| Action Date |
Action |
Description |
DEC Staff |
| 5/17/1994 |
Site Added to Database |
|
Former Staff |
| 5/17/1994 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
|
Former Staff |
| 5/17/1994 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST Site created in CSP for source area ID 77311 |
Former Staff |
| 5/27/1994 |
Update or Other Action |
Building 14410 (formerly Building 42-300) is associated with the AWACS Hangar and is
situated near the aircraft hardstands north of the East-West Runway. The site is a former
fueling station for Air-to-Ground Equipment (AGE). The fueling station was located on the
south side of the building and included three 2,500-gallon, single-walled USTs (Air Force
Identification [AFID] Numbers 306, 307 and 308; also referred to as Storage Tank
Management Plan [STMP] Nos. 419, 420, and 424) and an associated fuel dispenser island
approximately 15 feet to the west.
Tank 419 stored diesel, Tank 420 stored mogas, and Tank 424 stored JP-4. The site remained active for approximately 10 years. The tanks, associated piping, and dispensers were removed in May 1994. During tank removal, no leaks from the tanks were observed, and the tanks appeared to be in good condition, with uniform surface corrosion. The tank excavation was backfilled with stockpiled soils and approximately 25 yards of clean soils. Soil from the dispenser island area was not excavated. |
Louis Howard |
| 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 |
| 8/31/1996 |
Update or Other Action |
Site Evaluation and Bioventing Studies for SERA Phase V Sites, Workplan Final dated August 1996. All three tanks were excavated and removed in May 1994 and appeared to be in good condition. A PID was used to Screen soils during excavation, but no volatile organic
compounds (VOCs) were detected. Two soil samples were collected from the base of each tank
excavation, within 2 ft of the tank bottoms. DRO, GRO, and benzene, toluene, ethylbenzene, and xylenes (BTEX) were not detected in four of the six samples collected from beneath the fuel tanks. A sample collected from beneath the south end of the diesel tank contained 146-mg/kg DRO, 7-mg/kg GRO, and 0.07-mg/kg xylenes. The remaining sample, collected beneath the south end of the JP-4 tank, contained only a minor amount ofDRO (14 mg/kg).
An additional sample was taken at each of the three associated fuel pumps (diesel, MOGAS, and
JP-4). These samples were taken approximately 2 ft below the pipes leading from the fuel tanks to the pumps. Samples collected from near the fuel pumps contained significantly higher concentrations of contaminants than those collected beneath the tanks. The sample collected near the pipe to the diesel pump contained 4160 mg/kg DRO, and the sample collected near the pipe to the MOGAS pump
Sampling plan for ST505 was an initial boring in the area of greatest contamination, and the additional soil borings, both on a circle 10 ft. out from the estimated area of contamination and within the area of contamination.
Initial boring/potential bioventing well: depth to tank bottom (11 ft.), estimated depth to pipe (1.5 ft.), Depth to groundwater (35 ft.), 2 lab samples. Additional borings (2). Analyses includes AK 101, 102, 103, EPA Method 8020. Level "C" cleanup criteria was calculated for the site. |
Louis Howard |
| 4/11/2001 |
Update or Other Action |
During the SERA Phase IX site investigation conducted in 2001, four soil borings were advanced to the groundwater table. A split-spoon sampler was used to collect soil samples from the ground surface to the water table, which was encountered between 21.9 feet and 22.5 feet bgs. Two borings were placed within 4 feet of the former dispensers, where elevated levels of THP-G and EPH-D were detected during the 1994 UST site assessment. The third boring was placed hydraulically downgradient from the former UST and dispenser island. The fourth boring was placed near the former diesel UST, within 5 feet of the maximum 1994 EPH-D detection in this area.
Twelve samples were collected and analyzed for gasoline-range organics (GRO), diesel-range organics (DRO), residual-range organics (RRO) and BTEX. Three of the samples were also analyzed for poly-nuclear aromatic hydrocarbons (PAH). These constituents were either not detected or detected well below the most stringent cleanup criteria. |
Louis Howard |
| 2/28/2002 |
Update or Other Action |
SERA Phase IX Release Investigation Report ST505/9 AWACS Hangar UST AFID No: 306, 307, and 308 FINAL dated February 2002. The two major objectives of the investigation was to: delineate the extent of soil contamination in the vertical and lateral directions in the vicinity of the dispenser island. Fill the following specific data gaps: 1) no polycyclic aromatic hydrocarbon (PAH) data for soil had been collected to date at this site; and 2) previous non-detect benzene results were obtained at method recording limits that are in excess of ADEC Method 2 migration to groundwater cleanup level of 0.02 milligrams per kilogram (mg/kg) and therefore did not allow for determination of whether the Method 2 benzene cleanup level has been exceeded.
Soil analytical data indicate that no soil samples collected from the tank excavation, dispenser island, or downgradient of these two potential source areas exceed the most stringent Method 1, Level "A", soil cleanup standards for diesel range organics, residual range organics, or gasoline range organics. The borings around the dispenser island were placed within four feet of locations where diesel range organics (DRO) and gasoline range organics (GRO) had been detected previously. Boring at the DRO UST was placed within five feet of the former DRO detection.
Based on the results of the SERA IX RI and the UST site assessment, and the fact that the site falls into the OU5 modeling area, this site is recommended for closure. |
Louis Howard |
| 6/6/2003 |
Update or Other Action |
Decision Document received.
Elmendorf Air Force Base (AFB) site ST505/9 is located south of Building 14410 (former building 42-300), the Airborne Warning & Control Squadron (AWACS) Hangar 8, on 30th Street. ST505/9 is on the north side of the East-West runway & is within the OU5 Modeling Area.
Nature of Release
Three regulated 2,500-gallon underground storage tanks (USTs) were located at ST505/9. The USTs & associated dispensers formerly served as a fueling station for air-to-ground equipment. The Air Force Identification (AFID) numbers for these tanks are 306, 307, & 308. The Storage Tank Management Plan (STMP) numbers are 419, 420, & 424. The Alaska Department of Environmental Conservation (ADEC) numbers are 120, 121, & 122. AFID 306 stored diesel, AFID 307 stored motor vehicle gasoline (mogas), & AFID 308 stored jet propulsion fuel number 4 (JP-4). An associated dispenser island was located 15 feet west of the USTs. The USTs & dispenser island were removed in 1994. Any release from these USTs would have been regulated by 18 AAC 75 Contaminated Site regulations, Articles 3 & 9, & Alaska Statute 46.03 - 46.09.
Response Action History
During the 1994 removal, confirmation samples were collected from the bottom of the UST excavation from beneath the dispenser island area. The tanks appeared to be in good condition, with uniform surface corrosion & no evidence of leaks.
Six samples were collected from the UST excavation & analyzed for total petroleum hydrocarbons-gasoline (TPH-G), extractable petroleum hydrocarbons-diesel (EPH-D), & benzene, toluene, ethylbenzene, & xylenes (BTEX). The maximum TPH-G concentration detected was 7 mg/kg, collected in the sample from under the diesel tank in the south end of the excavation. The maximum EPH-D concentration was 146 milligrams per kilogram (mg/kg); this sample was collected from beneath the JP-4 & diesel USTs. BTEX constituents not detected, with the exception of one low-level xylene detection at 0.07 mg/kg.
Three samples were collected from the dispenser island area & analyzed for TPH-G, EPH-D, & BTEX. The maximum TPH-G concentration was 3,200 mg/kg & the maximum EPH-D concentration was 4,160 mg/kg in this area. The only significant BTEX concentrations were detected under the mogas dispenser. The maximum concentrations were: 57 mg/kg benzene, 510 mg/kg toluene, 140 mg/kg ethylbenzene, & 720 mg/kg total xylenes. A remedial investigation was planned for the site during State-Elmendorf Environmental Restoration Agreement (SERA) Phase V but was not conducted.
During the SERA Phase IX site investigation conducted in 2001, four soil borings were advanced to the groundwater table. A split-spoon sampler was used to collect soil samples from the ground surface to the water table, which was encountered between 21.9 feet & 22.5 feet bgs. Two borings were placed within 4 feet of the former dispensers, where elevated levels of THP-G & EPH-D were detected during the 1994 UST site assessment. The third boring was placed hydraulically downgradient from the former UST & dispenser island. The fourth boring was placed near the former diesel UST, within 5 feet of the maximum 1994 EPH-D detection in this area.
Twelve samples were collected & analyzed for gasoline-range organics (GRO), diesel-range organics (DRO), residual-range organics (RRO) & BTEX. Three of the samples were also analyzed for poly-nuclear aromatic hydrocarbons (PAH). These constituents were either not detected or detected well below cleanup criteria. The method reporting limit for benzene ranged from 0.02 mg/kg to 0.023 mg/kg.
All results were below ADEC, 18 AAC 75, Method Two, Migration to Groundwater cleanup criteria during the SERA Phase IX site investigation.
The selected remedy for this site is no further action & site closure. This remedy was selected because this site does not contain potential contaminants above ADEC 18 AAC 75 cleanup criteria nor any potential contaminant sources & does not present a risk to human health or the environment.
In accordance with State of Alaska regulation 18 AAC 75, the United States Air Force (USAF) has completed all activities required for the selected remedy at ST505/9, Elmendorf AFB, Alaska.
This declaration of decision supports the conclusion that all known sources of contamination have been removed to levels agreed to by the ADEC as being protective of human health & the environment. Therefore, no further action at this site is required.
The site has been adequately characterized under 18 AAC 75.335 & has achieved the applicable cleanup criteria under 18 AAC 75 for site closure. However, 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 Air Force to conduct additional actions that meet the requirements of 18 AAC 75 Contaminated Site regulations & Alaska Statute 46.03 – 46.09. |
Louis Howard |
| 12/5/2003 |
Site Closure Approved |
Letter from John Halverson (ADEC) to John Mahaffey (USAF) re: compliance funded contaminated sites review and response. The Air Force submitted thirty-eight (38) decision document packets to the Alaska
Department of Environmental Conservation (ADEC) Contaminated Sites Program, Department
of Defense oversight section. Each individual packet included a summary of the site history,
site characterization and cleanup work conducted to date along with a request for No Further
Action. All of the sites are petroleum contaminated sites associated with current or former fuel
storage tanks.
Residual soil andlor groundwater contamination is present at all ofthe sites. Based on our
review, thirty-six (36) of the sites (see the list below) do not appear to pose an unacceptable
risk to human health or the environment and are suitable for a No Further Remedial Action
Planned (NFRAP) determination. The ADEC's NFRAP determination indicates that no
additional cleanup is necessary but that institutional controls and/or long term monitoring are
necessary.
We have determined that the groundwater impacts at these sites are being
adequately addressed within the base-wide groundwater monitoring program and the Operable
Unit 5 groundwater treatment system. Because petroleum contaminated soil (contaminant
levels higher than the Method 2 cleanup levels in Tables BlIB2 found in 18 AAe 75.341)
remains at these sites, the Base Master Plan needs to be updated to document the locations of
residual contamination and the need to manage contaminated soil properly during any future
construction or excavation work. Upon notification that the Base Master Plan has been
updated, the ADEC will change the status of these sites in our contaminated sites database to
NFRAP with institutional controls in place.
The following 36 sites eligible for NFRAP (ignoring the ST portion of the title):
404 502 517 535
405 503 518 536
411 504 519 537
413 505/9 520 700
414 511 521 701
415 512 525 902
43019 513 528 903
431 514 530 904
501 515 533 906
Sites ST 420 and 524 are not located within the capture zone for the OU5 treatment system and
contain higher contaminant levels. Therefore, the ADEC is requesting additional site
characterization/cleanup at these two sites. |
Louis Howard |
