| Action Date |
Action |
Description |
DEC Staff |
| 6/15/1976 |
Update or Other Action |
An additional unknown quantity of avgas was lost from the 6-inch pipeline in the mid-1970s (approximately 1976) at Source ST46. Base personnel discovered a leak in the pipeline near Building 23-714, adjacent to POL aboveground tanks 734 and 735, where the pipeline crossed under a creek. This section of the pipeline was replaced with an aboveground section over the creek. |
Louis Howard |
| 1/6/1978 |
Update or Other Action |
ADF&G Memo Diagnostic/Inspection Report at the Ship Creek Hatchery by Kent Hauck Regional Fish Health Specialist- person contacted Lee Ohlinger. On January 4, 1978, a residue mixture of Jet-A 50 fuel and aircraft lube oil surfaced in gallery I during a routine water flow check using fluorescein dye. The fuel mixture with the dye passed separately through the cooling ponds containing 6,400 brood stock rainbow trout (Salmo gairdneri) and the raceways containing 818,000 fingerling chinook salmon (Oncorhynchus tshawytsca). A sample of the chinook examined on January 6, 1978 showed no pathological effects. Daily mortalities of chinook from January 6 to the present have been approximately 0.057%, which is normal for this facility (fish hatchery).
The extent of exposure of the fuel to the fish is unknown since the concentration of the contaminant as it enters the gallery is not known, On the day of the exposure, the gallery was emptied by pumping stream water and groundwater from the gallery at 1,200 gpm for approximately 45 minutes.
The possible impact of the presence of these pollutants in the hatchery system should be evaluated. It has been postulated that if exposure to hydrocarbon fuels is not extensive, long term biological effects will not occur. If exposure lasts a few days, uptake of the contaminants in fish will occur. After the fish have been in clean water several weeks after exposure, however, hydrocarbon contaminants are very difficult to detect analytically.
The concentration of fuel contaminant in Ship Creek was possibly much lower than 100 ppm. In addition, a fish kill soon after exposure should have occurred had the concentration of the contaminants been sufficient, since jet fuels are highly volatile and toxic. |
Jennifer Roberts |
| 3/8/1978 |
Update or Other Action |
ADF&G March 8, 1978 Memorandum from Bob Baker Regional Biologist to John McMullen Regional Program Manager both in the F.R.E.D. Division, Anchorage. This is in response to your memo of March 6, 1978 regarding the results of our investigation of the Ship Creek water supply contamination by petroleum products. Extent of Contamination: To date, petroleum products have been located at 14 sites within the Ship Creek watershed extending from the hatchery to the bluffs on the north and approximately 2,200 meters (approx. 1.36 miles) upstream.
These sites include: the facility's mixing building and the present cooling pond, four Tryck, Nyman, and Hayes (TNH) wells, four USGS wells, the west sump of the new ADF&G well field, the old cooling pond, and two ground seeps. Additionally all three (3) coring sites approximately 30 meters north of the sumps apparently yielded evidence of petroleum. This coring effort was requested by Tommy Heinrich at a meeting with the Air Force officials on February 7, 1978. A combination of factors within the Air Force delayed the coring until March 6.
These data suggest that the watershed of this system is inundated with oil over much of the area north of the creek and upstream for at least 2,000 meters. The contamination apparently stems from three (3) basic sources.
First, there is the area north of the facility which originated some 20 years ago from a major spill (200,000 to 300,000 gallons) caused by a break in one of the two military pipelines running along the bluff area. Tow other sources may have also contributed to pollution in this area: i.e. an 8,000 gallon arctic diesel spill two years ago (1976) of which some 6,800 gallons were recovered, and the Alaska Railroad operations in that area over the years.
The second pollution source area includes that zone of the watershed which is on the north side of the creek approximately 900 to 1,600 meters upstream of the facility. This zone was apparently used for dumping oil products years ago.
The third pollution source is also north of the creek in an area about 1,800 meters to 2,000 meters from the facility. This zone may also have received used products draining down from the aircraft maintenance area. These products are contaminating the eight (8) wells of TNH and the USGS.
The fourth contamination source is also a possibility. I can only speculate about this possibility now, but my speculations are shared by Ray Morris (EPA) and Tommy Heinrich. The source concerns "fresh" arctic diesel type fuel contaminating our sumps; i.e. the point source which initiated this investigation.
If, as I and others suspect, the three coring sites in the vicinity of the sumps do contain a petroleum product, there is a reasonable likelihood that this product is coming from the U.S. Army's line which originates in Whittier, crosses Ship Creek about 600 meters upstream of our facility, and then proceeds west along the north side of Post Road to the Air Force Terminal.
A determination of this fourth pollution source will take time. The most positive approach is a full scale pressure test of the line by the Army. Such a test is made annually and the next one is anticipated in April or May of this year (1978). Secondly, a trench could be cut downstream of this pipeline and at least test corings made above the line in an attempt to intercept products flowing downstream in the ground water. Thirdly, an attempt to chemically match fuel samples taken from the sump and the arctic grade diesel storage tanks on the bluff north of the facility. This matching effort will be attempted by the EPA and the Air Force. The EPA test results could be available next week, but the Air Force results could take 3-5 weeks since the sample will be sent to their laboratory in Texas. |
Jennifer Roberts |
| 3/14/1978 |
Update or Other Action |
FRED Div. Tommy Gene Heinrich memorandum to John McMullen Regional Program Manager FRED Div. RE: Ship Creek Water Pollution Engineering Summary. The pollution of the sumps proper appears to be from a recent pollution source. The Air Force has test cored three holes in an effort to determine where the petroleum product is coming from. In my opinion, this is inadequate and a trench is the only way to determine the direction of flow and the source. Ray Morris with EPA agrees, and has indicated he will try to get the Air Force to trench near the sumps.
An estimate has been obtained from a local contractor for grouting the sumps. Grouting the sumps, however, is only a cosmetic solution. By grouting this sump, we can probably eliminate the contaminants from the immediate pollution source, but not from those sources farther upstream. It also appears that we will get by the critical flow period without having to use the galleries this year, which gives another reason for EPA (the Air Force or the Army) to locate and cleanup the source. |
Jennifer Roberts |
| 3/14/1978 |
Update or Other Action |
March 14, 1978 Memorandum from Roger S. Grischkowsky Division Pathologist to John McMullen Regional Program Manager Subject: Position statement on Ship Creek Hatchery (SCH) - Effects of oil. In an attempt to facilitate the decision making process as pertains to SCH operation continuance and fish dispostion, I have gathered some information and will make some recommendations.
Hydrocarbon findings
January 4, 1978: Hydrocarbons found in Gallery I and passed through raceways and pond with fluorescein dye.
February 17, 1978: 1.2 ppm hydrocarbons in Tryck, Nyman and Hayes new well. 0.56 ppm hydrocarbon in old cooling pond.
Februayr 18, 1978: 0.03 ppm hydrocarbons found in above well (TNH) and four USGS wells in vicinity contained unidentified hydrocarbons.
February 24, 1978: 0.06 ppm, 1.2 ppm and 0.03 ppm hydrocarbons from above wells.
March 3, 1978: 2.8 ppm total hydrocarbons for 7 (1/2) livers equates to 0.06 ppm hydrocarbons/liver.
Discussion: Signs associated with toxic effects of oil are prominent in SCH fish. These signs are not specific and could be caused by other disease problems. Current operations of SCH is in violation of Title 18 chapter 70 Water Quality Standards. Films and sheens have been detected on water surface in raceways. Oil is present along the immediate shoreline. Projections of lowered immune response paint a pretty dismal picture for continued fish holding. A Ship Creek R&D facility would be constantly faced with oil toxicity. The question of credibility of experimental results would be omnipresent. Elmendorf cooling ponds fish have a history of serious disease problems which have not responded to routine treatment techniques. Is a legitimate human health problem from ingestions of adult returns on Elmendorf Derby caught fish present? Chronic oil release into this creek may be responsible for extremely poor returns.
Recommendations relative to SCH: 1) Terminate Phases I and II, 2) Don't plan or build an R & D Facility, 3) Request a formal position paper from the Dept. of Human Health&Social Services via the Commissioner, 4) If no human hazard exists, release all the fish as soon as possible, 5) If a human hazard exists, destroy all the fish as per hazard statement, 6) Terminate Air Force fishing derby immediately at the SCH, 7) Discontinue use of the facility for fish propagation, 8) Release fish only into Ship Creek if release is appropriate, 9) Conduct a petroleum search at other state hatcheries, and 10) Conduct petroleum searches routinely for hatchery site selections. |
Jennifer Roberts |
| 3/14/1978 |
Update or Other Action |
Roger S. Grischkowsky Div. Pathologist March 14, 1978 Ship Creek (SCH) support memorandum to A.K. Hauck Regional Fish Health Specialist. Effective March 13, 1978, I have removed the emergency status of SCH. During the last two months: 6 bacteriology, 4 parasitology and one virology diagnostic samplings have been accomplished. Findings for bacteriology and parasitology indicated mixed aeromonad/pseudomonad infection (which we have associated with that hatchery for 3 years) and essentially no metazoan parasites. Also, apparent (meaning it has been reported and I have confirmed it) are abnormal flashing behavior, lordosis, and scoliosis and hemorrhagic gills. These latter signs are associated with effects of petroleum, but are general enough to be cause by other factors.
The poor disease resistance apparent in fish at SCH over the past years of its operation do relate well to immunosuppression due to petroleum exposure. Known findings of petroleum there (at SCH) are well within chronic exposure limits. A freeze on fish removal and addition at SCH was initiated yesterday by myself. Mortalities are approaching 1%/day, but although sample collection is therapeutic for fish culturists, it will not reduce mortalities. As they reach 1-1 1/2%/day, place fish on drug therapy, but don't expect significant improvement if immunogenisis is truely suppressed. Daily/weekly examination doesn't seem an efficient resource utilization. |
Jennifer Roberts |
| 3/17/1978 |
Update or Other Action |
Bob Baker Regional Biologist FRED Div March 17, 1978 memorandum to John McMullen Regional Program Manger FRED Div RE: Ship Creek. As you know, we have found petroleum products throughout the 2,000 meters of the Ship Creek Watershed upstream of the facility. Laboratory results taken March 4, 1978 from the south side well: Number 6 TNH well (a flow sample 24 hours after pumping was started) contained 0.160 mg/L of petroleum. This was the highest value from any of the TNH wells. The presence of petroleum in the no. 6 well is important since it demonstrates that petroleum contamination of groundwater extends to both sides of the stream.
Analyses of samples taken from three cores in the vicinity of the ADF&G wells also revealed petroleum. Chem & Geo Labs: 1.18 to 2.3 mg/L and CORPS lab: 0.3 to 3.2 mg/L. Ray Morris (EPA) is attempting to arrange for a ditch to be dug on the N/S line some distance to the east of the wells. The ditch may help to further localize the source of the well contamination. These new data have demonstrated: That the contamination is even more extensive than indicated heretofore, and there is a substantial contamination of the ground water in the near vicinity (<30 meters) of our wells.
I now believe that : 1) petroleum products are possibly trapped in a shallow (1-3m) aquifer between two thin clay layers near our wells, and 2) that the possibility of a leak in the Army line (past or present) is even greater than before. GC analyses of fresh Arctic diesel fuel and the contaminate in the west sump were quite similar, thus supporting point 2). Trace metal (AA) analyses of these two samples may provide better evidence of this latter possibility. |
Jennifer Roberts |
| 4/28/1978 |
Update or Other Action |
Roger Grischkowsky Div. Pathology Fish Pathology Laboratory ADF&G April 28, 1978 memorandum to James Allen, Supervising Sanitarian, Dept. of Social Services, Environmental Health Section RE: Position Statement concerning Elmendorf, Ship Creek Fish. A position statement is appropriate concerning the Elmendorf, Ship Creek fish presently exposed to oil , as the enclosed documents indicate, relative to human health hazards. Two essential exposures are present in these fish. The large rainbow trout have received anywhere from 3 to 5 years of chronic exposure to hydrocarbons. This brood stock has been eliminated from future egg takes and the Air Force's annual fishing derby or plants in local lakes would be a normal disposition. The second exposure concerns the salmon juveniles which have had one year or less exposure to Ship Creek water and resultant hydrocarbons.
The first group in my opinion poses more of a threat to a consumer than the salmon juveniles which will depurate (To cleanse or purify or become cleansed or purified) or at least reside in natural waters years before return. |
Jennifer Roberts |
| 6/13/1978 |
Update or Other Action |
Memorandum Dated June 13, 1978 from Robert Fraser M.D. Director, Div. Public Health, thru James Allen, Supervising Sanitarian, Environmental Health Section, to Dr. Roger Grischkowsky Div. of Pathology, Dept. Fish & Game RE: Position Statment Concerning Elmendorf, Ship Creek Fish. It is impossible to make a definitive position paper with the knowledge available. Our impression however, is that the low level of hydrocarbons plus the very intermittant nature of human exposure in eating fish from the Ship Creek area would pose an extremely minimal risk to humans.
If further clarification is advisable, I would suggest Region X , EPA, be contacted regarding the study of hydrocarbons in fish and the relationship to this fairly low level of hydrocarbons in Ship Creek area. This might be a nice study for them to embark upon, but from the standpoint of public health, we feel the concern at this point is insignificant. |
Jennifer Roberts |
| 6/30/1982 |
Update or Other Action |
Interviews with personnel in the Liquid Fuels Office indicated a leak was detected in June 1982 in the JP-4 line at the low-point water drain pit west of Post Road, between Bluff Road and Second Street. |
Louis Howard |
| 3/31/1983 |
Update or Other Action |
A records search in 1983 documented that during the late 1960s quantities of brownish oil were observed seeping out of the bank near a "railroad maintenance facility" into a marsh area. The marsh area was south of the facility, and adjacent to Ship Creek (Engineering-Science 1983). The source of the oil is unknown. Also, the existence of a railroad maintenance facility has never been confirmed by Elmendorf AFB or the Alaska Railroad Corporation (ARRC).
Base maps show an abandoned railroad spur in the area, but interviews did not identify the purpose of the spur. A 6-inch JP-4
pipeline runs north of Source SD40 and along the south side of Second Street; however, no leaks in this portion of the
pipeline have been discovered through record searches, interviews or during a soil gas investigation. |
Jennifer Roberts |
| 3/17/1986 |
Update or Other Action |
Final Report, Installation Restoration Program Phase II— Confirmation/Quantification Stage 1, Elmendorf AFB received.
Site SP-11 JP-4 Fuel Line Leak
An unknown quantity of JP-4 leaked from an underground fuel line leak in 1978. The spilled fuel leaked from the bank of a stream north of two 840,000-gallon JP-4 storage tanks. In 1983 & 1984, fuel was still leaking from the bank of this stream, which discharges through a swampy area into Ship Creek.
This site is the location of a JP-4 underground fuel line leak of unknown volume. Fuel was noted to be seeping from the bank of a small stream that flows west, through a wetland, into Ship Creek (Dames & Moore, 1983). The seeps were noted again during the 1984 drilling & sampling program. One monitor well, W-14, was installed west of the pumphouse, Bldg. 23-714, on the bank of the stream to a depth of 25.5’.
Water was encountered at a depth of 5.0 feet, approximately the same elevation as the water surface in the adjacent creek, on 21 June 84. Soil moisture in the analyzed samples was 15 & 21 percent. Explosimeter & HNU photoionization meter readings were low at the borehole location; the explosimeter reading was 4 percent LEL, & the HNU reading was 100 ppm at 5 feet.
Two bottom sediment grab samples were taken in the wetland, approximately 1,800 feet west-southwest of the pumphouse. These samples contained 29 & 66 percent moisture.
W-14 was installed near this site of a JP-4 underground fuel line leak. No TOC, lead, phenol,: or pesticides were detected in this well, & TOX, TDS, & specific conductance levels were only slightly above expected background. However, pH, at 8.15, was elevated in W-14. Little oil & grease was detected in the W-14 soil samples, but one of the surface samples from the adjacent wetland, G-l, had a relatively high oil & grease concentration of 3.0 mg/g dry weight. G-2, the second wetland sample, had moderately high oil & grease at 0.159 mg/g dry weight.
The results of almost all the water quality analyses from W-14, the one well installed near this fuel line leak, are very near expected background levels. The elevated pH (at 8.15) suggests there has probably been some contamination of ground water at the site. Further, the oil & grease levels in grab samples in the nearby wetland (G-1 & G-2) indicate surface water contamination as well. This site is close to base well No. 1, & although it is probably downgradient from that shallow well, the contaminant plume could be intersected by the well's cone of depression. This may present a human health risk. Further, surface water contamination from Site SP-11 could threaten the fish hatchery on Ship Creek downstream from the base.
Well W-14 at Site SP-11 could be resampled & an analysis performed for indicator parameters to confirm the previous testing. An HNU survey could be performed along the small stream north of the site to determine whether JP-4 fuel has run off in this direction. An electromagnetic (metal detector) survey could be performed to accurately locate the underground pipes responsible for the leak. However, the survey will not be able to distinguish between leaking & nonleaking pipes. Historical information may have located the pipes sufficiently accurately for the present purposes.
Surface water was not sampled during this study, but it is potentially threatened near SP-11, where oil & grease was found in a soil sample (G-l) & by the discharge of contaminated ground water, especially to Cherry Hill Ditch (Site D-17) & Ship Creek. Surface water contamination could threaten the fish hatchery on Ship Creek.
Sites SP-7, SP-10, SP-5, SP-12, FT-1, SP-2, SP-11, & SP-14
Some ground water contamination was found at each of these sites, but a second round of sampling is necessary to confirm the presence of contaminants. Resampling the nine wells at these sites for the screening parameters (TDS, pH, specific conductance, & oil & grease) & for purgeable aromatics (USEPA Method 602) is recommended to confirm the presence of the contamination & to assess its severity.
In addition, one monitor well each should be installed downgradient of Sites SP-12, SP-11, FT-1, SP-14, & SP-2 because of their potential impact on base wells. Base wells Nos. 2, 52, & 16 should be sampled & analyzed for the same parameters. At SP-5, analyze W-7 & W-8 for major cations & anions. An HNU survey should be conducted at each fuel spill site to determine the areal extent of contamination. |
Louis Howard |
| 6/2/1986 |
Update or Other Action |
Field investigations for source ST46 conducted in 1984 included sampling from soil borings and groundwater monitoring wells (Dames & Moore, 1986). In 1984, petroleum hydrocarbons were detected at 1.7 mg/L in well W-14. In 1984, 19 mg/L of total petroleum hydrocarbons (TPH) was detected in well GW-4A. The water samples had petroleum odors. |
Jennifer Roberts |
| 6/30/1986 |
Update or Other Action |
According to personnel at the DFSC, there has never been a confirmed leak in the 8-inch multiproduct line [lnformation on the 8-inch multiproduct pipeline was obtained in telephone conversations with Jack Appelloni. U.S. Government contracting officer for DFSC; Paul Bestry, Tecom, Inc., contractor for DFSC; and Jack Walty, DFSC facility engineer in February 1992 and October 1992.]
On May 28 and 29, 1986, the Defense Fuel Support Center (DFSC) was called out to investigate fuel floating on puddles found in natural low spots in the marshy area north of the golf course clubhouse (Building 23-100). This area is represented by source SS53. The 8-inch multi-product line was plugged and passed a 24-hour pressure test. Samples of the fuel were taken and determined to be old fuel and not the product in the line. DFSC concluded that it had come from an old leak in a USAF line upgradient, and the USAF took over the investigation.
The USAF Fuel Response Team contained the fuel with absorbent booms, and earth berm, and a trench established to focus fuel runoff by lowering the water table with vacuum pumps. After the DFSC multiproduct pipeline passed the pressure test, the USAF tested the USAF fuel line three-eigths of a mile north of the contaminated area. That line was also shown to be intact. Initially, 650 gallons of fuel and water mixture were vacuumed off the area.
An attempt was made to establish the boundaries of the golf course contamination by using a tractor mounted post hole digger capable of digging 4 foot deep holes. A grid was established. Holes on the south side of the parking area near Building 23-100 and in a grass island in the cneter of the parking lot were free of fuel. Twenty-six holes were put in a marshy area north of the clubhouse parking lot where the contamination was discovered. Depth to water varied from 6 inches below the surface water to greater than 4 feet. Four holes in the immediate area of the original contamination had fuel on top of the water table.
A trench was established in the center of the four "positive" holes. A small amount of fuel was skimmed from the surface of the standing water. A culvert with slits cut in it was placed in the trench to act as an accumulation point and a focus for continued skimming. On May 29, 1986, approximately 1,000 gallons of fuel/water mixture were removed from the trenches. Reports do not indicate that any soil was removed during the cleanup effort. The "negative" holes were filled in. The "positive" holes were treated with absorbent pads.
Both the Army and the USAF ran lab analyses on the sampled fuel. The USAF results showed a mixture of JP-4 and diesel. The Army Lab identified the substance as "either very old JP-4 or a JP-4/diesel mix." The USAF concluded that the contamination was likely the result of residual fuel from historic spills surfacing on the rising water table. The water table had risen in the days preceding the discovery as a result of snowmelt at higher elevations and light rain. |
Jennifer Roberts |
| 11/28/1986 |
Update or Other Action |
Records show that a follow-up acoustic pipeline inspection was conducted by Advanced Technology International in November 1986, and that a broken "bleed line" was discovered to be plugged with dirt and ice. According to the Liquid Fuels Office, the line was repaired. No records were on file to indicate when the break was repaired |
Louis Howard |
| 3/31/1988 |
Update or Other Action |
Final Report, IRP Phase II— Confirmation/Quantification Stage 2, Elmendorf AFB received. This site is the location of a JP-4 underground fuel line leak of unknown volume. One monitor well, W-14, was installed west of the pumphouse, Bldg. 23-714, on the bank of the stream to a depth of 25.5' during the Phase II, Stage 1 investigation. An additional well (GW-4A) was installed approximately 300' hydraulically downgradient, based on analysis of available hydraulic data, of well W-14 to help determine the extent of migration of contaminants.
Most of the results during the Stage 1 investigation for the water from W-14 indicated either assumed ambient concentrations or values below the limit of detection. However, there were elevated levels of oil & grease in soils in wetlands adjacent to SP-11, the site of a JP-4 underground fuel line leak.
During the Stage 2 investigation, purgeable aromatics were not detected in W-14 or newly installed GW-4A; however, purgeable halocarbons were detected. In W-14, 0.53 ug/L of tetrachloroethene was detected. In GW-4A, the following parameters & levels were found: dibromochloromethane, 1.6 ug/L; trans-1, 2-dichloroethene, 2.4 ug/L; tetrachloroethene, 0.46 ug/L; trichloroethene, 3.0 ug/L; trichlorofluoromethane, 0.49 ug/L. Petroleum hydrocarbons were not detected in W-14, but were detected at a concentration of 19.0 mg/L in GW-4A.
Water quality results from the two wells downgradient of this fuel line leak indicate an elevated level (19.0 mg/L) of petroleum hydrocarbons in GW-4A & detectable levels of purgeable halocarbons in both wells. Dibromochloromethane, trans-1,2-dichloroethane, tetrachloroethene, trichloroethene, & trichlorofluoromethane were detected in GW-4A. Tetrachloroethene was detected in W-14. These analyses indicate water quality degradation in the area downgradient of the site.
The two areas of concern regarding SP-11 include the possible impact on the water quality in Ship Creek & the effects on base supply well BW-52. At the time of the sampling event, water quality in Ship Creek did not appear to be effected as only one purgeable halocarbon (trichlorofluoromethane) was detected in one sample from the Creek. It is believed that this compound may be attributable to trip or lab contamination. Also, GW-52 was found to have a low levels of chloroform, perhaps attributable to chlorination, as the only purgeable halocarbon in the sample. The current sampling event at SP-11 suggests no impact to either surface or GW.
Field investigations for source ST46 conducted in 1986-1987 included sampling from soil borings & GW monitoring wells (Dames & Moore, 1988). GW sampling conducted in 1986-1987 revealed trace levels of the following compounds in well GW-4A: tetrachloroethene (PCE) at 0.46 ug/L; TCE at 3.0 ug/L; dibromochloromethane at 1.6 ug/L; trichlorofluoromethane at 0.49 ug/L; & trans-1,2-dichloroethene (DCE) at 2.4 ug/L. PCE was also detected at 0.53 ug/L in W-14. NOTE: These solvents were not detected when GW-4A was resampled by Black & Veatch in 1988.
It is also recommended that Ship Creek be resampled during a period more nearly approaching the base flow of the stream (i.e., late winter). The reliability of the analysis indicating the presence of one purgeable halocarbon, trichlorofluoromethane in sample SC-1, is in question & resampling & analysis is recommended. It would be worthwhile to move one sampling location to the vicinity of SP-11. Monitor well GW-4A, at SP-11 had detectable levels of purgeable halocarbons & elevated petroleum hydrocarbons. Sampling Ship Creek immediately downstream of SP-11 will permit assessment of possible contaminants coming from this site into the stream in this area.
Because of the low levels of purgeable halocarbons in both monitor wells, & the elevated (19.0 mg/L) petroleum hydrocarbons in GW-4A, it is recommended that these analyses be confirmed by an additional round of analyses. Although base water supply well BW-52 did not appear to be effected by the contaminants from SP-11, the proximity of this fuel line leak to nearby wetlands draining into Ship Creek, is of concern.
The confirmation of Stage 2 analyses would then warrant classifying this area as a Category 3 site requiring remedial action. Because of the sensitivity of wetlands to petroleum hydrocarbons pollution, it is believed that removing the source of further pollution, rather than treatment in the wetlands area, would be the least damaging to the environment.
It is recommended that the wells be resampled & analyzed for petroleum hydrocarbons (USEPA 418.1), purgeable halocarbons (USEPA 601), pH, temperature, & specific conductivity. If warranted, it is recommended that remediation include the pumping & treating of water from well GW-4A & periodic analyses of GW for petroleum hydrocarbons & purgeable halocarbons to determine if contaminant levels decrease. |
Jennifer Roberts |
| 8/1/1988 |
Site Visit |
RCRA Visual Site Inspection conducted in July 1988.
Site SP-4, Railroad Maintentance Area Oil Spill
a. Location: This site is located north of Ship Creek, near the railroad maintenance facility in an abandoned railroad south of the airmen dorms; it is near the cooling pond on the south part of the base.
b. Operation: This was the site of a spill in the late 1960's. Brownish oil globs were noticed seeping from the bank near the railroad mantenance facility into a marsh area south of the facility and flowing into Ship Creek. Portions of the oil material sank into the marsh. The oil was presumed to be the result of maintenance activities at the railroad facility.
c. Contamination Potential: This site is a potential source of contamination and contaminant migration, since the marsh is a direct pathway for migration to Ship Creek. The extent of contamination is unknown.
d. Recommended Action: A study of this unit will be included in the Ship Creek investigation portion of the RFI Workplan. This investigation will determine the source and extent of plumes potentially causing contamination into Ship Creek to initially require soil coring and/or soil gas surveys. Ground-water monitoring wells may be required following details of soil study.
Site SP-11 JP-4 Fuel Line Leaks. A JP-4 leak was discovered in 1978 along the banks of a small stream north of the base golf couse and Ship Creek. An undetermined quantity of fuel was lost as a result of an underground pipe crack, although the pipe was repaired, fuel was noted to be seeping from the bank of a small stream that flows north, through a wetland, into Ship Creek. The seeps were noted again during the 1984 drilling and sampling program.
The two areas of concern regarding this site include the possible impact on the water quality in Ship Creek and the effects on base water suppy well BW-52. A reconnaissance was performed at this site; what appeared to be a petroleum sheen was observed on the south bank of the small stream immediately downstream of the pipleline crossing.
Site NS-3, Seep #4, Golf Course
a. Location: This site is located south of Post Road, north of Ship Creek, and immediately north of the Golf Course Pro Shop. See photograph #27 of Attachment 2.
b. Operation: Captain Hector Molave, USAF, indicated that every Spring, fuel of unknown origin appears on the ground in the area north of the Pro Shop. The fuel flows into a drainage ditch paralleling the south side of Post Road.
c. Contamination Potential: During a reconnaissance inspection, EAFB reported fuel in small holes dug in the ground and fuel stained soil in the ditch. The extent and source of contamination are unknown, further study is needed.
d. Recommended Action: Methods for determining the source and extent of the contamination will be described in the RFI workplan.
GROUP 1
Those sites which are high priority and will be addressed initially in the RFI Workplan, also to include those sites which will be involved in the investigation of Ship Creek; they are as
follows:
D-3, D-4, SP-7, SP-10, IS-2 through -8, NS-1, NS-3, OT-1, and FT-1
Ship Creek investigation sites:
SP-2, SP-4, SP-ll, SP-12, and SP-14. |
Max Schwenne |
| 8/2/1988 |
Update or Other Action |
Operable units' source area numbers that correspond to RCRA SWMUs from the RCRA RFA. Spill Sites:
SD40 SP-4 Railroad Maintenance area, north of Ship Creek near the railroad maintenance
facility in an abandoned railraod south of the airmen dorms, it is near the cooling pond on the south part of the base. site of a spill in the late 1960's and railroad maintenance
activities. This site is a potential source of contamination and contamination migration since the marsh is a direct pathway into Ship Creek. An investigation should include identification of the source, and extent of the plumes, alomg with site characterization and remediation if appropriate.
ST46 SP-11 JP4 Fuel Line Leak - Bldg. 23-714. Located within the Alaska Railroad
boundaries, north of former Cooling Pond W. 5,126. A undetermined amount of JP4 and other possible substances released for an undertermined amount of time.
Impacts include surface sheens, seeps and pooling of product and contamination of monitoring wells placed to investigate SP-11 (purgable hydrocarbons, petroleum hydrocarbons, Dibromochlormethane, trans-1,2- dichlorethane, tetrachlorethene, trichlorethene, trichlorflourmethane). Two area of concerns are the impacts to Ship Creek and to water supply well BW-52. Further study is warranted and this will be included in the Ship Creek RFI. The source of and extent of contamination needs to be defined as well as site charactorization and remediation measures.
SS-53 NS-3 Seep #4 and Golf Course, located south of the Post Road, north of Ship Creek, and
immediately north of the Golf Course Pro Shop. Elmendorf has reported that every spring fuel of unknown origin appears on the ground in the area just north of the Pro Shop. The extent and source of the contamination are unknown. Further investigation is needed. |
Louis Howard |
| 10/3/1988 |
Update or Other Action |
Monitoring wells, soil borings, sampling, soil gas survey conducted at source area SD40 (referred to as SP-4), ST46 (referred to as SP-11), and SS53 (referred to as NS-3) during the 1988 remedial investigation by Black and Veatch.
SP-4 Water: Total petroleum hydrocarbons (TPH) and benzene exceeded cleanup levels (TPH SP4-01 3.3 mg/L, SP4-02 3.2 mg/L, SP4-03 2.5 mg/L and SP4-01 benzene 27 ug/L). Toluene and ethylbenzene detected below cleanup levels.
Soil: TPH detected in one boring above ADEC cleanup guidelines (SP4-03 270 mg/kg). Proposed soil cleanup level guidelines for TPH in the State of Alaska are based on an assessment matrix developed by the State of California which is maximum allowable TPH in soil are either: 1000 ppm, 100 ppm or 10 ppm depending on depth to groundwaer, soil characteristics, and hydraulic conductivity, precipitation, and migratory routes. Based on features at the sites on Base, it appears that the maximum allowable TPH level is 100 ppm. Metals did not exceed background concentrations.
SP-11 Water: TPH (3000 mg/L Oil & Grease per 413.2 well GW-4A) and benzene (GW-4A 16 ug/L) exceeded cleanup levels. Chlorinated hydrocarbons detected but no cleanup levels were exceeded.
Soil was not sampled. Recommended action for SP4/11: Medium priority for further investigation. Rationale: contaminant levels exceed State of Alaska and EPA primary drinking water standards and evidence of off-site migration exists. This is evidenced by contamination in downgradient well GW-4A. This contamination extends offsite to well SP4-01.
NS-3 Water: TPH and trichloroethene detected below cleanup levels. TCE well NS3-02 (1.2 ug/L), TPH: NS3-02 2.0 mg/L NS3-03 0.7 mg/L
Soil: TPH detected below ADEC interim cleanup guidelines. Recommended action: No further action (for soil only). Rationale: Site adequately characterized to determine no significant impact to human health or environment will occur. |
Jennifer Roberts |
| 12/2/1988 |
Update or Other Action |
Proposed State of Alaska Soil and Groundwater Cleanup Standards, Discussion Draft dated December 2, 1988. A. Problem Statement: Interim cleanup standards for soil and groundwater remediation, and contaminated soil and water treatment and disposal are necessary to insure consistent standards are being applied by districts and regional program staff. Standards are needed to guide responsible party and ADEC cleanups of surface and subsurface hazardous substance spills.
B. Proposed Groundwater Cleanup Standards and Contaminated Water Discharged to Groundwater Standards: Authority: 18 AAC 70.020 (b) 18 AAC 70.050 (2)
a. Contamination from petroleum petroducts
1. EPA SDWA Maximum Contamination Levels (MCL) and EPA Water Quality Criteria
Volatile Aromatics: benzene: 5 ppb (SDWA MCL effective 1/89) ethylbenzene: 700 ppb (proposed)
toluene: 2000 ppb (proposed) xylenes: 440 ppb (proposed)
2. Non-aromatics:taste and odor
b. Contamination from other hazardous substances
SDWA standards (including proposed)
EPA Water Quality Criteria
AK Drinking Water Standards
c. Point of Compliance
The point of compliance for meeting groundwater cleanup standards shall be the spill site property line. The property line cannot be expanded through acquiring ownership or easements for point of compliance without the approval of the department. Active public and private water systems within the property line shall be included in the point of compliance.
d. Alternative Cleanup Levels (ACLS)
1. The responsible party (RP) may prepare at its own expense a risk assessment which shall include an exposure assessment, toxicity assessment, risk characterization and justification of alternative cleanup levels. The RP, at the department's discretion, must agree to reimburse the department for expenses incurred by the department if it chooses to contract for a risk assessment review. Attached is a description of risk assessment requirements taken from
an ADEC proposed Compliance Order by Consent which has been reviewed by the AGO (appendix 1). The language is currently used by the State of Florida. It is recognized that ADEC presently has limited capability to review risk assessments. It is recommended that a term contract be developed for the review of any submitted risk assessment. In the interim the 1988 petroleum and hazardous substance investigation term contract can be used for risk assessment reviews. It
is also recommended that regional risk assessment review panels consisting of representatives drawn from regional program staff and each district be covered to review risk assessment recommendations.
2. Non-responsible Party (NRP) Cleanups
It is recognized that the State may not have sufficient resources (HB 470, LUST TRUST, program management staff) to clean up NRP sites to the proposed standards and that the State may be criticized for not meeting its own standards. Limited state resources do not justify lesser standards for responsible party cleanups. The State is not the RP and its response is limited by available resources. The State has a duty to meet clean-up standards as resources permit. The
State must document for the record when ACLs are established due to limited resources.
C. Proposed Soil Cleanup Standards:
Soil contaminated by petroleum or other hazardous substances must be cleaned to background levels. Alternate clean-up levels may be permitted if it can be demonstrated that soil contaminant levels will not lead to groundwater contamination through leaching nor pose a risk to potential surface receptors.
The contaminant leaching assessment would include analysis of soil type using a uniform soils classification, logging of any horizon over six inches thick, an analysis of hydraulic conductivity, absorptive capacity, potential migratory routes, precipitation levels and
groundwater. The analysis can be conducted by a soils scientist, environmental scientist or
environmental engineer.
The assessment matrix developed by the State of California is acceptable as an assessment tool (Appendix 2). It is recommended that an assessment matrix calibrated to Alaskan environmental conditions be developed by ADEC.
Soil contamination levels shall be identified using EPA methods 8020 for volatile aromatics and 418.1 for total petroleum hydrocarbons or other appropriate EPA methods if soil is contaminated by hazardous substances other than petroleum products.
See site file for additional information. |
Ron Klein |
| 4/3/1989 |
Update or Other Action |
Prior to 1989, the Alaska Department of Health and Human Services posted signs along Ship Creek stating, "The municipality of Anchorage recommends against the eating of fish taken from these waters because of chemical contamination of stream sediment." The signs were removed in 1989 for administrative reasons. |
Jennifer Roberts |
| 4/6/1989 |
Meeting or Teleconference Held |
TELEPHONE MEMORANDUM USAF Elmendorf AFB EDB Levels Detected at Elmendorf AFB B&V Project 13833 B&V File April 6, 1989 To: Max Schewenne Alaska Department of Environmental Conservation (907) 563-6529 Recorded by J.L. Frizzell Vb I talked with Max regarding the levels of EDB detected at Elmendorf AFB. There are no drinking water regulations regarding the level of EDB in drinking water. The State of Alaska requires an excess cancer risk calculation be calculated. If the excess cancer risk is less than 10-6 , it is probable that the EDB concentration is not of concern. If the level is greater than 10-6 , a site by site review will be conducted by the Alaska Department of Environmental Conservation. |
Max Schwenne |
| 7/14/1989 |
Update or Other Action |
Conditions at NPL proposal (July 14, 1989): Elmendorf Air Force Base covers 13,100 acres in the Greater Anchorage Area Borough immediately north of Anchorage, Alaska. The base is bounded to the west by Knik Arm of the Cook Inlet, and to the east by Fort Richardson Army Base. Ship Creek flows along the southern perimeter. In operation since 1940, this base now hosts the 21st Tactical Fighter Wing.
Elmendorf is participating in the Installation Restoration Program (IRP), established in 1978. Under this program, the Department of Defense seeks to identify, investigate, and clean up contamination from hazardous materials. As part of IRP studies, the Air Force identified 12 areas where hazardous materials had been generated, stored, used, or disposed of. All require further investigation.
Initially, the Air Force focused on five areas. In the past, landfills D-5 (now closed) and D-7 (still active) received a variety of hazardous wastes, including lead acid batteries and waste solvents. The landfills, unlined and unbermed, are in sandy and gravelly soils. Shop wastes, including solvents and paint thinners, were disposed of in a naturally occurring unlined trench designated as Site D-17. Site IS-1 is where fuel in Building 42-400 spilled into floor drains that feed into gravel-bottom dry wells. The last of the five areas included in the initial investigation is Site SP5, where approximately 60,000 gallons of aviation fuel JP-4 spilled, of which only 33,000 gallons were recovered.
During IRP activities in 1983-87, trichloroethylene, tetrachloroethylene, 1,1,2,2-tetrachloroethylene, trans-1,2-dichloroethylene, 1,1-dichloroethane, 1,1,1-trichloroethane, and lead were detected in on-site monitoring wells. An estimated 121,000 Elmendorf employees and residents of Anchorage obtain drinking water from a blended water system that draws primarily from surface water but also uses wells within 3 miles of hazardous substances on the base on a standby basis.
EPA is reviewing the Air Force's workplan for a remedial investigation/feasibility study (RI/FS) to determine the type and extent of contamination at the base and identify alternatives for remedial action. The final workplan is expected to be completed in the fall of 1989. |
Jennifer Roberts |
| 12/29/1989 |
Document, Report, or Work plan Review - other |
ADEC Comment letter sent to Air Force Everett L. Mabry, Colonel, USAF Base Civil Engineer on RI/FS Stage 4 Second Draft work plan October 1989. 1. For several sites the disposal method for soil contaminated with high levels of TPH is quoted as "the sanitary landfill". The only area landfill that is permitted to received petroleum contaminated soil is the Municipality of Anchorage (MOA) Landfill.
The MOA Landfill will accept soils only if the TPH level is below 1000 mg/kg. In many cases the work plan was referring to soils with TPH in excess of 1000 mg/kg. The issue of proper contaminated soil disposal has been brought up by ADEC several times (reference letters: Klein to Gerken, October 20, 1989 and Klein to Mabry, November 2, 1989).
The Department requests clarification on the disposal method of soils contaminated with TPH levels over 1000 mg/kg and verification that the proposed sanitary landfill is the MOA Landfill. In addition, the Department requests written notification regarding disposal of all contaminated soils. The notification should include: date of disposal, quantity of soil, location that soil originated, and final disposal method.
2. The Department requests that an expanded seasonal sampling schedule be established for selected monitoring wells. In several sites (for example, well W-18 on site IS-1) there may be floating product. The Department is concerned that accurate data is not being collected based on a once a year sampling schedule. Seasonal water table fluctuations can easily dilute or mask the true concentration level of the contaminate. Determinations on site status and remedial actions are being based on incomplete information.
3. In all the proposed borings/monitoring wells the work plan calls for two soil samples per boring to be taken to determine the extent of vertical contamination. The exact depth of the sample is to be based on field screening results. Field screening techniques to determine the presences of TPH contamination is not reliable and it is not uncommon to miss contaminated zones using field screening in leu of analytical laboratory analysis. Also much of the contamination is from old fuel spills which may now be low in benzene and again would be very difficult to read on any field meter calibrated to benzene. The Department requests that
additional soil samples be taken in soil borings/monitoring wells and recommends that sampling be done on 5 foot or 10 foot intervals depending on the total depth of the boring.
4. Paragraph 2.2.1.2 and many other sections reference HNu readings of less than 1 ppm. Key data such as span setting, ambient HNu reading, and calibration gas used, need to be stated
to interpret HNu data. Ambient levels of greater than 1 ppm at span 9.8 calibrated to benzene are common. Relaying solely on HNu field screening may allow contaminated zones to be missed. Again the Department requests that additional soil samples be taken in soil borings/monitoring wells.
5. In many sites two deep borings/monitoring wells are proposed. The decision to drill the second boring would be based on the results of the first deep boring. The Department is concerned that using only two soils samples per boring to determine if contamination is present will allow layers of contamination to be missed. The Department requests that additional soil samples be taken to determine the vertical location of contamination and that this additional sampling be used to determine the depth of the second deep boring and the other shallow borings.
6. Paragraph 2.2.1.2 and other sections in the RI/FS state that well contamination is not likely because of the Bootlegger Cove aquitard. Stage 3 RI/FS analysis of base well BW-1 shows the presence of chlorinated solvents and TPH, also base well BW-51 had TPH present. This indicates contamination is currently infiltrating into drinking water aquifers. Has a survey of
possible routes through the aquitard been performed? For example, paragraph 3.3.1.5 states that over 400 wells are in the Elmendorf area. Well casings can offer excellent conduits for contamination migration. ADEC requests the following information for each of the base drinking water wells : total depth, wells logs (if available) and how these wells are completed (screened or perforated zones, etc.).
SITE SP-4/11
Paragraph 2.2.3.8 states that during Stage 2 investigation purgeable halocarbons were detected in groundwater from wells GW-4A and W-14. According to Table 5-4 groundwater samples for this site are not scheduled to be analyzed for purgeable halocarbon (5030/601).
The Department requests that the groundwater samples be analyzed for purgeable halocarbons, the source of the halocarbons be located, and that a season sampling schedule be developed to determine if there are seasonal fluctuations in halocarbon concentrations. |
Ron Klein |
| 12/30/1989 |
Site Added to Database |
Petroleum contaminant. |
Louis Howard |
| 2/16/1990 |
Meeting or Teleconference Held |
On 16 February 1990, a meeting was held to discuss Alaska Department of Environmental Conservation (ADEC) Stage 3 RI/FS & Stage 4 Work Plan review comments in their 15 November 1989 & 29 December 1989 letters. ADEC, AF, EPA, Black & Veatch attended.
Page 1, GENERAL COMMENT #1: State mentions "several sites"; we requested in the future that the State identify sites. The 1000 mg/kg TPH level was noted by the State of Alaska (State) to be a Municipality of Anchorage (MOA) landfill requirement only. It was suggested that Mr Mike Blair of the MOA be contacted in relationship to the MOA landfill accepting "mass balance" of soil to meet turn-in requirements. In relationship to this, Mr Doug Johnson noted that off-site disposal, as in the case of the MOA landfill, may include certain potential liabilities & the Air Force should be aware of these. Both the State & EPA stated that it may be better to treat contaminated soils on base. Mr Williamson reinforced this, stating that pretreatment of soil will always be considered for each operable unit. The California "LUFT Manual" was noted by Major Waterhouse as guidance the State should consider adopting. In addition, the Air Force requested that State guidance be clear & promulgated. The State added the Air Force should strive for 100 ppm TPH for nongasoline removal or treatment.
Page 1, GENERAL COMMENT #2: The State requested seasonal sampling, they said, to get a better picture of hydrologic data, especially along Ship Creek. The intent is seasonal water level sampling, not full analytical sampling. In addition, the seasonal water sampling is intended to give us a good baseline for the future. The Air Force agreed. Seasonal sampling was noted to be two periods: our dry & wet seasons.
Page 2, GENERAL COMMENTS #3 & #4: The Air Force & the contractor plan to take a minimum of two samples per boring. More will be taken as needed. The State & EPA indorsed collecting samples for routine laboratory analysis at every 2 to 5-foot interval of the bore holes in preference to using an HNu to screen the split spoon sample & sampling only those levels where a positive HNu reading was obtained.
Page 2, GENERAL COMMENT #5: Again, the State mentions "many sites"; request in the future that State identify sites. Also, as discussed in the meeting, the contractor has based the location of new wells on logical data. The well locations, however, are general & will be sited more precisely as the study continues.
Page 2, GENERAL COMMENT #6: Although it was agreed upon that a possible route of contamination exists along well casings, at least the Air Force & contractor felt this risk was, at best, minimal. Still, Major Waterhouse pointed out that Bioenvironmental Engineering monitors all deep aquifer potable water wells. To date, no signs of contamination has been noted. Well #1 is a 16-foot shallow well (cistern) collecting water from the shallow aquifer. The identified volatile organic contaminants in this well are not indicative of the deep water aquifer water quality.
Page 3, GENERAL COMMENT #7: Capt Godsave asked the State what an "approved oil/water separator" was & what regulations are entailed. The State elected to defer their answer. Mr Johnson noted that this was a NPDS or RCRA issue & not a CERCLA issue. Major Waterhouse noted that a team from Occupational & Environmental Health Laboratory (OEHL) are coming to Elmendorf AFB soon to achieve an inventory of floor drains as requested by the State. The State requested that the OEHL team discuss their methodology with the State up front. Major Waterhouse agreed to this.
Page 3, GENERAL COMMENT #8: The State stated this comment was essentially for our information. Both the State & EPA stated that a industrial waste water permit is not required for the storm sewers, but that the Air Force should meet the intent of such a permit.
Page 3, GENERAL COMMENT #9: The Air Force has asked the contractor to better define & consistently use the terms "off-site" & "off-installation," & be more definitive on the potential for contamination migration. Contaminant migration should only be inferred when enough technical data has been obtained to support such a statement.
Page 6, SITE SP-4/11: The Air Force will resample to validate or negate
the findings. |
Jennifer Roberts |
| 2/16/1990 |
Meeting or Teleconference Held |
On 16 February 1990, a meeting was held to discuss Alaska Department of Environmental Conservation (ADEC) Stage 3 RI/FS & Stage 4 Work Plan review comments in their 15 November 1989 & 29 December 1989 letters. ADEC, AF, EPA, Black & Veatch attended.
SITE NS-3: The Air Force asserted that this site is properly classified as a No Further Action (NFA) site. Although a fuel seep of unknown origin had appeared north of the Golf Pro Shop in the past, our present contractor has not been able to locate such an occurrence. In addition,
adequate subsurface investigation lends to the NFA characterization. In light of our comments, the State declined to make any determination and stated they would get back with us on this issue. |
Jennifer Roberts |
| 4/27/1990 |
Update or Other Action |
The 8-inch multiproduct pipeline was emptied in April 1990 as a result of a corrosion test on the line that indicated anomalies in the pipeline wall thickness. No leaks or spills were reported in connection with the test. |
Louis Howard |
| 5/1/1990 |
Update or Other Action |
PROPOSED STATE OF ALASKA SOIL AND GROUNDWATER
CLEANUP STANDARDS
DISCUSSION DRAFT DATED DECEMBER 2, 1988
A. Problem Statement:
Interim cleanup standards for soil and groundwater remediation, and contaminated soil and water treatment and disposal are necessary to insure consistent standards are being applied by
districts and regional program staff. Standards are needed to guide responsible party and ADEC cleanups of surface and subsurface hazardous substance spills.
B. Proposed Groundwater Cleanup Standards and Contaminated Water Discharged to Groundwater Standards:
Authority: 18 AAC 70.020 (b) 18 AAC 70.050 (2)
a. Contamination from petroleum petroducts
1. EPA SDWA Maximum Contamination Levels (MCL) and EPA
Water Quality Criteria
Volatile Aromatics:
benzene: 5 ppb (SDWA MCL effective 1/89)
ethylbenzene: 700 ppb (proposed)
toluene: 2000 ppb (proposed)
xylenes: 440 ppb (proposed)
2. Non-aromatics
taste and odor
b. Contamination from other hazardous substances
SDWA standards (including proposed)
EPA Water Quality Criteria
AK Drinking Water Standards
c. Point of Compliance
The point of compliance for meeting groundwater cleanup standards shall be the spill site property line. The property line cannot be expanded through acquiring ownership or easements for point of compliance without the approval of the department. Active public and private water systems within the property line shall be included in the point of compliance.
d. Alternative Cleanup Levels (ACLS)
1. The responsible party (RP) may prepare at its own expense a risk assessment which shall include an exposure assessment, toxicity assessment, risk characterization and justification of alternative cleanup levels. The RP, at the department's discretion, must agree to reimburse the department for expenses incurred by the department if it chooses to contract for a risk assessment review. Attached is a description of risk assessment requirements taken from an ADEC proposed Compliance Order by Consent which has been reviewed by the AGO (appendix 1). The language is currently used by the State of Florida. It is recognized that ADEC presently has limited capability to review risk assessments.
It is recommended that a term contract be developed for the review of any submitted risk assessment. In the interim the 1988 petroleum and hazardous substance investigation term
contract can be used for risk assessment reviews. It is also recommended that regional risk assessment review panels consisting of representatives drawn from regional program staff and each district be covered to review risk assessment recommendations.
2. Non-responsible Party (NRP) Cleanups
It is recognized that the State may not have sufficient resources (HB 470, LUST TRUST, program management staff) to clean up NRP sites to the proposed standards and that the State may be criticized for not meeting its own standards. Limited state resources do not justify lesser standards for responsible party cleanups. The State is not the RP and its response is limited by available resources. The State has a duty to meet clean-up standards as resources permit. The
State must document for the record when ACLs are established due to limited resources.
C. Proposed Soil Cleanup Standards:
Soil contaminated by petroleum or other hazardous substances must be cleaned to background levels. Alternate clean-up levels may be permitted if it can be demonstrated that soil
contaminant levels will not lead to groundwater contamination through leaching nor pose a risk to potential surface receptors.
The contaminant leaching assessment would include analysis of soil type using a uniform soils classification, logging of any horizon over six inches thick, an analysis of hydraulic conductivity, absorptive capacity, potential migratory routes, precipitation levels and
groundwater. The analysis can be conducted by a soils scientist, environmental scientist or
environmental engineer.
The assessment matrix developed by the State of is acceptable as an assessment tool (Appendix 2). It is recommended that an assessment matrix calibrated environmental conditions be developed by ADEC.
Soil contamination levels shall be identified using EPA methods 8020 for volatile aromatics and 418.1 for total petroleum hydrocarbons or other appropriate EPA methods if soil is contaminated by hazardous substances other than petroleum products.
Soils meeting the definitions of RCRA hazardous shall be treated and disposed of as required by RCRA. It is recommended that onsite assessment of UST abandonments follow the procedures outlined in SCROs draft UST abandonment standard procedures policy (to be finalized). |
Ron Klein |
| 5/1/1990 |
Update or Other Action |
Action-specific ARARs SOA requirements: 18 AAC 75.130. DISPOSAL OF HAZARDOUS SUBSTANCES.
a) Prior approval by the department is required for the ultimate disposal of a hazardous substances, and soil, cleanup materials, or other substances contaminated with a hazardous substance. Approval under this section may be granted orally by the regional supervisor or his designee.
(b) As used in this section, "ultimate disposal" includes disposal into or upon the waters or the surface or subsurface land of the state, and open burning. (Eff. 4/23/77, Reg. 62)
Authority: AS 46.03.020(10)(A) AS 46.03.020(10)(E) AS 46.03.140 AS 46.03.710 AS 46.03.740
18 AAC 75.140. CLEANUP.
(a) Immediately upon becoming aware of a discharge of a hazardous substance to the water or land of the state, persons responsible for that discharge shall cleanup and dispose of the material collected using methods for which prior approval, oral or written, has been given by the regional supervisor or his designee. The discharge must be cleaned up to the satisfaction of the regional supervisor or his designee.
(b) Upon request, the department will waive (a) of this section if, in the opinion of the department, it is technically impracticable must be cleaned up the discharge, or if the cleanup effort would result in greater environmental damage than the discharge itself. (Eff. 4/23/77, Reg. 62) Authority: AS 46.03.020(10)(A)
18 AAC 75.145. ADEQUACY OF CLEANUP.
(a) If the department determines that cleanup activities are inadequate, the department will, in its discretion, and unless the U.S. Coast Guard or U.S. Environmental Protection Agency otherwise directs under the authority of section 311(d) of the Federal Water Pollution Control Act Amendments of 1972 (33 U.S.C. sec. 1321(d)), either order the person engaged in cleanup operations to cease cleanup activities, or authorize other agents to begin cleanup activities, or both.
(b) Cleanup activities will be considered inadequate if (1) containment equipment is not deployed and used to intercept and concentrate oil discharges in their patterns of movement, unless environmental conditions exceed the limitations of the equipment;
(2) exclusion equipment is not deployed and used to protect sensitive environmental zones, unless environmental conditions exceed the limitations of the equipment;
(3) the area affected by the oil discharge is increasing at an avoidable rate despite containment and removal activities, unless environmental conditions exceed the limitations of
the equipment, or unless immediate containmant would pose greater environmental risks than to
allow the discharge to temporarily spread;
(4) the containment and exclusion equipment being used is not functioning effectively because of existing weather and oceanographic conditions, and other containment and exclusion equipment is reasonable available which can function effectively in existing weather and oceanographic conditions;
(5) containment, exclusion, is not deployed and response times specified chapter; and lightering equipment operational within its under sec. 310 of this
(6) major items of cleanup equipment, including skimmers, lightering pumps, and sorbent are not
operational, or not operating at efficiencies within their capabilities;
(7) supplies of sorbent material become depleted, and available sources of replacement are not being utilized; or
(8) available personnel or equipment resources are being unused or mismanaged, or additional
personnel or equipment is required but not being provided. (Eff. 9/16/77, Reg. 63) Authority: AS 30.25.040 AS 30.25.070 AS 46.03.020(10)(A) |
Ron Klein |
| 8/30/1990 |
Update or Other Action |
CERCLIS EPA ID AK8570028649 Final Listing on the National Priorities List August 30, 1990. This listing designated the facility as a federal Superfund site subject to the remedial response requirements of the Comprehensive Environmental Response, Compensation and Liability Act, as amended by the Superfund Amendments and Reauthorization Act of 1986. |
Jennifer Roberts |
| 5/22/1991 |
Update or Other Action |
Overview document anc:31026d:04 shows that total petroleum hydrocarbons (TPH) and benzene exceed cleanup levels in water and soil was not sampled. There is evidence of off site migration. five (5) borings are recommended for site and water samples should be taken from base well 52 with surface water samples obtained from ponds on site.
NOTE: Federal Facility Agreement Section 10.2 states-To the extent that this Agreement requires access to property not owned and controlled by USAF, USAF shall exercise its authorities to obtain access pursuant to Section 104(e) of CERCLA, 42 U.S.C. 9604(e), and will make every reasonable effort to obtain signed access agreements for itself, its contractors, agents, U.S. EPA, and ADEC, and provide U.S. EPA and ADEC with copies of such agreements.
With respect to non-USAF property upon monitoring wells, pumping wells, treatment facilities, or other response actions are to be located, the access agreements should provide no conveyance of title, easement, or other interest in the property shall be consummated without provisions for the continued operation of such wells, treatment facilities, or other response actions on the property.
The access agreements should also provide to the extent practicable that the owners of any property where monitoring wells, pumping wells, treatment facilities, or other response actions are located shall notify the USAF, ADEC, and the U.S. EPA by certified mail, at least thirty (30) days prior to any conveyance, or the property owner's intent to convey any interest in the property and of the provisions made for the continued operation of the monitoring wells, treatment facilities, or other response actions installed pursuant to this Agreement. |
Jennifer Roberts |
| 6/14/1991 |
Update or Other Action |
In 1991, a line leading to Building 23-714 was also found to be leaking. The fuel was recovered and the line repaired. [bInformalion on the 4-inch diesel pipeline and the 6-inch JP-4 pipeline was obtained in telephone conversations with Joe Pullyatd, USAF Liquid Fuels Office, and Clarence Jackson, USAF Fuels Management, in February 1992.] |
Louis Howard |
| 11/12/1991 |
Enforcement Agreement or Order |
Federal Facility Agreement under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) signed for docket # 1089-07-19-120. The agreement ensures that the environmental impacts associated with past and present activities at the Base are thoroughly investigated and appropriate removal and/or remedial action(s) taken as necessary to protect human health and the environment. Elmendorf Federal Facility Agreement signed.
The general purposes of this Agreement are to: (a) Ensure that the environmental impact associated with past and present activities at the Site are thoroughly investigated and appropriate removal and/or remedial action(s) taken as necessary to protect the public health, welfare, and the environment.(b) Establish a procedural framework and schedule for developing, implementing, and monitoring appropriate response actions at the Site in accordance with CERCLA, the NCP, Superfund guidance and policy, RCRA, RCRA guidance and policy, and applicable state law.
The FFA divided the CERCLA study source areas at Elmendorf AFB into the following seven operable unites (OUs), on the basis of geographic proximity and similar source characteristics or contaminants:
- OU1 Landfills (LF05, LF07, LF13, LF59, OT56)
- OU2 Tank Spill Sites (ST20, ST41, including the ST41 Sludge Disposal Area)
- OU3 Central Containment Area (SD16, SD31, SD52, SS21)
- OU4 Northern Containment Area (SD24, SD25, SD28, SD29, FT23, SSl0)
- OU5 Southern Containment Area (ST37)
- OU6 Surface Disposal Sites (LF02, LF03, LF04, SD15, SD73, WP14)
- OU7 Limited Field Investigation (SS19)
Proposed listing on NPL was 07/14/1989 and Final listing on NPL was on 08/30/1990.
See site file for additional information.
|
Jennifer Roberts |
| 11/12/1991 |
Update or Other Action |
Jennifer Roberts Federal Facility Coordinator sent letter to Joe Williamson and Rich Howard pursuant to Section 9.1 of the Elmendorf Air Force Base Federal Facility Agreement (FFA). ADEC designates Jennifer Roberts as the Project Manager and Ron Klein as the Alternate Project Manager for all activities covered under the FFA. |
Jennifer Roberts |
| 12/30/1991 |
Update or Other Action |
EPA sent letter to AF Rich Howard and Joe Williamson. The notification will serve as an addendum to the previous letter of November 4, 1991 which designates the USEPA project managers pursuant to Section 9.1 of the Elmendorf Air Force Base (EAFB) Federal Facilities Agreement (FFA). Marcia Combes will serve a lead remedial project manager (RPM) for Basewide activities, as well as Operable Units (OUs) 2, 3, 5, 6, 7. Michele Poirier-McNeill will serve as lead RPM for OUs 1 and 4. In addition both RPMs will serve as an alternative RPM on OUs for which they are not the lead. For communication and correspondence purposes, the lead RPM should be the point of contact, and the alternate should be copied. |
Jennifer Roberts |
| 3/24/1992 |
Document, Report, or Work plan Review - other |
Staff commented on the Draft Wetland Remediation System Startup Report dated January 1998 from the Air Force (AF). ADEC agrees that EPA Method 8015M will need to be modified to have detection limits lower than the cleanup levels established in the OU5 Record of Decision (ROD). However, rather than using Method 8015M, the AF may wish to use the sampling methodology found at 18 AAC 70.020 (see note 8 to the table found in regulations regarding TAH and TAqH). The AF may wish to continue to use 8015M by its labs if the lower detection limit is attainable with modification which will require ADEC and EPA concurrence. |
Louis Howard |
| 4/1/1992 |
Update or Other Action |
A small section of the pipeline in the middle of the driving range of the golf course on Elmendorf AFB also contained anomalies in pipe wall thickness and was repaired in early spring 1992. At that time, a hydrostatic pressure test was conducted on the pipeline. Fuel transport operations resumed in April 1992. |
Louis Howard |
| 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 |
| 8/7/1992 |
Update or Other Action |
CH2MHILL EAFB meeting minutes from a July 31, 1992 meeting to discuss the preliminary results of the OU5 soil gas survey field work and reach consensus among project managers on locations for placement of soil borings and groundwater monitoring wells for the next phase of the RI. Petroleum hydrocarbons generally have not been present in soil gas, potentially due to the weathering of the light end hydrocarbons.
The majority of the results of the seep samples indicated petroleum hydrocarbons preliminary results indicate heavy end hydrocarbons. The results of the soil gas survey also indicated widespread low level halogenated solvent contamination.
SS53 Golf Course Seep-petroleum contamination detected in groundwater probe sampling below Bluff Road. Soil borings/wells: 4 soil boring locations along the north side of the railroad tracks, one of these to be located at low point drain location; one soil boring/groundwater well to be installed west of golf course clubhouse; one soil boring/groundwater well to be installed north of Ship Creek midway between 2 existing wells.
SD40 Railroad Maintenance Area Spill/ST46 JP-4 Fuel Line Leak: preliminary screening indicates there is petroleum contamination; area around beaver pond was noted in ecological survey with presence of stressed vegetation and a potential decrease in number and diversity of organisms; visual observations of sediments in the area having noted petroleum sheens when the sediments are disturbed.
Soil borings and wells: soil boring located above cluster of 3 existing wells; one soil boring/well at north side of creek; one additional boring/well along north side of Ship Creek only if existing well is not suitable for sampling; one boring/well to be installed east of 2 above ground fuel tanks; and 2 wells along Ship Creek described above will be used for continuous water level measurements.
The rationale for locations of sampling along Ship Creek is to accomplish one of the objectives in the management plan- to try and determine any connections between the groundwater and surface water in the area, primarily Ship Creek. Wells, groundwater probes, temporary piezometers will be used to address this objective.
The Remedial Investigation divided OU5 into seven subareas based on geographic relationship to the suspected pipeline sources, and habitat and land use characteristics. The subareas are designated upgradient, pipeline corridor, waste paint tank, lower bluff, Post Road corridor, golf course beaver pond, and Ship Creek. The industrial area along Post Road was not investigated during this RI.
|
Jennifer Roberts |
| 3/26/1993 |
Update or Other Action |
DOD and ADEC joint Technical Memorandum of understanding signed concerning the Basewide 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...).
Also included in the file is the AF memo: Restricted Use of the Shallow Aquifer on EAFB signed by William R. Hanson P.E. GM-14 Chief Environmental Flight dated October 17, 1996 Memorandum for 3 SPTG/CEC/CEO from 3 SPTG/CEV
1) Due to the contamination and commitments to EPA/DEC the use of the shallow aquifer for any purpose on is not allowed. Attached Facilities Board minutes-03/29/1994 0930 Item 9 has Mr. William Hanson, briefing the Board on the policy to not use the shallow aquifer due to contamination. The Board approved this policy. Minutes approved by Thomas R. Case Brigadier General USAF Commander. The IRP has RODs for OUs 3 and 6 which require, the aquifer remain unused. 2) Personnel in the review process within CES must be aware of these policies and review them on a recurring basis. It is imperative this restriction be recognized and observed during engineer reviews and operations. |
Jennifer Roberts |
| 4/1/1993 |
Update or Other Action |
Source SS18 (Building 22-021) is included in Operable Unit (OU) 4 for purposes of remedial investigation at Elmendorf AFB under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Ten maintenance facilities were grouped together in OU4 for a Limited Field Investigation (LFI) during 1992. These maintenance facilities were suspected of having floor drains that emptied into dry wells, leach fields, or storm drains. Past practices at these buildings may have released hazardous substances to the environment through the floor drains and outfall structures.
Source SS18 was originally identified as a potential source of contamination in the 1983 Phase 1 record search. It is located about 850 feet south of Second Street along the east side of Maple Avenue. Building 22-021, which rests on a concrete floor, houses the pest management operations of the base. There is an abandoned floor drain in the mixing room that has been plugged with concrete
The purpose of the 1992 LFI conducted at SS18 was to identify and evaluate the drain outfalls at Building 22-021, and to assess the possible environmental impacts that may have resulted from past operations and disposal practices. The field investigation focused on soil sampling at locations of dry wells or other outfall structures. Groundwater sampling was not performed during the LFI. The results of the LFI were used to determine the final disposition of the outfalls and to recommend either No Further Action (NFA), or that a remedial investigation/ feasibility study be conducted.
As a result of the geophysical survey and soil sampling conducted at SS18, the recommended action for the outfall structure source areas investigated at SS18 is No Further Action (NFA). The primary criterion used to place floor drains and associated outfalls into the No Further Action (NFA) category at SS18 was whether the concentration of contaminants in any sample obtained during the LFI exceeded the risk-based criteria specified by the regulatory agencies. None of the soil samples collected during the LFI at SS18 contained analytes in excess of risk based criteria. The concentrations of pesticides detected during SS18 sampling are not expected to be mobile and act as an contaminant source. Groundwater was not evaluated during the LFI.
Any groundwater contamination present will be evaluated as part of the ongoing remedial investigation at Operable Unit (OU) 5. The criteria for NFA were met at each of the source sampling locations; therefore, NFA is justified for the building floor drains and outfalls at Source SS18.
The United States Air Force (Elmendorf Air Force Base), U.S. Environmental Protection Agency Region 10, and the Alaska Department of Environmental Conservation have completed a review of the information provided in the Final OU4 Limited Field Investigation Report for the source area located at Source SS18, Building 22-021, on Elmendorf Air Force Base. Based on this review, the above agencies have determined that No Further Action for purposes of investigation or study is justified for SS18. |
Jennifer Roberts |
| 8/16/1993 |
Update or Other Action |
Letter from Joseph Williamson (3 SG/CEVR) to Jennifer Roberts (ADEC) RE: Identification of State Proposed Applicable or Relevant and Appropriate Requirements (ARARs). 1. The Installation Restoration Program (IRP) at Elmendorf AFB is now reaching the point where decisions will have to be made at source areas, so it is necessary to identify all related State remedial requirements.
a. Section 121(d) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), as amended by
Superfund Amendments and Reauthorization Act, requires
selected remedial actions to attain a degree of cleanup of
hazardous substances, pollutants, and contaminants released
into the environment and of control of further release at a
minimum which assures protection of human health and the
environment. Such remedial actions shall be relevant and
appropriate under the circumstances presented by the release
or threatened release of such substance, pollutant, or
contaminant. Section 121(d) further requires attainment of
Federal ARARs and of State ARARs in State environmental or
facility siting laws when the State requirements are promulgated,
more stringent than Federal laws, and identified by the
State in a timely manner.
b. According to Environmental Protection Agency Publication
9347-3-15, Compendium of CERCLA ARARs Fact Sheets and directives, as the support agency, the State is responsible for:
(1) Receiving and reviewing information about proposed
Federal ARARs and to-be-considered's, as early as site
characterization;
(2) Coordinating State input on ARARs from all State
agencies;
(3) Identifying State ARARs during the remedial investigation/feasibility (RI/FS) study;
(4) Justifying proposed State ARARs; and
(5) Reviewing ARARs identified in the proposed plan and
record of decision.
States are always responsible for identifying State ARARs and
communicating them to the Federal-lead agency in a timely
manner.
c. A critical point for identifying ARARs is during the scoping of the RI/FS. We have reached this point on the majority of operable units (OUs). To avoid an issue of "timeliness" and prevent a delay in the scoping process, we request the State identify its ARARs with justification for OUs 1 through 6. As lead agency, the Air Force is not legally required to consider potential State ARARs that are not
identified in a "timely" manner.
d. To demonstrate that the State requirement is an ARAR, you
are required by the National Contingency Plan to provide
citations to the statute or regulation number. In addition, you
should provide the requirement's effective date and description
of scope, where appropriate. Furthermore, you should provide
evidence that the requirement is more stringent than the Federal
requirement. Finally, you should also describe in writing the
relationship between the State requirement and the site or
action, to show that the State requirement is applicable or
relevant and appropriate to that particular site or action.
2. Please provide the requested ARARs data so the information
can be used to complete the required evaluations of the source
areas in the previously-mentioned OUs.
-------------------------------------------
NOTE to the Database-EAFB FFA states: "Identification and Determination of Potential ARARs" 20.10 For those primary or secondary documents that consist of or include ARAR determinations, prior to the issuance of a draft document the Project Managers SHALL meet to identify and propose, to the best of their ability, all potential ARARs pertinent to the report being addressed. Draft ARAR determinations SHALL be prepared in accordance with Section 121(d)(2) of CERCLA, 42 U.S.C. S 9621(d)(2), the NCP, and pertinent written guidance issued by U.S. EPA and ADEC, that is not inconsistent with CERCLA and the NCP.
Also see: 20.11 In identifying potential ARARs, the Parties
recognize that actual ARARs can be identified only on a
source-specific basis and that ARARs depend on the specific
hazardous substances, pollutants, and contaminants at a source,
the particular actions proposed as a remedy, and the
characteristics of a source. The Parties recognize that ARAR
identification is necessarily an iterative process and that
potential ARARs MUST be re-examined throughout the RI/FS process until a ROD is issued. |
Jennifer Roberts |
| 11/17/1993 |
Update or Other Action |
USAF 3 SPTG/CEVR Sharon Stone letter to ADEC Jennifer Roberts. Subject: Remedial Investigation/Feasibility Study (RI/FS) for Operable Unit (OU) 5, Draft
1. Attached is a copy of the DraftRI/FS for OU5. Please review
and return comments to this office by 18 Dec 93.
2. We have attempted to identify all Federal and State ARARs for
this OU. In your comments, please advise us of any additional
Applicable, or Relevant and Appropriate Requirements (ARARs) that you believe apply to this OU, along with specific
reasons for their inclusion, as outlined in our letter to you
dated 16 Aug 93. |
Jennifer Roberts |
| 12/17/1993 |
Update or Other Action |
Letter from ADEC to USAF General Thomas R. Case 3 WG/CC Subject: Elevated Nitrate Levels in Ship Creek, Anchorage, Alaska ADEC project number 9421-WQ-347-011. ADEC obtained a copy of the AF's October 14, 1993 letter to Tom Kron of ADF&G. ADEC's review of the letter reveals that the AF has made one major error by using the Drinking Water Standards instead of Water Quality Standards to determine maximum contaminant level for nitrate.
When reviewing the same data that both parties (AF ADF&G) have provided, ADEC has to use the Water Quality Standards Regulations which state: "No person may conduct an operation that causes or contributes to a violation of the water quality standars set by this chapter. The water quality standards set by this chapter specify the degree of degradation that may not be exceeded in a water body as a result of human actions. The water quality standards are set by the anti-degradation requirement of (c) of this section, and the water chapter."
A review of ADEC's files reveals that the maximum concentration levle for nitrates in Ship Creek should range between 0.1 to 0.17 mg/L, not the 10 mg/L noted on the October 14, 1993 letter. Thus, the recorded highest nitrate level (3.42 mg/L) is approximately 20 times over the allowable maximum contaminant level for nitrates in Ship Creek. As a result, there appears to be a problem that will need to be resolved as soon as possible. To facilitate a solution for the AF, ADEC recommends that they schedule a meeting with ADEC and ADF&G by February 17, 1994. |
Kevin Kleweno |
| 1/11/1994 |
Document, Report, or Work plan Review - other |
Jennifer Roberts provided the Air Force (AF) with comments on the draft final Remedial Investigation/Draft Feasibility Study Report (RI/FS) for OU5 dated November 18, 1993. Additional evaluation of the remedial actions at the snow melt pond is requested. ADEC disagrees with the AF's proposed recommendation of no further action. The presence of PCBs are of ecological concern and ADEC would like the AF to consider the snow melt pond area as a passive constructed wetlands treatment system for the seeps in the western and central areas of OU5.
If, during construction of the wetland treatment system, the PCBs as an ecological impact are addressed, then two objectives would be satisfied by one action (*note to file-this is the first time that the Wetlands remediation system idea has been raised by ADEC).
The property boundary of the snow melt pond is located on property owned or managed by the Alaska Railroad (ARR). As discussed in our meeting on 1/10/1994, actions that take place on or may impact the property held by ARR must be coordinated with the ARR and undertaken with their permission. ADEC is in the process of contacting the ARR to discuss the need for PCB sampling of the railroad bed adjacent to the snow melt pond.
ADEC raises this issue to insure that any remedial action contingent on access and coordination with ARR is being addressed early in the remedial planning stages. Sheen is present from the pond at the base of the bluff and the text should reflect that the sheen is a violation of Alaska water quality standards.
ADEC agrees with the statement that as long as the Base maintains control over land use and that contamination does not migrate off Base, deed restrictions are a viable option to evaluate for groundwater contamination. It is ADEC's experience that deed restrictions are not effective when property is held by the private sector, since there is no mechanism in state law that supports deed restrictions for contaminated property. For that reason, ADEC does not agree with the U.S. EPA's comments.
ADEC does agree with EPA's comments regarding application of MCLs. In addition, state regulations consider all groundwater as drinking water and, therefore, MCLs (or in limited special cases, water quality standards) apply to groundwater.
In closing, after completing its review of the RI/FS for OU5, ADEC would like to make the observation that the previous agreement between EPA, DEC, and EAFB regarding the treatment of Base-wide groundwater contamination at OU5 should be reviewed and renegotiated between all 3 agencies. From the information presented by the OU5 RI/Fs, it is clear that the contamination source areas at OU5 have, for a number of reasons, been undergoing natural mitigation.
The report also indicates that passive wetlands treatment systems will address the contaminated seeps. In addition, the Base compliance monitoring of Ship Creek will insure that there is no degradation of natural water quality at Ship Creek from extremely low levels of contamination in groundwater that may be discharging directly into it.
With this information it is clear that developing an extensive and costly treatment system for groundwater at OU5 to address other operable units or two party agreement (SERA) sites' groundwater contamination may not be the best or most effective policy. Therefore, EPA, ADEC and EAFB should, with the new information provided, reexamine and renegotiate the current Base-wide groundwater agreement. |
Jennifer Roberts |
| 3/4/1994 |
Risk Assessment Report Approved |
Risk assessment as part of the final RI/FS was received and approved. The upper aquifer groundwater pathway generated non-cancer hazard index values exceeding 1.0 and total excess lifetime cancer risks equal to 1 x 10-4. The principal pathway at the Eastern area of OU5 is groundwater. Concentrations of trichloroethene (TCE) at MW06 and total fuel hydrocarbons (TFH) gasoline at GW5A also exceed the interim remedation goals of 5 ug/L TCE and 10 ug/L TFH gasoline, respectively. Monitoring well MW06 north of the bluff, yielded a sample of TCE of 52 ug/L. A sample from MW07 had a concentration of 8 ug/L of 1,1,2,2-tetrachloroethane, which does exceed an interim remedation goal of 1 ug/L.
The VOC and BTEX concentrations beneath the sourthern portion of the area my increase in the future because of greater concentrations of TCE in groundwater upgradient of MW06.
The groundwater pathway assumed future residential exposures through ingestion, inhalation of vapors, and dermal contact with upper aquifer groundwater over a lifetime. Total metals (arsenic and manganese) are the largest contributors to the groundwater risk estimates. Exposure by ingestion of the groundwater yields the highest risk values.
Under reasonable maximum exposure (RME) assumptions, organic contaminants contribute between 10-5 and 10-6 excess lifetime cancer risks for future residents through ingestion of groundwater through showering. That level of risk occurs as a result of organic contaminants in all OU5 subareas. The organic contaminants contributing to the estimated risks include gasoline- and diesel-range organics, benzene and TCE. A future residential scenario for the upper aquifer groundwater at OU5 is highly conservative. The upper aquifer at OU5 is unlikely to be used for domestic purposes because of low yield and availability of other piped water supplies. The aquifer is not currently being used at OU5.
Ecological risk: most likely impacts of contaminants on aquatic receptors in OU5 would be caused by dermal contact, absorption, or ingestion of fuel hydrocarbons, BTEX and PAHs by benthic macroinvertebrates in the golf course, beaver pond, wetland pond, and lower bluff pond. Impacts to aquatic bed plants in the golf course beaver pond and wetland pond hydrophyts by metabolic uptake of contaminants may also be a limiting factor to aquatic vegetation viability. Furthermore, PCBs (aroclor 1260) were detected in the near-shore sediment of the snowmelt pond above criteria for sediment level of concern.
However, the presence of chironomids at the water/sediment interface suggests that the contaminant in this near-shore is not biologically available, or that the taxa present are highly resistant to the contaminant (PCBs). Fish and invertebrates in Ship Creek do not appear to be at significant risk from OU5 contaminants.
Plant stress, and possibly the reduced egg-hatching success in semi-aquatic birds that nested near several surface water bodies, provided evidence of impaired ecosystem health. Causes of the plant stress could not be identified definitively, but they appear to be something other than fuel hydrocarbons. The most likely cause seemed to be mineral imbalances related to elevated manganese, and potentially cobalt, phosphorus, and pH in areas where plants showed signs of stress. The number of bird nests was not adequate to determine causes of nesting failure.
The risk characterization indicated that the most likely impacts of contaminants on terrestrial ecological receptors in OU5 would be most likely caused by: Inhalation exposure of small mammals to fuel hydrocarbon vapors when the animals were in their burrows. Dermal contact/absorption of fuel hydrocarbons by semi-aquatic mammals, birds, and wood frogs in the golf course beaver pond (or elsewhere when surface sheens are present). Metabolic uptake/inhibition effects of inorganics by plants near seeps and wetlands where plants exhibited signs of stress.
Federal ambient water quality criteria and Alaska water quality standards or fuel hydrocarbons are being exceeded in the lower bluff pond and golf course beaver pond. Water samples taken from the golf course beaver pond contained: 0.6 ug/L benzene, 0.7 ug/L toluene, 4.3 ug/L 1,1,2,2-tetrachloroethane, 6.6 ug/L trichloroethene, and 52 ug/L gasoline hydrocarbons. |
John Halverson |
| 3/4/1994 |
Site Characterization Report Approved |
Final version of the remedial investigation/feasibility study received and approved. Eastern OU5 consists of: SS53, SD40, ST46, area at top of the bluff, a bluff face less steep than in Central OU5, wetlands between the toe of the bluff and Ship Creek, and the Beaver Pond, NOTE: Aquifer Slug Testing was completed on 11 of the monitoring wells at OU5. Tests were conducted to estimate hydraulic conductivity values for the aquifer materials at wells: MW01, MW03, MW05, MW08, MW10, MW12 to MW16 and MW31. Results of the slug tests are in Appendix F of the RI.
Fly ash appears to have been used as fill along the should of the bluff in a 500 foot long area surrounding Monitoring Well SP1-02, and at least a 1,000 foot long area surrounding Monitoring wells SP2/6-03, SP2/6-04, GW-6A, SP2/6-05. Fly ash was a by-product of coal used by EAFB power plants until the late 1960s when plants were converted to natural gas. According the boring log for well SP1-02 fly ash was found from depths of 0.5 to 22.5 ft. bgs and soil with interbedded fly ash was found up to 46 ft. bgs. Fly ash is found as a continuous horizontal layer at least 8 ft. thick and 500 ft. long from SP1-02 to the edge of the bluff. By combining and extrapolating sampling results with drilling results and an inspection that identified the existence of a depression and new growth of trees, the fly ash can be interpreted to exist in a 500 foot long area that varies from 40 to 70 feet in width and is probably about 20 to 30 ft. deep. During the 1992 investigation, field confirmation was not performed for the reported fly ash around wells: SP2/6-03, SP2/6-04, GW-6A, and SP2/6-05.
Airborne volatiles near building foundations or in basements are not expected to be pathways of concern at OU 5 now or in the future because of low concentrations of volatiles and limited future building sites in the OU. Soil contamination was found only in low concentrations and at depth near the groundwater table in the pipeline corridor and upgradient subareas where current buildings are located. The groundwater throughout the OU has volatiles in the low ppb range, and soil gas studies during the RI showed few areas where volatiles were venting through the vadose zone. The bluff area is not likely to be used as building sites (as of 1994). Slope failure occurred along the bluff just west of OU 5 and near the snow disposal pond during the Alaska Quake of 1964. Also, much of the area between the bluff and Ship Creek is unsuitable for building because of standing water and areas that would probably be delineated as wetlands.
Direct air sampling was NOT done during the RI, but potential air exposures will be estimated from surface soil and surface water samples concentrations. Data from direct air measurements are seldom available from source investigations because measuring air volatiles and contaminants on particulates is a complex, expensive (as of 1994) endeavor. Other sources, such as power plants and off-base industrial activities, may also confound data obtained during air sampling.
The principal pathway in the Eastern Area of OU 5 is groundwater. Excess lifetime cancer risks to future residential receptors exceed 1 x 10-6 at the wells. Concentrations of TCE at MW06 and TFH gasoline at GW5A also exceed the interim remediation goals of 5 ug/L TCE and 10 ug/L TFH gasoline, respectively. The VOC and BTEX concentrations beneath the southern portion of the area may increase in the future because of greater concentrations of TCE in groundwater upgradient at MW06. These increasing concentrations may affect the surface water pathway through surface seeps. If volatile concentrations increase in seeps and surface water, the air pathway may be also be affected by increased concentrations of volatile compounds lost from the water surface.
The FS should focus on groundwater in Eastern au 5 because of potential health risks and exceedance of potential ARARs for groundwater. Surface water originating from groundwater seeps and sediment in the beaver pond also should be evaluated. |
John Halverson |
| 3/4/1994 |
Update or Other Action |
RI Outside of Source Areas-No further action is warranted for soils at SL16, SL19, SL25, SL27 for the following reasons: Concentrations of inorganic elements exceed soil background levels because of 2.7 to 19.5% natural organic carbon that has adsorbed the elements from water to a much higher degree than normal soils have, not because of contaminant discharge; With the exception of the near surface arsenic concentration at SL25, none of the inorganic element concentrations exceed interim remediation goals; and the arsenic concentration at SL25 is the result of naturally high arsenic concentrations in Elmendorf AFB soils and the high concentrations of organic carbon that has adsorbed the arsenic leached from soils by surface water and groundwater. The manganese concentrations at SL25 and SL27 are the result of the high concentration of organic carbon that has adsorbed the manganese leached from soils by surface water and groundwater. In addition, the manganese measurements at these locations have a high bias, indicating the actual concentrations are likely to be lower than reported. |
Louis Howard |
| 6/6/1994 |
CERCLA Proposed Plan |
Final Proposed Plan received.
Soil
Gasoline and diesel fuel are present in the soil at concentrations exceeding regulatory standards at two locations in OU5: at a location 10 - 12feet below the bluff face in the western end and at a seep in the middle of the operable unit. The source of the fuel was a leak in fuel pipelines. The leaks have been repaired.
Surface Water and Sediments
A small hydrocarbon sheen was observed on the surface of Snowmelt Pond and low concentrations of polychlorinated biphenyls (PCBs) were discovered in its sediments. The source for the sheen is a seep that enters the pond from the bluff. The source of the PCBs has not been identified.
Low concentrations of TCE were found in the Beaver Pond surface water. The TCE source probably lies well to the north of the Beaver Pond and is not associated with OU 5.
Groundwater
Only the upper aquifer has contaminated groundwater. Two plumes of impacted groundwater have been located in the upper aquifer:
• In the western area, an approximately 1,000 foot wide plume contains TCE, jet fuel, diesel fuel, gasoline, and benzene. The TCE is from a suspected upgradient source.
• At the eastern end of the operable unit, an approximately 1,000 foot wide plume contains gasoline and TCE. The TCE is suspected to be from an upgradient source.
SD40 and ST46 are located in the Eastern Area of OU5. The groundwater (GW) is impacted in the eastern end of OU5 with gasoline and TCE. TCE suspected to be from an upgradient source. The Eastern Plume consists of fuel constituents at 260 ug/L (cleanup standard is 10 ug/L) and trichloroethene at 52 ug/L (cleanup standard is 5 ug/L).
Eastern Area was not identified as having soil contamination in the Proposed Plan (PP). Surface water and sediment were identified as being contaminated. The Beaver Pond is in the Eastern Area of OU 5. Trichloroethene was identified as a contaminant for surface water at the Beaver Pond at a maximum concentration of 6.6 ug/L (5 ug/L is the cleanup standard).
The preferred alternative is Alternative 2: Wetlands/Passive extraction wtih a constructed wetland for seeps/isolation of Snowmelt Pond Sediments/Excavation, biopiling, and backfilling for soil, Natural Attenuation with Institutional Controls (ICs) for groundwater and Naturally attenuating seeps at the Beaver Pond. Seep water would be passively extracted from the upper aquifer before it reaches the seeps. Contaminated GW will be channeled to an engineered wetlands where biological processes would remove most of the contaminants from the water.
The elements of the preferred alternative achieve these objectives at a reasonable cost. A constructed wetland for seeps is included because it could effectively treat the seep water at a low cost and it serves a dual purpose of treating sheens on the Snowmelt Pond and isolates contaminated sediment. Biopiling is included because it could remediate the contaminated soil quickly, and at a reasonable cost, and is easily combined with the installation of passive seep water extraction wells. Finally, natural attenuation with institutional controls for groundwater would provide adequate exposure protection without the technical problems associated with active groundwater treatment alternatives.
It is extremely unlikely that future residents would use contaminated water from the upper aquifer for drinking and showering. None of the upper aquifer wells are being used for any purpose and none are expected to be used in the future. Furthermore, it is highly unlikely that residences would be constructed along the bluff since it is an industrial area. This reinforces the selection of natural attenuation with institutional controls for groundwater. |
Jennifer Roberts |
| 6/23/1994 |
Meeting or Teleconference Held |
Public meeting was held to discuss and take comment on the Proposed Plans for Final Remedial Action at Operable Units 2 and 5. |
Jennifer Roberts |
| 6/24/1994 |
Update or Other Action |
Determination of No Further Action (NFA) Source SS53: Soil samples collected at 3 borings did not show any detectable levels of petroleum or halogenated organic contamination in the vadose zone. In the saturated zone, below the GW table, petroleum hydrocarbons were detected in boring SB26.
JP-4 & diesel-range organics were detected at 165 & 172 mg/kg, respectively, at a depth of 25’ below surface at the GW table. Benzene, toluene, ethyl benzene, & xylene compounds were also detected at concentrations less than 1 mg/kg. This boring is located approximately 15’ from the low point water drain pit on the JP-4 pipeline where the 1982 leak occurred. It is likely that this pipeline leak was responsible for the petroleum seeps observed along Post Road that comprise Source SS53.
Given that the suspected source of contamination for Source SS53 is the low point water drain pit, these observations suggest that the leaking product migrated downward to the water table & did not create a large secondary source area of contaminated vadose zone soils. Two other borings located along the pipeline near Source SS53 did not yield any detectable contamination in the vadose zone.
It is likely that vadose zone contamination from the pipeline leak was localized & left a relatively small footprint as fuel products percolated rapidly downward through the sandy soils. Given the age of the leak (more than 10 years) & the relatively porous subsurface soils, it is also likely that vadose zone contamination has already been attenuated by natural processes such as flushing or biodegradation. This is based on studies that were done that show most of the petroleum-derived hydrocarbons reach ultimate biodegradation within a year with the exception of benzenes whose half lives range between 140 to 1400 days. (Dragun, 1988) (Knox, et. el., 1993). Therefore, it does not appear that vadose zone soil at Source SS53 is acting as a significant secondary source for GW contamination.
Soil contamination & groundwater/saturated soil contamination were evaluated separately in the RI. The OU5 feasibility study will address risks posed by GW, while this document will support taking NFA on vadose zone soils.
Validated chemical data from the 1992 RI was used in the quantitative human health evaluation. The environmental values to be protected & considered in the risk assessment for aquatic & terrestrial receptors included the integrity of wildlife habitats, no significant impacts of environmental contaminants in OU 5 on wildlife species, & compliance with federal or state applicable or relevant & appropriate requirements (ARARs).
Contaminated soil near the low point water drain pit at Source SS53 occurs only at the water table, 25’ bgs. Consequently those contaminants do not present a risk to human health through ingestion, inhalation, or dermal contact. Terrestrial receptors (plants or animals) are also not at risk from the vadose zone soils for the same reason. No aquatic receptors are found at the source area.
The baseline risk assessment for OU 5 also estimated risks from exposure to GW, sediment, & surface water. These media will be further evaluated as part of the feasibility study for OU 5.
Selected Action:
Based on the findings of the 1988 RI/FS, & the 1992 RI, No Further Action (NFA) is recommended for the vadose zone soils at Source SS53. The primary criterion that was used to place the source area into the NFA category was whether the level of contaminants in any vadose-zone soil samples exceeded risk-based criteria specified in the human health & ecological risk assessments.
No detectable levels of petroleum or halogenated organic contamination were found in vadose-zone soil samples during the 1988 & 1992 investigations. Therefore, no risk-based criteria for human & ecological receptors or regulatory actions levels were exceeded. Petroleum hydrocarbons were detected at Source SS53 in the saturated soil layer during the 1988 & 1992 investigation, which indicates residual contamination of the saturated soil & GW beneath the source areas. This contamination will be addressed by the OU 5 feasibility study.
FINDINGS OF NO FURTHER ACTION
The Federal Facility Agreement initiated a RI of source area SS53 within OU 5 at Elmendorf Air Force Base, Alaska. The U.S. Department of the Air Force (Elmendorf AFB), U.S. Environmental Protection Agency Region 10, & the Alaska Department of Environmental Conservation have completed a review of the information provided in the OU 5 RI Report for the vadose zone soils at Source SS53. Based on this review, the 3 agencies have determined that NFA purposes of investigation or study is justified for the vadose zone soils at this source area. GW & saturated soil contamination beneath & downgradient of Source SS53 was evaluated as part of the feasibility study for OU 5.
Signed by
USAF Patrick M. Coullahan
EPA Marcia Combes
ADEC Jennifer Roberts 8/4/1994 |
Jennifer Roberts |
| 8/5/1994 |
Update or Other Action |
June 1994 Determination of No Further Action Sources SD40 and ST46 signed on August 4, 1994 by EPA, USAF and ADEC. The purpose of the document is to explain the rationale for no further action (NFA) to be taken on soils within the vadose zone at Sources SD40 and ST46. The Federal Facility Agreement (FFA) initiated a remedial investigation (RI) of source areas SD40 and ST46 within OU5 at Elmendorf Air Force Base (EAFB). The U.S. Air Force (EAFB), U.S. Environmental Protection Agency (EPA), and the Alaska Dept. of Environmental Conservation (ADEC), have completed a review of the information provided in the OU 5 RI Report for the vadose zone soils at Sources SD40 and ST46.
Based on this review, the above agencies have determined no further action for purposes of investigation or study is justified for the vadose zone soils at these areas. Groundwater and saturated soil contamination beneath and downgradient of sources SD40 and ST46 WILL be evaluated as part of the feasibility study for OU 5. Signed by Patrick Coullahan Lt. Col USAF Base Civil Engineer, Marcia Combes EPA project manager, Jennifer Roberts ADEC project manager on August 4, 1994.
The Eastern Area of OU 5 extends from the eastern side of the waste paint tank to the eastern edge of source ST46. Source areas SS53, SD40, and ST46 are located in this area. Eastern OU 5 includes an area at the top of the bluff, a bluff face less steep than in Central OU 5, and wetlands between the toe of the bluff and Ship Creek.
The most significant feature in the wetlands is the Beaver Pond. Source SD40 is near the railroad tracks, approximately 600 feet north of Ship Creek at the golf course Beaver Pond area. Source ST46 was a JP-4 leak discovered in 1978 along the banks of a small stream north of two 840,000 gallon JP-4 fuel storage tanks. The leak was a result of a crack in an underground JP-4 pipeline. After the pipeline was repaired and replaced with an aboveground section, fuel continued to seep from the bank into the golf course beaver pond and Ship Creek.
Surface water, sediment and groundwater sampling were performed as part of the OU 5 RI field work. Upgradient wells sampled: OU5MW-06 had 52 ug/L trichloroethene. OU5MW-07 had 13 ug/L trichloroethene, 8 ug/L 1,1,2,2-tetrachloroethane. Beaver Pond: SW04 had 6.6 ug/L trichloroethene.
The primary criterion that was used to place the source areas into the NFA category was whether the concentration of contaminants in any vadose zone soil samples exceeded risk-based criteria specified in the human health and ecological risk assessments. No detectable levels of petroleum or halogenated organic contamination were found in vadose zone soil samples during the 1988 and 1992 investigations. Therefore, no risk-based criteria for human and ecological receptors or regulatory action levels were exceeded. Also the existence of a railroad maintenance facility at SD40 has never been confirmed.
Petroleum hydrocarbons, however, were detected in the saturated soil layer, which indicates residual contamination of the saturated soil, sediments, and groundwater beneath the source areas. Groundwater contamination has also been detected in upgradient wells, indicating that there is an upgradient source. This contamination will be addressed by the OU 5 remedial investigation/feasibility study during 1993.
Decision documents NFRA (no further response actions)
Site ID Source name, date written, Date signed
SS18 Building 22-021 1 April 1993 7 May 1993
SD26 Hangar 14/Building 43-550 1 April 1993 7 May 1993
SD27 Building 42-300/Hangar 8 1 April 1993 7 May 1993
SD30 Building 21-900 1 April 1993 7 May 1993
ST38 JP-4 Fuel Line Leak, Bldg. 22-010 24 June 1994 4 August 1994
SD40 Railroad Maintenance Area Oil Spill 24 June 1994 4 August 1994
SS42 Diesel Fuel Spill, Bldg. 22-013 24 June 1994 4 August 1994
ST46 JP-4 Fuel Line Leak 24 June 1994 4 August 1994
SD52 Cherry Hill Ditch 20 August 1993 20 August 1993
SS53 Golf Course Seep 24 June 1994 4 August 1994
SS63 Classic Owl, Bldg. 52-140 8 September 1994 27 September 1994
SS22 DRMO Storage Facility 25 September 1991 November 1991 (FFA) (REOPENED)
RW17 Radioactive Waste Site 25 September 1991 November 1991 (FFA) |
Jennifer Roberts |
| 11/17/1994 |
Document, Report, or Work plan Review - other |
Jennifer Roberts provided comments to the AF on the draft final OU5 Record of Decision (ROD). Additional detailed comments were verbally provided to the AF during a conference call between EPA, AF, and ADEC project managers on November 17, 1994. Reference to intrinsic remediation should be changed to read "natural attenuation" to be consistent with the OU5 Proposed Plan. Decide whether the term "cleanup goals" vs. "cleanup standards" should be consistently used in the document. Due to contamination left in place at OU5, it will be necessary to have the standard 5 year review.
Please add the reference in the Statutory Determinations section and Section 5.0 the Selected Remedy. Chemical Specific ARARs: The maximum contaminant concentration levels (MCLs) established for drinking water by 18 AAC 80.070 (drinking water) are applicable to groundwater as a chemical specific regulation. Waters discharged from the constructed wetland at the Snowmelt pond are considered a non-domestic wastewater since they have undergone treatment prior to discharge. Therefore this discharge is subject to the chemical specific discharge levels in Alaska non-domestic wastewater regulations, 18 AAC 72.500 and the water quality criteria listed in 18 AAC 70 (Water Quality Standards) as it applies to non-domestic wastewater discharges. For petroleum contaminated soil that will be removed and remediated, it is appropriate and relevant to apply the NON-UST Contaminated Soil Cleanup Levels guidance under 18 AAC 75 Oil Pollution Prevention Requirements. Use of this guidance is consistent with ADEC policy for petroleum contaminated soil at EAFB from both UST and NON-UST sources and, therefore, it is consistent to apply this guidance to OU5 soils.
Location Specific ARARs: Due to the work in the snowmelt pond (dredging and filling), it is possible that the Corps 404 Wetlands Policy may apply. This issue should be researched to see if the 404 Wetlands is an ARAR. Action specific ARARs: It is appropriate to apply Alaska Wastewater regulations (18 AAC 72) for the water treated by the constructed wetland at the Snowmelt pond. Due to the treatment of the water, it would be considered a non-domestic wastewater discharge and therefore subject to the substantive requirements of 18 AAC 72.500-72.600 and 18 AAC 70 Water Quality Standards, as it applies to non-domestic wastewater discharge. |
Jennifer Roberts |
| 11/18/1994 |
Document, Report, or Work plan Review - other |
The Department has reviewed the draft final Operable Unit 5 (OU5) Record of Decision (ROD)
for Elmendorf Air Force Base (EAFB) dated October 1994. The department has the following
significant comments that should be incorporated into the final OU5 ROD. Additional detailed
comments were verbally provided to EAFB during a conference call between EPA, DEC, and
EAFB project managers on November 17, 1994
GENERAL COMMENTS
The reference to "intrinsic remediation" should be changed to read "natural attenuation" to be
consistent with the OU5 proposed plan. The document inconsistently uses the terms "clean-up goals" and "clean up standards", which creates confusion. Due to contamination left in place at OU5, it will be necessary to have the standard 5 year review. Please add the reference in the Statutory Determinations section and Section 5.0, the Selected Remedy.
Through out the document there are multiple unclear references to the "beaver pond" and
"snowmelt pond". The document would read better if a clear description of the beaver pond and
snowmelt pond were expanded in the Section 1.0 Site Description. The information should
explain the significance of the wetlands, ecological, and how the local hydrogeology is related to the wetlands.
Section 5.1.2, Applicable or Relevant and Appropriate Requirements (ARARs)
Chemical-Specific ARARs
The Maximum Contaminant Concentration Levels (MCLs) established for drinking water by 18
AAC 80.070 (Drinking Water) are applicable to groundwater as a chemical-specific regulation.
The waters discharged from the constructed wetland at the Snowmelt pond are considered a
non-domestic wastewater since they have undergone treatment. Therefore this discharge is
subject to the chemical specific discharge levels in Alaska Non-domestic Wastewater Regulations,
18 AAC 72.500 and the Water Quality Criteria listed in 18 AAC 70 (Water Quality Standards) as
it applies to non-domestic wastewater discharges.
For petroleum contaminated soil that will be removed and remediated, it is appropriate and
relevant to apply the Non-UST Contaminated Soil Cleanup Levels guidance under 18 AAC 75,
Oil Pollution Prevention Requirements. Use of this guidance is consistent with department
policy for petroleum contaminated soil at Elmendorf AFB from both UST and non-UST sources
and, therefore, it is consistent to apply this guidance to OU5 soils.
Location-Specific ARARS
Due to the work in the snowmelt pond (dredging and filling), it is possible that the COE 404
Wetlands policy may apply. This issue should be researched to see if 404 Wetlands is an ARAR.
Action-Specific ARARS
It is appropriate to apply Alaska Wastewater Regulations (18 AAC 72) for the water treated by the constructed wetland at the Snowmelt pond. Due to the treatment of the water, it would be
considered as a non-domestic wastewater discharge and therefore subject to the substantive
requirements of 18 AAC 72.500-72.600 and 18 AAC 70, Water Quality Standards, as it applies to
non-domestic wastewater discharge |
Jennifer Roberts |
| 12/7/1994 |
Update or Other Action |
Mgt. Action Plan Appendix G No further Action Documents.
Source area SD40 is included in OU5 for purposes of remedial investigation at Elemndorf AFB under CERCLA. It is located near the railroad tracks, approximately 600 feet north of Ship Creek at the golf course beaver pond area. A records search in 1983 indicated that quantities of brownish oil were observed seeping out of the bank into a marsh area. The source of the oil is unknown. As part of the USAF IRP, investigations were conducted at source areas SD40 and
ST46 (located to the east of SD40) in 1984, 1986-1987, and 1988. During this time soil and groundwater samples were collected, surface water and sediment samples were collected from Ship Creek, and monitoring wells were installed.
In 1992, SD40 and ST46 were investigated as part of the remedial investigation for OU5. During the RI, groundwater seeps and surface water drainage patterns were mapped, groundwater levels were measured, a water use survey was conducted, and a baseline human health and ecological risk assessment was conducted. As a result of these investigations, the recommended action for vadose zone soils at SD40 is NFA.
The primary criterion that was used to place SD40 in the NFA category was whether the concentration of constituents in any sample obtained during the RI exceeded the risk-based criteria specified by the regulatory agencies. No soil samples collected in the vadose zone during the RI at SD40 were found to contain analytes in excess of risk-based criteria. The criteria for NFA were met at each of the source sampling locations; therefore, the recommended action at SD40 was NFA. Contamination found in surface water, sediments and groundwater are attributed to source areas unrelated to SD40 that will be investigated further under the OU5 RI/FS.
The NFA document for SD40 was signed on 4 August 1994. Site SD40 was considered closed with the signing of the NFA document.
----------------------------------------------------
Source area ST46 is included in OU5 for purposes of remedial investigation at Elemndorf AFB under CERCLA. It is located near the railroad tracks, approximately 600 feet north of Ship Creek at the golf course beaver pond area. ST46 was a JP-4 fuel leak discovered in 1978 along the banks of a small stream north of two 840,000-gallon JP-4 fuel tanks. The leak was a result of a crack in an underground JP-4 pipeline. After the pipeline was repaired and replaced with an
aboveground section, fuel continued to seep from the bank.
As part of the USAF IRP, investigations were conducted at source areas ST46 and SD40 (located to the west of ST46) in 1984, 1986-1987, and 1988. During this time soil and groundwater samples were collected, surface water and sediment samples were collected from Ship Creek, and monitoring wells were installed.
In 1992, SD40 and ST46 were investigated as part of the remedial investigation for OU5. During the RI, groundwater seeps and surface water drainage patterns were mapped, groundwater levels were measured, a water use survey was conducted, and a baseline human health and ecological risk assessment was conducted. As a result of these investigations, the recommended action for vadose zone soils at ST46 is NFA.
The primary criterion that was used to place ST46 in the NFA category was whether the concentration of constituents in any sample obtained during the RI exceeded the risk-based criteria specified by the regulatory agencies. No soil samples collected in the vadose zone during the RI at ST46 were found to contain analytes in excess of risk-based criteria. The criteria for NFA were met at each of the source sampling locations; therefore, the recommended action at ST46 was NFA. Contamination found in surface water, sediments, and groundwater are attributed to source areas unrelated to ST46 that will be investigated further in the OU5 RI/FS.
The NFA document for ST46 was signed on 4 August 1994. Site ST46 was considered closed with the signing of the NFA document.
See site file for additional information. |
Louis Howard |
| 1/9/1995 |
Update or Other Action |
OU5 Groundwater Modeling Report received. The objectives of the modeling task were to: Evaluate the movement of contaminants across Elmendorf AFB and within Operable Unit (OU) 5; Predict contaminant migration over the next 30 years; and Determine if selected receptor points along Ship Creek and an unnamed beaver pond will be impacted by contamination. A 3 dimensional finite element model (SALT) developed at the University of Waterloo was selected because of its versatility in handling complex geology and boundary conditions. Radian Corporation modified the model to improve the program's efficiency and to include contaminant decay and site specific boundary conditions along Ship Creek. This modified version called SALT 3, consists of groundwater flow and contaminant transport models. The hydrogeology of the modeled area was evaluated using lithologic data collected from all available boreholes within the modeled area and water level data collected from shallow water table monitoring wells in March and September 1993.
After a review of the groundwater quality data from September 1993 groundwater sampling and available OU 1, 2, and SERA site data, benzene and trichloroethene were selected as representative compounds for this modeling effort. Benzene and TCE were selected due to their potential health impacts. As metals and semivolatile compounds were only sporadically detected at concentrations near maximum contaminant levels (MCLs) they are not constituents of environmental concern in much of the aquifer beneath EAFB and were not modeled.
Concentrations in the recharge over the water table was set to zero except for at source areas. Since improvement in soil quality is expected over time, the sources were assumed to cease contributing benzene and TCE to groundwater after five years. All concentrations in the recharge zone were therefore set to zero at the end of the first five years.
The conclusions of the base case simulations show that benzene and TCE will migrate toward the south. However, the concentrations of these contaminants will decline over time. Because of infiltration, there may be some localized areas that experience a temporary increase in concentration as a "pulse" migrates toward the south. Benzene will be detectable in groundwater for over 20 years, however, the concentrations in groundwater basewide should be below the MCL after 15 years (1993-2008). NOTE: this decrease in benzene has not occurred due to the overly optimistic model or additional sources contributing to the benzene concentrations in groundwater or a combination of both. TCE concentrations will be detectable in groundwater after 30 years (2023) and should be less than the MCL basewide after 20 years (2013).
Benzene and TCE will spread and migrate toward the south from identified source areas. Concentrations in groundwater flowing toward Ship Creek and the unnamed beaver pond should not exceed 1 ug/L over the period modeled. The model predicts that the concentrations of these compounds in groundwater near surface water bodies will be approximately 1 ug/L after 5 years (1998) and will then steadily decline over time. The results of the groundwater modeling effort indicate that the groundwater can be remediated naturally (MNA) in all OUs without any predicted increase impact to sensitive receptors in OU5. The model predicted, that in five years, benzene and TCE concentrations in OU5 from upgradient sources will be above 1 ug/L but less than 10 ug/L. In 10 years (2003), the concentration of these compounds is predicted to be less than 1 ug/L in OU5, indicating a measurable improvement in water quality over time. |
Jennifer Roberts |
| 2/1/1995 |
Cleanup Level(s) Approved |
Groundwater: TCE 5 ug/L and TFH-Gas 10 ug/L Surface water: TFH-Gas 10 ug/L |
Jennifer Roberts |
| 2/1/1995 |
CERCLA ROD Approved |
Record Of Decision (ROD) was signed by Janice Adair. At Source Area SS53-No Further Action (NFA) is warranted for the soil pathway due to the following: TFH diesel, JP-4, and BTEX were detected in SB26 at 25 to 27'; TFH diesel in near soil was only 2 mg/kg; Detected concentrations pose less then 1 x 10-6 cancer risk and have a Hazard Index (HI) less than 1 for non-cancer risk; and Contaminant concentrations do not exceed ARAR or TBC levels.
Source Areas SD40 (formerly known as SP-4) and ST46 (formerly known as SP-11)-NFA for the following reasons: Detected concentrations in all soil samples pose less than 1 x 10-6 cancer risk and have a HI less than 1 for non-cancer risk; COC concentrations do not exceed ARAR or TBC levels; and there are no identifable effects of contaminants on aquatic biota or terrestrial plants and animals.
Beaver Pond-Remedial actions were evaluated for the surface water pathway for the following reason: A TFH gasoline concentration of 52 ug/L exceeds the Alaska Surface Water Quality (ASWQ) ARAR of 10 ug/L (Total Aromatic Hydrocarbons-TAH) and TCE exceeds the MCL ARAR of 5 ug/L.
The selected remedy includes passive extraction of seep water, natural attenuation for upper aquifer and surface water, institutional controls for upper aquifer water and sampling of water and sediment. ICs that prohibit use of the upper aquifer will ensure that people will not be exposed to contaminated GW until cleanup goals are met. ICs on land use and water use restrictions will restrict access to the contaminated groundwater throughout OU 5 until cleanup levels listed in Table 3-6 of the ROD have been achieved.
NOTE TO FILE: § 300.430 Remedial investigation/feasibility study and selection of remedy.(a) General—(1) Introduction. The purpose of the remedy selection process is to implement remedies that eliminate, reduce, or control risks to human health and the environment. Remedial actions are to be implemented as soon as site data and information make it possible to do so.
Accordingly, EPA has established the following program goal, expectations, and program management principles to assist in the identification and implementation of appropriate remedial actions.
(iii) Expectations. EPA generally shall consider the following expectations in developing appropriate remedial alternatives:
(D) EPA expects to use institutional controls such as water use and deed restrictions to supplement engineering controls as appropriate for short- and long-term management to prevent or limit exposure to hazardous substances, pollutants, or contaminants. Institutional controls may be used during the conduct of the remedial investigation/feasibility study (RI/FS) and implementation of the remedial action and, where necessary, as a component of the completed remedy.
The use of institutional controls shall not substitute for active response measures (e.g., treatment and/or containment of source material, restoration of ground waters to their beneficial uses) as the sole remedy unless such active measures are determined not to be practicable, based on the balancing of trade-offs among alternatives that is conducted during the selection of remedy.
Groundwater will be monitored to estimate the rate of natural attenuation, to provide an early warning of potential off-site contaminant migration, and to ensure protection of human health and the environment.
GW, seep water, and surface water will initially be sampled on a quarterly basis. Sediment will be sampled annually. Results from the monitoring program will be assessed annually for at least the first 5 years to determine if cleanup levels have been achieved. If cleanup levels have not been achieved, aggressive actions such as air sparging with SVE or active extraction with air stripping may be necessary. Bioventing of the soil is an additional option that could treat soil contamination.
Remedial Action Objectives (RAOs): Protect human health by preventing ingestion and contact with contaminated groundwater by people and preventing animal contact with contaminated seep water; Use treatment techniques whenever practicable; Implement a solution that is capable of managing impacts from upgradient sources as contaminants reach OU 5; and Implement a cost effective solution that can achieve cleanup levels for the final COCs. |
Janice Adair |
| 2/1/1995 |
Institutional Control Record Established |
ICs established by signing of ROD and subsequently been enforced by land planning department at the Base and environmental restoration staff oversight.
No current receptors exist for the groundwater at the Base due to the institutional controls (ICs). As a requirement of previously signed RODs for the Base, ICs have been established to restrict the use of the shallow aquifer in the outwash plain on Base. These restrictions are enforced through the Base Comprehensive Plan (BCP).
Projects and other activities are reviewed during the planning stage to ensure compliance with the BCP. In addition, construction projects and other activities also undergo an environmental review. This review helps ensures compliance with groundwater use restrictions. |
Jennifer Roberts |
| 2/1/1995 |
Conditional Closure Approved |
Record of Decision (ROD) memorialized decision that the soils do not require further action since they have been excavated to matrix cleanup levels for existing source areas. Based on the remedial investigation (RI) results, No Further Action (NFA) Decision Documents were prepared, signed and approved in August 1994 for the soil in the potential source areas in OU 5 except ST37, the western area diesel leak. The NFA sites which include SD-40, ST-46, SS-53, also included SS-42, ST-38.
No further action is warranted for the soil pathway for the following reasons: TFH-diesel, JP-4, and BTEX compound concentrations were detected in SB26 at a depth of 25 to 27 feet and is related to groundwater contamination; TFH-diesel concentration in near surface soil at SL20 was only 2 mg/kg; Detected concentrations pose less than 1 x 10 -6 cancer risk and have a Hazard Index less than 1 for non-cancer risk; and Contaminant concentrations do not exceed potential ARAR or TBC levels.
SD40 and ST46-No further action is warranted for soil pathway for the following reasons: Detected contaminant concentrations in all soil samples pose less than 1 x 10 -6 cancer risk and have a Hazard Index less than 1 for non-cancer risk; COC concentrations do not exceed potential ARAR or TBC levels; and There are no identifiably effects of contaminants on aquatic biota or terrestrial plants and animals.
However, the groundwater is contaminated above maximum contaminant levels (MCLs) and requires long-term groundwater monitoring. The greatest concentration of TFH occurs in the "smear zone" near the water table at SB26. This smear zone is likely resulted from fuel contaminants that migrated to a higher water table and were left in the vadose zone or capillary fringe as the water table receded. The smearing of hydrocarbons may occur between season as the water table rises and falls. Groundwater beneath Eastern OU5 contains compounds that have migrated to the bluff face and beyond to well GWA. |
Jennifer Roberts |
| 3/8/1995 |
Update or Other Action |
Operable Unit 3 Remedial Investigation/Feasibility Study approved contingent upon being monitored as part of OU 5 monitoring. Groundwater monitoring data will be collected from monitoring wells at OU 3 to ensure that groundwater from OU 3 will not impact the sensitve receptors at OU 5. The Basewide groundwater monitoring plan describes the monitoring locations, sampling frequency, analytical parameters, and reporting format. Since potential future impacts will be monitored (as part of OU 5 long-term monitoring), no further action is planned for this site (08-Mar-1995 OU 3 RIFS Report 7.6.5 Conclusions). |
John Halverson |
| 4/10/1995 |
Update or Other Action |
Ray Burger sent letter to AF regarding the Time Extension on OU5 Remedial Action. Since a formal agreement on acquiring necessary access to the property is still pending, despite Air Force diligence, ADEC agrees that good cause for this extension exists pursuant to Section 26.1 (Force Majeure) of the FFA. |
Ray Burger |
| 4/17/1995 |
Update or Other Action |
USAF sent action memorandum regarding State Concern about source of contamination at or near SS57 and SS62. One of John Halverson's comments, dated 28 February 1995, on the draft SERA Phase I corrective action plan was the possible lack of continuity between the CAP and the RI/FS for OU3. The comment questioned where the source was on a trichloroethylene (TCE) hit in the groundwater at or near SS57 and SS62.
During a meeting with the meeting on April 5, 1995 with Mr. Halverson, Mayer, and Underbakke, they agreed that the monitoring wells up gradient and down gradient of SS62 would be placed into our long-term monitoring program. These wells will be monitored to establish a trend in the TCE concentrations. Date from the monitoring wells will be gathered for a minimum of four rounds of biannual sampling (two years). At the end of this sampling period, the four sample rounds will be used to establish a trend and a decision made if the source still exists. The wells that will be included in these rounds of sampling will be up gradient: OU3MW11, 49MW02, at site: 48WL01 and 48WL03; and down gradient: OU5MW-01, SP1-02 and OU5MW-02. Sampling of wells 49WL02 and 48WL01 is pending funding. |
Jennifer Roberts |
| 5/3/1995 |
Document, Report, or Work plan Review - other |
ADEC J. Halverson sent comment letter to USAF J. Williamson & C. Mayer 3 SUG/CEVR RE: Review Comments SERA Phase I Corrective Action Plan April 1995.
NO FURTHER ACTION CANDIDATE SITES-Based on information that has been provided to date, closure of the following sites with
regard to soil contamination is warranted. If in the future contaminated soil or groundwater are generated at the sites it will need to be handled in accordance with the applicable laws
and regulations. Separate closure letters should be prepared for the sites in order to document them for the record.
ST69 - Diesel Leak (Building 76-520, UST #525)-Section 2.11.7 - The second sentence states cleanup efforts at the time of the tank removal successfully prevented soil contamination. Based on discussion with other program staff, it is my understanding that when the tank was removed a large volume of soil was excavated (to the depth of the water table) and hauled off-site. Therefore, it would be more appropriate to state that contaminated soil as "removed", rather than "prevented", during excavation of the tank.
Section 2.11.9 - The first paragraph states it appears ST41 is the source of groundwater contamination beneath ST69. Based on the information that petroleum contaminated soil was excavated to the depth of the water table at the time the UST was removed, it appears the former UST is the likely source of groundwater impacts rather than ST41.
Assessment work after the tank removal and excavation of soil has not located petroleum contaminated soil above the watertable at this site, however, the elevated concentration of benzene in the groundwater warrants further monitoring. Therefore, the department does not object to a no further action (NFA) decision under SERA for soil at ST69 based on the CONDITION that monitoring well 46WL01 be added to the Basewide Groundwater Monitoring program. |
John Halverson |
| 6/15/1995 |
Site Ranked Using the AHRM |
Score = 200. Initial ranking. Action code added because it wasn't when the site was originally ranked. |
Louis Howard |
| 7/31/1995 |
Update or Other Action |
SERA Phase II Site Assessment Report FINAL. Initial objective of the site assessment was to characterize the quality of soil and groundwater at sites with potential POL contamination in terms of the extent and degree of contamination. The secondary objective was to recommend further actions for each site: Closure Outright, Transfer further consideration to an adjacent unit, Closure through a risk assessment, Cleanup through *natural attenuation, Active cleanup following the remedy selection program. Sites covered by document: ST32 29 USTs by Northjet, by Hangar 1, 2, 3 Sites: SS50, Avgas Spill, ST68 Fuel Line Leak, ST48 Diesel Fuel Line Leak, ST67 Bldg. 11-400 Jet Fuel Leak, and SS49 Mogas Spill. ST74 UST at NOAA facility by North of Oil Well Rd., and ST66 Bldg. 62-255 Diesel Leak by Bldg. 62-255.
Conclusions-Based on 9 soil borings-The only soil contamination identified in this site assessment was associated with groundwater in the zone of seasonal fluctuation. Groundwater-Highest concentrations were found in samples from 60WL04 and ST20-01, although no free product was noted. Results from ST20-01, ST20-02, and 60WL01 indicate elevated levels of benzene. Source of hydrocarbon contamination appears to be the contaminated groundwater and smear zone contamination remaining from the 1991 fuel line rupture. ST48 is within the area encompassed by OU5 groundwater modeling zone and the contamination modeled for this area, including site ST20, is comparable to the levels found at ST48 during the SERA Phase II investigation.
*Results of the basewide groundwater modeling at ST48/ST20 attenuate upgradient of Ship Creek. Based on the minimal present and future health risks, natural attenuation is the recommended corrective action for ST48. Petroleum hydrocarbon concentrations in the zone of water table fluctuation will eventually decline through dissolution and degradation. It is recommended the results of the ST48 SERA II investigation be incorporated along with the OU5 natural attenuation program. Inclusion within the OU5 natural attenuation program may require including some ST48 wells within the ongoing basewide groundwater monitoring program. |
John Halverson |
| 12/8/1995 |
Document, Report, or Work plan Review - other |
EPA provided comments on the OU 3 draft ROD dated October 1995. The following comments apply to the October draft final, which will under further changes and review based on the results of the treatability study at SS21. Part I. Declaration, Assessment of the site, first paragraph (redline/strikeout version): The last sentence should be replaced with the following:
"Groundwater risks at OU3 are within EPA's acceptable risk range (less than 10-4) under a future residential use scenario, which is considered conservative. On that basis, it was determined that further remedial action for groundwater is not required. Groundwater at OU3 will continue to be monitored under the Base's Comprehensive Groundwater Monitoring Program until cleanup levels are achieved and institutional controls will restrict access to the groundwater throughout OU3."
|
John Halverson |
| 3/7/1996 |
Meeting or Teleconference Held |
Minutes from 7 March 1996 Conference Call. OU3 The project schedule will be completed today and distributed to the agencies Monday, March 11. Steve will be working to coordinate the delivery of the schedule to Tim Brincefield at EPA in Seattle.
OU5- Radian has not had any action items since completing the Alaska Railroad crossing permit. The Base design of the COMM line extension is complete and Kerry will pick up the drawing from Kim today. We will provide comment on the design. The RFP amendment for the COMM line is due out on March 27, we
need to have our comments prior to the March 17 so we don't delay the end of the bid period. Ross noted the plans for the COMM line are only being reviewed for compatibility of with the communications needs of the autodialer. This process should only take about 2 hours to complete. As soon as Skip receives the
drawing he will get the review process started.
Michelle noted the RFP for the construction work is on the street; there are currently 120 prospective bidders responding. Ross asked Michelle who should be contacted if Radian should receive calls from prospective bidders. Michelle stated the bidders should be instructed to contact her at (907) 552-9762 or Michelle Jones 552-3969 in base contracting with any questions. No one else should attempt to answer any questions while the bidding is still open. |
John Halverson |
| 4/3/1996 |
Update or Other Action |
Memorandum from Air Force received on the Time Extension on OU5 Remedial action. Attachment B to the Remedial Design/Remedial Action (RD/RA) scope of work states that the RA at OU5 is to begin on May 1, 1996. Based upon delays caused by the need to comply with statutes and regulations governing the acquisition of property, the AF anticipate that they will need a 60 day extension to commence construction of the remedial action.
In order to construct the RA at OU5, the AF needs the use of the property owned by the Alaska Railroad (ARR). More than 1 year ago, the Army Corps of Engineers (COE) began negotiations with the ARR to acquire the use of their property. Despite assurances from the ARR that they intend to lease the required property to the AF, a formal agreement has not yet been finalized. The obstacle to finalizing their agreement has primarily been clauses in the agreement proposed by the ARR which violate federal government contracting statutes.
The AF has diligently attempted to resolve differences with ARR. The AF has adjusted road construction and parcel size to meet their requests. It appears that the issue of compensation has been resolved; however, the exact language of the agreement has not yet been completed. On approximately March 2, 1996 the COE, on behalf of the AF, provided the ARR another proposed agreement. Based upon the comments from the Arr.'s vice president in charge of real property, the AF believe they are very close to reaching agreement; however, as on numerous occasions in the past, it is proving difficult to obtain a response from the ARR. As of March 26, 1996, the last proposed agreement was still under review in the ARR's legal office.
Pursuant to Section 25.1 (Extensions) of the Federal Facility Agreement, the Air Force requests a 60 day extension to begin construction of the remedial design. Good cause for this extension exists pursuant to section 26.1 (Force Majeure) of the FFA and the need to comply with the federal government contracting requirements. |
Ray Burger |
| 4/17/1996 |
Meeting or Teleconference Held |
Restoration advisory board meeting held and announced in the Anchorage Daily News 4/14/96 and the Sourdough Sentinel 4/12/96. |
Ray Burger |
| 6/24/1996 |
Update or Other Action |
Easement between the Air Force (AF) and Alaska Railroad Corporation (ARRC) was signed by the AF (Frank Destadio Colonel USAF Civil Engineer HQ Pacific Air Force) on June 24, 1996 and the ARRC Vice President, Real Estate and Facilities John G. Burns. ARRC Contract Number 7114/USA Contract Number DACA85-9-96-90 for the sum of $147,000.00 granted an easement in and to ARRC's property to be used for the purpose of remediating certain contamination associated with Operable Unit 5. The ARRC does not object to the ROD and the AF will not seek or agree to any change in the FFA, ROD, Remedial Design without prior notice and opportunity to comment being afforded to the ARRC.
Duration of the easement is temporary and rights granted shall terminate upon completion of the remediation required by the ROD but shall not extend beyond April 1, 2026. The AF will give the ARRC not less than sixty days prior written notice of its intent to terminate the easement. Subject to existing property rights, ARRC reserves the right of ingress and egress from the easement area and the right to enter any part of the property including structures thereon, for the purposes of inspection at any reasonable time, and in time of emergency.
The AF shall not grant to any person or entity permission to use the easement area for any purpose other than environmental remediation set forth in the ROD. ARRC specifically reserves the right to grant permission to others to use and occupy the real property subject to this easement. As to Parcel 5, said use and occupancy will not unreasonably interfere with the AF's use of the easement. As to Parcels 1 through 4, said use and occupancy will not interfere with the AF's use of the easement as determined by the AF in its sole discretion, which will be exercised reasonably and in good faith. However, no conveyance of title, easement or other interest in the property shall be consummated without provisions for the continued operation of the treatment facilities or other response actions on the property as required by the ROD.
To the extent practicable, the ARRC shall notify the AF, ADEC, and the EPA by certified mail, at least thirty (30) days prior to any conveyance, of the ARRC's intent to convey any interest in the property and the provisions made for the continued preparation of monitoring wells, treatment facilities, or other response actions installed pursuant to the ROD. This easement runs with the land and is binding upon any successors in interest to either party hereto. Total acreage is 12.891 acres: Parcel 1, 2.063 acres; Parcel 2, 0.390 acres; Parcel 3, 7.224 acres; Parcel 4, 0.582 acres; and Parcel 5 2.632 acres all located in the U.S. Survey Number 9112 and Number 9017, Sections 8 and 9 of Township 13 North, Range 3 West, Seward Meridian, Anchorage Recording District, Municipality of Anchorage, Third Judicial District. |
Jennifer Roberts |
| 6/27/1996 |
Site Ranked Using the AHRM |
Site reranked because it was on the Top 30 List. GW Exposure Index Value changed from 2 to 1. Score now = 123. |
Ray Burger |
| 7/15/1996 |
Long Term Monitoring Established |
Remedial action started which includes long term monitoring of the groundwater at Operable Unit 5 source areas which serves as the catch-all for the majority of groundwater on Base in the glacial outwash plain. |
Ray Burger |
| 9/12/1996 |
Update or Other Action |
EPA's Meeting summary of the September 12, 1996 meeting-Decisions reached by Air Force (AF), U.S. Environmental Protection Agency (EPA), and Alaska Dept. Environmental Conservation (ADEC).
1. AF/EPA/ADEC agree that institutional controls (ICs) are necessary to ensure that contaminated shallow groundwater aquifer is not used. There is now a basewide prohibition (AF please cite) on use of the shallow aquifer which appears to be an adequate IC, therefore no additional ICs area required
specific to OU3. OU3 ROD will note the need for ICs and the existence of the Basewide ICs and groundwater monitoring program, and that since they are in place, no further action is necessary under the OU3 ROD.
In summary, the ROD will say:
a. All sources have been addressed;
b. No current receptors for contaminated groundwater;
c. No potential receptors in OU3 areas;
d. Potential receptors are in OU5 area, which has a remedy in place to deal with them, plus ICs and a monitoring program;
e. Basewide ICs and groundwater monitoring are in place and will continue until MCLs have been achieved.
2. AF/EPA/ADEC will research whether the actions that have taken place at SD52, SD16, etc. allow for unrestricted use. If not, some ICs may be necessary. This includes consideration of whether deep contamination remains at levels which would pose unacceptable risk in the event of future excavation, and if so, whether some ICs should be added to protect in the event of such an occurrence.
3. In addition, ADEC raised the question of ICs on deep soils with high concentrations (didn't show risk because no curren exposure/receptors; concern is for proper handling/disposal in event of future excavation). |
John Halverson |
| 9/16/1996 |
Update or Other Action |
EPA comments on OU3 ROD which have not been addressed and summary of decision reached at a September 12, 1996 meeting. 5 Year Review: The purpose and focus of the 5 Year Review described in the draft ROD is not clear. Since SS21 soils will be remediated to levels which allow for unrestricted use, 5 Year Reviews will only be necessary for OU3 soils if the early actions elsewhere in OU3 (SD52, etc.) left contaminants in place above levels that would allow for unrestricted use. Based on the plan for
addressing groundwater we discussed, there should be no need for a review of groundwater under the OU3 ROD either. If groundwater is NOT addressed as we discussed, there MAY be a need for a review.
Groundwater: Since constituents in groundwater remain above MCLs, the ROD must clearly explain why No Further Action is appropriate. OSWER Directive 9355.0-30 "Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions" states the following: "Where the cumulative carcinogenic risk to an individual based on reasonable maximum exposure for both current and future land use is less than 10-4 and the non-carcinogenic
hazard quotient is less than 1, action is GENERALLY NOT warranted UNLESS there are adverse environmental impacts. However, if MCLs or nonzero MCLGs are exceeded, action is generally warranted."
Since MCLs are exceeded in groundwater associated with OU3, more explanation is required in this ROD to justify a No Further Action decision. As we discussed, this could be done by adding ALL of the following explanation to the draft ROD:
a. MCLs are exceeded, thus some action, specifically Institutional Controls and Monitoring, is warranted;
b. All known sources have been removed (provide details in Chapter 3);
c. There are no current receptors of contamianted groundwater in OU3;
d. Potential receptors downgradient are already being addressed by the OU5 ROD and OU5 actions which have taken place;
e. Basewide Institutional Controls are already in place to prohibit use of the contaminated shallow aquifer and prevent future use (provide citation);
f. Groundwater is now and will contiue to be monitored as part of the Basewide Monitoring Program. The Safe Drinking Water Act is relevant and
appropriate ARAR for this decision and includes the monitoring parameters
and cleanup goals that will be used in the Basewide Monitoring Program;
g. Thus, No Further Action is necessary for groundwater in the OU3 ROD.
ADEC expressed a concern that there should be some provision to ensure testing and proper disposal of contaminated subsurface soil in the event of development. Due to the nature of the contamination (Fuels) , this does not appear necessary to address in this ROD, but rather should be worked out between the Air Force and ADEC.
Section 4.0 needs to be better explained: Why action is necessary. That OU3 sources of contamination to groundwater have been identified and addressed. That there are no current or expected future receptors of contaminated groundwater within OU3 (due to basewide ICs, citing something other than the
OU5 ROD). The basis for concluding that Natural Attenuation is occurring (Are contaminants declining, or what? How long is it expected to take?). That No Further Action is necessary for groundwater, because Basewide ICs AND Monitoring are already in place and WILL continue until groundwater meets
MCLs.
The Safe Drinking Water Act needs to be identified in section 5.1.2 ARARs to show it was considered, even though it is not an ARAR for the selected action. EPA suggests an explanation be added such as "The SWDA is not an ARAR for this remedy, since No Further Action is necessary for groundwater under the OU3 ROD.
HOWEVER, it is the ARAR for the Basewide Monitoring
Program and the groundwater actions selected in the OU5 ROD to protect downgradient receptors. If further action to protect groundwater is ever necessary, it WILL be done pursuant to the OU5 or OU6 RODs." |
John Halverson |
| 10/31/1996 |
Update or Other Action |
Construction of the engineered wetlands system located at the southern end of Elmendorf AFB was completed in October 1996. The system was constructed to enhance natural chemical, physical, and biological processes to reduce contamination concentrations in seep waters to below cleanup levels. The initial construction included four seep collection areas, three pump stations, the overland flow cell (OFC) and the wetland cell. The primary source for the seeps is believed to be from POL fuel lines that historically ran along the top of the OU 5 bluffs.
Water from seeps 1 through 4 flows through gravel beds, into buried perforated collection pipes, and into a pump station. The seeps flow to pump stations located at the base of the bluff as follows: seeps 1 and 2 to Pump Station 1, seep 3 to Pump Station 2 and seep 4 to Pump Station 3. The water is pumped from the pump stations along the base of the bluff to the OFC, which is centrally located above the bluff. The water then flows throught the OFC (an inclined bed of gravel), where the water is oxygenated and volatilization of the aromatic hydrocarbons can occur. From the OFC, the oxygenated water flows by gravity to the wetland cell located below the bluff. The water then flows through the wetlands, where naturally occurring biologic processes remove any remaining contaminants be before the water is discharged and eventually flows into Ship Creek. Seeps 1, 2, 3, and 4 provide seep water loading to the WRS through collection areas at the pump stations. |
Jennifer Roberts |
| 1/3/1997 |
Update or Other Action |
Excavation and off-site disposal of soils containing PCBs greater than 5 mg/kg. GW is impacted in the shallow aquifer and institutional controls (ICs) exist at the base for the shallow aquifer and GW monitoring of selected wells within OU3 is included as part of OU5 GW monitoring. The ICs against use of the shallow GW at the base is through the EAFB facility board and the Base
Comprehensive Plan (BCP). Projects and other activities are reviewed during the planning stage to ensure compliance with BCP and also undergo an environmental review to ensure compliance with GW use restrictions. |
Louis Howard |
| 6/16/1997 |
Update or Other Action |
USAF Memorandum to ADEC regarding Clarifications to OU2 ROD. The letter is a follow-up to the discussions regarding institutional controls at OU2. The USAF hopes by this correspondence, to clarify appropriate land use controls at OU2 and setup a land use restriction method consistent with the most recent Elmendorf RODs. The OU2 ROD states that groundwater at ST41 needs remedial action and a part of the selected remedy was to restrict land use by implementing zoning controls. The Summary of the ROD on page 9-2 states that the selected remedy includes "Zoning the affected area for industrial use only, excluding the development of commercial aquaculture."
However, the Declaration of the ROD states "Zoning the affected area for undeveloped outdoor/recreational use only." In light of this contradiction and the use of "restricted use areas" under the RODs for OU3 and OU6 the USAF is providing clarification of the permissible land uses within the area affected by ST41 groundwater. The affected area should include those areas that exceed the groundwater cleanup levels established in the OU2 ROD. A map of the area currently and potentially impacted by the contaminated groundwater from ST41 is at attachment 1. This map may be revised based upon review of the contamination remaining in place, which will be conducted at least every 5 years. While the affected area remains above cleanup levels, it will be designated as a "restricted use area" in the base Planning Office.
This designation provides for recreational use of the parcel (such as cross country skiing, bicycling, etc.) and the construction of unmanned facilities (such as parking lots, storage buildings, etc. ) but prohibits the construction of any manned facilities (such as office buildings or a residence). Construction activities within the affected area of OU2 will be restricted to construction of unmanned facilities. Furthermore no construction will be allowed which comes within five feet of the groundwater. Existing industrial uses within OU2 are allowed as they are unmanned. This description conforms to the current base land use planning terminology and is consistent with the recently signed RODs for OUs 3 and 6. Land use restrictions will be enforced by the following method. When there is a construction project on Base, the project is to be approved by the Base Planning Office. The planner will route all projects through the Environmental Management Office. The project will be disapproved if it conflicts with the above construction restrictions. The USAF believes this will be a reliable and effective means of enforcing the zoning land use restrictions imposed by the various RODs. Signed by Randy E. Honnet Colonel USAF Vice Commander. |
Louis Howard |
| 2/20/1998 |
Document, Report, or Work plan Review - other |
EPA Tim Brincefield and ADEC Louis Howard project manager inspected the revised IC documentation February 20, 1998 at the Base and concurred that the controls were in place, and were operational and functional. |
Louis Howard |
| 4/20/1998 |
Document, Report, or Work plan Review - other |
Staff commented on the Air Force's (AF) Operable Unit (OU) 5 Surface Water Quality Analyses at EAFB. ADEC has the following comments regarding the use of fuel ranges, 18 AAC 70.020 and lab methods for determining cleanup levels for surface water. Since Alaska Water Quality Standards (AWQS) do not specifically address JP-4, TFH-diesel, or TFH-gas, it is more important for the AF to utilize lab methods which will detect the levels present in surface water for total aqueous hydrocarbons (TAqH) and total aromatic hydrocarbons (TAH).
ADEC requests the AF use the sample methodology found in Alaska Water Quality Standards (AWQS) for freshwater uses 18 AAC 70.020 (see note 8 to the table) for determining cleanup levels in surface water. The explanation regarding analysis of TAqH and TAH instead of specific fuel ranges is best served by inclusion in the "Lessons Learned" section of the remedial action report for OU5. It is ADEC's determination that the use of alternative lab methods vs. EPA method 8015M does not change the selected remedy found in the Record of Decision (ROD) nor does it change its overall protectiveness. |
Louis Howard |
| 5/1/1998 |
Update or Other Action |
Based on discussions in May 1998 between the Alaska Department of Environmental Conservation (ADEC), U.S. Air Force (USAF), and U.S. Environmental Protection Agency (USEPA), the analytical list was changed from EPA Method 8015M to include EPA Methods 602 for benzene, toluene, ethylbenzene, xylene (BTEX) and 8310 for PAH. Both methods have detection limits below 10
ug/L and allow for analysis of fuel hydrocarbon components. The lower detection limits have allowed for improved monitoring of contaminant concentrations that may exit the system in the effluent water.
No elevated contaminant concentrations were reported exiting the Wetland Remediation System (WRS) during the 1997-1998 Operations & Maintenance period. Analytical methods for Nitrate-Nitrite and Total Phosphorus were also updated. The methods are now Method E353.2 for Nitrate-Nitrite and E365.3 for Total Phosphorus. The new analytical methods do not quantify the identified contaminants of concern (COCs) specified in the OU 5 record of decision (ROD) (USAF 1995a), but are appropriate for determining contaminant levels and monitoring the effectiveness of the wetland system.
Since the new analytical methods do not quantify all of the specified COCs, clean-up levels from
the Alaska Water Quality Standards, 18 AAC 70.020, are utilized for comparison purposes. The Alaska Water Quality Standards for petroleum hydrocarbons, oils and grease contamination concerns for growth, and propagation of aquatic and wildlife specify 10 (ug/L maximum concentration for Total Aromatic Hydrocarbons (TAH) and 15 gg/L maximum concentration for Total Aqueous Hydrocarbons (TAqH). TAH and TAqH concentrations were determined from the BTEX (E602) and PAH (8310) analytical results. TAH concentrations were determined by summing the concentrations of all detected BTEX. TAqH concentrations were determined by summing the concentrations of all detected PAHs and BTEX compounds. These clean-up levels are required for the Wetland Cell effluent. |
Louis Howard |
| 8/5/1998 |
Update or Other Action |
The Record of Decision specified analyses total fuel hydrocarbons (diesel and gasoline)-TFH-Diesel and TFH-Gas were revised in 1998 to total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) for Operable Unit 5. Because there was no standard for these (TFH) contaminants of concern in groundwater, and because the groundwater emerges as surface water at the seeps that eventually ends up in Ship Creek (an aquaculture receptor), the aquaculture water standards for TAH and TAqH were used (18 AAC 70.020 ecological risk). |
Louis Howard |
| 10/1/1998 |
Update or Other Action |
Wetland Remediation System Startup Report: During the OU 5 investigation, TFH-Gas concentrations were measured as high as 400 ug/L in the samples collected from where the seeps emerge from the ground. During the Startup Period, the highest concentration of TFH-Gas measured in the samples collected from the pumpstations was 59 ug/L (Pumpstation 1, fifth sampling round). Assuming the concentration of TFH-Gas in the seep water at its point of emergence from the ground is approximately the same now as it was during the OU 5 investigation, there is approximately an 85% reduction in TFH-Gas concentrations as the seep water travels to the pumpstations.
During the original OU 5 investigation, jet fuel concentrations detected in the seep water, and used in the original design calculations, were as high as 770 ug/L. As with TFH-Gas, this significant reduction is because the seep water collected during the OU 5 investigation was taken from where the seeps "daylight" out of the ground, and the seep water collected from the pumpstations travels from where the seeps "daylight", through a wide, open, gravel channel prior to entering the pumpstations. It is apparent that there is significant volatilization of and degradation of contaminants occurring during this time. The degree to which it is occurring was unexpected during the original design.
During the original OU 5 investigation in 1993, a significant sheen was seen on the seep water as it emerged from the ground. As with TFH-Gas and jet fuel, significant volatilization and
degradation of contaminants is occurring from the time the seep water emerges from the ground until the time it enters the pumpstations, resulting in a lack of sheen on the water collected at the pumpstations during the Startup Period.
Overall, results from the Startup Period of the WRS show that the system is performing as designed. However, a few discoveries were made that will help to optimize future performance of the
system. First, original calculations of wetland cell retention times did not take into consideration additional input from seeps which emerge in the wetland cell. Also, assumptions about the required
minimum retention time in the Wetland Cell were incorrect. It is apparent, when comparing the analytical results to the change in retention time in the Wetland Cell, that there is a critical average
retention time of eight days.
Second, as seen by the lack of sheen on the seep water at the pumpstations, it is apparent that a significant amount of volatilization of contaminants is occurring from the time the seep water emerges from the ground to the time it is collected at the pumpstations. A decrease in the contaminants from traveling through the gravel prior to reaching the pump stations was expected from observations during the projects' design. However, its effectiveness was not estimated as part of the design.
Third, cleanup levels for OU 5 are well below established detection limits for the analyses that were approved in the Workplan for analysis of water samples from the system.
Based on the discussions in May 1998 between the U.S. Air Force (USAF), U.S. Environmental Protection Agency, and Alaska Department of Environmental Conservation, the analytical list was
changed to include EPA Methods 602 for BTEX and 8310 for PAH. Both methods have detection limits below 10 pg/L. The detection limits allow for improved monitoring of contaminant concentrations that may exit the system in the effluent water. |
Jennifer Roberts |
| 10/20/1998 |
CERCLA ROD Periodic Review |
Five-Year Remedy Review conducted by U.S. EPA, USAF, and ADEC staff to ensure that the remedial actions selected in the Record of Decision for the operable unit remains protective of public health, the environment and are functioning as designed. The start of construction of the OU2 Interim Remedial Action (IRA) on August 5, 1993 triggered this review requirement. Response actions at the OU are ongoing, all remedial actions are operational and functional as documented in the OU's remedial action report.
All required institutional controls have been established and incorporated into the Base General Plan and the management action plan. Site conditions and land use are consistent with the OU's ROD requirements and remain protective, based on evaluation of current monitoring data and trends.
Future Five Year reviews are necessary because contamination remains above levels that allow for unrestricted use and/or unlimited exposure at the operable units. The next five year review will be completed by August 2003.
Note to file:
Interim Actions
The purpose of the IA-OUs at the EAFB are to achieve early actio using remedial authority at
those sites which meet the IA deneral principles that are discussed in the NCP. If at anytime the information submitted to suppo-t the IA is found to be equivalent to that obtalned during an Rl/FS and the OU is separable, then he IA may be upgraded to an early final action.
The Preamble of the NCP, 55 Federal Register 8703-8706 (March 8, 1990) states that to Implement
an early action under remedial authority, an operable unit for which an interim action is appropriate is identified. IA decisions are intended for straightforward sites that are limited in scope.
Data sufficient to support the interim action decision is extracted from the ongoing RI/FS or from previous studies and an appropriate set of alternatives is evaluated. Few alternatives and in some cases only one should be developed for interim actions. A completed basellne risk assessment generally will not be available or necessary to justify an interim action. |
Louis Howard |
| 11/4/1998 |
Meeting or Teleconference Held |
Restoration Advisory Board meeting held to discuss: Update on completed Five-Year Remedy Review, review of 1999 Restoration projects, new alternate community co-chair selected, review of contingency planning for fuel spills and update on 1997 spills, review of asbestos and lead-based paint management procedures, poster displays: Summer 1998 restoration projects, ENVVEST, areas of concern, Elmendorf homesteaders. |
Louis Howard |
| 9/29/1999 |
Update or Other Action |
site information updated since street addresses and building numbers have been changed by the Base. |
Louis Howard |
| 11/15/1999 |
Update or Other Action |
OU5 Round 2 groundwater sampling received. TCE exceeded the MCL (5 ug/l) at five well during the 2nd round and 1st round of sampling. At 48-WL-03 the TCE increased slightly from 1998 levels of 33 ug/l to 35 ug/l. At OU5MW-07 TCE levels increased slightly from 20 ug/l to 21 ug/l. Benzene was below the MCL in all wells. Surface water sampling in the Beaver pond at SC-3 for TCE was at 4.8 ug/l in round 2 which is slightly lower than in round 1 at 6.6 ug/l. |
Louis Howard |
| 1/10/2000 |
Update or Other Action |
10/99-12/99 quarterly progress report received. Continued long-term operation and maintenance of wetland remediation system. Continued surface water sampling of wetland system with no detectable contaminants of concern have been discharged from the wetland system. Round 2 results received - 5 wells exceed MCL for TCE and surface water concentrations were below 5 ug/L. Target date to meet soil, surface water quality standards and groundwater cleanup levels for TCE, benzene, and petroleum contaminants is October 2025. |
Louis Howard |
| 2/28/2000 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Base-wide monitoring and well maintenance program annual technical memorandum. Staff requested that the three agencies review the wells which had been destroyed, damaged or otherwise lost from the monitoring program. Additional wells may be needed to replace them if suitable replacements cannot be used. |
Louis Howard |
| 8/7/2000 |
Update or Other Action |
2000 Groundwater monitoring results received. Methyl tert-butyl ether (MTBE) was added to the analyte list and was not detected in any wells. TCE exceeded the MCL in 6 well locations and benzene was not above the MCL in any well. |
Louis Howard |
| 10/19/2000 |
Update or Other Action |
OU5 Base-wide Groundwater Monitoring report received for Round 2. Benzene was below MCLs for 1999 and 2000. TCE was above MCL of 5 ug/L in 2000 for sampling rounds 1 and 2 respectively: 48-WL-03 (23 and 25 ug/L), GW-4A (5.1 and 8.4 ug/L), OU5MW-02 (9 and 8.1 ug/L), OU5MW-06 (28 and 26 ug/L), OU5MW-07 (22 and 18 ug/L) SP1-02 (19 and 30 ug/L). |
Louis Howard |
| 11/13/2001 |
Update or Other Action |
The Air Force has requested that URS further investigate the presence of trichloroethylene (TCE) in the OU5 Wetlands area through the sampling of upgradient groundwater wells. TCE was found in the seeps at the base of the bluff area southwest of the U.S. Corps of Engineers (USCOE) building on Elmendorf Air Force Base.
A method employing the use of a water-filled passive diffusion bag (PDB) will be used in this investigation. The PDB samplers typically consist of a 1- to 2-ft long low-density polyethylene (LDPE) lay-flat tube closed at both ends. The samplers contain deionized water enclosed in a LDPE sleeve and are deployed adjacent to a target horizon within a screened or open interval of a well. The amount of time the PDB should be left in the well depends on the time required for the sampler to equilibrate with the well water, contaminant distribution, and flow dynamics. Laboratory and field data suggests a period no less than 2 weeks. At the end of the sampling period the bags are to be removed and the water placed in sampling vials for analysis.
In order to determine the extent of contamination, a PDB will be used to investigate groundwater quality upgradient from the seeps. The samplers will be placed in the following upgradient wells; OU5MW-3, 403-MW-01, SP2/6-01, and 700-WL-01. A PDB will be placed in each well and will remain for a period of 14 days. These PDB’s will be weighted and placed approximately 1 foot above the bottom of the screened interval to maximize possible TCE intake. On the 14th day each bag will be removed and the water retained from them will be immediately transferred to 40-milliliter sampling vials for analysis. |
Louis Howard |
| 1/28/2002 |
Update or Other Action |
Staff commented on the Wetland Remediation System report. The text states the overall point of compliance for evaluation of cleanup levels is Ship Creek. The Alaska Water Quality Standards (AWQS 18 AAC 70) must be met in the surface water and the groundwater cleanup levels (18 AAC 75) need to be met in the groundwater. The AWQS apply to: The effluent from the wetland remediation system (WRS) and the groundwater, which emanates from the bluffs as seeps and is not captured and subsequently treated by the WRS.
Table 2-2 System Components Potentially Non-Protective of Human Health and the Environment Page 2-2
The text states groundwater at seeps 9, 10, and 11 are exceeding cleanup levels at the seeps. The potential exists for exceedance of cleanup levels at the point of compliance (Ship Creek). Again, it must be stressed that the Alaska Water Quality Standards must be met in all surface water and by not incorporating the seeps into the WRS, the Alaska Water Quality Standards are not being met.
The report’s recommendations are to continue monitoring at these seep locations, an upgradient soil gas investigation, and increased groundwater monitoring at upgradient monitoring wells. This temporary solution, if delayed beyond 2002, does not meet the ROD criteria that the selected remedy be protective of human health and the environment and utilize permanent solutions (see 5.1 Statutory Determination). Should the 2002 monitoring data for the seeps demonstrate contaminants remain above action levels, ADEC prefers seeps 9, 10 and 11 be incorporated into the WRS in a timely manner.
The ADEC recognizes that funding for incorporation of any additional seeps into the WRS is not likely to be available in the immediate future. Also, there is the issue of the Alaska Railroad’s expansion of its railroad yard, which may impinge upon the timing of incorporation of the new seeps into the WRS. Until the Railroad expansion work is completed, the ADEC is willing to continue to work with the EPA and AF on addressing Seeps 9, 10, and 11 in the most appropriate manner while continuing to be protective of human health and the environment.
2.2.2 Newly Identified Seeps Page 2-4
The text states the water from Seep 9 is mostly draining into the wetland cell; however some water appears to be bypassing the system and is flowing into the drainage that captures water originating from Seeps 10 and 11, thereby not being treated by the WRS. By allowing these seeps to continue to bypass the WRS, the Air Force is essentially choosing to implement the Alternative 1 “No Action” approach identified in the OU 5 ROD. This approach would not be as protective as incorporating the seeps into the WRS because people and environmental receptors would continue to be exposed to contaminants present in the groundwater seeps until it eventually degrades to acceptable levels. Continued monitoring of Seeps 9, 10 and 11 would not result in reduction in toxicity, mobility, and volume through active treatment.
See site file for additional information. |
Louis Howard |
| 1/28/2002 |
Update or Other Action |
Memorandum of understanding (MOU) signed by S. Bainbridge and L. Pearson (PERP) Alaska Department of Environmental Conservation (ADEC) and Elmendorf Air Force Base, Alaska (EAFB). It was agreed that it is in the best interest of both organizations to implement pre-approved release response and remedial action plans, hereinafter referred to as "presumptive remedies", for certain petroleum, oil and lubricant (POL) spills in the outwash plain portion of EAFB.
This MOU establishes and describes four such pre-approved presumptive remedies. This MOU does not establish an exclusive set of cleanup options, and nothing in this memorandum prohibits EAFB from seeking or obtaining ADEC approval to implement alternative release response and remedial action plans.
This MOU does not apply to any spills impacting surface waters.
For spills which occur on, or to the south of the southern boundary of the unit identified in Attachment 1 (a.k.a. Early Warning Line), EAFB reserves the right to petition ADEC to include these spills in this MOU if it believes the presumptive remedies defined herein would be protective of human health and the environment.
The distance between the Early Warning Line and Ship Creek represents the theoretical average distance over which groundwater would flow in two (2) years. This distance was selected because it represents the minimum possible time that the Air Force would require to obtain funding for an active seep capture or other remedial activity to prevent effect to Ship Creek. The actual distance in feet was calculated by using boring logs and groundwater gradient data. Soil permeability was determined by using published values for soil types encountered in soil borings. Conductivity values from an OU 5 pump test were also considered. From these data, a range of average linear velocity for groundwater was calculated. Velocities ranged from approximately 7 feet per year to approximately 1,000 feet per year. The Early Warning Line was drawn at the conservative end of this range and represents an average linear velocity of approximately 1,000 feet per year. Therefore, the Early Warning Line, as shown in Plate 1, is located approximately 2,000 feet upgradient of Ship Creek.
The requirements of this MOU under the scenarios described apply only to POL spills that occur on or after the date it is signed by both parties. If petitioned by EAFB, ADEC will consider historical sites for inclusion into this MOU on a case by case basis.
For any other POL spill that does not conform to one of the four cases described herein, EAFB and the ADEC will, in consultation, determine which current or future regulatory requirements apply. Nothing herein relieves, extends or changes the applicable requirements of 18 AAC 75 and 18 AAC 78 for the proper treatment, storage, or disposal of contaminated media that result from the implementation of this MOU. |
Steve Bainbridge |
| 2/21/2002 |
Update or Other Action |
Staff reviewed and commented on the base-wide groundwater monitoring report.
Regulatory Levels
ADEC requests removing the word “Potential” from the heading “Potential Regulatory Level” in the tables throughout the document. Listing the word “Potential” gives the reader the impression that compliance with the levels listed is optional or not required (e.g. Tables 4-7, 4-11, 4-15, 4-20, 4-25, 4-29, 4-32, and 6-2).
Free Product
Please note 18 AAC 75.325(f) states: A responsible person shall to the maximum extent practicable,
(A) use permanent remedies;
(B) recover free product in a manner that minimizes the spread of contamination into an uncontaminated area by using containment, recovery, and disposal techniques appropriate to site conditions.
ADEC recognizes that in some cases it may not be technically practicable to implement an active or passive recovery system for free product. The Elmendorf Remedial Action Report for Operable Unit (OU) 2 (September 1998) set a precedent for defining what is meant by “technically practicable” for free product recovery. Section 2.4.1 Product Recovery Endpoints at the 1st bullet on page 10 states: “As designed and constructed, the ST41 ground water treatment system cannot recover floating product when there is less than a measurable thickness of 0.1 feet of product. Therefore, as an endpoint for product recovery, if less than 0.1 feet is sustained for one year, recovery at that source can be discontinued. Floating product will be measured monthly. When product thickness falls below 0.1 feet for one year, the recovery of product at that source will not be considered “technically practicable”.
Therefore, where free product is greater than 0.10 feet, ADEC expects corrective action (active or passive) to be implemented for free product recovery. Currently, free product was found to exceed 0.10 feet or more in SERA Phase I well 43-WL-11. This well had the highest level of free product measured at 0.86 feet. The presence of measurable free product is generally not considered conducive for intrinsic (natural) attenuation. ADEC requests the identity of the free product be described in the text at each source area that it is found (e.g. gasoline, diesel, or chlorinated solvents).
3.3.4 Target Analytes Pages 3-10 and 3-11
Benzene and TCE are identified as target analytes to evaluate contaminant of concern (COC) trends in detail and be consistent with the Base-wide Groundwater model. ADEC concurs, however, focusing on these two analytes does not accurately reflect whether diesel range organics (DRO) and gasoline range organics (GRO) plumes are migrating, expanding, steady state, or receding (especially for wells noted to have either free product or fuel odor and/or sheen being observed during sampling). Benzene can be at low levels or even non-detectable while concentrations of DRO and GRO remain above cleanup levels (1.5 mg/L and 1.3 mg/L respectively). Please see the following examples below of where benzene was below the 5 ug/L cleanup level, but DRO and GRO are above cleanup levels.
OU 4
Round 1 sampling at well 49-WL-01 detected benzene at 0.11 ug/L and DRO at 2,400 ug/L and well OU4W-11 detected benzene at 4.3 ug/L while GRO was detected at 3,000 ug/L and DRO was detected at 6,100 ug/L.
OU6
Round 1 sampling at well OU6MW67 detected benzene at 2.8 ug/L, GRO at 2,500 ug/L and DRO at 1,700 ug/L during round 1 sampling. During round 2 sampling, well OU6MW-91 detected GRO at 25,000 ug/L and DRO at 9,500 ug/L while benzene was found to be non-detectable.
See site file for additional information. |
Louis Howard |
| 4/30/2002 |
Update or Other Action |
Basewide Environmental Monitoring Plan received.
2.5 Soil Gas Survey
A Gore-sorber® survey and passive diffusion sampling was performed in December 2001 at four
wells in the OU 5 source area (403-MW-01, 700-WL-01, OU5MW-03, and SP2/6-01). Both the sorber
and PDBs results indicated that the extent of contaminated soil and/or groundwater was concentrated in the area surrounding 403-MW-01. To confirm the levels of contamination detected in December 2001 and further investigate the possible source, a select number of sorbers will be placed within the area of 403-MW-01.
Additional sorbers will be installed around Building 4314, the most likely source of the chlorinated hydrocarbon contamination detected during the December 2001 investigation. Following analysis of the Gore-sorber®, up to two monitoring wells will be installed as step-out locations from areas with highest elevated detections during the soil-gas survey to further define extent of contamination and monitor migration.
A4.1.4 Operable Unit 5
All wells will be sampled according to the procedures outlined in this FSP. All of the wells in
the traditional OU 5 sampling program are affixed with dedicated sampling devices, and will be sampled accordingly via low-flow sampling techniques outlined in Section A4.2.1. The additional early warning wells will be also be sampled according to the procedures outlined in this FSP. These wells will be sampled according to the technique outlined in Section A4.3 using passive diffusion bags (PDBs).
These OU 5 groundwater samples collected will be analyzed according to the methods outlined in Table A4-4. Well purging and field analysis, however, will not be performed on wells sampled with PDBs. Details on the requirements for sample holding times and preservation, and the applicable QA/QC sample requirements, are provided in Appendix C of the EMP. |
Louis Howard |
| 6/3/2002 |
Update or Other Action |
Final work plan for Basewide Environmental Monitoring Plan received dated June 2002. 2.3.2.2 Program Area Modifications in 2002: Seven wells will be removed from OU 2 based on criteria in the Basewide Decision Guide provided on Figure 2-1. Table 2-2 provides the well-by-well rationale for continued monitoring, removal from, or addition to the sampling program. Groundwater monitoring Well 46-WL-01 will be removed from the OU 2 wells and reclassified under SERA Miscellaneous. One seep was added to the ST41 sampling locations in order to assess the possibility of contaminants migrating from groundwater and affecting surface water. For both wells and the seep, laboratory analytical methods will be limited to contaminants established as ARARs in the OU 2 ROD. For groundwater, these include BTEX, and for seeps they include benzene, toluene, and ethylbenzene.
Analytical methods removed from OU2: Trace Metals by ICP Screen, DRO, GRO. Total iron was kept to effectively monitor for natural attenuation of fuels. All other trace metals were removed from this program area. DRO and GRO are NOT ARARS for OU2 [ROD] and are NOT needed to monitor natural attenuation of BTEX. DRO and GRO were removed [from the Basewide Sampling Program].
Historically, OU 2 was sampled on a biannual schedule for statistical purposes. In 2002, the frequency will be adjusted to an annual schedule as specified in the OU 2 ROD. In addition, all wells at ST41 will be sampled with passive diffusion bags (PDBs) in 2002. Sampling methods used for PDBs are presented in the FSP Section A4.3.
A4.1.2 Operable Unit 2: Five monitoring wells and one seep location will be sampled as part of the long-term monitoring efforts at OU 2. The locations of these wells are provided in Figure A4-2. All of the wells will be sampled once in 2002, with events scheduled during the month of June. A detailed field schedule for this program is provided in Section 4 of the EMP.
All wells and will be sampled according to the procedures outlined in this FSP Section A4.3. The samples from OU 2 will be collected using a passive diffusion bags. The seep sample will be collected as detailed in Section A4.3. The samples will be analyzed according to the methods outlined in Table A4-2. Details on the requirements for sample holding times and preservation, and the applicable QA/QC sample requirements, are provided in Appendix C of the EMP.
Passive Diffusion Bag Sampler Procedures: In an effort to optimize the 2002 Basewide Program, 16 wells will be added to the OU 5 source area to help serve as an early warning system for Ship Creek (Figure A4-4). These wells will be sampled for VOCs only, using a PDB.
The typical PDB consists of a low-density polyethylene lay-flat tube closed at both ends and is
filled with analyte-free deionized water. The PBD membrane acts as a semi-permeable membrane to
O certain contaminants, especially specifically chlorinated VOCs. VOCs in the groundwater diffuse across the membrane into the deionized water in the bag until equilibrium is established between the diffusible VOC in the groundwater and in the deionized water.
PDB bags will be placed in the wells approximately 1 foot from the screen and will be attached
with a nylon string to the top of the well casings. The PDBs will be left in the wells for approximately two weeks and at that time will be removed and used to fill VOC sampling bottles. The bottles will then be handled and analyzed as outlined in Section A4.5. Field parameters will not be taken as part of the analysis for PDB samples. |
Louis Howard |
| 7/28/2002 |
Update or Other Action |
ADEC (CS Program S. Bainbridge, Leslie Pearson PER Program) and Air Force (Daniel Barnett) signed the Operational Agreement (OA) concerning presumptive remedies for cleanup of certain petroleum oil and lubricant releases on the outwash plain portion of Elmendorf AFB, Alaska. This OA establishes and describes pre-approved presumptive remedies but does not establish an exclusive set of cleanup options and nothing in the memorandum prohibits EAFB from seeking or obtaining ADEC approval to implement alternative release response and remedial action plans.
For new POL spills in the outwash plain that occur in areas with no operational restrictions or interference from surrounding structures, ADEC approves immediate remediation of contaminated media after free product has been recovered in a manner that minimizes the spread of contamination into an uncontaminated area by using containment, recovery, disposal techniques appropriate to site conditions. The presumptive remedy for new POL spills on the outwash plain consist of excavation, treatment, and disposal of all impacted soil.
On a case-by-case basis, ADEC will evaluated the need for recovery of free product from the water table. Finally groundwater monitoring and ICs placed on the shallow aquifer restricting its use as a drinking water source will be required until such a time that the appropriate groundwater remedial goals are met. If additional institutional controls are required, these controls will be developed by EAFB in consultation with ADEC.
The OA does not apply to spills impacting surface waters. Nothing in the OA relieves, extends or changes the applicable requirements of 18 AAC 75 and 78 for the proper treatment, storage or disposal of contaminated media that result from the implementation of this OA.
Note to file: Monitoring objectives for the Early Warning Line are as follows: Track chlorinated contaminants of concern concentrations in groundwater and detect any contamination above Operable Unit 5 ROD specific cleanup levels. The Record of Decision for OU 5 states: Chemical specific applicable or relevant and appropriate requirements for groundwater are trichloroethene at 5 ug/L, benzene at 5 ug/L, TFH Diesel 10 ug/L and TFH Gas at 10 ug/L. The ROD specified cleanup levels for TFH-diesel and TFH-gas were conceptually modified in 1998 to include TAH and TAqH. Because there was no standard for TFH-diesel and
TFH-gas in groundwater, and because the groundwater
emerges as surface water at the seeps that eventually flow
into Ship Creek (an aquaculture resource), the Alaska Water
Quality Standards, aquaculture standards, for TAH and
TAqH were used. (18 AAC 70.020, based on ecological
risk). |
Steve Bainbridge |
| 8/28/2002 |
Meeting or Teleconference Held |
STATUS MEETING MINUTES ELMENDORF BASEWIDE MONITORING PROGRAM AUGUST 28, 2002-Attendees: Joe Williamson (USAF), Cindy Hood (AFCEE), Terry Beach (AFCEE), Kevin Oates (EPA), Louis Howard (ADEC), Cory Hinds (URS), Russ Beck (URS). Agenda: Review of soil gas surveys and new well locations, Recommendation for treatment of TCE at OU5 Seeps 9, 10, and 11 in the existing Wetland Remediation System and Well sampling frequencies for 2003.
Results from Gore Sorber® soil gas surveys at two locations in OU5 (Diesel Maintenance Shop and Gas Station plume) were discussed. The survey consisted of placement of the passive Sorbers® in server lines perpendicular to the direction of groundwater flow in areas associated with TCE plumes in groundwater. The purpose of the soil gas survey was to further delineate the source of the TCE plume and to guide placement of monitoring wells. Color plots of contaminant mass at each area were distributed for discussion.
The soil gas survey at the Diesel Maintenance Shop (upgradient of Seeps 9, 10, and 11) indicated that the source of TCE was the Diesel Maintenance Shop. It was brought to the attention of Kevin Oates that EPA granted RCRA closure at this facility in 1995. URS agreed to send Kevin a copy of the closure report. Interestingly, no TCE was detected immediately upgradient or down gradient of monitoring well 403-MW-01 which contained approximately 60 ppb TCE in recent sampling. Additional soil gas investigation is underway near this well to find out what is going on. Discussions with the Gore representative indicated that the technology should be capable of sensing TCE at our depths to groundwater. Two new wells (OU5MW-35 and –36) have been installed downgradient of the Diesel Maintenance shop but upgradient of the Seeps 9, 10, and 11.
The soil gas survey at the Gas Station plume (AKA the Dallas Housing area) indicated that there was little to no TCE contamination extending south of the known TCE plume. Low levels of TCE was identified south of the Corps of Engineers Building. One new well was installed south of the known plume.
OU5: Seeps 9, 10, and 11-A report titled Draft Technical Memorandum Trichlorethene Collection and Treatment Alternatives Operable Unit 5 Engineered Wetland Remediation System was summarized and discussed. The report concluded that the best (technically appropriate, least cost, fastest) method of treating the TCE in Seeps 9, 10, and 11 is to divert these seeps into the adjacent Wetland Cell. TCE is degraded via phytoremediation (breakdown and synthesis by plants).
Diversion of the seeps could take place as early as 2004. The Air Force needs to make sure that the seeps are on the EAFB easement. Design will need to take place in 2003. Diversion of the seeps will also be based on upgradient water quality. New data upgradient of the seeps will be provided by the installation of two new wells (OU5MW-35 and –36) in 2002. The decision on whether to proceed with seep diversion will be based on all available data and will be made in October, 2002.
EPA felt this was a fair assessment, but wanted to know what would happen if increasing concentrations of TCE were found upgradient of the seeps. AF will use the OU 5 Wetlands decision guide [Decision Process for Increased Remedial Activity, Figure 5-2, 2001 Annual Technical Report Operable Unit 5], which may need to be revised. It was agreed that the decision guide should be modified so that seeps are collected if there is evidence of a continued source or increasing COC concentrations.
The diversion of seeps will require excavation of soil/sediment that may be contaminated. Air Force may need to treat excavated soil from the project off-site because landfarming of contaminated soil, as outlined in the OU 5 ROD, is no longer an option on EAFB. This change will require an ESD. If the Air Force will keep a list of things that differ from the ROD, the EPA would be able to direct them as to which of these need an ESD. Both ADEC and EPA are comfortable with the Air Force approach to dealing with the seeps. |
Louis Howard |
| 8/28/2002 |
Meeting or Teleconference Held |
STATUS MEETING MINUTES ELMENDORF BASEWIDE MONITORING PROGRAM, Attendees: Joe Williamson (USAF), Cindy Hood (AFCEE), Terry Beach (AFCEE), Kevin Oates (EPA), Louis Howard (ADEC), Cory Hinds (URS), Russ Beck(URS)
Agenda:
• Review of soil gas surveys and new well locations
• Recommendation for treatment of TCE at OU5 Seeps 9, 10, and 11 in the existing Wetland Remediation System
• Well sampling frequencies for 2003
OU5: Seeps 9, 10, and 11
A report titled Draft Technical Memorandum Trichlorethene Collection and Treatment Alternatives Operable Unit 5 Engineered Wetland Remediation System was summarized and discussed. The report concluded that the best (technically appropriate, least cost, fastest) method of treating the TCE in Seeps 9, 10, and 11 is to divert these seeps into the adjacent Wetland Cell. TCE is degraded via phytoremediation (breakdown and synthesis by plants).
Diversion of the seeps could take place as early as 2004. The Air Force needs to make sure that the seeps are on the EAFB easement. Design will need to take place in 2003. Diversion of the seeps will also be based on upgradient water quality. New data upgradient of the seeps will be provided by the installation of two new wells (OU5MW-35 and –36) in 2002. The decision on whether to proceed with seep diversion will be based on all available data and will be made in October, 2002.
EPA felt this was a fair assessment, but wanted to know what would happen if increasing concentrations of TCE were found upgradient of the seeps. AF will use the OU 5 Wetlands decision guide [Decision Process for Increased Remedial Activity, Figure 5-2, 2001 Annual Technical Report Operable Unit 5], which may need to be revised. It was agreed that the decision guide should be modified so that seeps are collected if there is evidence of a continued source or increasing COC concentrations.
The diversion of seeps will require excavation of soil/sediment that may be contaminated. Air Force may need to treat excavated soil from the project off-site because landfarming of contaminated soil, as outlined in the OU 5 ROD, is no longer an option on EAFB. This change will require an ESD. If the Air Force will keep a list of things that differ from the ROD, the EPA would be able to direct them as to which of these need an ESD. Both ADEC and EPA are comfortable with the Air Force approach to dealing with the seeps.
2003 Monitoring Well Sampling Frequencies- URS presented the new proposed Basewide decision guide for determining sampling frequencies for monitoring wells. Proposed monitoring frequencies are based on position of plumes relative to environmental receptors. Plumes immediately upgradient of a receptor were proposed for annual sampling. Plume not immediately upgradient of a receptor were proposed for sampling every 2 to 5 years.
EPA pointed out that this guide is only appropriate for stable plumes and suggested that we add a box to include a decision for unstable plumes. Unstable plumes should be sampled semi-annually if upgradient of a receptor or within the early warning line in OU 5.
URS presented the new sampling frequency table, which is based on plumes rather than program areas. EPA and ADEC agree that it makes sense to organize on a plume-by-plume basis instead of by program area. The Air Force mentioned that there will be additional wells required for the early warning system at OU5, and that some of the early warning sampling will be conducted using passive diffusion bags. Use of the passive bags may mean that it is feasible to sample in the winter. EPA, ADEC, and URS agreed on modification of sampling frequencies. In general, sampling frequencies were increased when the plumes were close to a receptor (i.e., Ship Creek) or the concentrations of contaminants were increasing. A list of the agreed sampling frequencies is attached. |
Louis Howard |
| 11/18/2002 |
Update or Other Action |
Staff reviewed and commented on the base-wide institutional controls management plan for the Base. 1.2.2 Environmental Restoration Program Page 1-2
The text states that no ICs are associated with the SERA program. The Department requests the Air Force clarify how it will implement and manage ICs at sites not in the CERCLA program, such as those sites in the environmental restoration and compliance programs, where ICs would normally be required. For example, sites requiring ICs would include those sites where long term groundwater or surface water monitoring is being conducted, or sites where monitored natural attenuation (MNA) is being considered/have been established, or where alternative cleanup levels are being considered or have been established.
The Department is in receipt of a compliance program document which identifies several compliance sites where MNA was identified as a remedy. In order for MNA to be accepted by the Department for any site, it will require that ICs be in place and enforceable on the impacted soils and/or groundwater until cleanup levels have been achieved.
Additionally, preliminary data results for the ST 401 investigation were obtained during a project manager meeting held on November 12, 2002. The data shows that groundwater results from two monitoring wells located upgradient of two groundwater seeps are contaminated with diesel range organics (DRO) above cleanup levels. Specifically, wells 401-WL-03 and 401-WL-04 had 38.6 mg/L and 13.2 mg/L DRO detected in the groundwater. Residual range organics (RRO) results could not be conclusively ruled out for well 401-WL-03 since the detection limit was above the Table C cleanup level. In view of this new data, the Department will require continued monitoring in the OU5 area for DRO and RRO in addition to the other petroleum constituents that are being monitored.
If monitoring for petroleum fuel range constituents will not be conducted under CERCLA as a part of the base wide program, then the Department will require groundwater monitoring be conducted under environmental restoration/compliance programs as required by 18 AAC 75 Contaminated Sites regulations (see 18 AAC 75.335 Site Characterization, 18 AAC 75.345(g-j)) and 18 AAC 78 Underground Storage Tank regulations (see 18 AAC 78.235 Release Investigation and 18 AAC 78.615 Groundwater and Surface Water Sample Number and Location). |
Louis Howard |
| 12/27/2002 |
Update or Other Action |
Staff reviewed and commented on the Draft OU5 wetland remediation system dated December 2002.
1.0 Introduction Page 1: The text states this is the first five-year review for the operable unit (OU) 5 Wetland Remediation System (WRS). The Department disagrees. The OU 5 Remedial Action Report and 1998 Five Year Review have both mentioned and addressed the OU 5 WRS. This may be the first OU 5 WRS “specific” five-year review but not the first time the OU 5 WRS was reviewed.
2.0 Description, Background and Current Status Page 1: The text states the OU 5 WRS and Beaver Pond treat contaminated groundwater from OU 5. The Department wishes to expand on this particular statement since it is not entirely true. The Department requests the Air Force include the following information that was mentioned in the 1998 five-year review, but is now absent in this document.
Approximately 90 percent of the shallow aquifer flowing through Elmendorf Air Force Base (AFB) is believed to flow into OU 5. Upgradient sources from OU 5 are the source of some of the groundwater contamination in OU5. These sources include, but are not limited to, OUs 1, 2, 4 and several petroleum source areas which include contaminants such as: gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO) and BTEX (benzene, ethylbenzene, toluene, and total xylenes). Regardless of the source, the majority of the groundwater from the shallow aquifer is being treated through the OU 5 WRS.
3.2 Remedy Implementation Page 2: The text states that the Base-wide program was established to ensure that both OU-specific and base-wide groundwater issues are addressed and the majority of the shallow aquifer discharges into wetlands adjacent to Ship Creek. While DRO, GRO, and RRO, are not specifically included in the OU 5 ROD as specific action levels, the Air Force cannot ignore their presence in the shallow aquifer and therefore not monitor for them in the area known as OU 5. As stated in the Department’s letter commenting on the Draft Institutional Controls Management Plan, preliminary data for the ST 401 investigation shows the presence of DRO above 18 AAC 75 Table C groundwater cleanup level for DRO. The two monitoring wells located upgradient, but in close proximity, of two groundwater seeps at the OU 5 bluff area were shown to have 38.6 mg/L and 13.2 mg/L of DRO contamination present in the groundwater.
If monitoring for petroleum fuel range constituents will not be conducted under CERCLA as a part of the base-wide program, then the Department will require groundwater monitoring in OU 5 be conducted separately under environmental restoration/compliance programs as required by 18 AAC 75 Contaminated Sites regulations (see 18 AAC 75.335 Site Characterization, 18 AAC 75.345(g-j)) and 18 AAC 78 Underground Storage Tank regulations (see 18 AAC 78.235 Release Investigation and 18 AAC 78.615 Groundwater and Surface Water Sample Number and Location). How this issue gets resolved either in the five year review or as an added monitoring requirement under the Air Force restoration/compliance program is up for discussion.
4.0 Technical Assessment Question B Page 4: The text states that no other exposure assumptions, toxicity data, cleanup levels or remedial action objectives have changed since the time of the remedy selection. The Department disagrees. The State of Alaska has promulgated in regulation, cleanup levels for: DRO, GRO, and RRO contamination in groundwater and surface water. Specifically, 18 AAC 75.345 “Groundwater and Surface Water Cleanup Levels.” states: (a) Except as otherwise provided in this section, cleanup of a discharge or release of a hazardous substance to groundwater or surface water must meet the requirements of this section. This section includes Table C which identifies the following cleanup levels: DRO-1.5 mg/L, GRO-1.3 mg/L, and RRO-1.1 mg/L. |
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 |
| 2/6/2003 |
Update or Other Action |
Staff reviewed and commented on the annual report for base-wide environmental monitoring dated January 2003.
General comments-The document states in several areas that cleanup levels may not be met as predicted by the groundwater model used by the Air Force. The Department requests clarification on whether a memo to the file or an explanation of significant difference will be created for each operable unit that groundwater will not meet the predicted cleanup goal deadline or where it is stated in the document “…it is unlikely that this (cleanup) goal will be met.” (e.g. OU 6 page 3-47).
A single monitoring well with contamination above cleanup levels does not necessarily delineate the extent of a plume in the groundwater as presented in this document (e.g. SP1-02, OU5MW-02, LF59-MW-03, OU3MW-25, 62-WL-05, 64WL-01). Typically, if the direction of groundwater flow is known, at least three monitoring wells must be installed and sampled, one upgradient and two downgradient of the potential contamination source. If the direction of groundwater flow is unknown, it is recommended that the number of wells installed be sufficient to characterize the groundwater flow using horizontal and vertical control measures; at least three monitoring wells must be installed and sampled.
The Department recommends the Air Force either install enough wells for the adequate plume delineation for these point source plumes or state that these plumes are merely inferred and do not reflect the extent of contamination present in the groundwater. Alternatively, the single well plumes presented on Plate 4 could be reflected by dashed lines rather than clearly delineated plume shading.
3.1.4 OU 1 Conclusions and Recommendations Page 3-5: The text states it is recommended to continue sampling for manganese at OU 1 until 2004 and at that time, if manganese levels remain below cleanup levels, remove it from the sampling scheme. The Department concurs with this recommendation and others found in this section.
See site file for additional information. |
Louis Howard |
| 2/10/2003 |
Update or Other Action |
Staff reviewed and commented on the annual report for the wetland remediation system. Staff concurred with the recommendations listed in the report. |
Louis Howard |
| 7/17/2003 |
Update or Other Action |
Staff reviewed and commented on the second draft five-year review for Elmendorf's Operable Unit (OU) OUs 1, 2, 4, 5, 6. Section 121 of CERCLA, as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), requires that remedial actions which result in any hazardous substances, pollutants, or contaminants remaining at the site be subject to a five-year review. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) further provides that remedial actions which result in any hazardous substances, pollutants, or contaminants remaining at the site above levels that allow for unlimited use and unrestricted exposure be reviewed every five years to ensure protection of human health and the environment. The requirement applies to all remedial actions selected under CERCLA §121. Therefore, sites with CERCLA remedial actions may be subject to a five-year review. Consistent with Executive Order (EO) 12580, other Federal agencies are responsible for ensuring that the reviews are conducted at sites where five-year reviews are required or appropriate.
The text makes several recommendations and follow-up actions for various operable units. The Department suggests the Air Force formalize these recommendations or follow-up actions in either a separate technical memorandum or separate formal document, as appropriate, to EPA and ADEC for concurrence or non-concurrence to be placed in the administrative record.
General comment: OU (matrix and units) listings are not consistent with the rest of the document. Operable unit 4 is listed as OU 4 instead of “OU4” as is Operable Unit 5 and 6 which are listed as OU 5 and OU 6 instead of OU5 and OU6. Please correct this to be more consistent within the document. The Department requests clarification on the origin of the OU 4 soils cleanup level for 4, 4-DDT at 34 mg/kg. In 18 AAC 75.341 Table B-1 states that DDT has a cleanup level for ingestion in the Under 40-inch zone of 24 mg/kg. Additionally, for OU 5, Di-n-butyl phthalate and Diethyl phthalate have 2,700 ug/L and 23,000 ug/L listed as groundwater cleanup levels in the table.
In 18 AAC 75.345 Table C, the groundwater cleanup levels listed for Di-n-butyl phthalate is 3.65 mg/L or 3,650 ug/L and for Diethyl phthalate it is listed as 29.0 mg/L or 29,000 ug/L. Please correct Table B-1 to reflect the correct cleanup levels or provide justification as to leaving the cleanup levels unchanged.
General comments: The Department requests changing the column heading for Current Applicable Standard (Table B.1.) to include Table C or drop Table B.1 reference and leave it as Current Applicable Standard. Otherwise, the reader will infer that Table B.1 (Soil Cleanup Levels) applies to groundwater cleanup levels, which is incorrect. Also, see comment above regarding OU labeling within Table B-2 to match rest of the document (e.g. OU1 vs. OU 1). See comments above regarding cleanup levels for: 4, 4-DDT, Di-n-butyl phthalate, Diethyl phthalate.
General comment: Also see comment regarding Operable Unit labeling within the table to match rest of the document (e.g. OU1 vs. OU 1). The Department requests that the origin of the cleanup levels for the three OU 4 contaminants of concern be clarified. The Table B1 soil cleanup inhalation values for: 1,1,2-Tricholorethane is 460 mg/kg not 457 mg/kg, benzene is 9 mg/kg not 8.64 mg/kg, and for methylene chloride it is 180 mg/kg not 457 mg/kg. Please correct text in Table B-3. |
Louis Howard |
| 1/5/2004 |
Document, Report, or Work plan Review - other |
ADEC Review comments OU2 draft RI/FS: The only response action for the groundwater identified for ST20 is a no action scenario. This is based on the fact that contaminant will be intercepted in Operable Unit (OU) 5, where it will be treated. For this action to be considered, more information is necessary to assess the impact of the contaminants on OU5. This information includes fate and transport of contaminant related to OU5.
AF RESPONSE: Based on additional EPA comments received December 29, 1993, and subsequent communication with Air Force, EPA, and ADEC, the ST20 feasibility sections will be significantly revised. Since benzene, BEHP, and EDB exceeded MCLs (in groundwater), contaminant fate and transport were evaluated for these contaminants. The evaluation concluded that the contaminants originated either at an upgradient source or as a laboratory contaminant and will be incorporated into the existing ST20 risk management section (17.0 of the RI/FS). Since no contaminants detected in the ST20 groundwater pose unacceptable risks that can be attributed to ST20, no further action is warranted at ST20 under CERCLA. The upgradient source area (ST48) will be cleaned up under the State program (i.e. SERA). Based on these conclusions and communication with Air Force, EPA, and ADEC, the FS sections pertaining to ST20 (18.0 through 21.0) were removed from the document and no further action was recommended in the risk management section. |
Jennifer Roberts |
| 1/27/2004 |
Update or Other Action |
The second five year review was signed by ADEC. The purpose of this five-year review is to evaluate the implementation and performance of the remedial actions that were selected in the Record of Decision (ROD) for each Operable Unit (OU). The assessment of this five year review found that the remedies were constructed and in general are operating and functioning as intended by decision documents. For the source areas within OU1, OU2, OU4, and OU6 that have not met groundwater cleanup levels, the remedies are expected to be protective of human health and the environment. At some sites it is expected to take longer to achieve goals predicted in the RODs. In addition, a treatability study that includes system optimization efforts is underway to address remaining soil contamination at OU6 and the remedy is expected to be protective upon completion. In the interim, exposure pathways that could result in unacceptable risks are being controlled (i.e. with land use controls).
The OU5 wetland remediation system (WRS) and Beaver Pond continue to operate and function as designed. Seep water from OU5 continues to be collected and treated through the WRS. Past and current sampling of the seeps, WRS influent and WRS effluent shows that contaminated water enters the system but no water leaves the system with contaminants above cleanup levels. System O&M procedures continue to keep the system operating as designed.
TCE groundwater cleanup levels may not be met by 2026. To address the three newly identified TCE contaminated seeps at OU5, the USAF will contract design of additional discharge structures to capture and divert the seeps to the WRS in 2003. Construction will occur in 2004. The WRS will be operated and monitored until cleanup levels are met.
Recommendations and Follow-up actions: Review and revise the frequency of sampling for some wells in OU4, OU5, and OU6 in accordance with the decision guide. Benzene monitoring may be reduced at wells within OU5 that have historically been below cleanup levels. Some wells associated with unstable plumes in OU5 may require more frequent monitoring.
Progress since the last Five Year Review-No areas of non-compliance were identified during the first five-year review in 1998. At that time, all remedies were protective of human health and the environment and LUCs adequately prevented potential exposure to contaminants present in soil and shallow aquifer. No recommendations for follow-up actions were made during the 1998 review.
The remedial systems were operating and functioning as designed and no modifications were required. Since 1998, contamination at OUs 1, 2, 4, 5, and 6 has decreased and the remedies continue to protect human health and the environment-as long as LUC are in place Contamination remains above levels that allow for unlimited use and unrestricted exposure at OUs 1, 2, 4, 5, and 6.
The USAF agreed, during a meeting with EPA and ADEC on January 14, 2003, because both DRO and GRO have been shown to be associated with non-carcinogenic human health risks since the signing of the RODs, funding will be included to add DRO and GRO to the sampling scheme of the Basewide Groundwater Monitoring Program. This will apply at wells associated with fuel plumes. It was also agreed that until a decision document is signed with ADEC, concentrations will be compared to the current cleanup levels of 1,500 ug/L and 1,300 ug/L for DRO and GRO respectively (18 AAC 75) in annual reports and subsequent five-year reviews. The USAF will not be required to add DRO and GRO as a CERCLA ARAR. |
Louis Howard |
| 3/31/2004 |
Update or Other Action |
Staff reviewed and concurred with the recommendations for the annual report for wetlands monitoring and system optimization. Pending incorporation of EPA comments, the document can be finalized. |
Louis Howard |
| 4/2/2004 |
Update or Other Action |
Staff reviewed and commented on the annual report for base-wide groundwater monitoring program. Staff concurred with all the recommendations listed in Section 6.0 and Table 6-1. Pending EPA comments being addressed, the document can be finalized. |
Louis Howard |
| 2/3/2005 |
Meeting or Teleconference Held |
Meeting minutes from RPM meeting February 3, 2005, ADEC and EPA agreed to decrease the frequency of quarterly reports to semi-annual or twice a year. Elmendorf FFA XIII. REPORTING 13.1 USAF shall submit to the other Parties quarterly written progress reports. The reports will include, but not be limited to, the following information: (a) A detailed summary of all of the remedial, removal, and investigation activities during the previous quarter, including any analytical results, any community relations activities, and any community contacts or inquiries related to the hazardous substance contamination at the Site; (b) An outline of the planned activities for the upcoming quarter;(c) A detailed statement of the manner and the extent to which the timetables and deadlines are being met;(d) The status of efforts to obtain rights-of-entry necessary for monitoring and well installation off base; and(e) The status of any other activities proposed or underway that may affect any phase of the activities described in the Attachments.
13.2 The quarterly written progress reports shall be submitted on the tenth (10th) day of each calendar quarter following the effective date of this Agreement.
Groundwater (GW) Remedial Process Optimization (RPO) Recommendations (Mr.Fink). Mr. Fink explained that we asked an outside team to look at the Fairchild and Slammer TCE plumes. Previous modeling efforts left data gaps and too many uncertainties. It was unclear if monitored natural attenuation (MNA) was progressing at the rate required to meet our projected cleanup dates. Additionally, we asked the team to review the recently developed long-term monitoring plan for DP98, to determine if we were taking the correct approach. We also asked the team to look at ST36/66 since we are considering shutting down bioventing systems at these sites. In summary, the team suggested that we would not be able to meet the 2025 proposed cleanup dates for the Fairchild and Slammer plumes. The team suggested more of a risk-based approach, specifically at the seeps. Mr. Fink stated that he was not really comfortable with the
suggested approach.
The team suggested cutting back on sampling within the plume and increasing sampling down gradient. Additionally, they suggested that we use a mass based or I-dimensional model instead of a complex numerical model. We intend to run the simpler models, and we expect that our projected cleanup dates will change. EPA remarked that it doesn't really matter what model we use and emphasized that compliance sampling is really the bottom line. Mr. Williamson agreed but pointed out that we need an accurate prediction of cleanup times so that we can effectively develop our budget for the out-years. He also pointed out that we have leases that may expire,
without the possibility of renewals, and we need to plan accordingly. Mr. Fink discussed
the team's suggestion of changing the allowable limits of contamination into Ship Creek.
EPA stated that this would be a move in the wrong direction since Elmendorf has always taken an aggressive protective stance towards Ship Creek, which has been appreciated and well-received in the local community. As far as DP98 is concerned, the RPO team suggested some sampling well points but no outstanding recommendations.
For ST36/66, the team stated that existing sentry wells seemed sufficient and indicated that nothing was leaving the perched aquifer. They didn't think that revamping the bioventing system in an attempt to reach the contaminated lens was worthwhile. They suggested that a vapor test might provide enough additional information to justify shutting down the bioventing system. The team suggested changing the clean-up goals basewide, but Mr. Mayer stated that he rejected that proposal and would only consider the possibility of cleanup goal changes on a site-by-site basis. EPA asked where steps Elmendorf intended to take in light of the team's suggestions. Mr. Fink stated that we plan to implement mass based modeling, establish "best guess" cleanup dates, focus on the Slammer plume, determine if TCE is leaving the beaver pond, and determine if creating a new mulch barrier is needed for the beaver pond.
Quarterly Progress Reports (QPRs) (USAF). EPA and ADEC confirmed that the information they receive in the report, in its current format, is quite useful to them when they are briefing their higher headquarters. Both agreed that we could reduce submittals to semi-annual reports, which will be submitted in December and May of every year. ADEC requested that we continue to break sites out by Operable Unit since that is the way their database has been designed to track. |
Louis Howard |
| 3/3/2005 |
Update or Other Action |
Memorandum to Site File OU5: The purpose of this document (Memorandum to the Site File) is to present non-significant or minor changes to the 1995 Record of Decision (ROD) signed for Operable Unit (OU) 5 at Elmendorf AFB. The minor change to the OU 5 ROD is routing of additional seeps to the constructed wetland cell for treatment. Other components to the OU 5 selected remedy will not be significantly affected by this minor change; this change is required to ensure protectiveness of remedy.
The OU 5 ROD was signed in February 1995 by the United States Air Force (USAF), with concurrence from the Environmental Protection Agency (EPA) and Alaska Department of Environmental Conservation (ADEC) (Environmental Restoration Program, Record of Decision, Operable Unit 5, EAFB, Alaska, 1995). It was prepared in accordance with Section 117 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986, and to the extent practicable, Title 40 of the Code of Federal Regulations, Section 300 of the National Oil and Hazardous Substance Pollution Contingency Plan (NCP).
This Memorandum to the Site File was prepared in accordance with the EPA’s “Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision Documents,” July 1999, Section 7.3.1 and Highlight 7-1 (Examples of Post-Record Decision Changes) and will become part of the Administrative Record for OU5.
This change in the ROD does not significantly change or fundamentally affect the remedy selected in the ROD; therefore no public comment is required. Seeps 9, 10, and 11 were routed to the Wetland Cell in August 2004. Seeps 17 and 18 were identified flowing into the Wetland Cell in 2002. Routing of flows from Seeps 9, 10, and 11 to the Wetland Cell were discussed in the August 28, 2002 meeting between the USAF, Region X of the EPA, and the ADEC.
2003 Monitoring Well Sampling Frequencies:URS presented the new proposed Basewide decision guide for determining sampling frequencies for monitoring wells. Proposed monitoring frequencies are based on position of plumes relative to environmental receptors. Plumes immediately upgradient of a receptor were proposed for annual sampling. Plume not immediately upgradient of a receptor were proposed for sampling every 2 to 5 years.
EPA pointed out that this guide is only appropriate for stable plumes and suggested that we add a box to include a decision for unstable plumes. Unstable plumes should be sampled semi-annually if upgradient of a receptor or within the early warning line in OU 5.
URS presented the new sampling frequency table, which is based on plumes rather than program areas. EPA and ADEC agree that it makes sense to organize on a plume-by-plume basis instead of by program area. The Air Force mentioned that there will be additional wells required for the early warning system at OU5, and that some of the early warning sampling will be conducted using passive diffusion bags (PDBs). Use of the passive bags may mean that it is feasible to sample in the winter. EPA, ADEC, and URS agreed on modification of sampling frequencies. In general, sampling frequencies were increased when the plumes were close to a receptor (i.e., Ship Creek) or the concentrations of contaminants were increasing. |
Louis Howard |
| 3/21/2005 |
Update or Other Action |
TCE is the COC currently monitored at the OU3MW-25 Plume. TCE concentrations are very close to meeting the OU 5 ROD-required cleanup level of 5 µg/L. The TCE concentration during 2002, the most recent sampling event, was 5.6 µg/L, and the specified closure date for this plume is 2025.
A linear regression trend line was applied to the TCE plot for well OU3MW-25 but was subsequently removed because it showed a flat trend. Because the TCE concentration is so close to meeting this closure criterion, it is recommended that performance monitoring continue in its current form at this plume. Software modeling efforts have been recommended at other plumes to optimize various performance monitoring components such as well selection and sample frequency, cleanup time predictions, and contaminant mass calculations. Similar refinement of these performance monitoring components is not recommended at the OU3MW-25 Plume.
This plume appears on course to reach the OU 5 ROD TCE cleanup level and does not require these optimization efforts at this time. Those resources should be allocated to plumes with more sharply elevated COC concentrations and closure dates that occur sooner. The next monitoring event for COC samples should be performed as specified in 2007. It is also recommended that MNA samples no longer be collected at the OU3MW-25 Plume. MNA monitoring is currently performed at each well that is sampled to ascertain COC levels. MNA samples are collected at the same frequency as for COC samples.
It is recommended that these two sampling suites be disconnected. Only one well is monitored at the OU3MW-25 Plume. As has been previously stated, an MNA evaluation is performed by comparing differences between geochemical parameters from several wells within a plume. This evaluation cannot be performed with a high degree of accuracy when only one well is analyzed. The installation of additional monitoring wells at this plume to perform an accurate MNA assessment is not recommended.
|
Louis Howard |
| 3/22/2005 |
Update or Other Action |
2004 Phase I RPO Annual Report (Draft Final) Groundwater Performance Optimization Monitoring Program received. It has been concluded that natural attenuation is not removing TCE from the Kenney Avenue Plume. Although this TCE contaminated groundwater is migrating to the south and not naturally attenuating, dilution and dispersion will dilute these low TCE concentrations further. It is unlikely TCE in excess of 5 ug/L will reach Ship Creek from the Kenney Avenue Plume. To optimize performance monitoring at this plume, it is recommended that the following evaluations be performed on the Kenney Avenue Plume:
COC monitoring: It is recommended that COC monitoring and contaminant mass calculations at the Kenney Avenue Plume be performed by using decision guides presented in Appendix H. This plume does not have enough sampling events at enough wells to use MAROS.
Contaminant mass calculations: It is recommended that SourceDK Tier 2 be used to calculate the contaminant mass at the Kenney Avenue Plume.
MNA monitoring: It is recommended that MNA monitoring be reduced to a 5-year frequency. An evaluation of MNA results in 2004 indicates that natural attenuation is not active at this location. This finding is supported by historical analytical results.
Cleanup date predictions: It is recommended that a new cleanup date for the Kenney Avenue Plume be developed by using SourceDK Tier 2. Milestones should be established manually when this predicted cleanup date is known.
Remedy protectiveness summary: MNA is the selected remedy at the Kenney Avenue Plume. it is uncertain whether this remedy should be considered protective of human health and the environment. It is likely groundwater with low levels of TCE that does not daylight at the Kenney Avenue seeps is migrating to the south and not being collected by the WRS. However, it is unlikely TCE in excess of 5 ug/L will reach Ship Creek from the Kenney Avenue Plume because dispersion and dilution will act to decrease the TCE concentrations.
It is recommended that the COC monitoring network be reevaluated with existing decision guides and a revised cleanup date and contaminant mass for this plume be developed during summer 2005. These exercises should be performed and the findings should be submitted as a stand-alone report before the 2005 Annual Report is prepared. The results of the reevaluation would not be generated in time to guide field activities during 2005, but would be available to influence recommendations in the 2005 Annual Report.
|
Louis Howard |
| 4/1/2005 |
Update or Other Action |
The Alaska Department of Environmental Conservation (ADEC) received the RPO draft report on March 21, 2005. Below are ADEC’s comments on the document. General Comments- Typically, delineating a plume of contaminated groundwater takes more than one well in the source area. ADEC requests the Air Force redraw boundaries for “plumes” in the following figures where one well is defining a “plume” of contaminated groundwater with a bold line and replace it with a dashed line to show it as being “inferred” or “interpreted” rather than a distinct boundary.
Zone 1
Figures 3.2-1 and 3.3-1 for wells: OU6MW-46 and OU6MW-63
Figure 3.3-3 for well OU6MW-46
Figures 3.5-1 and 3.6-1 for well ST41-10R
Figure 3.9-1 for wells: OU6MW-46 and OU6MW-63
Figure 3.10-1 for well OU6MW-46
Zone 2
Figure 4.1-1 for well 59WL-31
Figure 4.3-1 for well SP7/10-04
Figures 4.3-1 and 4.5-1 for well OU4MW-04
Figure 4.6-1 for well OU4MW-08R
Figure 4.7-1 for IS6-01
Figures 4.9-1 and 4.10-1 for wells: SP7/10-04 and W-4
Zone 3
Figure 5.3-1 for well OU3MW-25
Figure 5.5-1 for wells: 60WL-04 and 64WL-01
Figure 5.6-1 for wells: 64WL-01 and 62WL-05
Figure 5.10-11 for well LF59MW-03
3.2.4 Phase I RPO Conclusions and Recommendations
Verifying that plume expansion is occurring with one monitoring well is nearly impossible to do without additional monitoring wells. The text states that the OU6 ROD mandated 5-year reviews be performed to evaluate the performance of the selected remedy (MNA). However, the recommendation in this section for MNA monitoring states MNA assessments cannot be accurately performed at one-well plumes. Also the text states plume expansion is not occurring and potential downgradient receptors are not being exposed to groundwater contaminants. ADEC requests clarification on how it can be demonstrated with one monitoring well that downgradient receptors are not being exposed to groundwater contaminants and whether or not it can be shown a plume is expanding or shrinking when sampling data is limited to one well.
The comments above apply to: PL81 South Plume (Section 3.3.5), ST41 North Plume (Section 3.5.4), 59WL-31 (Section 4.1.5), Hangar 10 Plume (Section 4.5.4), Hangar 11 Plume (Section 4.6.4), OU4 East Plume (Section 4.7.5), SS43 Plum (Section 4.9.4), W4 Plume (Section 4.10.4), OU3MW-25 Plume (Section 5.3.4), and SP01-2 Plume (Section 5.8.4).
7.0 Phase I RPO Recommendations Summary Page 7-1
ADEC concurs with updating the conceptual site models for inclusion in the 2005 Program Baseline Calculations Report.
7.1 Plume-Specific Recommendations
ADEC concurs with the plume-specific recommendations listed in this section which are not provided in Table 7.1-1.
|
Louis Howard |
| 6/15/2006 |
Update or Other Action |
OU5 Wetlands Monitoring & System Optimizations 2005 Annual Report-Recommendations are presented in the following categories: Wetland Program decision guides, WRS evaluation components, WRS wetland cell, WRS pump stations, WRS protectiveness issues, and Beaver Pond wetland area protectiveness issues.
Wetland Program Decision Guides: The current Wetland Program decision guides (see Appendix A) provide two sets of guidelines, (1) for increasing WRS remedial activity either through addition of a seep to the monitoring program or by providing guidance to construct a new seep collection area, or (2) decreasing WRS remedial activity through shut down of a pump station. Current guidelines, while ensuring protectiveness, do not allow program optimization through a pathway that would reduce monitoring frequency at a seep if identified and determined to not contain COCs. It is recommended that during 2006 existing decision guides be re-evaluated and revisions submitted for agency review by memorandum and associated meetings as necessary.
WRS Evaluation Components: The existing OU 5 treatment system can be separated into three separate treatment systems. The current WRS requirement is to continue operating the pump stations until the contaminant concentrations at the seep sampling point are below clean up levels. If the WRS were broken into three separate treatment areas, then the pump stations could be mothballed prior to the contaminant levels in the seep sampling point reaching clean up levels, if 1) trends of significant contaminant reduction at the seep water at the heads of seeps, prior to the seep water reaching the pump stations, is confirmed, and if 2) the trend shows contaminant concentrations will reduce to below cleanup levels on their own.
The ROD should be modified to indicate separation into three treatment systems. This will allow stopping the treatment of the clean water from seep collection areas and possibly adding new seeps identified from the ARRC rail yard expansion. The proposed system changes are considered a minor change; there would be no significant change to scope, performance capabilities, or the generalized cost of the system. A memo to site file should be prepared evaluating the referenced changes.
WRS Wetland Cell: The OU 5 selected remedy continues to be protective of the environment, following the routing of seeps 9, 10, and 11 to the wetland cell. Sampling of the influent flow from seeps 9, 10, and 11 should be at the same frequency as for the influent flows routed through the OFC to the wetland cell. TCE treatment capabilities of the wetland cell should be further evaluated. Remediation capabilities for current TCE contaminant loading to the wetland cell have been generally evaluated; however evaluation of possible future TCE contaminant loading to the wetland cell requires additional evaluation of system conditions.
Protectiveness issues are a concern at seep 2 and near seep 9.
The variability of and elevated benzene, TAH, and TAqH concentrations identified at seep 2 are a concern; these variable concentrations may affect the ability to achieve the 2025 cleanup date for the OU 5 Wetland Program. It is recommended that Direct Push technology with a membrane interface probe be used to evaluate the source area upgradient of seep 2 and downgradient of the former pipeline source in attempt to identify the source responsible for increasing benzene concentrations at seep, and to determine whether a more aggressive remedial action is practicable.
To ensure protectiveness of the OU5 Wetland Program continues, the OU 5 bluff area should continue to be monitored for new or previously unidentified seeps. Seep 9 TCE concentrations increased significantly in 2005. Seeps in the area of seep 9 not currently monitored should be sampled to ensure COCs are not present.
Current TCE concentrations at the Beaver Pond wetland area are not a concern. However, influent waters still contain variable concentrations of TCE above cleanup levels. Additionally, the upgradient Slammer Avenue has does not have decreasing TCE contaminant trends. Continued monitoring for natural attenuation is recommended for the Beaver Pond wetland area. This area should continue to be monitored biannually, as a minimum requirement. |
Louis Howard |
| 11/6/2006 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft ROD Memo to Site File OU 5, Elmendorf Air Force Base 2006. Statement of Purpose Page 1 - The text states the minor change to the remedy selected in the OU 5 Record of Decision is routing of the side-seeps, in close proximity to existing seeps 9, 10, 11, to the constructed wetland cell for treatment.
ADEC supports this change and concurs that the other components to the OU 5 selected remedy will not be significantly affected by this minor change which is required to ensure protectiveness of the remedy. The document may go final upon incorporation of any other comments by EPA. |
Louis Howard |
| 6/22/2007 |
Update or Other Action |
Failure of land use controls (LUCs) on property owned by the Alaska Railroad Corporation (ARRC) and leased to the Air Force. An equipment operator for the ARRC, contacted the Air Force this morning about 10 am. He told the Air Force that during roadside trenching operations being performed by ARRC along the road at the bottom of the bluff, an equipment operator exposed some pipeline near a pump station.
Air Force called Weston, and they were dispatched to inspect the area. Weston and Air Force staff went to the site. They saw that on either side of Pump Station 2, a new ditch had been dug and water was running along the ditch. On the west side of the pump station, liner was exposed and pieces of the previously-buried pipe (black, plastic, corrugated) had been removed from the ditch and put up on the dirt berm on the side of the ditch opposite the road. On the east side of the pump station, a smaller quantity of this pipe was exposed and placed on the dirt berm.
About 50 feet east of the pump station, the source of the water running through the ditch was visible: a seep zone with the majority of water running out of one area, and smaller amounts of water running from a zone approximately 20 feet wide and 5 feet high on the face of the newly-exposed bluff. Sheen was also visible, but it was not obvious if this sheen was natural or from petroleum. Air Force asked Weston staff to check with the Weston PM about if there is enough room in the budget to collect a sample from this new seep.
ARRC staff arrived at the site and Air Force staff spoke to him briefly. He told us that the earthwork was done by an operator who is working today in Hurricane, so the damage had been done previously in the week.
Air Force and Weston staff left the site and Air Force staff returned to the office where they reported the findings to Joe Williamson. He reported the situation to Jamie Spell and Jim Miller. Wade Gilpin and Air Force staff called the ADEC spill line to determine if this was a reportable spill (it is not and were instructed to alert the ADEC CS Project manager to the situation), then we left a voice mail message for the CS project manager. Meanwhile, Jamie Spell called Susan Schrader at ARRC.
Weston PM emailed and told the Air Force that there is enough room in the budget to collect a sample from the new seep. His staff is proceding with that, and Air Force expects to hear back from Weston sometime today on exactly what was damaged and how it needs to be fixed. |
Louis Howard |
| 6/25/2007 |
Update or Other Action |
Report completed by Weston (Air Force contractor) of ARRC damage to Operable Unit 5 Seep Collection Area. On 22 June the ARRC cleaned out and regraded the ditchline between the road from Elmendorf to the ARRC's yard road to the west side of the OU 5 Seep 3 Collection Area. In this process they:
* Exposed two new seeps located between the road from Elmendorf AFB to the ARRC's yard road and the Seep 3 Collection Area. Each of these seeps is currently flowing at between 3 and 5 gallons per minute. An analytical sample was taken from the western of these two seeps.
*Unearthed and damaged the 12 inch diameter corrugated HDPE
culvert that carried the water in the drainage ditch from just east of Lift Station 2 to approximately 80 feet west of the lift station. This culvert was left in place immediately in front of the lift station and therefore the regrading of the ditchline should not have damaged the 3 inch diameter force main that carries the water from Lift Station 2 to Valve Box 1.
* Shifted the north edge of the ditchline to within the seep
collection berm at the southern edge of the seep collection area. The edge of the impermeable liner in the seep collection area is now exposed in the north side of the ditch.
*Pushed the material from the north edge of the ditch over the
seep collection area berm and over the perforated pipe that collects the seep water at the south edge of the berm and conveys it to the lift station. An attached photo shows the end of the cleanout for the perforated line that was partly covered by the soil from the ditch.
* Blocked the emergency overflow in the berm around the seep
collection area.
The following need to be evaluated:
* The soil from the ditch is now covering the drainage rock that
surrounds the perforated pipe that collects the seep water and conveys it to the lift station. Rain will likely transfer the fines from this soil to the clean drainage rock and may block its pore space blocking the flow of water to the lift station. This soil should be removed. It must be removed carefully near the top of the drainage rock to not disturb the rock and perfoated line and yet ensure that all the fines are removed. Some drainage rock may be removed and replaced with clean drainage rock.
* The emergency overflow must be repaired. This overflow prevents water from getting to the elevation of non-waterproof electric devices in the lift station in the event of a sustained power-outage.
* Evaluate whether the newly exposed seeps are contaminated and if so evaluate collecting and treating them.
* Cleanout the remaining portion of the 12 in corrugated culvert. |
Louis Howard |
| 5/30/2013 |
Update or Other Action |
Draft Annual Field Activities report received for review & comment.
Ten seeps, ten surface water locations, two control points (OU5CP-01 and OU5CP-02), and one sediment location (WCSD-09) were sampled in 2012 at varying frequencies. Samples from all locations were submitted to a fixed-based laboratory for analysis of VOCs and PAHs. Surface water was sampled at two locations in Ship Creek, three locations at the Wetland Treatment Cell, one location outside of the Pump Station #1 seep collection area, and four locations in the Beaver Pond Area. Sediments were also sampled at one point in the Wetland Treatment Cell near the outfall of the discharge points for seeps OU5SP-09, OU5SP-10, and OU5SP-11.
TAH and TAqH concentrations measured at seeps OU5SP-01 and OU5SP-02 exceeded the cleanup criteria of 10 µg/L for TAH, and 15 µg/L for TAqH. Benzene concentrations measured at seep OU5SP-02 exceeded the cleanup criteria of 5 µg/L during at least three sampling events in 2012 (Figure 12-6). COC concentrations in surface water samples collected from control points OU5CP-01 and OU5CP-02 were below cleanup levels for all sampling events in 2012. This indicates that the exceedances at OU5SP-01 and OU5SP-02 did not impact downstream receptors. TCE concentrations measured at seeps OU5SP-07, OU5SP-10, and OU5SP-11 exceeded the cleanup level of 5 µg/L during at least one sampling event in 2012.
Samples were collected from three surface water locations (WCSW-02, WCSW-03 and WCSW-04) and one sediment location (WCSD-09) at the Wetland Treatment Cell. All results for VOCs, TAH, and TAqH were below cleanup levels in surface water samples collected from WCSW-02, WCSW-03 and WCSW-04 during 2012. All VOC and PAH results for the sample collected from sediment location WCSD-09 were non-detect.
Samples were collected from four surface water location (BPSW-01, BPSW-03, BPSW-04 and BPSW-05) at the Beaver Pond Area. TCE concentrations measured in the Beaver Pond Area surface water samples from location BPSW-04 exceeded the cleanup level of 5 µg/L during all 2012 sample events (Figure 13-7). In addition, surface water sample from BPSW-05 exceeded the TCE cleanup level during the second quarter sampling round. Concentrations measured from locations BPSW-03 were below the TCE cleanup level. Concentrations of other VOCs, TAH, and TAqH were below cleanup levels at sample locations BPSW-03, BPSW-04 and BPSW-05.
All VOC, TAH, and TAqH concentrations were below cleanup levels at surface water sample point BPSW-01, located at the Beaver Pond Area discharge point. All VOC, TAH, and TAqH concentrations were below cleanup levels in surface water samples collected from Ship Creek (SC-01B and SC-08) in 2012.
Site Summary
Sampling at seep and surface water locations has been conducted for more than a decade at a high frequency (up to four times per year). These data indicate consistency of results, which suggests that a reduced seep and surface water sampling frequency would suffice to demonstrate protectiveness.
The source of petroleum hydrocarbon contamination detected in seeps OU5SP-01 and OU5SP-02 is uncertain. A future effort to define the source(s) of contamination in these seeps is recommended. The results of this investigation should then be used to determine if source area treatment is a feasible and appropriate approach for reducing or eliminating COC concentrations in seeps that flow into the Pump Station #1 seep collection area.
The results of visual inspection and assessment of analytical data collected over 28 months demonstrate that pumping is not required for the Wetland Remediation System to reduce influent COC concentrations in seeps to concentrations that are below applicable cleanup levels. Continued operation of the Wetland Remediation System in a passive configuration is recommended.
Monitoring data from the seeps flowing into the seep collection areas for Pump Station #2 and Pump Station #3 have demonstrated that these pump stations and their associated seep collection areas are not needed to comply with the requirements of the OU5 ROD (USAF, 1995c). In addition, the overland flow cell has not been used as part of the Wetland Remediation System since fall 2008. Based on this information, these components of the Wetland Remediation System are no longer needed and can be abandoned as funding is available. If implemented, care should be to take to avoid damage to the pipes in and around Pump Station #2 that connect Pump Station #1 to the Wetland Treatment Cell. |
Louis Howard |
| 6/10/2013 |
Update or Other Action |
Draft Letter Work Plan received for review and comment. The purpose of this letter work plan is to conduct quarterly, semi-annual, and annual environmental monitoring; an annual erosion survey and debris removal; land use control/institutional control (LUC/IC) inspections, and the necessary tasks related to the operation and maintenance of the Operable Unit (OU) 5 Wetland Remediation System. These programs include sites at both JBER-Elmendorf and JBER-Richardson.
Monitoring the OU5 Wetland Remediation System will consist of clearing debris and ice at the weir v-notch, ensuring beaver activity is not adversely impacting the system, measuring influent/effluent flow rates at the wetland treatment cell, and calculating the retention time in the wetland treatment cell. The following operational data will be collected weekly during the summer and fall months and monthly during winter and spring months: 1) flow rates from seeps that discharge directly to the wetland treatment cell via the black and white pipes located on the west side of the wetland and 2) wetland treatment cell water level and weir gate height. The inspection form used is provided as Attachment 2 of this letter work plan.
Surface water, seep, and sediment samples at the OU5 Wetland are collected throughout the year during quarterly and annual events. Locations and frequency for collection of samples at OU 5 including the Seep 1 and 2 collection area, beaver pond area, and wetland treatment cell are listed on Table 1. |
Louis Howard |
| 6/10/2013 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 71617 name: auto-generated pm edit Elmendorf OU5 SD40, ST46, SS53 |
Louis Howard |
| 6/13/2013 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation has received the 2013 Letter Work Plan Addendum on June 10, 2013 for review and comment. One minor comment for the LUC/ICs Inspections at both CERCLA and State sites, ADEC will require photo documentation of the sites’ LUCs/ICs and inspections of major items on the checklists (where not strictly prohibited by concerns of national security) in addition to the inspection forms in Attachment 1A.
|
Louis Howard |
| 7/3/2013 |
Document, Report, or Work plan Review - other |
EPA Sandra Halstead provided review comments on the 2013 Letter Work Plan Addendum.
1.0 Introduction
The 2012 Annual Report was not reviewed or finalized at the time of review of the draft 2013 LTM workplan. It is unknown if the tables are consistent with the recommendations. The table from 2011 was used as the basis for sampling location, COC group, and frequency.
2.1.2 LUC/IC Inspections
These site names are provided in Table 11-1 of the 2013 UFP-QAPP. It would be good to refer to that Table since some of the sites have changed names since the 2011 workplan.
Suggest using the same inspection sheet for both JBER-E and JBER-R LUC inspections. Attachment 1B provides more detailed information and is the preferred format.
2.1.3 OU5 WRS O&M
Add observer name to inspection form.
Table 1 JBER-Elmendorf CERCLA Regulated Sites
What happened to well OU6MW-67? It was on a 2 year frequency for VOCs.
FT023 & SD015
Well FP56 missing and well OU4MW-11 was not in the 2011 workplan. Are these the same?
Well OU6MW-18 is missing for annual sampling for VOCs.
ST037 Seeps
2011 Workplan lists BTEX as a constituent, not PAH for the Seeps.
Pump Stn #1, Ship Cr., Beaver Pond Area
2011 workplan included BTEX analysis for Pump Station #1, Ship Creek, Beaver Pond, and Wetland Treatment Cell samples.
Wetland Treatment Cell
No PAH in 2011 workplan; please make sure a sample is taken without MeOH preservative for SW8260 for soils/sediment. |
Louis Howard |
| 1/13/2017 |
Update or Other Action |
Data Compilation and Remedial Action Evaluation Report received. The data review was conducted to identify potential primary and secondary source areas that may be contributing to the ST037 trichloroethene (TCE) plume areas. Sites where subsurface soil is impacted with petroleum hydrocarbons as a result of releases from USTs, fuel lines, oil-water separators and/or dry wells—or where petroleum hydrocarbons or TCE contamination is present in saturated or “smear zone” soils—were ranked as secondary sources.
The smear zone is defined as the range of depths within which the groundwater will fluctuate under normal seasonal conditions, and therefore, contaminated groundwater would move and “smear”
the soil in response to these seasonal changes. Contamination remaining in finer grained soils after contact with contaminated groundwater could remobilize to groundwater via back diffusion (rerelease as dissolved phase contamination from smear zone or saturated zone soils) when water
levels rise, thus acting as a continuing source.
SD040 and ST046 are associated with the Eastern (Slammer Avenue and SS022) Plume Area as a secondary source.
Sites SD040 and SS046 are located inside the plume area and will be retained due to their position in the plume and ability to impact surface water. Site SS053 is not located inside the plume area and will not be retained. A permeable reactive barrier (PRB) in the form of mulch baffles is proposed at the areas of groundwater discharge to the beaver pond wetland area.
This remedial action would prevent migration of TCE contaminated groundwater to surface water within the drainage ditch, downgradient of ST046. To monitor the effectiveness of the mulch baffles, quarterly sampling currently being performed at surface water points BPSW-01, BPSW-03, BPSW-04, and BPSW-05 would be evaluated. The mulch baffles would extend across the drainage ditch in two locations; at the head of the drainage and further down drainage.
See site file for more information. |
Louis Howard |
| 2/9/2018 |
Document, Report, or Work plan Review - other |
Staff commented on the Annual Report for CERCLA sites. Main comments were to request all the early warning and sentry wells be sampled for perfluorooctane sulfonate (PFOS) and perfluorooctoanoic acid (PFOA). According to the March 26, 1993 “Basewide Groundwater” memorandum of agreement between USAF, USEPA and ADEC indicated that any groundwater contamination from upgradient of OU5 would be dealt by OU5 regardless of CERCLA or POL source areas and not be limited to COCs identified specifically in OU5 Record of Decision.
The list of contaminants analyzed for in groundwater at these sentry, sentinel and early warning wells must be increased and encompass those releases from upgradient CERCLA, petroleum (both UST and non-UST which includes DRO and GRO) and Aqueous Film Forming Foam (AFFF) source areas (e.g. sample all wells for PFOS, PFOA). Because OU 5 serves as the downgradient receptor for most of the other program areas, routine monitoring for COCs will not be discontinued at OU 5 unless monitoring for that COC has been has been similarly discontinued first from all upgradient program areas.
Use of passive diffusion bags may not be allowed for certain contaminants (i.e. DRO/GRO PFOS/PFOA) being sampled for in groundwater and the early warning/sentry well monitoring program may need to be adjusted from PDB sampling to low-flow sampling. Where these results are reported can either be in the CERCLA or State Sites annual groundwater monitoring report.
The purpose of the groundwater monitoring program is to monitor groundwater quality upgradient from Operable Unit (OU) 5 to provide an early warning of potential contamination migration from immediately upgradient sources that may impact the effectiveness of the OU 5 Wetland System or the Beaver Pond Wetland Area. To provide sentinel well monitoring for environmental receptors (e.g. Ship Creek and Knik Arm) to ensure protection of these resources and to provide long-term monitoring of selected groundwater seeps, as required by the RODs. Immediately upgradient means within a two-year warning line (i.e., the distance groundwater would travel in two years, ignoring retardation processes.).
See site file for additional information. |
Louis Howard |
