| Action Date |
Action |
Description |
DEC Staff |
| 6/1/1983 |
Update or Other Action |
Wells at Elmendorf AFB and some at Fort Richardson.
Well Bldg ft. depth yield
1 23-990 16' Shallow 1350 gpm in use South of North-South Runway
2 22-001 850' Artesian 840 gpm in use South of West Power Plant
4 65-600 78' Shallow 7 gpm in use Returnagain Six Mile Lake
8 52-140 252' Artesian 12 gpm in use EMS Office Loop Road
16 32-189 228' Artesian 95 gpm in use Standby Diesel Plant
25 63-320 155' Artesian 9 gpm in use Underground Six Mile Lake
27 62-250 210' Artesian 12 gpm in use Receiver Site
29 42-500 406' Artesian 40 gpm in use C.A.P.
39 35-750 141' Artesian 115 gpm in use Transmitter Ft. Richardson
40 5-800 209' Artesian 228 gpm in use AAC 5-800
41 52-820 56' Shallow 12 gpm in use Hillberg Lake Ski Bowl
42 11-200 225' Artesian 139 gpm in use DAC Building
43 24-800 159' Artesian 54 gpm in use USAF Hospital
46 63-621 60' Shallow 10 gpm in use Chalet MAC Six Mile Lake
47 63-740 23' Shallow 16 gpm in use CE Shady Lane Six Mile Lake
49 52-560 130' Shallow Artesian 16 gpm in use Green Lake Rec Area
50 BLM - - - in use Oil Well Road
51 63-501 - - in use 6981st Rec Area Six Mile Lake
52 23-100 166' Artesian 36 gpm in use Golf Course Pro Shop
53 62-145 125' Artesian 8 gpm in use EMS Ammo Storage Six Mile Lake
23 33-358 71' Shallow 36 gpm inactive Riding Stables
32 52-725 246' Artesian 12 gpm inactive Gun Site No. 1
34 53-125 186' Artesian 12 gpm inactive Gun Site No. 10
45 63-552 40' Shallow 50 gpm inactive Ranch Six Mile Lake
48 63-612 109.5' Artesian 30 gpm inactive Field Maint. Six Mile Lake
54 62-140 - - inactive EMS Six Mile Lake
2 old 33-000 78' Shallow 30 gpm inactive Old Round House
3 23-400 153' Artesian 104 gpm inactive Artesian Village, South
6 44-544 314' Artesian 40 gpm inactive Old 625 Radar
30 62-700 142' Artesian 18 gpm inactive Fish Camp D Battery
31 24-500 158' Artesian 60 gpm inactive BLM Old C Battery
- 64-560 - - - inactive -
35 44-705 405' Artesian 12 gpm inactive Site No. 3
36 24-025 189' Artesian 12 gpm inactive Site No. 5
4 old 23-396 45' Shallow 35 gpm abandoned Artesian Village, North
14 73-400 60' Shallow 12 gpm abandoned Old AFSC Receiver Site
20 52-812 70' Shallow 9 gpm abandoned Hillberg Lake (Resident)
- - 202' Artesian 12 gpm abandoned Site No. 6
- - 189' Artesian 12 gpm abandoned Site No. 2
44 63-615 87' Shallow 20 gpm abandoned Six Mile Lake, 21st Trans
NOTE: Three wells on Hospital Lin: 1. 1000 gpm 2. 1000 gpm 3. 800 gpm (Source Installation Documents 1983). |
Louis Howard |
| 3/26/1993 |
Update or Other Action |
DOD & ADEC joint Technical Memorandum of understanding signed concerning the Basewide Groundwater (GW) signed by: ADEC Jennifer Roberts RPM & USAF Joseph Williamson Chief Environmental Programs & Restoration. Due to the basewide GW study & the FY92 field work that occurred at Operable Units (OUs) 1, 2, & 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 & Record of Decision (ROD). This means addressing all GW from upgradient sources (CERCLA (ST20, OUs 3 and 4) & OUs 1 & portions of OU2) & 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...).
Also included in the file is the AF memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV
1) Due to the contamination & 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 & 6 which require, the aquifer remain unused. 2) Personnel in the review process within CES must be aware of these policies & review them on a recurring basis. It is imperative this restriction be recognized & observed during engineer reviews & operations. |
Jennifer Roberts |
| 4/21/1995 |
Update or Other Action |
Air Force AF memo: 18 April 1995 Underground Storage Tank (UST) Meeting. Elmendorf AFB will accomplish the following actions regarding UST Projects. These actions are based upon conversation between, John Mahaffey, Larry Opperman and yourself. EAFB will make every effort to accomplish a clean closure of a UST removal site if possible. UST removal locations requiring cleanup action will be transferred into the State-Elmendorf Environmental Restoration Agreement (SERA).
A list of sites requiring cleanup will be coordinated with your office. The presumptive remedy for contaminated UST sites in the outwash plain only will be bioventing technology. Contaminated soils exceeding cleanup levels may be placed back into the excavation only if the site assessment (SA) indicates a need for further cleanup action. Contaminated UST sites not in the outwash plain will require further investigation to determine appropriate cleanup options. We will make every attempt possible to assure new USTs or new aboveground tanks are not installed in any way that would hamper future access for cleanup. The project will first accomplish removal of all of the USTs. SA information will be used to prioritize sites for cleanup using existing project funds.
Additional funding will be requested to complete cleanup if available. Sites not addressed for cleanup due to exhausted funding will be placed into SERA Phase IV. John Halverson signed on April 21, 1995. Memo was signed by Douglas G. Tarbett, Maj, USAF, Chief, Environmental Compliance. CC: 3 WG/JA and 3 SPTG/CE. |
John Halverson |
| 8/11/1995 |
Document, Report, or Work plan Review - other |
ADEC (John Halverson) sent letter to Air Force (L. Opperman) RE: Disposition of petroleum contaminated soil generated during underground storage tank (UST) Closures at Elmendorf AFB. I met with you and Mr. John Mahaffey on April 18, 1995, to discuss UST closures planned at Elmendorf this summer and the issue of how contaminated soil would be handled. We agreed that if "clean closure" could be reached through excavation, all contaminated soil should be removed and taken to an off-site treatment facility.
We also agreed that petroleum contaminated soil could be placed back in the ground, on the condition bioventing systems would be installed starting this year, if clean closure was not feasible. However, it has become apparent the Air Force has not been able to implement corrective action at leaking underground storage tank sites in a timely manner.
Therefore, our April 21, 1995 agreement on soil management must be revoked. Starting immediately, the department requests that all contaminated soil removed from the ground during closure or upgrade of USTs be completely contained in accordance with our petroleum contaminated soil stockpiling guidelines referenced in the UST regulations. Please notify your project managers, the Army Corps of Engineers project manager and all of your UST contractors of this change. The rationale behind the need to contain all excavated petroleum contaminated soil is provided below.
Failure to implement Corrective Action-Tank #805, at building 24-805, failed a tightness test in 1994 and was removed from the ground. Tanks #96-104 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 at both sites. Department approval was granted on the condition corrective action be started at each site no later than June 30, 1995.
The Air Force had committed to doing this work under Phase IV of the SERA. However, we have been informed that contracts for SERA Phase IV have not yet been awarded, work plans have not been developed, and it does not appear the field work will be started this year. This is a violation of the corrective action requirements outlined in the UST regulations and our prior agreements.
Management Action Plan (MAP) for transfer of LUST sites into the SERA-On several occasions the department has requested a formalized process for transfer of leaking UST sites from the UST agreement into the SERA. The January 3 1, 1995 annual UST report states that a MAP was being prepared to formalize such a process and that a copy would be forwarded to us as soon as it was completed. We have not received a copy of the MAP. Numerous LUST sites have been identified during the past two years and transfer of sites between the UST and SERA compliance agreements has not been working.
It appears the UST agreement needs to be amended to address release investigation and corrective action requirements. Based on the above and the fact that funding for DoD environmental cleanups is being reduced, we are 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.
|
John Halverson |
| 8/29/1997 |
Update or Other Action |
During July 1997, a 1,200 gallon single-walled underground storage tank (UST) was removed from the north side of the newly constructed 611th Chalet (Building 31-562). The tank reportedly held diesel fuel used as heating oil for the former MAC Chalet (Building 63-621). Photoionization detector (PID) results indicated hydrocarbon contamination was present at the bottom of the excavation at 7 ft. bgs (29 ppm) and along the east wall (30 ppm). Excavation was backfilled using excavated soils that were shown to be clean during field screening, not based on any laboratory analytical sample results.
Concentrations of diesel range organics (DRO) were detected as high as 330 milligrams per kilogram (mg/kg) in soil samples collected from the bottom of the tank excavation. Approximately 12 cubic yards of DRO-contaminated soil were excavated and removed from the site. |
Tim Stevens |
| 9/15/1997 |
Site Added to Database |
Heating oil release. |
Louis Howard |
| 9/15/1997 |
Site Ranked Using the AHRM |
Initial ranking. |
Louis Howard |
| 3/1/1999 |
Update or Other Action |
Eleven soil borings were installed as part of the release investigation conducted in July and October 1998 under SERA Phase VII. Eight were completed as monitoring wells (702WL01-702WL08). Samples were collected for DRO, GRO, BTEX, and PAHs. In the vicinity of the former UST, soil contamination was identified as extending from the bottom of the former tank excavation to groundwater, with DRO concentrations up to 12,500 mg/kg at 15.5 ft. bgs, GRO concentrations up to 1,320 mg/kg. (Table B2 Maximum allowable concentration for DRO: 12,500 mg/kg)
Downgradient from the former UST site, soil contamination appears to be limited to the smear zone; DRO concentrations were high as 2,000 mg/kg, GRO concentrations up to 1,360 mg/kg, benzene concentrations up to 0.242 mg/kg.
Groundwater samples from 7 out of 8 wells contained DRO in excess of the DRO groundwater cleanup standard of 1.5 mg/L. Concentrations of DRO ranged from 0.19 mg/L to 131 mg/L. GRO was detected above ADEC cleanup level of 1.3 mg/L in three wells with a maximum concentration of 4.6 mg/L.
Benzene was detected above the cleanup level of 0.005 mg/L in two wells with a maximum concentration of 0.0666 mg/L. The monitoring well with the highest DRO is located southwest of the former UST site, monitoring well 702WL03, and had free product detected in the monitoring well. Local groundwater flow is to the west/southwest towards Six Mile Lake. |
Louis Howard |
| 12/31/1999 |
Update or Other Action |
Four soil borings were installed and completed as monitoring wells (702WL09-702WL12) during a release investigation in 1999 under SERA Phase VIII. DRO was detected in nine samples ranging from 0.12 to 39 mg/L. GRO was detected in five wells ranging from 0.0022 to 0.021 mg/L. Benzene was detected in four samples from 0.0022 to 0.021 mg/L. All twelve wells at the site were sampled in November 1999. Only one groundwater sample exceeded the GRO cleanup level of 1.3mg/L in well 702WL05, with a concentration of 3.8 mg/L. DRO cleanup level was exceeded in eight wells (702WL01 through 702WL07 and 702WL09) ranging in concentration from 1.7 to 39 mg/L. Benzene cleanup level was exceeded in 2 wells at 0.014 mg/L (702WL02) and 0.021 mg/L (702WL07). |
Louis Howard |
| 2/17/2000 |
Document, Report, or Work plan Review - other |
Staff conducted a review of the SERA VII release investigation report for ST702 (Building 63-621) MAC Chalet), a non-regulated underground storage tank, Elmendorf AFB, Alaska; facility ID 0-001525, STMP 495. On October 15, 1999, the Department of Environmental Conservation (Department) received the SERA Phase VII ST 702 final release investigation report.
The report summarizes information collected during a release investigation of a known petroleum release associated with a 1,200-gallon underground heating oil tank (HOT) located adjacent to the MAC Chalet. Based on information contained in the report, the Department agrees with the recommendations made and is requesting the Air Force to conduct additional release investigative work to further define the extent of soil and ground water contamination associated with the release. |
Tim Stevens |
| 7/1/2002 |
Update or Other Action |
SERA Phase IX Release Investigation Report ST702/8/9 MAC Chalet. Groundwater contamination and free product were discovered at the site. Numerous wells were installed at the site including groundwater monitoring wells: 702WL13, 702WL16, 702WL17. Their purpose was to determine the downgradient extent of free product and dissolved phase contaminants on and in the groundwater. Petroleum was detected in wells but were all below Table C values with the exception of well 702WL13 (24 mg/L DRO).
All soil samples collected for laboratory analysis were analyzed for GRO, DRO, RRO, and BTEX compounds. A total of three soil samples were analyzed for PAHs, and two soil samples were additionally analyzed for VOCs. Analytical results indicated that none of the soil samples analyzed exceeded cleanup levels for GRO, RRO, BTEX, PAHs and VOCs.
One soil sample with a concentration of 1,400 mg/Kg DRO, exceeded the cleanup level of 300 mg/Kg. Although no free product was measured in any monitoring wells during the 2001 sampling event, observations such as fuel sheen and fuel odor in combination with analytical results indicate that groundwater in the vicinity of 702WL01, 702WL02, 702WL03, 702WL04, 702WL05, and 702WL07 continues to exceed ADEC drinking water cleanup levels for DRO. Additionally, groundwater collected from 702WL02 exceeds ADEC drinking water cleanup levels for GRO, RRO, and benzene.
In general, during periods of high water table elevations, free product typically is smeared
through the vadose zone and typically is nonexistent or very thin. Additionally, during periods of low water table elevations, free product is typically measureable in thickness. These do not
appear to be the trends observed at ST702/8/9 {ENSR 2001).
Free product likely remains downgradient of ST702/8/9, however it was not measured in July 2001. It is believed that this is because the plume is moving in response to fluctuations in groundwater gradient and no wells are installed where the plume has moved to. Routine monitoring with an oil/water interface probe is recommended for the site to monitor for the presence of free product.
In summary, based upon a review of the data collected to date, it is estimated that the
groundwater contaminant plume exceeding ADEC drinking water cleanup levels has nearly
doubled in lateral extent since the SERA VIII field investigation conducted in 1998.
Therefore, it is believed that the contaminant plume could potentially impact Six Mile Lake in the near future depending upon precipitation levels, depth fluctuations to the aquifer, soil type, and current DRO concentrations in groundwate |
Louis Howard |
| 9/2/2002 |
Update or Other Action |
Contaminant Assessment Plan - objectives of the plan were to 1) to evaluate the immediate threat of fuel oil in groundwater discharging to Six Mile Lake; and 2) to determine appropriate remediation measures, if any, to protect human health and the ecological environment. Based on calculations provided it was estimated that it would take groundwater 0.23 years and free product 3.6 years to migrate the 200 feet from well 702WL13 to Six Mile Lake. |
Louis Howard |
| 9/30/2002 |
Update or Other Action |
Corrective action plan for twelve SERA Phase IX sites (including ST702) was prepared. Recommendations were for installation of additional wells downgradient of the plume to define the extent of contamination and continued monitoring of site conditions. The site was determined to have a HIGH relative risk ranking (DOD) and it was stated that additional response actions may be required based on extent of contamination and rate of migration.
Subsurface soils were described as sands and gravels, with a high potential for petroleum hydrocarbon vertical migration through the soil (NOTE:this is already demonstrated by the presence of petroleum contamination in groundwater). At the time of the report, the extent of groundwater contamination downgradient of well 702WL13 had not been characterized and additional sentinel wells were recommended. |
Louis Howard |
| 10/21/2002 |
Update or Other Action |
J. Roberts sent a letter to Joe Williamson dissolving the State Elmendorf Environmental Restoration Agreement. The Alaska Department of Environmental Conservation (DEC) has reviewed the issue of abolishing the State Elmendorf Environmental Restoration Agreement (SERA) per your recommendation. Elmendorf Air Force Base and DEC entered into the SERA in 1992. The agreement was developed as a tool to bring the Base into compliance with Alaska's regulations addressing underground storage tanks, oil and other hazardous substance releases and solid waste.
Since that time, Elmendorf has made significant progress in investigating and cleaning up historic contamination problems. Many of the sites covered by the SERA have been successfully cleaned up and closed. Cleanup is underway at the remaining sites.
Additionally, Alaska has amended the regulations addressing fuel storage tanks, oil and other hazardous substance spills and solid waste. We concur with you that the SERA is no longer a necessary or beneficial. This letter serves as notice that DEC will end oversight on environmental work at Elmendorf by using the SERA. Instead, it is understood that the sites and programs formerly addressed by SERA: solid waste, underground storage tanks (UST), and oil and other hazardous substance discharges will be addressed in accordance with 18 AAC 60, 18 AAC 78 and 18 AAC 75. |
Jennifer Roberts |
| 3/31/2003 |
Update or Other Action |
Final Technical Memorandum for ST702 site-Limited site investigation and modeling effort. Free product was found in two of the 14 wells: 702WL10 had 0.12 feet and 702WL07 had 0.86 feet of free product floating on top of the groundwater. 702WL13 had DRO at 2.80 mg/L out of three wells sampled and two piezometers at the site. BIOSCREEN Version 1.3 modeling was conducted at the site. The simulations show that immediate impacts to Six Mile Lake are highly unlikely. The worst-case scenario included: a higher groundwater gradient (enhancing groundwater/contamination flow), a higher groundwater conductivity (enhancing groundwater/contamination flow), the more solubile (lighter end) of the two contaminant types (resulting in enhanced contaminant mobility), the higher concentration at well 702WL13 (most recently non-detect) and no contaminant breakdown from biodegradation.
Free-product bail-down testing was performed at well 702WL07 in an attempt to estimate the "actual" product thickness versus the "apparent" product thickness in that well. Based on the data observed, the estimated "actual" product thickness at ST702 is approximately 0.2 feet. However, significant changes in water level elevation, both seasonal and in response to precipitation events, have been documented at this site. The fact that the product is consistently present suggests that contamination in soil and in the soil "smear zone" remains significant. Since free product has been consistently observed in the wells at ST702, and since it appears that its actual thickness may be at least 0.2 feet, action can be taken per ADEC regulations to attempt to recover the product. Product recovery is often feasible when product thicknesses are greater than 0.05 feet.
Based on the data collected and the modeling effort performed as part of this limited site investigation, impacts to Six Mile Lake from contaminants released from the former MAC Chalet UST are highly unlikely. Whle free product on top of the groundwater table as well as dissolved phase groundwater contamination is present at the site, it is not likely that the contamination will migrate sufficiently to impact Six Mile Lake. |
Louis Howard |
| 5/30/2003 |
Update or Other Action |
Additional site data was collected during a sampling event in May 2003. Samples were collected from monitoring wells: 702WL13, 702WL16, 702WL17, 702WL18, 702WL19. Monitoring well 702WL13 had DRO detected in the sample at 3.67 mg/L. Two of the other wells had DRO concetrations below ADEC regulatory criteria, with the remaining two wells being non-detect for DRO. |
Louis Howard |
| 4/21/2004 |
Update or Other Action |
Site moved from LUST to CS DB this date. Facility ID = 1525, Event ID = 1832, File 2101.38.038. |
Former Staff |
| 2/9/2007 |
Exposure Tracking Model Ranking |
|
Louis Howard |
| 9/28/2007 |
Update or Other Action |
In September 2007, monitoring wells 702WL02, 702WL13 and 702WL16 were sampled. Final results for monitoring well 702WL02 indicate detections for DRO at 28 mg/L and GRO at 1.5 mg/L. Detections for DRO and GRO at monitoring wells 702Wl13 and 702WL16 were below regulatory cleanup levels. Detections for BTEX in all three monitoring wells were below cleanup levels or non-detect. |
Louis Howard |
| 3/6/2008 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Corrective Action Plan at Former UST Site ST702, Elmendorf AFB February 2008 Contract No. F41624-03-D-8622/TO 0134. ADEC concurs with the preferred corrective action which includes: continuation of site contaminant level monitoring, product removal (skimming), enhanced oxidant attenuation and monitored natural attenuation. |
Louis Howard |
| 5/29/2009 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Work Plan Six-Mile Lake Drum Removal Elmendorf AFB, AK April 2009. The Alaska Department of Environmental Conservation (ADEC) received the document for review and comment on May 20,2009. The document is well written and ADEC will approve the work plan as a final version. ADEC review and approval of this work plan is to ensure that the work is done in accordance with State of Alaska environmental conservation laws and regulations. While ADEC may comment on other state and federal laws and regulations, our approval of the plan does not relieve responsible persons from the need to comply with other applicable laws and regulations. |
Louis Howard |
| 1/5/2010 |
Update or Other Action |
Draft Six Mile Lake Drum Removal Summary Report received.
The following measures were used to locate, remove drums and debris from the lake and properly dispose all recovered materials.
• Equipment and personnel were mobilized to the project site on Elmendorf AFB, AK;
• Drums were located by sight and by using two hand-held global positioning system (GPS) units to verify the positions of drums listed in the Six-Mile Lake Drum Survey Corrective Measures Study (USAF, 2003);
• Empty drums, partial drums and debris were removed from the Lake and surrounding shoreline;
• Recovered drums, partial drums and debris were transported by skiff or pick up truck to a
temporary staging area at 611th Chalet, which included a 15 foot roll-off container for
containment of drums;
• All drums that had intact tops and bottoms were de-headed for proper disposal with the Municipality of Anchorage Landfill.
• Recovered drums were transported to the Anchorage Municipal Solid Waste Landfill for disposal; and
• The roll-off container with the final load of drums was removed, and the staging area was
cleaned up.
For drums that were not intact, such as those in varying stages of disintegration, including containing holes, missing bungs, partial drums, or for miscellaneous metal debris, it was possible for the technicians to hook the drum or item with a grappling hook. To prevent potential spills, no drums suspected of being intact were hooked. Drums appearing to be intact were retrieved using a rope sling fastened around the drum.
All but four of the drums listed in the Six-Mile Lake Drum Survey Corrective Measures Study (USAF, 2003) were found and removed. Despite having GPS coordinates and an on-board magnetometer, two of the drums, Drum 38 and Drum 48 were not located likely due to heavy sediment, vegetation, and settling. In the case of Drum 38, it is likely that the large heavy-duty dock, under which it was originally located, has become water-logged, settled into the water, and is covering the drum.
During the 2009 drum recovery efforts, it was determined that none of the drums were intact, and that no drums had content other than lake water, sediment, rocks, gravel and lake vegetation, therefore no sampling was conducted during this project.
Once all of the drums were removed from the lake and determined to be acceptable for disposal, they were loaded into the roll-off and the container was removed from the site and transported to the Anchorage Municipal Landfill. The 15 cubic yard container was filled three times, for a total approximate volume of 45 cubic yards of drums and debris removed from the lake and transported to the landfill.
All of the drums that could be found were removed from the lake including several pieces of miscellaneous debris not noted in the 2003 survey. No additional drum removal or surveys are required or recommended for Six Mile Lake. |
Louis Howard |
| 4/1/2010 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (ADEC) received the Draft Six Mile Lake Drum Removal Summary Report for review and comment on March 30, 2010. The cover letter states comments are requested by April 23, 2010. ADEC requires thirty (30) days of review upon receipt of a document sent for review. ADEC will provide an expedited review as a courtesy to the Air Force, however, the Air Force should not expect this abbreviated review as be standard practice.
4.0 Conclusions and Recommendations Page 4-1: The text states it is recommended that Phase 4 of the CAP during 2010 be performed which includes: One round of soil sample collection (same locations as pre-treatment sample location); Three rounds of groundwater collection (same constituents as collected during Phase 2 from wells 702WL-Ol, 02,03,04,07 and 20); Evaluation and modeling to determine natural attenuation timeframe based on residual site contamination following remedial actions.
ADEC concurs for the most part with these recommendations. However, ADEC requests the Air Force collect groundwater samples at wells: 702WL-10, 13, 16, 18, and 19. Wells 702WL-16, 18 and 19 are point of compliance wells for Six Mile Lake. Lf the groundwater "plume" of petroleum contamination is stable then annual monitoring is appropriate for these three wells. If he Air Force cannot state whether or not the plume is stable, then these three wells need to be sampled semi-annually (see Basewide Monitoring Program Well Sampling Decision Guide).
ADEC requests the Air Force delete total metals as an analytical requirement for all groundwater and, soil samples unless there was a release from a waste oil tank that was not mentioned in the report. Diesel fuel releases from tanks where the age and date of service are unknown (as with ST702), are assumed to be diesel fuel #l/arctic diesel and require GRO, DRO, BTEX and polynuclear aromatic hydrocarbons [PAH] analyses (Table 2A UST Procedure Manual, 2002).
Metals analyses are not a requirement for diesel fuel releases. For well 702WL-02 and 07, ADEC requests the Air Force include PAH analyses for one round of sampling. The rationale for PAH sampling is that well 702WL-07 had the highest historic DRO levels and well 702WL-02 has the highest DRO currently at the site. If PAHs are not above cleanup levels in samples from th{;se two wells, then PAHs may be eliminated as a contaminant of concern in groundwater at the site. It is not apparent from the text in the document whether or not PAHs were ever analyzed at the site.
See site file for additional information. |
Louis Howard |
| 7/26/2010 |
Update or Other Action |
2010 Environmental Compliance work plan received.
Collect groundwater samples from six existing monitoring wells at site ST702 to monitor remedial progress. Based on the fall 2009 groundwater analysis, DRO and arsenic remain in the groundwater throughout site ST702. Additionally, benzene concentrations in well 702WL-07 continue to exceed ADEC cleanup criteria. Total metals exceed the cleanup criteria in well 702WL-01. The groundwater will be analyzed for DRO, GRO, BTEX, total metals and MNA parameters to provide consistent post-treatment analysis to evaluate the effectiveness of chemical oxidation at this site.
This final round of post-treatment samples will be used to evaluate whether the chemical oxidation treatment was effective. If the groundwater analysis for a particular well indicates concentrations below the ADEC cleanup criteria, a schedule for future well
monitoring will be proposed.
If analysis indicates contaminant concentrations above the ADEC cleanup criteria, the most appropriate path forward and monitoring frequency will be recommended based on analytical results. |
Louis Howard |
| 3/16/2011 |
Update or Other Action |
Draft Annual Report Monitoring of Compliance Restoration Program Sites received. A separate summary report is being prepared for the field activities and results at ST702 in 2010. A Corrective Action Plan (CAP) for site ST702 (USAF, 20Q,8b) was submitted to ADEC in March 2008. The CAP provided the preferred corrective action, which included continuation of site contaminant level monitoring, product removal, enhanced oxidant attenuation (recommended to be performed as a treatability study), and MNA. The corrective actions were initiated in 2008 and 2009. The 2010 summary report will provide field activities, results, and recommendations of the follow-up sampling to the corrective actions at the site. |
Louis Howard |
| 3/17/2011 |
Update or Other Action |
Post Corrective Action GW Summary Report Received for Compliance Program Site ST702. A Corrective Action Plan (CAP) was prepared in 2008 to address soil & GW contamination associated with ST702 using the following phases:
• Phase 1 established baseline levels of GW contamination & free-product.
• Phase 2 included recovery & removal of free-product.
• Phase 3 included performing a chemical oxidation & enhanced bioremediation treatability study & collecting 1 round of post-treatment GW samples.
• Phase 4 included 2 rounds of additional GW sample collection, soil sample collection, & an evaluation of the timeframe to achieve natural attenuation following the corrective action.
This report summarizes the results of GW sampling performed during Phases 3 & 4 of the CAP in order to evaluate the effects of the chemical oxidation & enhanced bioremediation treatability study. Fieldwork in 2008, 2009, & June 2010 was conducted. The goal of this phase of the project was to implement the GW sampling portion of Phase 4 of the CAP for ST702 by collecting 2 additional post-CA GW samples. Phase 4 began with collecting the second round of post corrective action GW samples from 6 wells in June 2010. The final post-treatment GW samples were collected from the same 6 wells in September 2010. This report compares the pre- & post-treatment GW sample results to evaluate the effectiveness of the chemical oxidation treatment.
Fall 2010 sample results indicated DRO generally decreased immediately post-treatment & then increased in some wells over the next year. The exception was 702WL-01, where DRO did not exceed cleanup levels prior to chemical oxidation treatment but exceeded the cleanup level post-treatment. Levels of DRO continued to exceed the cleanup level (1.5mg/L) in 5 MWs near & downgradient of the source area. Levels of GRO did not exceed the cleanup level of 2.2 mg/L in any well. Benzene continued to exceed the cleanup level of 5 micrograms per liter (µ/L) only in well ST702WL-07.
Samples collected from downgradient wells 702WL-02, 702WL-03, 702WL-07, & 702WL-20 showed DRO levels exceeding the ADEC cleanup level of 1.5 mg/L during the final round of sampling. DRO levels generally decreased immediately post-treatment in fall 2009, but increased again by spring 2010 (Table 4-1). No DRO results were available for 702WL-20 in spring 2010 but the DRO levels in GW continued to follow this pattern with an increase in fall 2010. After initially decreasing post-treatment, DRO in 702WL-02 increased to 56 mg/L, exceeding the pretreatment levels in this well. These spikes in DRO may be attributable to the injection of the chemical oxidation compound used for enhanced bioremediation pushing contamination from the pore spaces into the GW. No baseline soil samples were collected in the vicinity of these wells to provide inference for soil contaminant mobilization. The variations may also be a result of seasonal fluctuations in GW.
See site file for additional information.
|
Louis Howard |
| 4/26/2012 |
Update or Other Action |
2011 Annual Report for Compliance Restoration Program Sites received.
Groundwater monitoring wells 702WL-01, 702WL-02, and 702WL-16 were sampled using the approved procedures provided in the 2011 Work Plan (USAF, 2011f). The samples were analyzed by an analytical laboratory for GRO, DRO, BTEX compounds, and metals. Concentrations of arsenic exceeded the cleanup level in samples collected from 702WL-01 and 702WL-02. DRO exceeded the cleanup level in well 702WL-02. All other results were below their respective cleanup levels.
Groundwater monitoring wells 702WL-03 and 702WL-20 were also planned to be sampled. However, they were found to be dry and could not be sampled. Monitoring well 702WL-07 was found to have 0.33-feet of free product and therefore not sampled.
Analytical results from samples collected during annual monitoring and during implementation of the CAP for ST702 indicate that DRO, benzene, and arsenic remain in groundwater at concentrations exceeding the ADEC cleanup level. In addition, baseline data collected prior to the chemical oxidation treatability study show that GRO and DRO continue to exceed the cleanup levels in soil at the site.
Well 702WL-07 had 0.33-feet of free product in 2011. No changes to compliance monitoring are being recommended at this site due to the 2012 PBC. |
Louis Howard |
| 6/6/2012 |
Update or Other Action |
Draft Project Management Plan received.
Performance Objective
Site Closure
Performance Indicators
· Prepare an approved Addendum to Current LTM Workplan by September 2012
· Conduct 2012 RA-O Monitoring Event with an approved Annual RA-O Monitoring Memo by February 2013
· Prepare an approved Characterization Workplan by December 2012
· Coordinate, mobilize, and execute Site Characterization concurrently with 2013 RA-O Monitoring event by August 2013
· Prepare an approved Characterization Report by January 2014
· Prepare an approved Cleanup Workplan and coordinate, mobilize, and execute Cleanup Activities
· Prepare an approved Construction Completion Report and Cleanup Report
· Continue RA-O Monitoring as scheduled to meet ROD and ADEC requirements
· Prepare and implement an approved Optimized Exit Strategy Report to achieve SC
Potential Risk
Dual-phase extraction required at more locations than estimated; plume stability alters during POP.
Risk Mitigation
Extraction would be completed at all locations required to maximize free-product removal, plume dynamics would be evaluated, and appropriate treatment (enhanced bioremediation) would be implemented at targeted locations to ensure stable plume is achieved.
Date of achieving Performance Objective
1st Quarter FY 2019
Planned Approach
Prepare an approved Characterization Workplan with an updated CSM.
Coordinate, mobilize, and execute Characterization by installing and sampling six soil borings and three monitoring wells.
Use HRC to evaluate SC based on risk to future residential receptors for all pathways.
Prepare an approved Characterization Report with an updated CSM, documented HRC risk evaluation, and document groundwater plum meeting stability requirements.
Prepare an approved Cleanup Workplan and coordinate, mobilize and execute Cleanup by installing duel-phase extraction system, conduct free product removal, conduct O&M and monitoring, and conduct recharge test to ensure free product has been removed.
Prepare an approved Cleanup Report documenting success of free product removal, plume stability information, and expected time to remediation.
Prepare an approved Decision Document, detailing requirements of ICs on groundwater, detail LTM only required at predicted times, and include estimated time to achieve cleanup. Receive ADEC concurrence with Cleanup Complete with ICs and provide documentation to AFCEE. |
Louis Howard |
| 4/30/2013 |
Update or Other Action |
Draft Annual Monitoring report received for review and comment.
Historic sampling results for CG702 have indicated fuel constituents present in groundwater above cleanup criteria in 18 AAC 75 Table C and fuel constituents in soil above 18 AAC 75 Tables B1 and B2. In addition, free product has been found in site groundwater monitoring wells. Current monitoring requirements at Site CG702 include annual groundwater sampling for DRO, GRO, BTEX compounds, and metals at groundwater monitoring wells 702MW-01, 702MW-02, 702MW-03, 702MW-07, 702MW-16, and 702MW-20.
Additional investigation to identify data gaps will be conducted under the new PBR contract. No changes to the annual monitoring are being proposed for this site. |
Louis Howard |
| 1/31/2014 |
Update or Other Action |
Site Characterization work plan received for review and comment.
The overall objectives for the site are to meet “unrestricted or residential site use” criteria and achieve a “Cleanup Complete without Institutional Controls (ICs)” determination. Within the short term (the period of performance of the Weston Solutions, Inc. [WESTON] Performance-Based Remediation [PBR] contract), the site may only be eligible for a “Cleanup Complete with ICs” determination. To meet these objectives, soil and groundwater samples will be collected in order to characterize risk to human health and the environment within the framework of the ADEC site cleanup process (Title 18 of the Alaska Administrative Code [AAC] 75 Sections 325 to 390, and Title 18 AAC 78 Section 600). If 18 AAC 75 Method Two cleanup criteria are exceeded, the Hydrocarbon Risk Calculator (HRC) approach under Method Three will be used to assess whether site conditions meet ADEC risk criteria (in which case, a “Cleanup Complete without ICs” determination will be requested), or whether the site poses unacceptable risk (in which case, remediation, ICs, or both may be required). If unacceptable risk is indicated by the HRC, remedial options that address the compounds and exposure routes that contribute most significantly to the cumulative risk will be evaluated.
A minimum of three new soil borings will be drilled, as follows:
• One boring will be advanced near the location of well 702WL-02, in order to resample the soil at the location and depth where previous sampling showed an exceedance of the maximum allowable criteria for DRO. Two samples will be collected from the boring in order to evaluate source area soil for GRO, DRO, RRO, and BTEX concentrations (i.e., to generate source area samples for statistical characterization of the source). The proposed new boring is located where the zone of seasonal water table fluctuation (smear zone) is interpreted to be contaminated. Soil screening samples will be collected at a minimum of five-foot intervals through the vadose zone and almost continuously through the zone of seasonal water table fluctuation to a depth of approximately 20 ft. If the soil at the 20-ft depth appears to be contaminated, additional samples will be collected as needed to define the maximum depth of contamination. Approximately two saturated zone soil samples will be collected from the boring for laboratory analysis. One sample will be collected at 12 ft (the depth of the maximum DRO concentration) if the soil appears to be relatively heavily contaminated based on photoionization detector (PID), visual, and/or olfactory screening. If the soil does not appear to be impacted, an interval from a greater depth will be selected. The sample collected at the 12-ft depth is proposed to replace the sample collected at a similar depth in 1998. The other smear zone sample will be collected from what appears to be the next most heavily-impacted soil encountered in the boring based on PID, visual, and/or olfactory screening. At least one of the relatively heavily-contaminated soil samples from this boring will be analyzed for PAHs, EPH, and VPH (in addition to the analytes listed above). |
Louis Howard |
| 2/13/2014 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 73761 name: Underground tank |
Louis Howard |
| 2/14/2014 |
Document, Report, or Work plan Review - other |
Comments on the SC work plan.
The use of the Method Three Hydrocarbon Risk Calculator (HRC) is premature at sites with existing GW contamination above Table C cleanup levels [18 AAC 75.345(b)(1)]. Soil contamination at CG702 greater than the migration to GW cleanup levels is acting as a continuing source of GW contamination at ST702 based on the GW sample results from wells at the site which exceed Table C cleanup levels.
As long as there remains contamination above Table C cleanup levels regardless of risk, use of the HRC would not be applicable. At such time that the GW monitoring wells achieve Table C cleanup levels for two years in a row, then ADEC may consider alternative cleanup levels (as long as they are below the MAC) for soil on a case-by-case basis.
These remarks are consistent with ADEC’s previous comments on June 22, 2012 for the Draft Project Management Plan.
Executive Summary Nature & Extent of Contamination
1st Paragraph
The text states: “The source of the hydrocarbons is attributed to leaks & spills prior to the removal of the UST & piping.”
The text shall state: “The source of the hydrocarbons is attributed to leaks & spills prior to the removal of the UST & piping resulting in unpermitted discharge or release of petroleum hydrocarbons to GW & soil at CG702.”
Site Specific Background
Page ES-2
1st Paragraph
The text states: “A subsequent State-Elmendorf Environmental Restoration Agreement (SERA) VII investigation took place in 1998 & included the installation of 11 borings at the site.”
Please provide a reference to the SERA VII 1998 investigation in the “References” section of this UFP-QAPP.
Last sentence
The text states: “DRO remained above the ADEC default cleanup level.”
The text shall state: “DRO remained above the ADEC Table C GW Cleanup level of 1.5 mg/L.”
GW Characterization
The text states: “The purpose of the GW samples collected inside the source area is to help characterize the human health risk posed by the fuel hydrocarbons at Site ST702.”
Since Method Three does not allow for the determination of risk from GW outside of Method Four Risk Assessment by regulation, the text shall state: “The purpose of the GW samples collected inside the source area is to help characterize the fuel hydrocarbons exceeding Table C GW Cleanup Levels at Site ST702.” Human health risk from GW may be calculated by the Method Three HRC, but the results may not be used in lieu of complying with Table C cleanup levels.
Page ES-4
The text states: “The purpose of the downgradient dissolved phase plume samples is to help confirm the extent of the source area, document that the dissolved plume is stable (not migrating downgradient), & to help assess compliance with water quality criteria in Six Mile Lake.”
The text states: “Analysis of arsenic is not included in the sampling program, because the site is not associated with a waste oil tank.” This is inconsistent with the previous statements earlier in the document which state: “Arsenic will continue to be monitored as part of the long-term monitoring scope of work, but will not be evaluated as part of the scope outlined in this Work Plan.”
Please add clarifying text that arsenic analysis is not part of the site characterization sampling program, but is included as part of the long-term monitoring scope of work or delete reference to GW monitoring for arsenic at this site if not part of the long-term monitoring program.
ADEC requests clarification on how sampling water from downgradient GW wells will assess compliance with water quality criteria (i.e. TAH & TAqH & no visible sheen).
See site file for additional information.
|
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.
During 2013, monitoring wells 702MW-01, 702MW-02, 702MW-03, 702MW-07, 702MW-12, 702MW-14, 702MW-16, 702MW-19 and 702WL-20 were sampled for GRO, DRO, BTEX compounds, and metals. In addition, six of the wells were also sampled for polycyclic aromatic hydrocarbons (PAH) and seven for residual-range organics (RRO). Analytical laboratory results exceeded 18 AAC 75 Table C cleanup criteria for DRO in wells 702WL-02, 702WL-07, and 702MW-20. GRO and 1-Methylnaphthalene also exceeded their cleanup criteria in well 702WL-07. All other analytes were below 18 AAC 75 Table C cleanup criteria. Free product was not observed in any monitoring well including 702WL-07, where it has been observed in the past.
The ADEC site status for CG702 is “Open.” Analytical results from samples collected during
annual monitoring indicate that DRO remains in groundwater at concentrations exceeding the 18
AAC 75 Table C cleanup criteria. Free product was not observed in any monitoring wells in
2013 including 702WL-07, where it has been observed in the past. Additional investigation to identify data gaps will be proposed under the JBER PBR contract in 2014. No changes to the annual monitoring are being proposed for this site.
|
Louis Howard |
| 11/25/2014 |
Meeting or Teleconference Held |
Soil Gas Sampling JBER Nov. 25, 2014 meeting
Objectives of the meeting were to (1) discuss Alaska Department of Environmental Conservation (ADEC) comments (dated October 13, 2014 and November 18, 2014) on the Draft Site Characterization Addendum for Sites TU075 and TU085 regarding soil gas sampling field documentation and (2) the path forward to achieve ADEC concurrence with Cleanup Complete (Site Closure) for those sites and others where soil gas sampling was conducted during the 2014 field season.
ADEC comments regarding additional documentation of the helium leak check that is conducted prior to soil gas sampling are noted below.
• “ADEC requests the Air Force describe in detail where the documentation that helium underneath the shroud was greater than ten percent (10%). It appears that this section is the only place where this statement is documented. This information must also be documented in field notes and/or soil gas sampling log.
• Without documentation required supporting a helium leak check, ADEC does not have full confidence in the soil gas data to support a closure determination at this time and the report addendum and initial Site Characterization report for TU085 cannot and will not be approved.
• The concentration of helium gas under the shroud is not reported on soil gas sampling logs or in the field notes; ADEC will require that a leak check be conducted again by the Air Force and at least a three day notice provided to ADEC’s project manager so technical staff can be on site and observe the procedure from start to finish.”
ADEC commented that without documentation that the helium concentration beneath the shroud was greater than 10 percent, either on the sampling log or in the field notes, ADEC will not concur with site closure and will require that leak checks be conducted again for all soil gas probes present at one site on each installation (JBER-Elmendorf and JBER-Richardson). ADEC will also require that a representative(s) is on site to observe these additional helium leak checks from start to finish. There was discussion regarding the potential for the soil gas probes to be compromised due to Base operations and weather since initial installation and sampling (dating back to June 2014) and what additional action would be required if a leak check fails.
The path forward was outlined as follows:
• At each site with a site closure objective, inspect soil gas probes for obvious damage that may have compromised the surface seal since the probe was last sampled.
o Sites TU075, TU085, and TU074 at JBER-Richardson
o Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
• Select a site at each installation (JBER-Elmendorf and JBER-Richardson) for additional helium leak checks of all probes at that site.
• Provide ADEC 48 hours advance notice of the helium leak check/shroud measurements, so ADEC staff can observe field procedures, any necessary repairs, and testing and measurements (helium concentrations in the port and under the shroud).
• If a leak test fails at a specific probe, the seal will be repaired, the leak test performed again at that probe, and soil gas resampled for all probes at the site.
• If all leak tests pass for all of the probes at the site, no resampling of the soil gas at the site will be required.
• If ADEC notes a systematic problem (absent noticeable damage, leak checks fail for all probes at a site and multiple attempts to seal/repair the probes fail), then ADEC will require the 2014 soil gas data for those sites to be rejected. Following this occurrence of systemic failure (i.e. failure to get a leak check to pass at multiple sites and multiple soil gas probes even after remedies are attempted), JBER, ADEC, Weston, and CH2MHILL will meet to discuss to remedy the situation. |
Louis Howard |
| 2/3/2015 |
Update or Other Action |
Staff sent Air Force email regarding soil gas sampling.
*Sites TU075, TU085, and TU074 at JBER-Richardson [currently ADEC has received the SC Report addendum for TU074 and will not provide any comments on it until the leak check test is performed at a predetermined site of the contractor's (CH2MHILL) choosing as agreed upon below from the November 25, 2014 meeting notes.]
AND
*Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
*please do not submit any SC reports/SC report addendums to ADEC for review from these sites if there is a "Cleanup Complete" request since they are being held up until such time that ADEC has observed and the leak checks performed by the contractor at the selected site have passed.
If they include a CC with ICs request, they may not be dependent the leak check results. It will have to be determined on a case by case basis.
There will be a helium leak check on JBER-Elmendorf this week (Thursday at 11 a.m. at SO552) which will determine the fate for the 2014 soil gas sites (e.g. CG702, SO552, ST048, SO525, TU091).
The path forward was outlined as follows:
* At each site with a site closure objective, inspect soil gas probes for obvious damage that may have compromised the surface seal since the probe was last sampled.
o Sites TU075, TU085, and TU074 at JBER-Richardson
o Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf
* Select a site at each installation (JBER-Elmendorf and JBER-Richardson) for additional helium leak checks of all probes at that site.
* Provide ADEC 48 hours advance notice of the helium leak check/shroud measurements, so ADEC staff can observe field procedures, any necessary repairs, and testing and measurements (helium concentrations in the port and under the shroud).
* If a leak test fails at a specific probe, the seal will be repaired, the leak test performed again at that probe, and soil gas resampled for all probes at the site.
* If all leak tests pass for all of the probes at the site, no resampling of the soil gas at the site will be required.
* If ADEC notes a systematic problem (absent noticeable damage, leak checks fail for all probes at a site and multiple attempts to seal/repair the probes fail), then ADEC will require the 2014 soil gas data for those sites to be rejected. Following this occurrence of systemic failure (i.e. failure to get a leak check to pass at multiple sites and multiple soil gas probes even after remedies are attempted), JBER, ADEC, Weston, and CH2MHILL will meet to discuss to remedy the situation. |
Louis Howard |
| 2/5/2015 |
Site Visit |
WESTON performed a helium leak test demo for the sub-slab soil vapor Site SO552 on Thursday, February 5, 2015 at SO552 (aka Bldg. 8326 ST402). L. Howard (ADEC PM) and Todd Blessing (ADEC) VI technical expert observed WESTON staff performing helium leak check with JBER (D. Baumler & D. Aide) on hand to observe as well. WESTON staff passed helium leak check procedures. Sites CG702, SO552, ST048, SO525, TU091 at JBER-Elmendorf are now okayed to proceed with draft submittal to ADEC for review and comment. |
Louis Howard |
| 3/24/2015 |
Update or Other Action |
Distance to Subsurface Water Right Location is approximately 445 feet, Drinking Water Program System No. AK2218747 (http://dec.alaska.gov/eh/dw/DWP/protection_areas_map.html).
Customer Name: USDOD USAF 673 CEC/CEIEC, Water system name: USAF Elmendorf - Six Mile Chalet, Active, Source Facility ID: 45851, Groundwater Well source, Source of water name: WL Well #4, Source ID WL001, 1 service connection, 18 persons served. Legacy PWSID: 218747.001. AF POC Jennifer Kehn, SSGT, 907-552-6502, 104449 Luke Avenue, Elmendorf AFB AK 99506 Jennifer.kehn@elmendorf.af.mil. |
Louis Howard |
| 3/24/2015 |
Update or Other Action |
Memorandum for helium leak check received.
On February 5, representatives from the Alaska Department of Environmental Conservation (ADEC) observed Weston Solutions, Inc. (WESTON) demonstration on soil gas sampling procedures. The demonstration was conducted at Site SO552 (ST402) on JBER and performed for verification that appropriate techniques were being implemented during the tracer (helium) leak check procedure.
The work was conducted in accordance with the Uniform Federal Policy-Quality Assurance Project Plan (UFP-QAPP) – Addendum SO552 (ST402) Additional Site Characterization Work Plan (including Soil Gas Collection SOP-5e) and consisted of the collection of one soil gas sample from a previously installed subslab sampling probe. WESTON preformed a shut-in test and helium tracer leak check on the sample setup.
Following an acceptable shut-in test and helium tracer leak check one sample was collected using a one –liter Summa™ canister for analyses of the parameters listed in the Work Plan Addendum. A building survey was completed to document information on the building, the occupants, and potential sources of background contaminants and assist in determining potential risk associated with the soil gas is present to occupants of the building. The building survey, field notes, subslab probe construction diagram, and the soil gas sampling form are all included as attachments to this memorandum.
Mr. Blessing (ADEC) made the following recommendations regarding the helium tracer leak check procedure:
· Consider the use a helium shroud of sufficient size to allow a helium leak check of the entire sampling apparatus.
· Consider connecting a valve immediately adjacent to the probe connection for the shut-in test.
· Verify the concentration of the helium gas supplied by the helium cylinder,
· Look for contaminant sources within the building.
As indicated on the field sampling sheet, the initial concentration of helium under the shroud was
99.3% and the helium concentration in the Tedlar bag was 3,850 ppm. This resulted in a 0.4%
helium leakage, well below the 10% leakage allowed per ADEC Vapor Intrusion Guidance.
ADEC indicated that the result was acceptable and would allow approval of all WESTON 2014
soil gas measurements. |
Louis Howard |
| 4/8/2015 |
Update or Other Action |
Draft Site Characterization Report received for review & comment.
The data set for CG702 supports the following conclusions:
• Fuel has infiltrated to the water table over the vadose zone source area, & the nonaqueous phase liquid (NAPL) is interpreted to have spread laterally on the water table to a width of approximately 160’, & to have migrated approximately 450’ downgradient. The NAPL has been smeared through the zone of seasonal water table fluctuation over this footprint area.
• The average & 95% upper confidence limit (UCL) DRO concentrations within the NAPL source area are 2,374 & 3,924 mg/kg, respectively; as shown on Table 5-2.
• Soil contamination in the area of the removed UST greater than cleanup levels was treated with chemical oxidation. The remaining soil contamination at the site is limited to the smear zone.
• GW samples collected from monitoring wells located in the NAPL-contaminated smear zone & screened across the water table remain above ADEC Table C cleanup levels in wells 702WL-02, 702WL-03, 702WL-05, 702WL-07 & 702WL-20.
• Mann-Kendall GW concentration trend analysis shows that source area wells 702WL-01, 702WL-02, 702WL-03 & 702WL-04 have decreasing total DRO concentration trends over the period of record for the wells (1998 to 2014).
Wells 702WL-05 & 702WL-07 have stable concentrations over the last 16 years (1998 to 2014). The biodegradation of the dissolved hydrocarbon emanating from the CG702 source area is demonstrated by the low &/or not detected results of the monitoring conducted in well 702WL16, which is about 50 to 100' downgradient of the CG702 source.
• The section of the contaminated site regulations addressing the need for long-term monitoring (18 AAC 75.345(h)(2)) indicates that long-term monitoring may be eliminated if the monitoring shows that the GW has a stable or decreasing concentration trend & that the monitoring is not necessary to ensure the protection of human health or the environment. These criteria are met at CG702.
Recommendations
GW at CG702 is shown to have a stable or decreasing concentration trend. Therefore, monitoring is not necessary to ensure the protection of human health or the environment.
Based on this analysis, it is recommended that the ADEC grant Site CG702 at JBER a “Cleanup Complete with ICs” determination. This would be equivalent to an Air Force “Response Complete” determination. Following ADEC concurrence with this conclusion, GW monitoring of the site should be terminated. Based on the proximity of drinking water well # 46 to the former UST location, it is recommended to add fuel-related parameters to the sampling program at drinking water well # 46.
See site file for additional information. |
Louis Howard |
| 4/23/2015 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft Site Characterization Report. Main comments centered on the use of TO-15 instead of TO-17 when analyzing soil gas with elevated PAHs above Method 2 cleanup levels in soil or groundwater. Also, staff required that the drinking water well on site be sampled for fuel related parameters as soon as possible. Absent this testing, no cleanup complete with institutional controls decision will be made by ADEC for the site. See site file for additional information. |
Louis Howard |
| 5/19/2015 |
Document, Report, or Work plan Review - other |
Staff commented on the annual State Sites monitoring report which included this site. Main comment was regarding the need for sampling the drinking water well #46 for a minimum of two sampling rounds with no Table C groundwater cleanup levels exceedances before a "cleanup complete" determination with ICs is considered. |
Louis Howard |
| 7/27/2015 |
Cleanup Complete Determination Issued |
Staff provided a cleanup complete determination with institutional controls for contaminated groundwater which does not meet Table C cleanup levels for petroleum hydrocarbons. The groundwater plume does show a decreasing trend in contaminants using statistical analysis. Nearby drinking water well #46 has been sampled twice and no contaminants of concern have been detected above applicable cleanup levels.
Based on a review of the environmental records, ADEC has determined that CG702 has been adequately characterized and has achieved the applicable requirements under the site cleanup rules. ADEC is issuing this written determination that cleanup is complete with ICs subject to a future department determination that the cleanup is not protective of human health, safety, welfare, or of the environment [18 AAC 75.380(d)]. A “cleanup complete with ICs” designation will be entered for CG702 in the Contaminated Sites Database. |
Louis Howard |
| 7/27/2015 |
Institutional Control Record Established |
Institutional Controls established and entered into the database. |
Louis Howard |
| 11/15/2017 |
Update or Other Action |
Draft 2016 Annual Report Monitoring of State-Regulated Sites received. Checklist observations: The tree that has fallen near well 702WL-10 remains in place, but the well is accessible and
can be sampled if needed. A tree service will be needed to remove the fallen limb. Wells 702WL-01, 702WL-02, 702WL-04 require some rethreading to the outer casing lids. However, the lids were securely fitted to the top of the casing and the inner PVC casing is protected.
The base of well 702WL-18 needs to be secured with concrete; the well is still in good condition. The concrete base at well 702WL-12 was previously noted to be cracked, but the well is not compromised and is secure. No repair is necessary for this well. |
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 |
| 2/7/2023 |
Document, Report, or Work plan Review - other |
DEC reviewed the 2023 Letter Work Plan Remedial Action Operations and Long-Term Management, Draft, dated January 2023. The work plan describes the site inspections, maintenance activities, and groundwater, seep, and surface water monitoring, at multiple sites located on Joint Base Elmendorf- Richardson (JBER), Anchorage, Alaska. The scope of work briefly summarizes the site locations, sampling/monitoring schedules, and activities such as free-product removal from monitoring wells and monitoring/maintenance activities at the Operable Unit 5 wetlands. The details regarding the procedures for the remedial action operations and long-term management activities will remain consistent with the 2021 Uniform Federal Policy Quality Assurance Project Plan (UFP-QAPP). |
Ginna Quesada |
| 4/25/2023 |
Document, Report, or Work plan Review - other |
DEC approved the 2023 Letter Work Plan Remedial Action Operations and Long-Term Management, Final, Dated April 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 |
