 59BH94 prior to any no further action consideration by ADEC.
ADEC concurs with the recommendations that the bioventing system be shut down since it does not appear to be remediating the soils at ST 32 Tank 5. However, before ADEC can concur with monitored natural attenuation at the site for soils or GW, it will require the following:
* Soils at the site (near 59BH98 & 59BH99) need to be resampled once every three years (at a minimum) through soil borings for petroleum contaminants to assess the degradation of soil contamination which remains above site closure criterion (currently Alaska Cleanup Matrix Level "D" for GRO, benzene, toluene, & ethylbenzene);
Sampling of GW will continue until two years (four events) of GW monitoring have shown that all applicable cleanup levels (18 AAC 75 Table C) have been met. Additionally, soil borings will have to be have met cleanup levels in the vicinity of 59GBH98 & 59BH99 prior to any no further action consideration by ADEC.
See site file for additional information.
|
Louis Howard |
| 3/21/2001 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft 2000 Bioventing Annual Report dated February 28, 2001 received on March 5, 2001. ADEC concurs with the recommendations that the bioventing system be shut down since it does not appear to be adequately remediating the soils at ST 32 (tanks 4, 5, 6) and ST 68. However, before ADEC can concur with can concur with abandoning the bioventing system at the site and relying on
passive remediation (monitored natural attenuation) for soils or groundwater, it will require the following:
* ADEC requests the soils at the site be resampled once every three years (at a minimum) through soil borings for petroleum contaminants to assess the degradation of soil contamination, which remains above site closure criterion.
* For the purposes of final closure sampling, the required minimum number of samples (from a minimum of three borings) will be three per boring-at the area with the highest PID reading, at the
highest historical contaminant level and at soil/groundwater interface. DEC will require analysis of benzene, toluene, ethylbenzene, and total xylenes (BTEX), diesel range organics (DRO) and gasoline range organics (GRO) contaminants of concern (sampling for PAHs will be required if the Air Force
chooses to cleanup under Method Two). Laboratory analyses, where applicable, will utilize approved AK lab methods, i.e. AK 101 and 102.
Sampling of groundwater will continue until two years (four events) of groundwater monitoring have shown that all applicable cleanup levels (18 AAC 75 Table C) have been met. Additionally, soil borings will have to be have met cleanup levels prior to any
proposed no further action consideration by ADEC. |
Louis Howard |
| 1/2/2002 |
Update or Other Action |
Staff received the seventh Annual Report of Groundwater Sampling Activities developed for the Elmendorf Air Force Base (AFB) Basewide Environmental Monitoring Program, hereafter referred to as the Basewide Program. The Basewide Program encompasses two field programs, the Basewide Groundwater Sampling Program and the Basewide Water Level Monitoring and Well Optimization Program.
This Annual Report of Groundwater Sampling Activities contains a summary of 2001 water quality data and interpretations from the Basewide Groundwater Sampling Program. The Annual Technical Memorandum (United States Air Force [USAF], 2002a) developed and distributed as a separate deliverable report, addresses activities associated with the Basewide Water Level Monitoring and Well Optimization Program.
The Basewide Program was established through the Elmendorf AFB Installation Restoration Program (IRP) to address the needs of multiple programs on the base. These programs include the Federal Facilities Agreement (FFA), and the State-Elmendorf Environmental Restoration Agreement (SERA). Over the following two program years, 2002 and 2003, the focus of the Elmendorf AFB Basewide Program will be modified to reflect the requirements outlined in appropriate Records of Decision (RODs), decision documents, corrective action documents, and/or any other binding agreements. In an effort to optimize the program, several changes may occur in sampling frequency, in the wells sampled, and in groundwater seep sampling.
The following are conclusions derived from intuitive and statistical groundwater data analysis
within SERA Phase II:
* As a result of the 2001 Decision Guide analysis and the SERA II Site Assessment Report, none of the wells or analytical methods met the criteria for removal from the SERA Phase II program area in 2002. It is recommened, however, that ten wells, 59-WL-38, 59-WL-39, 59-WL-40, 59-WL-41, 59-WL-42, 59-WL-43, 62-WL-02, 62-WL-06, ST20-03, and ST41-22 be sampled only one round in 2002.
* For wells in the SERA Phase II program area, a measurable free product layer was not detected in 2001. However, a fuel odor was noted in 2001 at five wells (59-WL-30, 60-WL-04, 62-WL-02, 62-WL-05, and 64-WL-01).
* Four SERA Phase II groundwater COCs exceeded MCLs in 2001 (GRO, DRO, benzene, and toluene). Benzene exceeded the MCL at six well locations (59-WL-30, 59-WL-31, 59-WL-36, 60-WL-04, 62-WL-05, and 64-WL-01); DRO exceeded the MCL at two well locations (59-WL-31 and 62-WL-05); GRO exceeded the MCL at five well locations (59-WL-30, 59-WL-31, 59-WL-36, 60-WL-04, and 62-WL-05); and toluene exceeded the MCL at one well location (59-WL-31).
* Nine wells at SERA Phase II contained statistically valid trends using current available data for benzene (59-WL-30, 59-WL-37, 59-WL-40, 59-WL-42, 60-WL-04, 62-WL-02, 62-WL-05, 64-WL-01, and ST20-03). All of these had decreasing trends. Wells 59-WL-30, 59-WL-31, 59-WL-36, 60-WL-04, 62-WL-05, and 64-WL-01 exceeded the benzene MCL of 5 ,tg/L. Of the six wells exceeding the MCL, 59-WL-30, 60-WL-04, 62-WL-05, and 64-WL-01 had decreasing trends and the two remaining wells, 59-WL-31 and 59-WL-36 showed no established trend
* For all wells in SERA Phase II, a review of natural attenuatin parameters indicates that the process is actively removing the contaminant mass.
* Well 59-WL-31 appears to have high, fluctuating levels of benzene contamination, possibly due to pulses of contamination migrating past the well. As with other contaminated wells in SERA II, data indicate high levels of microbial activity. Further, the downgradient well 59-WL-38, contains no benzene. Natural attenuation parameters in 59-WL-38 indicate that microbial activity has reduced the concentration of most electron acceptors and the contaminant mass. Natural attenuation appears to be working well for this plume. |
Louis Howard |
| 3/7/2002 |
Document, Report, or Work plan Review - other |
ADEC sent letter to USAF RE: Draft 2001 Basewide Bioventing Systems Annual Report dated February 2002.
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 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 Depainment 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.
Based on a review of the data by the Department, it appears the bioventing system has reached the end of its usefulness at remediating contamination at ST32 Tank 2. The system can be
decommissioned and further remedial action for soils above the soil/groundwater interface (smear zone) is not required at this time. The Department will require the Air Force to perform
additional containment or cleanup if subsequent information indicates that
(1) the level of contamination that remains does not protect human health, safety, or welfare, or the environment; or (2) the information the Department relied upon for its decision was invalid, incomplete, or fraudulent. The Department requests the soils at the site be resampled once every three years (at a minimum)
through soil borings for petroleum contaminants to assess the degradation of soil contamination which remains above site closure criteria. The Department concurs with the recommendations that soil sampling be performed to document any remaining contamination levels presently at the site. For the purposes of closure sampling, the required minimum number
of samples taken will be three per boring. The samples will be obtained from two areas, which have the highest PID readings, and one obtained from the area with the highest historical contaminant level. |
Louis Howard |
| 10/2/2002 |
Update or Other Action |
Seven of the ten wells were removed from the Base wide Groundwater Monitoring Program as they met the decision guide criteria listed in the Base wide Monitoring Program. Monitoring wells 59-WL-30, 59-WL-31, and 59-WL-36 will continue to be monitored. |
Louis Howard |
| 10/21/2002 |
Update or Other Action |
State Elmendorf Environmental Restoration Agreement dissolved. The Alaska Department of Environmental Conservation (DEC) has reviewed the issue of abolishing the State Elmendorf Environmental Restoration Agreement (SERA) per Air Force request. 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.
From this date forward, any contaminated sites formerly covered under SERA that were not formally closed are subject to the current contaminated sites and underground storage tank regulations (18 AAC 75 and 18 AAC 78, respectively). |
Jennifer Roberts |
| 1/14/2003 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (the Department) is in the process of reviewing our files on storage tank removals and assessment work done in the past to ensure that all sites where releases of oil or other hazardous substances have been documented are cleaned up in accordance with state regulations. Many former tank sites had been incorporated into the State Elmendorf Environmental Agreement (SERA), but it appears that others were not. Now that the SERA has been closed out, releases that have not been cleaned-up and closed out need to be addressed following the current contaminated sites and underground storage tank regulations (18 AAC 75 and 18 AAC 78).
The Department recently completed a review of the document referenced above and has provided comments below. The site is located near Building 41-659 now referred to as 13251 Airlifter Drive. Information in the report indicated that a release occurred at the site and 350,000 mg/kg of gasoline range organics was detected in the soil (see Figure 3, sample 707007SS of the assessment).
The Department requested in a November 1, 1999 letter that the Air Force conduct a release investigation of the former UST Excavation to determine the full extent of the contamination associated with the UST. In the interim, the Department requested the Air Force submit: 1) a map showing the location of existing monitoring wells within 1,000 feet of the UST site; 2) analytical results of water samples collected from the monitoring wells during the last two years; 3) a map showing the location of any bioventing wells in close proximity (defined as within the zone of influence of the bioventing well) of the UST site; and 4) and any soil or vapor results of the bioventing system(s). The 1999 letter is still valid and the Department requests the Air Force provide the documentation to satisfy each item raised in previous letters submitted by the Department.
The Department requests the Air Force provide a copy of the release investigation it conducted for AFID 707 for the Department’s review and comment. If comments by the Department have been provided on the release investigation, please provide them in your response to the Department. The Department requests a written response from the Air Force within thirty (30) days of receipt of this letter on how the Air Force will address the items discussed in the letter. Please include in your written response the Reckey # 199821X025101, which is assigned to this site. |
Louis Howard |
| 1/31/2003 |
Update or Other Action |
2002 Annual Report Basewide Environmental Monitoring Program Draft January 2003 received. Note to file under:
ARARs
This data-reporting category addresses groundwater constituents for each individual program area specifically identified as COCs. The original list of cleanup levels for each program area is listed in Table 2-1. These chemical-specific cleanup levels were identified either in decision documents prepared for these sites (FFA program areas) or as contaminants which were found to significantly exceed cleanup levels where groundwater COCs were not specifically identified in previous investigations (SERA and Taxiway “N” program areas). Source documents that listed cleanup levels are referenced in Section 4.
Within the context of the Basewide Program, the list of COCs for each program area can change as data are continuously evaluated and the quality of data improves with new methods. For instance, as natural attenuation occurs, select constituents will reach cleanup levels and additional monitoring for that constituent will not be required unless mandated by a regulatory agreement. Specifically, if a COC is below cleanup levels for two consecutive sampling rounds, sampling for that COC can be discontinued.
Similarly, if cleanup levels for all COCs in a given analytical method are met across an entire program area, analysis using that method in that program area will no longer be required. An exception to the above guideline is made for OU 5. Because OU 5 serves as the downgradient receptor for most of the other program areas, COCs will not be eliminated from OU 5 unless the COC in question has been similarly eliminated first from all upgradient program areas.
The three SERA Phase II Program locations where groundwater sampling occurs include: ST32, ST48, and ST68, as identified in the Site Assessment Report for SERA Phase II. |
Louis Howard |
| 2/28/2003 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Basewide Bioventing Technical Report, Elmendorf Air Force Base, AK, Dated February 2003.
3.0 Conclusions and Recommendations Page 3-5
The text mentions the identifying of sites that have achieved closure since the cleanup regulations for contaminated sites have changed since the SERA program was established. The Department agrees, however, wishes to state the State-Elmendorf Environmental Restoration Agreement (SERA) is no longer applicable since it has been dissolved by the State and Air Force effective October 21, 2002. Since the SERA has been dissolved, releases to the land and waters of the State which have not been properly characterized and formally closed out will need to be addressed following the applicable current contaminated sites and underground storage tank regulations (18 AAC 75 and 18 AAC 78, respectively).
3.8 ST32 Page 3-8
The text recommends that closure sampling and decommissioning of the bioventing system be performed if the bioventing system is no longer contributing to the remediation at this site. The
Department concurs with that recommendation.
|
Louis Howard |
| 8/12/2003 |
Cleanup Plan Approved |
Decision document for excavating and treating petroleum contaminated soil at ST32. The cleanup approach shall be limited hot spot removal with off site low thermal desorption. This remedy shall be used for areas within ST32 not meeting closure criteria.
These areas have pockets of soil contamination and are isolated from the bioventing system by low permeability soils or there is recontamination of the soils by groundwater. Also, several areas of contamination (valve pits) still exist from the removal of the fuel pipeline. Specific dimensions of the excavation shall be agreed to in the coordination of the work plan for each site identified for excavation as the cleanup remedy. However, in general excavation shall be to the saturated layer or not past the depth of 15 feet, which ever is encountered first.
Cleanup Criteria: benzene: 0.02 mg/kg, toluene 5.4 mg/kg, ethylbenzene: 5.5 mg/kg, total xylenes: 78 mg/kg, GRO: 1,000 mg/kg, & DRO: 2,000 mg/kg.
If additional contamination is discovered at the site, which is not protective of human health, safety, or welfare, or of the environment, ADEC will require the USAF to conduct additional actions that meet requirements of: 18 AAC 78 Underground Storage Tank regulations, 18 AAC 75 Contaminated Site regulations and Alaska Statue 46.03 - 46.09. |
Louis Howard |
| 6/2/2004 |
Site Added to Database |
DRO. |
Sarah Cunningham |
| 6/10/2004 |
Update or Other Action |
File number assigned 2101.38.122. |
Sarah Cunningham |
| 6/30/2004 |
Meeting or Teleconference Held |
During a meeting held between 3 CES/CEVR and the Alaska Department of Environmental Conservation (ADEC) on 30 June 2004, it was agreed that no further action, including sampling, is required for the soil at ST32 Tank 2. This agreement was made because remaining soil contamination at this site is limited to 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.).
Bioventing systems are unable to effectively treat soil saturated with water including those in the smear zone. The groundwater at this site will continue to be monitored under the Basewide Groundwater Monitoring Program. |
Louis Howard |
| 7/16/2004 |
Update or Other Action |
2003 Annual Technical Report Environmental Monitoring and System Optimization of base wide bioventing systems. Cleanup standards ST32 (all sites): diesel range organics (DRO) 2000 mg/kg, gasoline range organics (GRO) 1000 mg/kg, (BTEX) benzene 0.02 mg/kg, toluene 5.4 mg/kg, ethylbenzene 5.5 mg/kg and total xylenes 78 mg/kg.
ST32 Tank 2: Historical: A summary of seven in-situ respiration tests conducted in 1996 and 1997 indicated that biodegradation rates during that time consistently decreased at both implants (all depths), indicating that hydrocarbon levels in the soil were decreasing.
Recommendations: This site is in close proximity to ST41, where groundwater modeling has demonstrated that BTEX contamination will be treated though natural attenuation. Prior recommendations for this site include closure sampling and the decommissioning of the bioventing system with continued groundwater monitoring as part of the Base wide Monitoring program.
The bioventing system is no longer contributing to the remediation effort at this site since remaining contamination exists only in 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.) where bioventing is not effective.
ADEC concurred with the shutdown of the bioventing system, and that further remediation for soils in the smear zone is not required at this time provided that ongoing monitoring of soil and groundwater is performed. Soil sampling will be conducted in 2004 (utilizing directional drilling) to support this decision.
ST32 Tank 4: Historical: Closure soil sampling was conducted at ST32 Tank 4 during 2000; therefore, in-situ respiration tests have not been conducted at the site since that time. The results of the closure sampling are reported in the Year 2000 Bioventing Closure Effort Report. The data suggest that contamination is present only in isolated areas within the non-homogeneous subsurface and quickly dissipates outside the localized area.
Continued operation of the bioventing system is unlikely to result in the reduction of hydrocarbons below the soil cleanup criteria. ADEC concurred with shutdown of the bioventing system, provided that ongoing monitoring of soil and groundwater is performed. An excavation is programmed for 2004 to cleanup this site.
ST32 Tank 5: Historical: Closure soil sampling was conducted at ST32 Tank 5 during 2000. The results of this closure sampling are presented in the Year 2000 Bioventing Closure Effort Report. The data suggest that contamination is present only in isolated areas within the nonhomogeneous subsurface and quickly dissipates outside the localized area.
Continued operation of the bioventing system is unlikely to result in the reduction of hydrocarbons below the soil cleanup criteria. ADEC concurred with shutdown of the bioventing system, provided that ongoing monitoring of soil and groundwater is performed. An excavation is programmed for 2004 to cleanup this site.
See site file for additional information. |
Louis Howard |
| 7/23/2004 |
Site Ranked Using the AHRM |
Site ranked by project manager since it was not ranked before. |
Louis Howard |
| 8/12/2004 |
Document, Report, or Work plan Review - other |
Staff reviewed and approved the removal action work plan. The cleanup approach shall be limited hot spot removal with off site low thermal desorption. This remedy shall be used for areas within ST32 not meeting closure criteria. These areas have pockets of soil contamination and are isolated from the bioventing system by low permeability soils or there is recontamination of the soils by groundwater.
Also, several areas of contamination (valve pits) still exist from the removal of the fuel pipeline. Specific dimensions of the excavation shall be agreed to in the coordination of the work plan for each site identified for excavation as the cleanup remedy. However, in general excavation shall be to the saturated layer or not past the depth of 15 feet, which ever is encountered first. |
Louis Howard |
| 10/4/2004 |
Update or Other Action |
Air Force (C. Mayer) sent ADEC (L. Howard) a letter. RE: Terminate State-Elmendorf Environmental Restoration Agreement (SERA)
1. We believe the goal of SERA in providing a schedule and mutually agreeing to an approach in cleaning up contaminated sites on Elmendorf has served its purpose and is currently not needed. We have either closed or have treatment systems in place at all of the sites originally identified in the SERA. We have dealt with new sites not identified in SERA and have been successful in making significant progress towards cleaning up these contaminated sites after 1992. More importantly, however, since 1992 the regulations in 18 AAC 75 (Oil and Hazardous Substances Cleanup Regulations) have been comprehensively reorganized and revised. There is a now a conflict between SERA and the new regulations. In light of this conflict and fulfillment of the purpose of SERA, we believe we should mutually agree to formally terminate SERA.
2. You have expressed a need for regular updates on the status of sites. However, we do not see that this need requires the continuation of SERA. The AF currently supplies information on sites in a routine manner. For example Quarterly Progress Reports are sent to you throughout the year. Remedial Project Manager Meetings cover the status of sites. Our annual reports sent to you cover site status. Also, if needed we could meet to discuss sites you are interested in.
3. Please provide signature in the block provided on the attached signature page to indicate your concurrence with the termination of SERA or provide written comments on this request within 30 days after receiving this letter. |
Louis Howard |
| 3/1/2005 |
Update or Other Action |
Staff reviewed the draft annual technical report for basewide bioventing systems. |
Louis Howard |
| 3/10/2005 |
Update or Other Action |
Staff reviewed and commented on the draft report for soil sampling at bioventing systems at ST32. ADEC concurs with the recommendations that the bioventing system is no longer contributing to the remediation effort at ST32 Tank 7. The system should be shut off and removed from the site and the remediation method be changed to natural attenuation with confirmation sampling. ADEC concurs with the recommendations that the bioventing system be shut down and removed since the soil sampling shows the soil cleanup levels have been met at ST32 Tank 8. Groundwater has not been sampled since 1995 and ADEC concurs that well 59-WL-20 be resampled to show it meets groundwater cleanup levels. |
Louis Howard |
| 3/31/2005 |
Update or Other Action |
2004 Phase I Remedial Process Optimization (RPO) annual report received. The 59WL-31 Plume is approximately 300 feet in diameter and located just west of the intersection of Fairchild Avenue and Airlifter Drive. This plume is considered to be stable. It was determined to be associated with Source Area ST32, a site with multiple USTs. It is believed that plumes associated with this source area are relatively isolated. Vertically, they occupy a shallow, generally unconfined aquifer, but because of local stratigraphic conditions, they can occur in the moraine as perched or semi-confined units. Groundwater flow in this vicinity is toward the southeast. Well 59WL-31, a downgradient well of ST32 Tanks 1 and 2, is the only well used to monitor the associated plume.
Avgas found while investigating the West Ramp Fuel Spill is unrelated to this release. However, its presence was previously unknown. The existence of the avgas may affect plume stability and require an increased sampling frequency of the in-source well. With the recent discovery of previously existing avgas in this region, the long term monitoring plan for the 59WL-31 Plume should focus on monitoring benzene, DRO, and GRO concentrations and verifying that these levels are not increasing.
Because of the recent discovery of a previously unknown avgas source, a cleanup date should not be calculated for this plume until several additional rounds of sampling have occurred. Although historical data exist for this plume, the discovery of additional contaminants in the subsurface qualifies these data. It is recommended that an additional well be installed to delineate the avgas source and determine its effect on the ability of the MNA remedy to remain protective at the 59WL-31 Plume.
|
Louis Howard |
| 3/6/2006 |
Update or Other Action |
Staff reviewed and commented on the 2005 Phase I RPO report. The text states if significant downgradient migration were to occur, the contaminants found at SS43 would be detected at downgradient sites. ADEC requests the text be corrected.
ADEC requests the text include reference to exactly which specific sites are downgradient of ST32 that are monitoring these same COCs. The COCs associated with the 59WL-31 Plume are benzene, GRO, and DRO, the COCs associated with the 59WL-30/36 Plume are benzene and GRO. |
Louis Howard |
| 2/9/2007 |
Exposure Tracking Model Ranking |
|
Louis Howard |
| 11/30/2007 |
Update or Other Action |
Zone 2 Remedial Process Optimization Report received. The monitoring well network in place at Plumes 59WL-31 & 59WL-30/36 adequately tracks the reduction of contaminant concentrations associated with these plumes. The limited spatial distribution of monitoring wells at ST32 does NOT, however, allow a complete assessment of the lateral extent or stability of these plumes, particularly with respect to the increasing or undefined trends observed with GRO & DRO concentrations.
Existing site conditions are protective because 1) no human or ecological receptors are present immediately downgradient of the ST32 plumes, & 2) LUCs prevent exposure to contaminated GW.
Both the 59WL-31 & 59WL-30/36 plumes are considered Red priority sites because the absence of clearly decreasing trends prevents determination of cleanup dates. The elevated concentrations of GRO & DRO in ST32 GW suggest that residual contamination from a source may remain in the subsurface. A focused soil investigation has been scheduled for the summer of 2008 to collect data to assess the magnitude & extent of residual contamination. A limited field investigation should also be conducted to address the floating product previously observed at 59WL-01. If significant residual contamination is identified as contributing to GW contamination at this site, methods reducing the mass flux of contaminants into the GW will be assessed.
The benefits of continued operation of the bioventing system should also be assessed. Results from the latest in situ respiration test (conducted in 2001) indicated moderate to low total volatile hydrocarbon concentrations (6 to 180 ppm) at all soil vapor monitoring points & low to undetectable degradation rates (0 to 0.067 milligrams per kilogram per day [mg/kg/day]) across the site (USAF, 2005c).
Although benzene concentrations in soil at the former Tank 7 location are currently above the cleanup goal, the respiration test results suggest that continued bioventing may no longer be the most cost-effective option at this site. A static soil vapor test should be conducted to evaluate the benefits of continued bioventing operation. The specific goal of this test should be to determine whether natural diffusion of oxygen into the vadose zone is sufficient to sustain current degradation rates. If natural processes are deemed sufficient, continued operation & maintenance (O&M) of the bioventing system would not be necessary.
The recommendations for the 59WL-31 & 59WL-30/36 plumes are as follows:
Short-Term (FY08-FY09)
• Continue monitoring per Figure 1.4.
• Characterize the magnitude & extent of residual contamination remaining upgradient of the existing GW plumes.
• Assess floating product at well 59WL-01.
• Perform a static soil vapor event to measure natural oxygen diffusion into vadose zone soils & assess the benefits of continued bioventing.
• Update the CSM.
Long-Term (FY10 or Longer)
• Continue monitoring per Figure 1.4.
• Conduct source area removal or in-situ treatment.
• Sample soil at Tank 7 to evaluate progress toward achieving soil cleanup goals.
• Perform RPO evaluation. Perform long-term monitoring optimization study & implement with approval from regulatory agencies.
• If cleanup goals for soil are achieved or if natural oxygen diffusion rates are deemed sufficient, remove bioventing system at Tank 7.
• Monitor according to optimized monitoring schedule. Remove monitoring wells that are identified for abandonment in the long-term monitoring optimization study.
See site file for additional information.
|
Louis Howard |
| 2/11/2008 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Basewide Bioventing System, dated January 2000. DEC concurs with most of the recommendations for ST43/55. For negotiating cleanup levels beyond the Level A criteria, DEC will consider adopting the cleanup criteria in 18 AAC 75. However, this move to a Method 2 cleanup level will require more analytical work on the Air Force's part to show the site has achieved cleanup levels.
DEC does not concur with the cleanup levels for 2,400 mg/kg to 9,100 mg/kg for soil. DEC recalls that the cleanup level for DRO in those sites in the Elmendorf Moraine sites (similar to ST41) was 2,000 mg/kg for DRO. Based on lab bench scale leachability studies with |
Louis Howard |
| 3/7/2008 |
Update or Other Action |
Zone 2 Remedial Process Optimization Report received. The monitoring well network in place at Plumes 59WL-31 and 59WL-30/36 adequately tracks the reduction of contaminant concentrations associated with these plumes. The limited spatial distribution of monitoring wells at ST32 does not, however, allow a complete assessment of the lateral extent or stability of these plumes, particularly with respect to the increasing or undefined trends observed with GRO and DRO concentrations. Existing site conditions are protective because 1) no human or ecological receptors are present immediately downgradient of the ST32 plumes, and 2) LUCs prevent exposure to contaminated groundwater.
Both the 59WL-31 and 59WL-30/36 plumes are considered Red priority sites because the absence of clearly decreasing trends prevents determination of cleanup dates. The elevated concentrations of GRO and DRO in ST32 groundwater suggest that residual contamination from a source may remain in the subsurface. A focused soil investigation has been scheduled for the summer of 2008 to collect data to assess the magnitude and extent of residual contamination. A limited field investigation should also be conducted to address the floating product previously observed at 59WL-01. If significant residual contamination is identified as contributing to groundwater contamination at this site, methods reducing the mass flux of contaminants into the groundwater will be assessed.
The benefits of continued operation of the bioventing system should also be assessed. Results from the latest in situ respiration test (conducted in 2001) indicated moderate to low total volatile hydrocarbon concentrations (6 to 180 ppm) at all soil vapor monitoring points and low to undetectable degradation rates (0 to 0.067 milligrams per kilogram per day [mg/kg/day]) across the site (USAF, 2005c). Although benzene concentrations in soil at the former Tank 7 location are currently above the cleanup goal, the respiration test results suggest that continued bioventing may no longer be the most cost-effective option at this site.
A static soil vapor test should be conducted to evaluate the benefits of continued bioventing operation. The specific goal of this test should be to determine whether natural diffusion of oxygen into the vadose zone is sufficient to sustain current degradation rates. If natural processes are deemed sufficient, continued operation and maintenance (O&M) of the bioventing system would not be necessary.
The recommendations for the 59WL-31 and 59WL-30/36 plumes are as follows:
Short-Term (FY08-FY09)
• Continue monitoring per Figure 1.4.
• Characterize the magnitude and extent of residual contamination remaining upgradient of the existing groundwater plumes.
• Assess floating product at well 59WL-01.
• Perform a static soil vapor event to measure natural oxygen diffusion into vadose zone soils and assess the benefits of continued bioventing.
• Update the CSM.
Long-Term (FY10 or Longer)
• Continue monitoring per Figure 1.4.
• Conduct source area removal or in-situ treatment.
• Sample soil at Tank 7 to evaluate progress toward achieving soil cleanup goals.
• Perform RPO evaluation. Perform long-term monitoring optimization study and implement with approval from regulatory agencies.
• If cleanup goals for soil are achieved or if natural oxygen diffusion rates are deemed sufficient, remove bioventing system at Tank 7.
• Monitor according to optimized monitoring schedule. Remove monitoring wells that are identified for abandonment in the long-term monitoring optimization study.
|
Louis Howard |
| 8/21/2009 |
Update or Other Action |
Draft Work Plan for OT092 Fuel Pipeline and SS43/ST68 Bioventing Systems Decommissioning received.
OT092 included multiple segments of buried fuel pipeline that transported diesel fuel from the
Port of Anchorage to and around Elmendorf AFB during the 1940s to 1990s. These pipeline
segments total approximately 27,000 linear feet and include valve pits. On 15 April 1998,
OT092 was validated under the Environmental Restoration Program. The results of a limited
site assessment were reported in 1999 and included a general remedial design. OT092 is considered a state program site because the expected contaminants are petroleum products. However, because no releases are known to have occurred, no Decision Document has been produced for OT092.
In 1993, site SS43 was investigated under a Superfund Emergency Response Actions (SERA) Phase I assessment, which identified gasoline-range organics (GRO), diesel-range organics (DRO), and benzene, toluene, ethylbenzene, and xylenes (BTEX) as contaminants in soil and groundwater. In 1995, a corrective action plan recommended bioventing as the soil remedy and monitored natural attenuation (MNA) as the groundwater remedy. In 1996, the bioventing system started operating. 2003 soil sampling showed that GRO,DRO, and BTEX concentrations no longer exceed cleanup levels above the smear zone. Because the vadose zone is clean, the only soil contamination remaining is in the smear zone,where bioventing is not effective; therefore, the bioventing system at SS043 will be decommissioned in accordance with state regulations.
Soil field screening samples will be collected from the floor and sidewalls of the excavations
at a rate of 1 per 100 square feet of area (10-foot by 10-foot grid). Field screening will be used to guide the excavations and help segregate the clean overburden stockpile from contaminated soil. The SAP (Appendix B) presents additional field screening information. Confirmation sampling will begin once excavation and field screening are completed.
Excavations will be sampled at a frequency of one confirmation soil sample per 250 square feet, with two soil samples from the first 250 square feet of excavated area. At least one sample will be collected from the floor of each excavation. For excavation of pipeline segments, at least one sample will be collected from each 50 linear feet of excavated area. Confirmation soil samples will be collected at the location of the highest field screening results, at the frequency specified above. Samples will be collected and submitted to an approved laboratory for analysis. Samples will be analyzed for GRO, DRO, and BTEX.
Clean Stockpile Sampling-Soil sampling from the clean soil stockpiles will be performed in accordance with 18 AAC 78 and as described in the SAP (Appendix B). Field screening samples will be collected from the stockpiles at a minimum frequency of one per 25 cy. Analytical confirmation soil samples will be collected from random locations within the stockpile, with a frequency of one sample per 50 cy of stockpile and two samples from the first 50 cy. Analytical samples will be submitted to an approved laboratory and analyzed for GRO, DRO, and BTEX.
Valve Pit Sampling-At least two soil samples will be collected to assess conditions at each valve pit location. If excavation is necessary to expose the valve pits and decommission pipeline segments, then the valve pit area will be sampled and backfilled as detailed in Section 2.7.2. If the valve pit is accessible at grade and no excavation is required, the valve pit area will be inspected visually, and surficial soils will be field screened inside and outside of the valve pit. Field screening data and visual observations will be used to guide the collection of soil samples in and around the valve pits. Analytical samples will be analyzed for GRO, DRO, and BTEX, in accordance with the SAP (Appendix B). |
Louis Howard |
| 1/26/2010 |
Update or Other Action |
For releases where leaded gasoline and aviation gasoline are suspected contaminants of concern, ADEC requires analysis for EDB and 1,2-DCA and lead. EPA 8260 is required for the analysis of 1,2-Dichloroethane (1,2-DCA). EPA 8011 or EPA 504.1 should be used when evaluating ethylene dibromide (EDB). EDB soil samples should be field preserved in hexane. EPA 8260 will quantify EDB in ground water; however, the detection limits do not meet the Table C cleanup level of 0.00005 mg/L. |
Louis Howard |
| 4/14/2010 |
Update or Other Action |
This annual report includes a qualitative evaluation of the 2009 GW 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.
The following text summarizes observations and recommendations for groundwater monitoring at the 59WL-31 and 59WL30/36 Plumes at Site ST32:
The 2007 RPO evaluation identified both the 59WL-31 and 59WL-30/36 plumes as Red priority sites because the absence of clear decreasing trends prevents determination of cleanup dates. As shown on Figures 9.3 and 9.4, there is still no discernable downward trend to either GRO or DRO concentrations in the 59WL-31 Plume. GRO is now below the cleanup level of 2,200 µg/L in both wells in the 59WL-30/36 Plume (Figures 9.5 and 9.6), and benzene is only slightly above the cleanup standard in well 59WL-30. In addition, the supplemental groundwater investigation performed at Site ST32 in 2009 and described in Section 9.5 indicates that the current boundaries of the two plumes at Site ST32 do not adequately illustrate the extent of groundwater contamination at this site.
Based on this information, the Red priority designation remains appropriate for Site ST32.
The findings from the 2009 groundwater investigation and the combined 2008/2009 soil investigations at Site ST32 are summarized as follows:
The extent of groundwater concentrations that exceed ADEC cleanup levels is larger than the historically-depicted extents of the 59WL-31 and 59WL-30/36 Plumes. Available data has been used to identify the following five areas of groundwater contamination:
Area 1 - GRO, DRO, benzene, toluene, and total lead concentrations measured in selected 2009 groundwater samples from the western portion of Site ST32 exceeded ADEC cleanup levels. The Area 1 groundwater contamination extends beyond the previously-defined extent of the 59WL-31 Plume, and is not sufficiently delineated to the south and west/northwest of identified contamination.
Area 2 - GRO concentrations measured in the 2009 groundwater sample from well 59WL-23 exceeded ADEC cleanup levels. The extent of contamination for this area appears to be sufficiently delineated by existing data, and an estimated plume extent should be developed to support future monitoring and remediation decisions.
Area 3 - GRO, DRO, benzene, ethylbenzene, and toluene concentrations measured in 2009 groundwater samples from well 59WL-10 exceeded ADEC cleanup levels. The downgradient extent of groundwater contamination in this area is undefined.
Area 4 - GRO, DRO, benzene, and toluene concentrations measured in 2009 from at least one well in Area 4 exceeded ADEC groundwater cleanup levels. The downgradient extent of groundwater contamination in this area is undefined. Area 4 groundwater contamination extends beyond the previously-defined extent of the 59WL-30/36 Plume, and is not sufficiently delineated south of identified contamination.
Area 5 - GRO, DRO, benzene, and total lead concentrations measured in samples from well 59WL-13 in 2009 exceeded ADEC groundwater cleanup levels. The downgradient extent of petroleum hydrocarbon contamination observed at 59WL-13 is undefined. In addition, the eastern and downgradient extents of lead contamination are undefined.
The nature and extent of soil contamination at Pipeline Locations 123+80, 301+40, and 200+03 have been defined and do not require additional investigation.
The extent of soil contamination at Pipeline Location 201+00 is undefined, and should be further evaluated and assessed as part of a comprehensive evaluation of the extent of soil and groundwater contamination within Area 1.
|
Louis Howard |
| 7/9/2010 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the 2009 Annual Report Monitoring of Compliance Program Sites, Elmendorf Air Force Base (EAFB) dated June 2010.
Worksheet #30 Page 57 of 67
ST422 had a former 500 gallon UST which stored diesel fuel. GRO, benzene, and toluene were detected above cleanup levels in samples collected near the groundwater interface (11 to 15.5 feet bgs) in downgradient borings. It is not believed that these high GRO and benzene concentrations are from the former UST at ST422. Therefore, analyzing for EDB and 1,2-DCA in soil or groundwater at this site is warranted.
However, monitoring for EDB and 1,2-DCA at ST32 is warranted. ST422 is located within the SERA Phase II (ST32) source area and there is a known benzene plume located to the northwest. It is likely that the GRO and benzene contamination detected during the investigation of site ST422 is associated with the ST32 plume rather than the former UST at ST422. The nearest crossgradient monitoring wells currently in the Basewide Groundwater Monitoring Program are 59-WL36 and W4, located approximately 400 feet southwest and 1400 feet southeast of ST422, respectively. |
Louis Howard |
| 11/17/2010 |
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: at ST32 - 20 additional wells were monitored and 2 were abandoned in an attempt to better define the groundwater plume for this site. |
Louis Howard |
| 12/2/2010 |
Update or Other Action |
Letter Report for the Treatment System Removal at SS43, ST32 Tank 7, and ST68 received.
ST32 Tank 7: The blower assembly, one injection well, and four vapor monitoring probes were decommissioned. The field team was unable to disassemble the electrical connections from the utility box to the CONEX; therefore, the utility box was left in place.
See site file for additional information. |
Louis Howard |
| 1/24/2011 |
Update or Other Action |
Staff received the 2010 Zone 2 Mgt. Area Annual Report.
AREA 1
GW contamination in Area 1 is present in the western portion of Site ST32 (Figure 9.2). GRO, DRO, benzene, toluene, & total lead measured in samples from at least one well within Area 1 exceeded ADEC GW cleanup levels in 2009. Both locations where free product was noted (wells 59WL-01R & 59WL-11) were also within this area. A review of historical soil & GW data within the Area 1 boundary suggests that sources of GW contamination may include former Tanks 1, 10, 11, & 12; Pipeline Locations 201+00 & 301+40 (Vault 1A); & the 2004 release from the West Ramp Hydraulic Fueling Facility.
GW Sample Results:
• Benzene (5 µg/L cleanup level): 59WL-07 (370 µg/L), 59WL-11 (5,800 µg/L), primary & field duplicate samples from 59WL-31 (39 / 34 µg/L), & T41206 (540 µg/L);
• Toluene (1,000 µg/L cleanup level): 59WL-31 (6,600 / 6,900 µg/L), T41206 (1,200 µg/L);
• Total lead (15 µg/L cleanup level): 59WL-11 (22 µg/L), 59WL-31 (37 / 43 µg/L);
• GRO (2,200 µg/L cleanup level): 59WL-07 (2,400J µg/L), 59WL-11 (10,000 µg/L), 59WL-31 (23,000 / 24,000 µg/L), & T41206 (5,900 µg/L);
• DRO (1,500 µg/L cleanup level): 59WL-07 (6,300 µg/L), 59WL-11 (7,800 µg/L), & 59WL-31 (7,300 / 6,300 µg/L);
• 1,2-DCA (5 µg/L cleanup level): 59WL-11 (5 J µg/L); &
• EDB (0.05 µg/L cleanup level): 59WL-07 (5.8 J µg/L); 59WL-11 (1.8 J µg/L); T41206 (18 J µg/L).
As expected, the biogeochemical environment was most strongly anaerobic within areas of significant petroleum hydrocarbon contamination. The range of individual parameter values, & the corresponding interpretation of the active electron acceptor processes for 2010, are generally consistent with findings from the 2009 monitoring event, indicating that the dominant contaminant degradation processes did not change over those indicated last year.
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 & other petroleum hydrocarbons are often significant in anaerobic environments. Available biogeochemical data also supports the conclusion that the lead scavengers 1,2-DCA & EDB are degrading under strongly anaerobic conditions at the source areas for former Tanks 10, 11, & 12.
Specifically, ethane & ethene, which can be intermediate degradation products of 1,2-DCA or EDB (USEPA, 2008),were only detected in samples from wells where 1,2-DCA or EDB were also detected (i.e., wells 59WL-07, 59WL-11, & T41709). These data, when combined with the absence of these lead scavengers in downgradient wells, suggests that natural attenuation processes are preventing significant migration of 1,2-DCA & EDB from source areas.
AREA 2
GW contamination in Area 2 is at the northern boundary of Site ST32, near former Tank 15 (Figure 9.2). GRO concentrations measured in samples from well 59WL-23 in 2009 exceeded ADEC GW cleanup levels. A review of historical soil & GW data suggests that the most likely sources of GW contamination in Area 2 are former Tank 15 & Pipeline Location 123+80.
Biogeochemical indicator parameters measured in samples from three wells associated with Area 2 using field & fixed-base analytical laboratory methods indicate conditions that ranged from an aerobic environment at well 59WL-24 to a reducing, anaerobic environment at well 59WL-41 (Table 1.3). As expected, the biogeochemical environment was reducing at in-source monitoring well 59WL-23 & downgradient monitoring well 59WL-41 due to the impact of significant petroleum concentrations associated with the former Tank 15. The absence of petroleum contamination at well 59WL-24, which is side gradient of Area 2, indicates that background biogeochemical environment in this portion of Site ST32 is aerobic.
See site file for additional information.
|
Louis Howard |
| 7/15/2011 |
Update or Other Action |
Draft Work Plan Environmental Remedial Action-Operations & LTM & Maintenance received.
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 ST32 is an 80-acre site in the western portion of Zone 2, north of Airlifter Drive (formerly Burns Road). Site ST32 encompasses the former locations of 29 50,000-gallon USTs (Tanks 1 through 29) and the associated underground fuel distribution pipelines, vaults, and valve pits. The tanks originally stored aviation gasoline before conversion to JP-4 between the mid-1950s and 1975. These fuels were distributed through the pipelines via gravity flow to the flight line of the East/West Runway.
Five new groundwater monitoring wells will be installed within the Zone 2 Management area in
2011. The new wells will be installed in locations that will help better define three of the five plume areas of Site ST32. There is no decision document for ST32 groundwater. These constituents are assumed to be contaminants of potential concern based on existing groundwater data.
See site file for additional information.
|
Louis Howard |
| 1/27/2012 |
Update or Other Action |
2011 Annual Monitoring Report for Zones 1, 2, & 3 received.
The soil remedy for Site ST32 was established in the Decision Document for ST32 (USAF, 2003b) & consisted of limited hot-spot removal with off-site low-temperature thermal treatment of excavated soil. When implemented, the depth of excavation was prescribed as the top of the saturated zone or 15 ft bgs, whichever was encountered first (USAF, 2003b). A final remedy for GW has not been established for Site ST32.
Area 1
GW samples were collected from 11 wells in & around Area 1 in 2010. Contaminant concentrations exceeded ADEC cleanup levels in 4 of the 11 wells (59WL-07, 59WL-11, 59L-31, & T41206) as follows:
• Benzene (5 µg/L cleanup level): 59WL-07 (370 µg/L), 59WL-11 (5,800 µg/L), primary & field duplicate samples from 59WL-31 (39 / 34 µg/L), & T41206 (540 µg/L);
• Toluene (1,000 µg/L cleanup level): 59WL-31 (6,600 / 6,900 µg/L), T41206 (1,200 µg/L);
• Total lead (15 µg/L cleanup level): 59WL-11 (22 µg/L), 59WL-31 (37 / 43 µg/L);
• GRO (2,200 µg/L cleanup level): 59WL-07 (2,400J µg/L), 59WL-11 (10,000 µg/L), 59WL-31 (23,000 / 24,000 µg/L), & T41206 (5,900 µg/L);
• DRO (1,500 µg/L cleanup level): 59WL-07 (6,300 µg/L), 59WL-11 (7,800 µg/L), & 59WL-31 (7,300 / 6,300 µg/L);
• 1,2-DCA (5 µg/L cleanup level): 59WL-11 (5 J µg/L); &
• Ethylene dibromide (EDB) (0.05 µg/L cleanup level): 59WL-07 (5.8 J µg/L); 59WL-11 (1.8 J µg/L); T41206 (18 J µg/L).
No contaminants exceeded their respective ADEC cleanup levels in the remaining seven wells
(59WL-38R, 59WL-39, 59WL-40, ST41-23, ST41-24, T40001, & T40905).
Area 2
GRO measured in samples from well 59WL-23 in 2009 exceeded ADEC GW cleanup levels. A review of historical soil & GW data suggests that the most likely sources of GW contamination in Area 2 are former Tank 15 & Pipeline Location 123+80. GW samples were collected from monitoring wells 59WL-23 & 59WL-24 on 30 September 2010 & 59WL-41 04 October 2010. GRO concentrations measured in the sample from 59WL-23 (3,600 µg/L) were lower than those measured in 2009 (3,900 µg/L) but still exceeded the GW cleanup level of 2,200 µg/L.
Benzene concentrations, which were below the ADEC cleanup level of 5 µg/L in Area 2 in 2009, were above the cleanup level in the sample collected at 59WL-23 in 2010 (6.1 J µg/L). No contaminants exceeded their respective cleanup levels in either of the other two wells sampled in the vicinity of Area 2 (59WL-24 & 59WL-41).
Area 3
GW sampling was attempted at four wells in & around Area 3 in 2010. Well 59WL-05 could not be sampled due to a lack of water & well 59WL-32 could not be sampled due to a broken PVC casing. Samples were collected from monitoring well T41709 on 30 September 2010 & from BH-05 on 01 October 2010. Benzene (440 µg/L), ethylbenzene (1,000 µg/L), GRO (4,400 µg/L), & DRO (1,600 µg/L) concentrations measured in the samples from T41709 exceeded their respective GW cleanup levels. No contaminants exceeded their respective cleanup levels in the GW sample collected at BH-05.
Area 4
GW sampling was attempted at five wells in & around Area 4 in 2010. Well 59WL-28 could not be sampled due to a lack of water, & well 59WL-29 could not be found & is assumed to have been abandoned or destroyed prior to the 2010 field season. Samples were collected from monitoring wells 59WL-30, 59WL-35, & 59WL-36 in June & October 2010. No contaminants were detected above their respective cleanup levels in the samples collected from wells at Area 4 in 2010.
Area 5
GW sampling was attempted at five wells in & around Area 5 in 2010. Wells 59WL-12, 59WL-13, & T42810 could not be sampled due to a lack of water, & well 59WL-16 could not be sampled due to an obstruction above the water table that prevented the passage of the pump intake. A sample was collected from monitoring well 59WL-21 on 06 October 2010. No contaminants were detected above their respective cleanup levels in the sample collected from well 59WL-21.
Wells 59WL-30, 59WL-31, & 59WL-36R were measured with contaminant concentrations exceeding ADEC cleanup levels in 2011. Well 59WL-30 had a GRO concentration of 5,500 & Well 59WL-36R had a GRO at 3,200 µg/L, which both exceed the ADEC cleanup level of 2,200 µg/L. Well 59WL-31 had a GRO at 34,000 µg/L, DRO at 2,300 µg/L, total lead concentration of 32.6 µg/L, benzene concentration of 41 µg/L, & a toluene concentration of 8,600 µg/L, all exceeding ADEC cleanup levels.
See site file for additional information.
|
Louis Howard |
| 6/6/2012 |
Update or Other Action |
Draft Project Management Plan received.
ST032 (0009FN) Abandoned Underground Storage Tanks (USTs)
Performance Objective
Optimized Exit Strategy for Site Closure
For those sites that do not achieve SC within the POP, develop an Optimized Exit Strategy (OES) that will reduce monitoring and treatment requirements, optimize the operation of existing systems, and/or accelerate the achievement of SC in the post-POP period. The outcome of the optimization studies/evaluations will be summarized in a report for Air Force review and approval, which will also outline clear exit strategies with defined metrics, decision logic, scenario development, and anticipated outcomes and durations for advancing SC.
Performance Indicators
· Prepare an approved Optimized Exit Strategy Workplan by August 2012
· Prepare an approved Characterization Workplan by December 2012
· Coordinate, mobilize, and execute Characterization Investigation
· Prepare an approved Characterization Summary Report
· Perform 2012 RA-O Monitoring Event under Addendum to Current LTM Plan with approved Annual RA-O Monitoring Event Memo by February 2013
· Conduct 2013 RA-O Monitoring Event
· Prepare an approved Decision Document
· Continue RA-O Monitoring to meet ROD and ADEC requirements
· Prepare and implement an approved Optimized exit Strategy Report to achieve SC
Potential Risk
Characterization requires more effort than estimated; new COCs are identified in either
media.
Risk Mitigation
Additional soil borings and monitoring wells will be installed to define source areas and
plumes; a concerted effort will be made to identify the source of any newly identified COCs
during the characterization.
Date of Acheiving Performance Objective
2nd Quarter 2020
Planned Approach
Prepare an approved Site Characterization Workplan with an updated CSM.
Coordinate, mobilize, and execute Site Characterization by installing and sampling 35 soil borings and completion of 25 borings to monitoring wells and free product removal.
Use HRC to evaluate SC based on risk to future residential receptors for all pathways.
Prepare an approved Site Characterization Report with an updated CSM, documented HRC risk evaluation, documentation of findings of investigation including source and plume boundaries and recommend remedial action for addressing complete pathways.
Prepare an approved Decision Document including HRC evaluation, various sources, plume nature, and extent, successful remedial actions at ST032 in the past, and preferred remedial actions for ST032 sources and plumes.
Develop an Optimized Exit Strategy Plan to achieve SC. |
Louis Howard |
| 6/22/2012 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft Project Mgt. Plan.
Table 6-3 JBER-Elmendorf
General comments
Risk mitigation: In general, vadose zone soils shall not exceed maximum allowable levels for petroleum contamination for soil from 0 – 15’ bgs (i.e. direct contact for BTEX, PAHs and ingestion for DRO, GRO, RRO) regardless of HRC calculated levels. Treatment or excavations deeper than 15’ bgs may be warranted on a site-specific basis to prevent the soil from acting as a continuing source of groundwater contamination.
In addition, sites with existing groundwater contamination above Table C cleanup levels will require that migration to groundwater cleanup levels be used for soil and ICs will be required. Once groundwater is below Table C for for a period of time (per the latest approved “Basewide Monitoring Program Well Sampling Frequency Decision Guide”), the maximum allowable levels may become the cleanup levels as determined by ADEC on a case by case basis.
7.1.2
Independent QA Oversight on Performance Based Contracts
The site cleanup rules require that “collection, interpretation, and reporting of data, and the required sampling and analysis is conducted or supervised by a qualified, impartial third party”. Depending upon the specific terms in a performance based contract, a contractor may no longer be considered an impartial third party with respect to collecting, interpreting and reporting data.
This should be taken into consideration when preparing scopes of work. ADEC strongly recommends the Air Force provide an on-site Quality Assurance Representative or a third party QA oversight contractor to monitor fieldwork for consistency with approved plans and contract requirements.
UFP-QAPP Requirements (Planning)
Any existing approved UFP-QAPPs will be updated to reflect current regulations and guidance that have been updated since they were approved.
Page 7-6
The text states: “Our Technical Site Managers and Project Chemists will ensure that, prior to sampling activities, full service analytical laboratories to be used are, at a minimum, DoD ELAP accredited and in good standing based on standard business information sources (e.g., Dunn & Bradstreet). In addition to DoD ELAP, the Project Chemist will also ensure that the supporting laboratories are approved for work in the State of Alaska, when required. Analytical methods used will be
Alaska and EPA standard methods, unless technically impractical.”
ADEC disagrees. The full service analytical laboratories have to be both DoD-ELAP accredited AND Alaska approved. Any non-EPA and/or Alaska methods must be approved by the department prior to sample collection. |
Louis Howard |
| 4/30/2013 |
Update or Other Action |
Draft Annual Monitoring Report received for review and comment.
Site ST032 encompasses the former locations of 29 50,000-gallon USTs (Tanks 1 through 29) and the associated underground fuel distribution pipelines, vaults, and valve pits (Figure 18-1). The tanks originally stored aviation gasoline before conversion to JP-4 between the mid-1950s and 1975. These fuels were distributed through the pipelines via gravity flow to the flight line of the East/West Runway. There are five separate plume areas at ST032.
Historic sampling results for ST032 have indicated fuel constituents present in groundwater above cleanup criteria in 18 AAC 75 Table C and fuel constituents in vadose and smear zone soil above 18 AAC 75 Tables B1 and B2. The DD for ST032 (USAF, 2003c) established the COCs and applicable cleanup levels for BTEX, DRO, and GRO in soil. A final remedy for groundwater has not been established for this site.
During 2012, groundwater monitoring wells 59WL-30, 59WL-31 and 59WL-36R were sampled for GRO, DRO, BTEX, lead and dissolved lead. Groundwater contamination in Area 1 is present in the western portion of Site ST032. GRO, DRO, benzene, toluene, and total lead concentrations measured from 59WL-31 within Area 1 exceeded Table C groundwater cleanup levels for Benzene (31 µg/L), Toluene (3900 µg/L), GRO (29000 µg/L), DRO (µg/L 7700) and Total Lead (95.3 µg/L).
Additional investigation to better define soil and groundwater contamination will be proposed for ST032 in 2013 under the new PBR contract. No changes to the annual monitoring are being proposed for this site. |
Louis Howard |
| 3/13/2014 |
Update or Other Action |
Draft 2013 Annual report received for review and comment. The overall project objectives included collecting sufficient data to:
• Monitor concentrations of contaminants of concern (COCs) at each site with sufficient precision and accuracy to evaluate their concentrations with respect to cleanup goals.
• Identify potentially toxic and/or mobile transformation products.
• Verify individual plume characteristics, such as downgradient, lateral, or vertical expansion or retraction.
• Evaluate groundwater flow directions and hydraulic gradients to monitor plume migration and assess contaminant sources.
• Evaluate the effectiveness of land use controls/ institutional controls (LUCs/ICs) to protect human health and the environment.
• Identify and repair damaged monitoring wells to protect groundwater.
• Identify monitoring wells that are no longer needed or are damaged beyond repair.
Historic sampling results for ST032 have indicated fuel constituents present in groundwater above cleanup criteria in 18 AAC 75 Table C and fuel constituents in vadose and smear zone soil above 18 AAC 75 Tables B1 and B2. The DD for ST032 (USAF, 2003c) established the COCs and applicable cleanup levels for BTEX, DRO, and GRO in soil.
A final remedy for groundwater has not been established for this site. 18 AAC 75 Table C Groundwater Cleanup levels are used to evaluate the significance of contaminant concentrations measured in ST032 groundwater. Current monitoring requirements at ST032 include annual groundwater sampling and an annual LUC inspection. Annual groundwater sampling is required for GRO, DRO, BTEX compounds, total and dissolved lead at groundwater monitoring wells 59WL-30, 59WL-36R, and 59WL-31.
During 2013, groundwater monitoring wells 59WL-30, 59WL-31 and 59WL-36R were sampled for GRO, DRO, BTEX compounds, total lead and dissolved lead. A field duplicate was collected from well 59WL-31 for GRO, DRO, BTEX compounds, and dissolved lead. A field duplicate was collected from well 59WL-36R for total lead.
GRO concentrations from well 59WL-30 (2.4 mg/L) within the ST032 Area 4 Plume (Figure 17-1), exceeded the 18 AAC.75.345 Table C groundwater cleanup level. GRO (19 mg/L), DRO (15 mg/L), benzene (27 ug/L 37 ug/L FD), toluene (6.3 mg/L 6.6 mg/L FD) and total lead (29 ug/L) concentrations from well 59WL-31 within the ST032 Area 1 Plume (Figure 17-1), exceeded their respective 18 AAC.75.345 Table C groundwater cleanup levels. No contaminants exceeded their respective cleanup levels in well 59WL-36R (Area 4 Plume).
The ADEC site status for ST032 is “Open.” Fuel constituents continue to be present in groundwater above the cleanup criteria in 18 AAC 75 Table C and in vadose and smear zone soil above 18 AAC 75 Tables B1 and B2. Five areas of groundwater contamination have been identified at ST032 as Areas 1 through 5 (see Figure 17-1). Additional investigation to better define soil and groundwater contamination will be proposed for ST032 in 2014 under the JBER PBR contract.
Following the investigation, the monitoring well network will be analyzed to determine if it is adequate for LTM of this site. |
Louis Howard |
| 9/19/2014 |
Update or Other Action |
Draft SC work plan received for review & comment.
Site ST032 as a whole will not meet ADEC “Cleanup Complete” (CC) criteria until every identified sub-site within ST032 meets “Cleanup Complete” criteria. The term “sub-site” is used to describe individual UST, vault, valve pit, & pipeline locations within Site ST032 that have historically been identified as contaminated or potentially contaminated locations.
Category 1 sub-sites exhibit no exceedances in either soil or GW above the applicable cleanup criteria. Therefore, these sites will not be investigated & will not be addressed in this Work Plan. Rather, the entirety of existing data will be provided in the SC Report in order to obtain concurrence from the ADEC to close the respective sub-site, moving the overall Site ST032 closer to “CC”.
The objective for Category 2 sub-sites is to collect sufficient data to fill data gaps, & evaluate risk via the HRC. Depending on analytical results, soil gas data may also be collected per the ADEC VI Guidance for Contaminated Sites (2012). The results will be used in support of achieving no further action (NFA) for the sub-site, moving the overall Site ST032 closer to “CC” or to confirm the 2003 DD remedy already in place.
Category 3 sub-sites pose unacceptable risk based on the levels of GW contamination. For these sub-sites, if contaminant concentrations in GW are more than 3 times the ADEC Table C criteria, no field investigation is proposed. Rather, the SC Report will assess concentration trends, estimate cleanup timeframes & protectiveness of ICs, & recommend a MNA sampling schedule. Field investigation activities will be focused on Category 2 sub-sites where analytical data indicate there is impact to soils & GW & there is potential to obtain closure based on the results of additional sampling & subsequent risk evaluation.
Category 2a
Vault 2 (302+85)
The extent of contamination (vertical & horizontal) is not thoroughly documented. Additional site characterization is required to refine the extent & magnitude of contaminants in soil & GW. Data is needed in order to adequately support risk calculation using the HRC.
SCOPE OF WORK
Further characterization will include installation & sampling of at least 1 in-source soil boring & 1 potential downgradient boring at Vault 2. The in-source soil boring will be completed through the zone of seasonal GW fluctuation immediately adjacent to SB-40. If the 2 5’ sample intervals above GW meet DD criteria, then a monitoring well is not needed. If contamination extends to within 5’ of GW, then an in-source GW monitoring well will be needed for GW sampling for analyses of DD parameters & HRC parameters. Soil & GW samples will be analyzed for GRO, DRO, RRO, BTEX, petroleum related VOCs, PAHs (including 1-methylnaphthalene & 2-methylnapthalene), VPH & EPH.
Additional borings will be installed approximately 20 to 25’ downgradient if smear zone contamination is encountered to delineate the extent of vadose & smear zone contamination. Soil samples from downgradient borings will be analyzed for GRO, DRO, RRO, & BTEX.
Tank 6 & Vault 6
The extent of contamination (vertical & horizontal) is not thoroughly documented. Additional site characterization is required to refine the extent & magnitude of contaminants in soil. Data is needed in order to adequately support risk calculation using the HRC.
See site file for additional information.
|
Louis Howard |
| 10/2/2014 |
Document, Report, or Work plan Review - other |
ADEC has reviewed JBER's responses to ADEC's comments and finds the responses satisfactory. Please finalize the document. |
Louis Howard |
| 7/31/2015 |
Update or Other Action |
Draft SC Report received for review & comment. No additional work is recommended for Category 1 sub-sites (tanks): 3, 4, 7, 8, 9, 13, 14, 18, 19, 20, 21, 23, 24, 27, & 29. A no-further action status is recommended.
Tanks 16 & 22 require additional soil characterization for benzene to verify current soil conditions meet decision document status before they will be eligible for a NFA status.
Category 2 Sub-sites-Vault 2: No additional soil investigation work is recommended. Additional GW monitoring for EDB, GRO, benzene, toluene, ethylbenzene & lead is recommended before an NFA status can be obtained.
Tank 6/Vault 6: Additional characterization for EDB in soil & additional GW monitoring for benzene is recommended before NFA status can be obtained.
Tank 1/Vault 1: No additional soil investigation work is recommended. Because of benzene exceedances, additional GW monitoring is recommended before an NFA status can be obtained.
Tank 5/Vault 5: Additional soil characterization for GRO & ethylbenzene is recommended to verify current soil conditions meet decision document status. Additional GW monitoring for EDB, 1,2-DCA, petroleum related VOCs, & PAHs is recommended before an NFA status can be obtained.
Valve Pit 11/Vault 8: Additional soil sampling for GRO & GW is recommended before an NFA status can be obtained.
Tank 15/Vault 15: No additional soil investigation work is recommended. Additional GW monitoring will be required to verify cleanup levels are met before an NFA status can be recommended.
Tank 25/Vault 25/Vault 24A: No additional soil characterization is recommended because EDB contamination is below 15 feet bgs. Additional GW monitoring for DRO, GRO, benzene, toluene, lead, & EDB at 59WL-49 will be required to verify cleanup levels are met before an NFA status can be recommended.
Tank 26: No additional soil investigation work is recommended. Additional GW monitoring will be required to verify cleanup levels are met before an NFA status can be recommended.
Tank 28/Vault 28: No additional work is recommended. An NFA status is recommended.
Category 3 Sub-sites-301+40/Vault 1a, 200+00/200+03/Valve Pit 16, Vault 4a/400+00, Vault 6a, Tank 11, & Tank 17 all require additional soil & GW characterization to verify cleanup levels are met at these sub-sites before an NFA status can be recommended.
Tank 10 & Tank 12 do not require additional soil investigation work. Additional GW monitoring will be required to verify cleanup levels are met at these sub-sites before an NFA status can be recommended.
See site file for additional information. |
Louis Howard |
| 8/12/2015 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft SC report.
For each sub-site associated with ST032, ADEC is requesting the Air Force discuss and address any potential vapor intrusion issues for the following: occupied buildings, buildings that could be occupied or future buildings that could be built and occupied. This would be particularly relevant for those sites with soil hydrocarbon contamination within 30 horizontal or vertical feet of an existing building. If there are no occupied, occupiable buildings, or plans for future buildings within 30 horizontal or vertical feet of existing contamination, then please state so in the text which would eliminate the VI issue for that particular sub-site.
Please evaluate for the vapor intrusion pathway per the July 9, 2013 “Meeting Minutes Vapor Intrusion Discussion on 28 June 2013 Alaska Group Performance-Based Remediation Contract Number: FA8903-09-D-8S89, Task Order No. 0016”, ADEC VI Guidance and, as applicable the October 15, 2013 Soil Gas Sampling Work Plan addendum if the VI pathway is complete.
The July 9, 2013 meeting minutes provide for ADEC’s requirements for VI pathway investigations consistent application of VI requirements across JBER to support site closure decisions. The Work Plan addendum provides standard operating procedures (SOPs) that will be used to guide the soil gas investigations.
One exception to the 2013 Meeting Minutes listed above is that the soil cleanup levels for BTEX, GRO and DRO in the 2003 DD are to be used as action levels which in some cases the levels are lower than current 18 AAC 75 soil cleanup levels found in Table B1 Method Two
For all sub-sites (Category 1, 2, 3) the 2003 DD soil cleanup levels will be applicable.
Despite what the 2003 Decision Document (DD) states , treatment or excavation deeper than 15’ bgs may be warranted at those sub-sites (e.g. Category 2 and 3) with groundwater contamination above Table C groundwater cleanup levels to prevent the soil from acting as a continuing source for the groundwater contamination
ADEC is notifying the Air Force that use of the HRC for ST032 would require a new decision document since any hydrocarbon levels at any sub-site which are below the maximum allowable concentrations, but above the 2003 decision document (DD) cleanup levels (e.g. hydrocarbon concentrations were determined as “acceptable risk” by the HRC) would nullify the DD since use of the HRC was not anticipated at the time the 2003 DD was signed.
See site file for additional site information. |
Louis Howard |
| 4/5/2016 |
Update or Other Action |
Site update: no additional action will be required at the site besides LUCs, LTM. Because site conditions for many of the ST032 sub-sites require further characterization & thus do not meet ADEC requirements for a “Cleanup Complete” determination, the site as a whole does not meet “Cleanup Complete” criteria. A recommendation for either NFA status or that additional characterization is needed, has been made for each ST032 sub-sites based on the evaluation of both historical & the 2014 data. Category 1 sub-sites were initially interpreted to pose acceptable risk by exhibiting no exceedances in either soil or GW above the DD cleanup levels, or having older historical results very close to DD document cleanup levels
Category 2 sub-sites contained data gaps & were further investigated in 2014 to determine if the sub-sites posed acceptable or unacceptable risk. The results of the 2014 site characterization activities & historical data were combined & presented in this report to determine if the subsite should become a Category 1 (eligible for NFA) or Category 3 sub-site (not eligible for NFA).
Category 3 sub-sites levels of GW contamination exceed the ADEC Table C criteria. This report will present all existing data, assess concentration trends if practical, & recommend an ongoing monitoring/sampling schedule.
Where recommended, the parameters for additional soil characterization are site specific. At each sub-site where additional GW characterization is recommended, the analytical suite should include the parameters GRO, DRO, BTEX, total lead, dissolved lead, 1,2-DCA, & EDB unless otherwise specified.
Category 1 Sub-sites
No additional work is recommended at these sub-site. An NFA status is recommended.
Tank 3, 4, 7, 8, 9, 13, 14, 16, 18-24, 27, 29.
Category 2 Sub-sites
Vault 2: No additional soil investigation work is recommended at this sub-site. Additional GW monitoring for EDB, GRO, benzene, toluene, ethylbenzene & lead is recommended at this subsite before an NFA status can be obtained.
Tank 6 / Vault 6: Additional characterization for EDB in soil & additional GW monitoring for benzene is recommended before this sub-site can achieve an NFA status can be obtained.
Tank 1 / Vault 1: No additional soil investigation work is recommended at this sub-site. Because of benzene exceedances, additional GW monitoring is recommended at this sub-site before an NFA status can be obtained.
Tank 5 / Vault 5: Additional soil characterization for GRO & ethylbenzene is recommended to verify that current soil conditions meet decision document status before this sub-site will be eligible for an NFA status. Additional GW monitoring for EDB, 1,2-DCA, petroleum related VOCs, & PAHs is recommended at this sub-site before an NFA status can be obtained
Valve Pit 11 / Vault 8: Additional soil sampling for GRO & GW characterization is recommended at this subsite before an NFA status can be obtained.
Tank 15 / Vault 15: No additional soil investigation work is recommended at this sub-site. Additional GW monitoring will be required to verify that the cleanup levels are met at this sub-site before an NFA status can be recommended.
Tank 25 / Vault 25 / Vault 24a: No additional soil characterization is recommended because EDB contamination is below 15 feet bgs. Additional GW monitoring for DRO, GRO, benzene, toluene, lead, & EDB at 59WL-49 will be required to verify that the cleanup levels are met at this sub-site before an NFA status can be recommended.
Tank 26: No additional soil investigation work is recommended at this sub-site. Additional GW monitoring will be required to verify that the cleanup levels are met at this sub-site before an NFA status can be recommended.
Tank 28 / Vault 28: No additional work is recommended at this sub-site. An NFA status is recommended.
Category 3 Sub-sites: 301+40 / Vault 1a, 201+00 / 200+03 / Valve Pit 16, Vault 4a / 400+00, Vault 6a, 10, 11, 12, & 17: Additional soil & GW characterization will be required to verify that the cleanup levels are met at these sub-sites before an NFA status can be recommended.
See site file for additional information. |
Louis Howard |
| 4/27/2016 |
Document, Report, or Work plan Review - other |
Staff commented on the Draft Annual Report for Monitoring State Sites (including this one) on JBER.
Site Summary and Recommendations
ADEC concurs with the recommendations for this site. As to discontinuing groundwater monitoring at well 59WL-30, due to trend analysis showing a stable plume, ADEC concurs. However, the well shall be maintained for future sampling needs, such as demonstrating compliance with Table C cleanup levels for a “cleanup complete” determination by ADEC. At that time, groundwater will require the following analytes be analyzed: BTEX, lead, GRO, DRO.
The text states: “The trend analysis is included in Appendix D.” There is no Appendix D in this document. Please include Appendix D in this document or please refer the reader to the document that contains Appendix D.
|
Louis Howard |
| 11/15/2017 |
Update or Other Action |
Draft 2016 Annual Report Monitoring of State-Regulated Sites received. Fuel constituents continue to be present in groundwater (GW) above the cleanup levels and in vadose and smear zone soil above cleanup levels. Five areas of GW contamination have been identified at ST032 as Areas 1 through 5. It is recommended that GW sampling at monitoring well 59WL-36R be discontinued and removed from the sampling program. This well has four consecutive years of contaminant concentrations below Table C cleanup levels.
It is recommended to incorporate two new monitoring wells for annual monitoring to provide
greater coverage of the site. Monitoring well 59WL-47 is located in the north eastern side of site (Area 5 Plumes) and will replace monitoring well 59WL 36R in the sampling program. Monitoring well 59WL-11 is located on the western side of the site (Area 1 Plume). Both wells have sample results that currently exceed cleanup levels. Annual site inspections will continue until the site is determined “Cleanup Complete.”
See site file for additional information. |
Louis Howard |
| 11/30/2017 |
Update or Other Action |
Draft VI report received for review and comment. BTEX, GRO, and naphthalene were detected in indoor and outdoor air during FSE1 and FSE2, with indoor air concentrations higher than outdoor air concentrations during both sampling events. With the exception of naphthalene, all other COIs were detected in soil gas during FSE1. The highest indoor air concentrations for several COIs were detected in the indoor air sample located in the garage (location 13272-AA001) suggesting that vehicle fuel could be contributing to these results at this location. However, an elevated concentration for GRO was also detected in the southeastern portion of the building (location 13272-AA004).
Based on available information, impacts to outdoor air from a nearby ambient air contaminant
source of similar characteristics to soil gas (e.g. petroleum-related) appears to be the most likely scenario. However, this possibility cannot be confirmed based on sampling results and conditions observed during the VI Study.
Regardless of the uncertainties associated with the relationship between indoor and outdoor air
results, the presence of multiple COIs in indoor air and soil gas suggest the presence of a
potentially complete VI pathway at Building 13272.
See site file for additional information. |
Louis Howard |
| 5/21/2018 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the draft annual report for monitoring at state sites which included ST032. Main comment was to ensure that final rounds of sampling at ST032 will include DRO, GRO and lead as well as the PAHs and petroleum related VOCs listed in the document.
See site file for additional information. |
Louis Howard |
| 6/20/2019 |
Document, Report, or Work plan Review - other |
Staff provided comments on the Draft 2018 Annual Report Monitoring of State-Regulated Sites dated June 2019. Main comments were on the need to use the most current cleanup levels for 1,2,4-trimethylbenzene from October 27, 2018 18 AAC 75 regulations. Other comments dealt with well maintenance and decommissioning well activities.
See site file for additional information. |
Louis Howard |
| 4/12/2021 |
Document, Report, or Work plan Review - other |
DEC submitted comments on Draft JBER Basewide UFP-QAPP dated February 2021. |
William Schmaltz |
| 5/19/2021 |
Document, Report, or Work plan Review - other |
DEC Reviewed and approved of Basewide Uniform Federal Policy - Quality Assurance Project Plan. QAPP summarizes general activities for a 5 year period on JBER. |
William Schmaltz |
| 2/16/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed and provided comments regarding the 2023 Letter Work Plan Remedial Action Operations and Long-Term Management, Draft, dated January 2023.The work plan describes the site inspections, maintenance activities, and groundwater, seep, and surface water monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. The scope of work briefly summarizes the site locations, sampling/monitoring schedules, and activities such as free-product removal from monitoring wells and monitoring/maintenance activities at the Operable Unit 5 wetlands. The details regarding the procedures for the remedial action operations and long-term management activities will remain consistent with the 2021 Uniform Federal Policy Quality Assurance Project Plan (UFP-QAPP). |
Ginna Quesada |
| 5/18/2024 |
Document, Report, or Work plan Review - other |
DEC submitted comments regarding the 2023 Annual Remedial Action-operations And Long-term Management Report for Select State-regulated Sites Draft, Dated April 2024. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections were recommended to continue for all sites to ensure that conditions remain protective of human health and the environment. The report recommends updating land use controls (LUC) site boundaries at CG534, a ‘Cleanup Complete’ determination without institutional controls (ICs) for SS522, the removal of groundwater LUCs at SS041, and a ‘Cleanup Complete with ICs determination for TU101. |
Ginna Quesada |
| 6/25/2024 |
Document, Report, or Work plan Review - other |
DEC approved the 2023 Annual Remedial Action-operations And Long-term Management Report for Select State-regulated Sites Final, dated June 2024. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections were recommended to continue for all sites to ensure that conditions remain protective of human health and the environment. The report recommends updating land use controls (LUC) boundaries at CG534, a ‘Cleanup Complete’ determination without institutional controls (ICs) for SS522, the removal of groundwater LUCs at SS041, and a Cleanup Complete with ICs determination for TU101. |
Ginna Quesada |
| 4/15/2025 |
Document, Report, or Work plan Review - other |
DEC provided comments for the 2024 Annual Remedial Action-Operations and Long-Term Management Report for Select State-Regulated Sites Draft, dated April 2025.The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections were recommended to continue for the majority of the sites to ensure that conditions remain protective of human health and the environment. DEC concurs with the recommendation to close SS522 site without ICs, discontinue groundwater sampling at TU107, and reducing the sampling frequency for some wells at TU103. |
Ginna Quesada |
| 5/6/2025 |
Long Term Monitoring Workplan or Report Review |
DEC approved the 2024 Annual Remedial Action-Operations and Long-Term Management Report for Select State-Regulated Sites Final, dated May 2025. The report describes the site inspections, maintenance activities, and groundwater monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. Site inspections were recommended to continue for the majority of the sites to ensure that conditions remain protective of human health and the environment. DEC concurs with the recommendation to close SS522 site without ICs, discontinue groundwater sampling at TU107, and reducing the sampling frequency for some wells at TU103. |
Ginna Quesada |
