| Action Date |
Action |
Description |
DEC Staff |
| 1/6/1978 |
Update or Other Action |
See further actions concerning this matter at Elmendorf OU5 SD40, ST46, SS53 CS DB Reckey# 198921X136415.
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 |
| 9/1/1983 |
Update or Other Action |
Installation Restoration Program Phase I Records Search by Engineering-Science (ES) September 1983. SP-2: JP-4 Line Leak from 1964-1965 and SP-6 Diesel Fuel Spill in 1976. NOTE TO FILE: JP-4
is the military equivalent of Jet B with the addition of corrosion inhibitor and anti-icing additives; it meets the requirements of the U.S. Military Specification MIL-DTL-5624U Grade JP-4. (As of Jan 5, 2004, JP-4 and 5 meet the same US Military Specification). JP-4 also meets the requirements of the British Specification DEF STAN 91-88 AVTAG/FSII (formerly DERD 2454),where FSII stands for Fuel Systems Icing Inhibitor. NATO Code F-40. JP-4 is a mixture of aliphatic and aromatic hydrocarbon compounds (kerosene 35-65%, light naptha and benzene at 0.1 to 0.4%) of which meet the requirement of military specifications MIL-J-5624E
SP-2 recommended monitoring: Conduct geophysical survey using EMC and ER. If plume is present install wells and sample. Findings: Site SP-2 JP-4 Fuel Line Leak. As a result of a fuel line leak, an unknown quantity of JP-4 seeped out of the bank southeast of Building 22-010, near the drainage ditch crossing Post Road (Site SP-2) during 1964-1965. In fact, this area was known for periodic seeps throughout the 1950's and 1960's. No fuel was recovered at this location. The potential for contamination exists at Site SP-2 due to the nature of the material spilled and the proximity of the spill to Ship Creek.
Site SP-6 Diesel Fuel Spill (Bldg. No. 22-013): An estimated 8,000 gallon spill of diesel fuel occurred on March 31, 1976. The spill occurred during transfer of fuel from an above-ground tank to an underground tank when the overflow valve failed. Collection ditches were excavated in the ice and snow to channel spilled fuel to catchment locations, where it was removed by pumping into a tanker. Since the ground was frozen at the time of the spill, no appreciable
fuel penetrated the subsurface and none of the fuel reached surface waters. As a result of the recovery operation and frozen site conditions, no potential for contamination exists at this site.
Phase II Monitoring recommendations: SP-2 --At each of these locations it is recommended that a geophysical survey using both electromagnetic conductivity and electrical resistivity methods be conducted. The results of these surveys may be used to detect and delineate a contaminant plume, if present. If a plume is detected, monitoring wells should be installed. The exact number and location of the monitoring wells should be based on the results of the geophysical survey. The wells, once installed, should be sampled for phenols, TOC, oil and grease, pH, and a volatile organics scan.
It is recommended that land use restrictions at the identified disposal and spill sites at Elmendorf AFB be considered. The purpose of such land use restrictions would be: (1) to provide the continued protection of human health, welfare, and the environment; (2) to insure that the migration of potential contaminants is not promoted through improper land uses; (3) to facilitate the compatible development of future USAF facilities; and (4) to allow for identification of property which may be proposed for excess or outlease. Land use restrictions at sites recommended for Phase II monitoring should be reevaluated upon the completion of Phase II monitoring program and changes made where appropriate. |
Louis Howard |
| 3/17/1986 |
Update or Other Action |
Final Report, Installation Restoration Program Phase II— Confirmation/Quantification Stage 1, Elmendorf AFB received. The Phase II field evaluation of the Installation Restoration Program (IRP) consisted of investigations at the following 11 sites, including Site SP-2 JP-4 Fuel Line Leak.
As a result of a fuel line leak, an unknown quantity of JP-4 fuel seeped out of the bank southeast of Bldg. 22-010, near a culvert crossing Bluff Road, during 1964-1965. Periodic seeps have been noted in this area throughout the 1950s and 1960s. This spill site is near Ship Creek.
This is the site of a JP-4 underground fuel line leak of unknown quantity near Bldg. 22-010. One monitor well, W-16, was installed near a culvert under Bluff Road, approximately 150 feet southwest of Bldg. 22-010, to a depth of 52.0 feet at the location shown on Plates 2 and 15.
Subsurface materials in W-16 are primarily sand with varying amounts of gravel and silt. Water was encountered at a depth of 32.0 feet on 20 June 84. Soil samples had 11 and 39 percent moisture. Explosimeter and HNU photoionization meter readings were low at the borehole location; the explosimeter reading was 4 percent LEL, and the HNU readings were 14 ppm at 35 feet and 140 ppm at 45 feet.
During an investigation in 1984 by Dames and Moore, monitoring well W-16 was installed near the site of this JP-4 underground fuel line leak near a culvert under Bluff Road, approximately 150 ft. from Building 22-101. TOC was low in this well, but oil and grease and specific conductance levels indicate some contamination is present. Soil samples from W-16 had slightly elevated oil and grease at 35 feet and none detected at 40 feet.
W-16 is probably located on the edge of a plume from this underground fuel line leak; oil and grease and specific conductance levels are only slightly elevated. Detectable oil and grease in a soil sample from 35 feet suggests relatively deep contamination. The proximity of this site to base well No. 2 is not likely to pose a threat to human health because well No. 2 is very deep (850 feet) into the lower aquifer, assuming No. 2 is properly completed to exclude water from the upper aquifer.
Groundwater samples collected during this investigative stage were analyzed for total organic compounds (TOC), oil and grease, specific conductances, and pH; soil was analyzed for oil and grease and moisture content. Oil and grease were 28 mg/kg at 35 ft. and were below the detection limit of 8 mg/kg at 40 ft. Oil and grease and specific conductance, in the groundwater sample, were only slightly elevated.
Recommendations: Some ground water contamination was found at SP-2, but a second round of sampling is necessary to confirm the presence of contaminants. Resampling at SP-2 for the screening parameters (TDS, pH, specific conductance, and oil and grease) and for purgeable aromatics (USEPA Method 602) is recommended to confirm the presence of the contamination and to assess its severity.
In addition, one monitor well each should be installed downgradient of Site SP-2 because of the potential impact on base wells. Base wells Nos. 2, 52, and 16 should be sampled and analyzed for the same parameters. A HNU survey should be conducted at each fuel spill to determine the areal extent of contamination. |
Jennifer Roberts |
| 10/1/1987 |
Update or Other Action |
Groundwater monitoring well (the second one at this site) GW-6A, was installed at ST38 ( ST = underground storage tanks, tanks, POL lines) during the Dames and Moore 1986-1987 field effort. Monitoring well GW-6A was installed near the top edge of the bluff south of Building 22-010 and approximately 100 ft. from well W-16. Groundwater was encountered at approximately 30 ft. Water quality sampling in both wells revealed total petroleum hydrocarbons (TPH) concentrations of 0.8 mg/L from well W-16 and 61 mg/L from well GW-6A. |
Louis Howard |
| 11/30/1987 |
Update or Other Action |
In September 1987, Harding Lawson Associates' field reconnaissance of the SS42 (SS= spill site/area.) source area identified significanct quantities of floating oils and greases on stagnant waters in Ship Creek immediately opposite the diesel fuel storage site. The extent of contamination identified in the marshy area of Ship Creek extended approximately 150 yards east of the building at the fuel storage area. The nature of the observed material was undetermined. |
Louis Howard |
| 3/1/1988 |
Update or Other Action |
Final Report, IRP Phase II— Confirmation/Quantification Stage 2, Elmendorf AFB received. Water was encountered at a depth of 30.0’ (13 September 1986). In well W-16, the explosimeter reading was 4% LEL & the HNU meter readings were 14 ppm at 35’ & 140 ppm at 45’. In well GW-6A, HNU readings were nil from the surface to 25’, 15 ppm at 30’, 20 ppm at 35’, & 13 ppm at 40’. Samples below 30’ were noted to be saturated with water & fuel & a benzene odor was detected coming from the samples.
In monitor well W-16, oil & grease & specific conductance levels were elevated during the Stage 1 study at SP-2, the site of a JP-4 underground fuel line leak. The Stage 2 analyses indicate petroleum hydrocarbons at a level of 0.8 mg/L in W-16 & 61.0 mg/L in GW-6A installed 100’ downgradient from W-16. Specific conductivity was elevated in both wells, 442 umhos/cm in W-16 & 457 umhos/cm in GW-6A. Site SP-2 has a GW gradient of 40’/mile to the S-SE.
Extent of Contamination at Site SP-2
Both wells downgradient of this site have detectable levels of petroleum hydrocarbons of 0.8 mg/L (W-16) & 61.0 mg/L (GW-6A). The impact to base water supply well BW-2 is unclear. Well BW-2 is located approximately 2000’ to the SW of Site SP-2. The GW gradient in this general vicinity is to the SE.
It is believed that a more southwesterly gradient in this portion of the map is more accurate. Certainly, surface water flow in this area is to the S-SW toward Ship Creek. The concern with base water supply well BW-2 is the appearance of an oily sheen on the water sample obtained from this well, although no petroleum hydrocarbons or purgeable aromatics were detected in the BW-2 water sample. Because BW-2 is completed at a depth of 850’ in the artesian aquifer, it is presumed that SP-2 does not pose a threat to human health. It remains to be determined if the oily sheen on water from BW-2 is a one-time event or if some source of on-going contamination regularly generates this condition.
The results of the Phase II, Stage 2 investigation confirm the conclusions of the Stage 1 study regarding the existence of GW contamination in the downgradient vicinity of the landfills, Sites D-5 & I D-7, & in the vicinity of Sites SP-7 & SP-10, the area near Site D-17, SP-11, SP-2, & IS-1. Probable GW degradation was indicated in base supply well BW-1. Minimal or no ground water degradation was detected during the Stage 2 sampling effort in Ship Creek, base supply wells BW-2 & BW-52, & Sites FT-1, SP-12, SP-5, & SP-14. With the exception of Sites SP-7 & SP-10, the levels of contamination are generally low.
Although the majority of the contaminants detected are low, the presence of certain purgeable halocarbons in the GW in the area near the landfills, in base supply well BW-1, Sites D-17, IS-1, & SP-11 are of concern.
An alternative which was briefly explored but not rigorously executed during Stage 2 is the concept of soil gas surveys at spill sites. The current analytical data set indicates petroleum hydrocarbon contamination at Sites SP-7, SP-10, SP-2, SP-11, and possible contamination at SP-12 and SP-14. A soil gas survey carried out with an OVA unit in shallow boreholes (depths of 3 to 5’) in the area downgradient of Sites SP-7 and SP-10 would help to delineate the plume associated with the spills. Because of the presence of taxiways and flight aprons immediately downgradient of these sites, a comprehensive grided survey may not be feasible.
An alternative method would be to perform a soil gas survey along two lines of boreholes. One line of boreholes, spaced on 100-foot centers and located 200’ S of W-3 could be used to define the width of the plume immediately downgradient of the site. An additional set of borings on 300-foot centers in the infield area south of taxiway 8 would monitor the more distant portion of the plume, if it exists.
Gridded surveys, with boreholes to depths of 2 to 5’ dependent on site conditions, may be feasible for Sites SP-2 and SP-11. If results of the next set of petroleum hydrocarbon analyses indicate significant contamination, soil gas surveys for Sites SP-12 and SP-14, would be likely candidates for this technique.
To confirm the analysis of Stage 2, it is recommended that wells W-16 and GW-6A be resampled and analyzed for TDS (USEPA 160.1), petroleum hydrocarbons (USEPA 418.1), pH, temperature and specific conductivity. Although base well BW-2 does not appear impacted by Site SP-2, the current levels of petroleum hydrocarbons were measured within 600 feet of Ship Creek. If the current analyses are confirmed, it is recommended that Site SP-2 be placed in Category 3, requiring remedial actions. |
Louis Howard |
| 8/1/1988 |
Update or Other Action |
RCRA Facility Assessment Report and Preliminary Review and Visual Site Inspection (VSI) conducted in July 1988. Site SP-6 Diesel Fuel Spill: EAFB reported uncertainty of this site's potential for contamination. However, a reconnaissance was performed at this site and the following observations were made: Significant
quantities of floating oils and greases on stagnant water were noted in Ship Creek immediately opposite the diesel fuel storage site. The difference in elevation from the ground surface at the diesel fuel storage area to the creek bottom is about 40 feet. There was no visible evidence of seeps along the very steep
embankment, except for a band of stressed vegetation at
an elevation of around 25 feet above the flow line of Ship Creek. Soils were probed to a depth of approximately 6 inches in one area of stressed vegetation and no obvious hydrocarbons were apparent. |
Max Schwenne |
| 8/2/1988 |
Update or Other Action |
CERCLA Operable Units' source areas that correspond to RCRA SWMUs from the RCRA RFA. Spill Sites: ST39 SP-3 JP4 Fuel Line Leak, RFA map # 5, In 1963 - 200 gals. of JP4 leaked onto the grass. The top half of the soil was removed and disposed of propely. NO further action is warranted. Ship Creek RFI may include this in its investigation. |
Louis Howard |
| 10/3/1988 |
Update or Other Action |
Monitoring wells, soil borings, sampling, soil gas survey conducted at source area ST38/SS42 during the 1988 remedial investigation by Black and Veatch. Soil gas survey detected benzene, with concentrations ranging from trace amounts to 0.88 ppm. Toluenes and xylenes ranged from not detected to 2.55 ppm for toluene and 8.91 ppm for xylenes. Additionally concentrations of unidentified organics up to a maximum of 0.80 ppm were detected at 22 of 28 locations.
Water: TPH (Oil & Grease 413.2 W-16 8.5 mg/L W-16-8 28 mg/L), ethylbenzene, toluene, and xylenes detected. No cleanup levels exceeded, water samples, however, had a visible odor and sheen, thereby exceeding TPH cleanup values (SP2/6-03 3.3 mg/L, SP2/6-04 1.0 mg/L, SP2/6-05 5.8 mg/).
Soil: TPH detected at levels exceeeding ADEC Interim cleanup guidelines (Boring SP2/6-10 9,840 mg/kg SP2/6-04 1,760 mg/kg).
Recommended action: 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. |
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.).
Paragraph 5.2.2.14 states that petroleum odors and sheens were evident in samples for wells SP2/6-03, SP2/6-04, SP2/6-05, and GW-6A. The Department requests that additional seasonal sampling be done to determine if there is seasonal contamination concentration
fluctuations. Figure 5-18 indicates that the groundwater flow direction is south-southeast.
The current monitoring well and boring configuration does not verify the presence of contamination in the southwest area of the proposed soil gas work. Since odor and sheen were found in SP2/6-05 the Department requests that the southwestern edge of contamination is determined. |
Ron Klein |
| 12/30/1989 |
Site Added to Database |
Petroleum, contaminants. |
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-2/6: Comment is noted. Again, the Air Force stated that
product probes will help define where wells will be placed, or be used in lieu
of wells. |
Jennifer Roberts |
| 5/1/1990 |
Update or Other Action |
IRP Stage 3 RI/FS Final Report May 1990 received. As a result of a fuel line leak at Site SP-2 during 1964-1965, an unknown quantity of JP-4 fuel seeped out of the bank southeast of building 22-010 and near a culvert crossing bluff road. Periodic JP-4 seeps have been noted in this area throughout the 1950's and 1960's (Harding Lawson, 1988). Site SP-6 encompasses building 22-013 and is adjacent to Site SP-2. An 8,000 gallon diesel fuel spill occurred at this site from an above-ground tank in the winter of 1976. Collection ditches were excavated in the ice and snow to channel the fuel from the 1976 spill to catchment basins for later removal by tanker truck. The ground was frozen at the time of the spill, and no substantial quantities of fuel were expected to have penetrated the ground surface. The two sites have been combined.
Previous data shows: ethylbenzene, toluene, and xylenes detected in groundwater, no cleanup levels were exceeded. Water samples had visible odor and sheen, thereby exceeding TPH cleanup levels. TPH detected in soil at levels exceeding ADEC interim cleanup guidelines. The maximum TPH concentration in soil was approximately 10,000 mg/kg at a 30-foot depth at ST38.
Evidence of probable contamination was recorded during the field investigation based on HNu readings, odor and visual evidence. Well SP2/6-01: 30' 5 ppm (slight odor), 40' 9 ppm, SP2/6-05 30' 750 ppm (odor), 40' 5 ppm (odor), Boring SP2/6-08 49' 5 ppm (odor), and Boring SP2/6-10 30' 500 ppm (odor), 35' 10 ppm (odor), and 40' 5 ppm (odor). The most pervasive contaminant was petroleum hydrocarbons detected in 4 water samples and 2 soil samples from the southern portion of the site. Total petroleum hydrocarbon concentration in the water samples from wells SP2/6-03, SP2/6-04 and SP2/6-05 were 3.3, 1.0 and 5.8 mg/L, respectively. Total petroleum hydrocarbon content of soils from a depth of 30 feet in boring SP2/6-10 and from 35 feet deep in boring SP2/6-04 were 9840 and 1,760 mg/kg, respectively. A concentration of fuel hydrocarbons (9,843 mg/kg) was detected in a soil sample from 30 to 31.5 feet below surface in the boring SP2/6-10 beneath ST38, the JP-4 Fuel Line Leak source area.
Water samples from wells SP2/6-02, SP2/6-03, SP2/6-05, and GW-6A had petroleum odors and sheen, thereby exceeding State of Alaska Drinking Water Standards. Petroleum hydrocarbons are probably migrating in the groundwater as evidenced by contamination detected in water samples from the downgradient wells (wells SP2/6-03, SP2/6-04, SP2/6-05 and GW-6A). Boreholes SP2/6-06, SP2/6-07, SP2/6-08 and SP2/6-09 are located upgradient of well SP2/6-05, but soil samples collected at or below the water table in these boreholes did not contain petroleum hydrocarbons at levels above the method detection limits. A soil sample collected at the water table from borehole SP2/6-10, upgradient from wells SP2/6-04 and GW-6A, was contaminated with 9840 mg/kg of total petroleum hydrocarbons.
Contamination by petroleum hydrocarbons detected in 1986 in well W-16 was not found in 1988. However recent samples from well GW-6A, further downgradient of the site, were more contaminated. These findings suggest that there may be a contamination plume and that it is migrating downgradient. The installation of 3 new monitoring wells is required at this site. The wells should be situated downgradient, between the toe of the bluff and the railroad tracks, if there is sufficient space. A soil gas survey and use of field screening probes would be useful in plume delineation between the site and Ship Creek and selection of locations for the propose monitoring wells. Additional sampling of the 5 existing wells is needed. Water shall be sampled seasonally from the wells and shall be analyzed for total petroleum hydrocarbons, purgeable aromatics and purgeable halocarbons. In addition, the water of Ship Creek at a point immediately downgradient of the site should be sampled and analyzed for total petroleum hydrocarbons, purgeable aromatics and purgeable halocarbons. |
Jennifer Roberts |
| 10/31/1991 |
Update or Other Action |
CH2MHILL site summary found the following data gaps and deficiencies: the horizontal and vertical extent of contamination has not been delineated at the source areas, off source migration of JP-4 and possibly diesel products has not been assessed. No water or soil samples were taken south of the privately owned railroad tracks or from Ship Creek to verify the lack of off source migration.
Source ST38/SS42 should be moved from a medium priority source area to a high priority source area based on the high total petroleum hydrocarbon (TPH) levels verified at the source (above) and the sheen present at the pond located between the base of the bluff and the Alaska Railroad Corporation (ARRC) track. Additional remedial investigations are required at this source.
JP-1 (1944) was kerosene with a -77 oF freeze point and 109 oF (Min) flash point. Fuel availability was seriously limited. JP-2 (1945) was an experimental fuel with unsuitable viscosity and flammability characteristics. JP-3 (1947 to 1951) had a high vapor pressure, similar to avgas. Fuel boil-off loss and vapor lock were problems at high altitudes. JP-4 (1951 to 1995), also designated as Jet B, is a blend of gasoline and kerosene. It has a Reid vapor pressure of 2-3 psi to reduce boil-off and vapor lock problems, and a -77 oF freeze point. Flash point (~ 0 oF) was not specified. An anti-static additive was introduced in the mid-1980s. |
Jennifer Roberts |
| 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 Base wide activities, as well as Operable Units (OUs) 2, 3, 5, 6, 7. Michele Poirier-McNeill will serve as lead RPM for OUs 1 and 4. In addition both RPMs will serve as an alternative RPM on OUs for which they are not the lead. For communication and correspondence purposes, the lead RPM should be the point of contact, and the alternate should be copied. |
Jennifer Roberts |
| 8/7/1992 |
Meeting or Teleconference Held |
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.
ST38 JP-4 Fuel Line leak/SS42 Diesel Fuel line spill- significant petroleum contamination detected in seeps below source areas; solvent contamination detected in soil samples; one hit was near the RCRA waste paint tank location.
Soil borings/monitoring well locations: 4 new soil borings proposed along source areas; the farthest east location was moved to just below the waste tank location and consensus was reached to install a monitoring well there. Data from this well will help determine if tank should be added to the OU5 CERCLA activities (tank is currently undergoing RCRA closure). CH2MHILL will check in RCRA Part B documents for information on planned closure activities for waste paint tank for coordination with CERCLA sampling plans. |
Jennifer Roberts |
| 3/26/1993 |
Enforcement Agreement or Order |
DOD and ADEC joint Technical Memorandum of understanding signed concerning the Base wide Groundwater (GW) signed by: ADEC Jennifer Roberts RPM and USAF Joseph Williamson Chief Environmental Programs & Restoration. Due to the base wide GW study and the FY92 field work that occurred at Operable Units (OUs) 1, 2, and 5 it appears a large portion of the GW flows into OU5 (attach. 1-contour map). Based on this fact, Elmendorf (EAFB) will move all upgradient GW into the OU5 Feasibility Study, Proposed Plan and Record of Decision (ROD). This means addressing all GW from upgradient sources (CERCLA (ST20, OUs 3 and 4) and OUs 1 and portions of OU2) and SERA) at OU5 instead of at each individual source area (see attach. 2-Area Map).
Sites with free phased product would be looked at to see if there is an available technology to clean them up in a cost effective way. Soil contamination would be addressed at the source areas. NOTE: addressed at the source areas is interpreted by ADEC as removal through excavation or active treatment systems (e.g. high vacuum extraction, bioventing, etc...). |
Jennifer Roberts |
| 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 OU5. 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 |
| 1/11/1994 |
Document, Report, or Work plan Review - other |
Jennifer Roberts provided the 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 noncancer hazard index values exceeding 1.0 and total excess lifetime cancer risks equal to 1 x 10-4. 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 semiaquatic 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 semiaquatic 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. |
John Halverson |
| 3/4/1994 |
Site Characterization Report Approved |
Final version of Remedial Investigation/Feasibility Study received and approved which contains the Central Operable Unit (OU) 5 contains the source areas storage tank (ST) ST38 and surface spill (SS) SS42. Central Area of OU5 extends from the western outlet of the snowmelt pond east to the Waste Paint Tank. The area includes source areas ST38, SS42 and the snowmelt pond. The fish hatchery is located in this area between the toe of the bluff and Ship Creek. Eastern Area of OU5=SS53, SD40 and ST46 and the Beaver Pond. Western Area of OU5=ST37
FYI: Waste Paint Tank area is 400 ft. northeast of source SS42. Contaminants of concern (COC) total fuel hydrocarbons (TFH)-Diesel, JP4, BTEX was reported in soil 10 feet and 60 feet bgs in SB23, MV11, SP2/6-10, and SP2/6-04. Detected contaminant concentrations pose less than 1 x 10-6 cancer risk and have a Hazard Index less than 1 for non-cancer risks. COC concentrations do not exceed Applicable, Relevant or Appropriate Requirements (ARARs) or to-be-considered (TBC) levels; and there are no identifiable affects of contaminants on aquatic biota or terrestrial plants and animals.
Depth of groundwater is 36 ft. at this location. Xylenes were also reported at 10 ft. at a total concentration of 9.4 mg/kg, higher than expected for the low levels of fuel. Total BTEX at 10 ft. level was 10.2 mg/kg. Total petroleum hydrocarbons (TPH) detected in two locations ranged from 1763 mg/kg to 9843 mg/kg.
Diesel fuel (720 mg/kg) in soil 1 to 2 feet below surface, the result of groundwater seepage, does not pose a significant health risk. However, the soil should be evaluated in the FS because it exceeds the interim remediation goal of 200 mg/kg. Sediments, represented by sample SE06, containing TFH diesel and gasoline, should be considered a part of the area of soil contamination. Hydrocarbon concentrations of 50 to 9,843 mg/kg that occur from 30 to 60 feet below surface pose no risk to surface receptors unless they migrate to the surface as seeps in the future. Because these concentrations are at or below the water table, they should be addressed with groundwater.
Although the inorganic element concentrations exceed soil background concentrations, they are present because of natural processes and do not exceed interim remediation goals. Therefore, soil remediation on the basis of inorganic element concentrations is not warranted.
A groundwater plume with gasoline and benzene concentrations that pose greater than 1 x 10-6 cancer risk was detected at MW13. Because of the potential health risks, the gasoline and benzene plume should be evaluated for feasibility of remedial action. In initial sampling, the concentration (20 ug/L) of bis (2-ethyl hexyl) phthalate at MWll exceeded the interim remediation goal of 6 ug/L. The well was resampled in December 1993 because this compound is atypical in au 5. No phthalates were discovered in this second sample. Since the phthalate is a potential laboratory contaminant, it was concluded that the first sampling results were inaccurate.
|
John Halverson |
| 6/6/1994 |
Proposed Plan |
ST38/SS42 are located in the central area of OU5 and the proposed plan lists the following as COCs: soil-diesel fuel, Surface water-fuel constituents (sheen), TCE and PCBs in the sediment. Fuel constituents listed in the seeps from the bluff.
The preferred alternative is: Natural Attenuation with Institutional Controls for Groundwater and Beaver Pond Wetlands/Passive Extraction with a Constructed Wetland for Seeps/Isolation of Snowmelt Pond Sediments/Excavation, Biopiling, and Backfilling for Soil.
Capital Costs: $0.8 million Annual Cost: $0.59 million Present Worth Cost: $8.1 million
Time to Complete Cleanup: 30 years
Groundwaterwould be remediated by natural processes that break down and dilute contaminants, as described above. In addition, institutional controls in the form of deed restrictions would prevent future use of the contaminated water. The Air Force would continue to monitor groundwater quality and would regularly update off-base land owners of the monitoring results. If there is any indication that contamination is getting worse, the remedial actions will be
reevaluated and additional action will be taken if necessary.
Seep water would be passively (by natural flow, without pumps) extracted from the upper aquifer before it reaches the seeps. Thus, the seeps would be eliminated. The contaminated water would be channeled to Snowmelt Pond where engineered wetlands would be constructed. Biological processes would remove most of the contaminants from the water. The treated water would flow from the constructed wetlands into a drainage ditch. Tests to determine treatment effectiveness wouldbe necessary. The engineered wetland would also isolate the Snowmelt Pond sediments.
This alternative would treat all the contaminated seep water except the seep water flowing into Beaver Pond. As discussed before, treatment of those seeps must rely on natural attenuation to avoid damaging the wetland habitat. About 1,500 cubic yards of soil would be excavated from both of the areas with surface soil contamination. Much of this soil would have to be removed to install the passive extraction wells. The holes would be backfilled with treated soil or clean soil. The contaminated soil would be transported to the eastern end of the base to the existing biopiling system.
Biopiling involves supplying air and required nutrients to a soil pile to maximize natural degradation. Degradation of contaminants would be monitored to document the breakdownrate
and confirm that cleanup levels are being met. The treated soil would be used on base for fill after cleanup levels are achieved. It would take approximately 4 months to remove the contaminants from the excavated soil by biopiling. |
Jennifer Roberts |
| 7/26/1994 |
Meeting or Teleconference Held |
Technical review committee meeting held to discuss General base wide information,
Power plant contamination, Off-base sampling, Status update on environmental cleanup activities. |
Jennifer Roberts |
| 8/4/1994 |
Conditional Closure Approved |
No Further Action Document for Sources ST38 & SS42. ST38 is the area where a fuel line leak occurred during 1964 & 1965. An unknown quantity of JP-4 jet fuel seeped out of the bank southeast of Bldg. 22-010 near a drainage ditch crossing Post Road. No fuel was recovered at this location. ST38 was combined with SS42. Source SS42 is next to Bldg. 22-013. An estimated 8,000 gallon one-time spill of diesel fuel occurred on March 31, 1976. The spill occurred when the overflow valve failed during transfer of fuel from an aboveground tank to an underground tank. Most of the fuel was reportedly recovered from the frozen ground.
The purpose of the document is to explain the rationale for no further action (NFA) to be taken regarding the soils/*vadose zone at ST38 & SS42. Ten soil borings were drilled at Sources ST38 & SS42 during a 1988 remedial investigation/feasibility study [RI/FS) by Black & Veatch. Five of these borings were converted to monitoring wells (SP2/6-01 through SP2/6-05). Evidence of contamination, indicated by portable photoionization analyzer HNu) readings, odor, & visual inspection of samples, was recorded during drilling. Soil samples from the borings were analyzed for TPH, halogenated volatile organic compounds (VOCs), semivolatile organic compounds, & soil moisture content.
Soil contamination appeared til be located in a zone at the top of the water table. Contaminants detected in the soil at boring SP2/6-10 included 2-methylnaphthalene at 17 mg/kg & TPH at 9,843 mg/kg at a depth of 30 to 31.5 feet. Groundwater in boring SP2/6-10 was encountered at 30.2 feet. Total petroleum hydrocarbons were also detected in boring SP2/6-04 at 1,763 mg/kg at a depth of 35 to 36.5 feet Groundwater in boring SP2/6-04 was encountered at 33.5 feet. A review of boring logs shows positive HNu readings in eight of the borings with the maximum readings at depths of 30 to 40 feet (Black & Veatch 1990).
Monitoring well samples collected by Black & Veatch confirmed groundwater contamination. TPH was detected in groundwater in four of the seven monitoring wells at Sources ST38 & SS42. ranging from 1.0 microgram per liter ug/l to 64 ug/L at GW-6A. Ethylbenzene, toluene. & xylenes were also detected in GW-6A at concentrations of 30 ug/L. 4.5 ug/L. & 25 ug/L. respectively.
Petroleum hydrocarbons were detected at ST38 & SS42 in only 3 samples taken from the saturated soil layer, which indicates residual contamination of the saturated soil & groundwater beneath the source areas. Petroleum hydrocarbons were detected in soil only at the water table in borings SP2/6-04 & SP2/6-10, which is indicative of saturated soil with groundwater contamination. This contamination WILL be addressed by the OU5 feasibility study during 1993.
The Federal Facility Agreement (FFA) initiated a remedial investigation (RI) of source areas ST38 & SS42 within Operable Unit (OU) 5 at Elmendorf Air Force Base (EAFB). The U.S. Air Force (EAFB), U.S. Environmental Protection Agency (EPA), & 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 ST38 & SS42.
Based on this review, the above agencies have determined that No Further Action (NFA) for purposes of investigation or study is justified for the VADOSE ZONE SOILS at this source area. Groundwater & saturated soil contamination beneath & downgradient of Source SS53 were evaluated as part of the feasibility study for OU 5 & is not attributed to SS42. Signed by Patrick Coullahan Lt. Col USAF Base Civil Engineer, Marcia Combes EPA project manager, Jennifer Roberts ADEC project manager on August 4, 1994.
NOTE to file: RI/FS states for ST38 & SS42- No further action for the soil, surface water, & sediment pathways are warranted for the following reasons: Total Fuel Hydrocarbons (TFH) diesel, JP-4, & BTEX compounds were only detected in soil at depths of 10 to 60 feet below ground surface (SB23, MW11, SP2/6-10, & SP2/6-04) & are not in a surface soil pathway accessible by residents or terrestrial animals.
Detected contaminant concentrations pose less than 1 x 10 -4 cancer risk & have a hazard index (HI) less than 1 for non-cancer risks; Contaminant of concern (COC) concentrations do not exceed ARAR or TBC levels; &; There are no identifiable affects of contaminants on aquatic biota or terrestrial plants or animals. |
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 nondomestic 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 nondomestic 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 nondomestic 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 nondomestic wastewater discharge. |
Jennifer Roberts |
| 12/7/1994 |
Update or Other Action |
Mgt. Action Plan Appendix G NO Further Action Documents.
Source area ST38 is included in OU5 for purposes of remedial investigation at Elmendorf AFB under CERCLA. It is located near the southern boundary of Elmendorf AFB, just north of Bluff Road and east of Maple Street. ST38 is the area where a fuel line leak occurred during 1964 and 1965. An unknown quantity of JP-4 jet fuel seeped out of the bank southeast of Building 22-010 near a drainage ditch crossing Post Road. No fuel was recovered at this location. The exact location for this area has not been clearly identified. The area is thought to be near an aboveground fuel storage tank and a gasoline fill stand at Building 22-010.
As part of the USAF IRP, investigations were conducted at source area ST38 and SS42 in 1984, 1986-1987, and 1988. During this time soil samples were collected, soil borings were drilled, and two groundwater monitoring wells were installed.
In 1992, ST38 and SS42 were investigated under the RI conducted for OU5. Soil borings were drilled. Five of the borings were converted to monitoring wells. As a result of these investigations, the recommended action at source area ST38 was NFA. No contamination was detected in the vadose zone soils. Contamination detected in the saturated zone is not attributed to ST38 and will be evaluated as part of the feasibility study for OU5.
The primary criterion that was used to place sources 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 ST38 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 ST38 was NFA. Contamination found in the saturated zone is attributed to source areas unrelated to ST38 that will be investigated further under OU5.
The NFA document for ST38 was signed on 4 August 1994. Site ST38 was considered closed with the signing of the NFA document.
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Source area SS42 is included in OU5 for purposes of remedial investigation at
Elmendorf AFB under CERCLA. Source area SS42 is next to Building 22-013. An estimated 8,000-gallon, one-time spill of diesel fuel occurred on 31 March 1976. Most of the fuel was reportedly recovered from the frozen ground. SS42 is located near the southern boundary of Elmendorf AFB, just north of Bluff Road and east of Maple Street. The exact location for this area has not been clearly identified. The area is thought to be near an aboveground fuel storage tank and a gasoline fill stand at Building 22-010.
As part of the USAF IRP, investigations were conducted at source areas ST38 and SS42 in 1984, 1986-1987, and 1988. During this time soil samples were collected, soil borings were drilled, and two groundwater monitoring wells were installed.
In 1992, ST38 and SS42 were investigated under the RI conducted for OU5. Soil borings were drilled. Five of these boring were converted to monitoring wells. As a result of these investigations, the recommended action at source area SS42 was NFA. No contamination was detected in the vadose zone soils. Contamination detected in the saturated zone is not attributed to SS42 and will be evaluated as part of the feasibility study for OU5.
The primary criterion that was used to place sources 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 SS42 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 SS42 was NFA. Contamination found in the saturated zone is attributed to source areas unrelated to SS42 that will be investigated further under OU5.
The NFA document for SS42 was signed on 4 August 1994. Site SS42 was considered closed with the signing of the NFA document. |
Louis Howard |
| 1/19/1995 |
Document, Report, or Work plan Review - other |
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 afar 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 base wide should be below the MCL after 15 years (1993-2008). TCE concentrations will be detectable in groundwater after 30 years (2023) and should be less than the MCL base wide 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 |
Record of Decision |
ROD states that based on remedial investigation in summer of 1992, fuel constituents and low levels of solvents found in the soils and groundwater (GW). Impacts to soil were found in areas where impacted GW seeped from the bluff. The major components of the selected remedy include:
* Contaminated seep water in the western and middle portions of the OU will be passively drained using horizontally inserted extraction wells in the bluff. The water will flow to a constructed wetland, currently planned to be built in the snowmelt pond. A layer of material such as gravel will be placed over the sediments which contain PCBs in order to isolate the contamination.
* Approximately 3,000 cubic yards of soil contaminated with fuel products will be excavated and treated at an on-base treatment facility to reduce contaminant concentrations below cleanup goals. The treated soil will be reused on base either to fill the excavation or for general
fill.
* Natural attenuation will be relied upon to attain cleanup levels in the contaminated upper aquifer and surface water other than seep water, including the beaver pond wetland area.
* Institutional controls that prohibit use of the upper aquifer will ensure that people will not be exposed to contaminated groundwater until cleanup goals are achieved.
* Groundwater, seep water, and surface water will initially be sampled on a quarterly basis. Sediment will be sampled annually. Results of 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 reached, aggressive actions such as air sparging with soil vapor extraction or active extraction with air stripping may be necessary. Bioventing of soil is an additional option that could treat soil contamination. If there are any significant differences between the actions being taken as part of this ROD, an explanation of significant differences or a ROD amendment will be issued.
Because the remedy will result in hazardous substances remaining on-site above health-based levels, a review will be conducted within five years after commencement of remedial action. The review will ensure that the remedy continues to provide adequate protection of human health and the environment.
Specific remedial action objectives are:
* Protect human health and the environment 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 the contaminants reach OU 5; and
* Implement a cost effective solution that can achieve the cleanup levels for the final COCs.
Alternative 2 was selected because it best provides the following specific 5 benefits at OU 5:
* Existing habitat in the beaver pond wetlands area is preserved. The monitoring will ensure that the current health state of the wetlands is I being maintained and improved as contaminant concentration levels are decreasing.
* The habitat in the snowmelt pond will be improved from an open pond to a vegetated wetlands system. This alternative is consistent with the city of Anchorage's land-use plan that calls for the snowmelt pond to t be a greenbelt preservation area.
* The pathway for PCBs found in the snowmelt pond sediment is broken by constructing the wetland in this off-base location.
* The impacts from seep water are isolated, thus protecting wildlife and plants. Collecting the water protects surface water bodies. This action prevents the spread of contaminants on the land surface.
* Shallow contaminated soil source areas potentially contributing contaminants to groundwater are removed.
* Institutional controls will eliminate risk to human health by ensuring that contaminated upper aquifer groundwater will not be consumed by people until cleanup levels (MCLs for benzene and TCE. |
Jennifer Roberts |
| 2/1/1995 |
Cleanup Level(s) Approved |
Record of Decision identified chemical specific ARARs for Groundwater: TCE and benzene-5 ug/L (MCL), TFH Diesel and Gas-10 ug/L (AK Water Quality Standards). Surface Water: Sheen-No Sheen (AKWQS), TFH-Gas and JP-4-10 ug/L (AKWQS). Soil: TFH-Diesel-1,000 mg/kg AK Cleanup Matrix Level "C" (18 AAC 78.315).
NOTE: RI/FS concluded diesel fuel in soil exists in soil 1 to 2 feet below ground surface (bgs) at 720 mg/kg, the result of groundwater seepage, however it does not pose a significant health risk. The soil will need to be evaluated since it does exceed the interim remediation goal of 200 mg/kg. Hydrocarbon concentrations of 50 to 9,843 mg/kg that occur from 30 to 60 feet bgs pose no risk to surface receptors unless they migrate to the surface as seeps in the future. Because these concentrations are at or below the water table, they should be addressed with groundwater.
A groundwater plume with associated gasoline and benzene concentrations that pose greater than 1 x 10-4 cancer risk was detected at MW13.
Institutional controls will remain in place until groundwate cleanup levels are 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. |
Jennifer Roberts |
| 3/8/1995 |
Site Characterization Report Approved |
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, dispute Air Force diligence, ADEC agrees that good cause for this extension exists pursuant to Section 26.1 (Force Majeure) of the FFA. |
Ray Burger |
| 6/15/1995 |
Site Ranked Using the AHRM |
Initial ranking. Action code added because it wasn't when the site was originally ranked. |
Louis Howard |
| 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. |
Jennifer Roberts |
| 6/24/1996 |
Institutional Control Record Established |
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 (i.e. POL in groundwater) 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 operation 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.
ICs: 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). ICs on land use and water use will restrict access to the contaminated groundwater throughout OU5 until cleanup levels have been achieved.
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 |
| 4/2/1997 |
Meeting or Teleconference Held |
Restoration advisory board meeting held to discuss: presentation of the Pentagon Crystal Award to the RAB for its excellence, charter revisions approved, including widened focus of RAB, review of FY97 and FY98 Restoration budgets
Review of Elmendorf’'s Environmental Investment (ENVVEST) air quality initiative. |
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 and ADEC project managers 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 |
| 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 as cleanup levels for surface water. These methods were revised in 1998 to total aromatic hydrocarbons (TAH 10 ug/L) and total aqueous hydrocarbons (TAqH 15 ug/L) for Operable Unit 5. 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). The revised analytical methods and cleanup levels provide equivalent protection of human health and environmental receptors and bring the cleanup levels in line with current ADEC regulations. Detection levels for the new methods are lower and provide data that can be compared to cleanup levels. |
Louis Howard |
| 10/1/1998 |
CERCLA ROD Periodic Review |
First Five Year Review received. The purpose of this five-year review is to ensure that remedial actions selected in the Records of Decision (RODs) for Operable Units (OUs) 1 through 6 at Elmendorf Air Force Base (AFB) remain protective of public health and the environment and are functioning as designed. The start of construction of the OU2 Interim Remedial Action (IRA) (August 5, 1993) triggered this periodic (five-year) review requirement. The scope of this review covers selected remedies at all of the OUs and is considered a Type Ia review in accordance with the Environmental Protection Agency (EPA) OSWER Directive 9355.7-02A (July 26, 1994).
OU5 is located along the southern boundary of Elmendorf AFB adjacent to Ship Creek. OU5 covers an area over 7,000 feet long and over 1,200 feet wide. Approximately 90 percent of the shallow aquifer flowing through Elmendorf AFB is thought to flow into OU5. Upgradient sources from OU5 (OUs 1, 2, 4 and several SERA sites) are the source of some of the groundwater contamination in OU5. Regardless of the source, groundwater contamination is being treated through OU5 remedial actions (including the ST37 wetland system). Due to minimal soil contamination at ST38, SS42, SD40, ST46, and SS53,these sites have been designated as NFA sources and decision documents were signed in August 1994.
All remedial actions are operational and functional, as documented in the OU5 RA report. The ST37 wetland system is operational and the O&M manual is being written. Groundwater monitoring and sediment sampling is continuing at OU5 and upgradient locations in accordance with the Environmental Monitoring Plan. The ST37 wetland system and all monitoring wells have been inspected and are in good condition. Institutional controls have been established and are being maintained to prevent exposure until cleanup goals are attained throughout OU5.
Site conditions and land use are consistent with the OU5 ROD requirements and remain protective, based on evaluation of current monitoring data and trends, and the most recent joint
inspection conducted by the USAF, EPA and ADEC project managers on February 20, 1998. Shallow contaminated soils at the four seep locations were removed during construction of the wetland system. These soils were placed in a land-farm and are awaiting confirmation sampling to ensure that cleanup goals have been reached. No other monitoring of shallow soils is being done at these sites.
COCs in sediments at ST37 and groundwater in the shallow aquifer still exceed cleanup goals.
Summaries of monitoring information are available in the 1997 Groundwater Monitoring Annual
Report. Due to current land use and institutional controls, there is no human and ecological
exposure to the groundwater. Response actions at OU5 are ongoing and are expected to continue
for another 23 years, based on current estimates of the time to remediation documented in the
1997 Groundwater Monitoring Annual Report. The OU5 remedies remain protective of human health and the environment and are functioning as designed. OU5 remedies will be addressed in future periodic reviews and, if necessary, further actions will be evaluated. |
Louis Howard |
| 11/13/2001 |
Update or Other Action |
Air Force Tech Memo-RE: Work plan for TCE investigations at OU 5. 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 |
| 6/28/2002 |
Update or Other Action |
Final work plan for Basewide Environmental Monitoring Plan received dated June 2002. 2.3.4.2 Program Area Modifications in 2002: All of the wells will remain for the 2002 OU 5 sampling scheme. Five wells, 403-MW-01 OU5MW-15, 61-WL-01, 61-WL-02, & ST20-MW-11 will be added to aid in monitoring & characterization of trichloroethene (TCE) plumes. Nine more wells will be added to improve the monitoring well network used as the early warning system for contaminant migration toward Ship Creek.
All of the wells are located upgradient of Ship Creek at a distance that will give approximately two years of advanced warning of new or increased contamination moving in the direction of this environmental receptor. In addition, two analytes, TOC & dissolved gases, will be added to the OU 5 suite of analytes in wells associated with chlorinated solvent contamination to better monitor natural attenuation in this program area.
GRO & DRO were added to the analyte suite at several wells in OU 5 at the request of the ADEC. All wells included in the early warning well network will be sampled for VOCs only using passive diffusion sample bags as outlined in the FSP in Section A4.3.
A4.1.4 Operable Unit 5: Twenty-eight monitoring wells are included in the long-term monitoring program for OU 5. Twelve of these wells will be sampled to track known contaminant plumes & will provide data necessary to track natural attenuation as a part of the OU 5 source area. The remaining 16 wells will be sampled as a part of the Ship Creek early warning system. The locations of these wells are provided in Figure A4-4. The OU 5 source area wells & the 13 early warning wells will be sampled biannually in 2002, with events scheduled during the months of May & July. The 3 wells, upgradient of OU5MW-07 which will be used to provide additional data for the early warning network, will be sampled once. A detailed field schedule for this program is provided in Section 4 of the EMP. 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, & 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 GW samples collected will be analyzed according to the methods outlined in Table A-4. Well purging & field analysis, however, will not be performed on wells sampled with PDBs. Details on the requirements for sample holding times & preservation, & 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.
PDB bags will be placed in the wells approximately 1 foot from the screen & 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 & at that time will be removed & used to fill VOC sampling bottles. The bottles will then be handled & analyzed as outlined in Section A4.5. Field parameters will not be taken as part of the analysis for PDB samples.
During the 2001 field season, the OU 5 Wetlands program identified TCE above ADEC cleanup levels at Seeps 9, 10, & 11. A limited field investigation indicated that GW had been impacted with TCE at Well 403-MW-0 1; however, the nature & extent were not identified. An additional investigation to delineate both the horizontal & vertical extents of contamination will take place this season. This investigation will include, but is not limited to, a soil gas survey, additional soil borings, subsurface soil sampling, & monitoring well installation.
Also during the 2001 field season, a similar investigation will occur in the Dallas Housing Area. This limited investigation will help delineate the nature & extent of the plume associated with Wells 48-WL-03, 49-WI-01, & OU3MW-11 in OU 4 & OU 5. As with 403-MW-01, this investigation will include, but is not limited to, a soil gas survey, additional soil borings, subsurface soil sampling, & monitoring well installation.
|
Louis Howard |
| 7/28/2002 |
Enforcement Agreement or Order |
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 |
Meeting minutes from August 28, 2002 EPA, AF, ADEC and contractor re: Review of soil gas surveys and new well locations, TCE at OU5 seeps 9-11 in existing WRS, and well sampling frequencies. Soil gas survey at the Diesel Maintenance Shop (upgradient of seeps 9, 10, & 11) indicated the source of the TCE was the Diesel Maintenance Shop. It was brought to EPA's attention that the EPA granted a RCRA Closure at this facility in 1995. Low levels of TCE was identified south of the Corps of Engineers building and one new well was installed south of the known plume.
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). Seeps 9-11 diversion could take place as early as 2004. Air Force needs to make sure seeps are on EAFB easement. Design will need to take place in 2003. Diversion of the seeps will require excavation of the soil/sediment which may be contaminated. Air Force may need to treat excavated soil from the project off-site since landfarming of contaminated soil, as outlined in the OU 5 ROD, is no longer an option on EAFB.
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 2-5 years. Unstable plumes should be sampled semi-annually if upgradient of a receptor or within the early warning line in OU 5. |
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 |
| 5/2/2003 |
Update or Other Action |
Memorandum to the Site File OU5. The purpose of this document (Memorandum to the Site File) is to present non-significant or minor changes to the Record of Decision (ROD) signed for OU 5 at EAFB. The minor changes to the OU 5 ROD involve modifying the sampling frequency of groundwater wells. Other components to the OU 5 selected remedy will not be affected by this minor change.
The OU 5 ROD for was originally signed in February 1995 by the United States Air Force (USAF), Environmental Protection Agency (EPA) and Alaska Department of Environmental Conservation (ADEC). 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, 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 and will become part of the Administrative Record for OU 5.
ROD: Groundwater will be monitored and evaluated semi-annually to assess contaminant migration and timely reduction of contaminant concentrations by intrinsic remediation.
Revised Remedy: Sampling for groundwater will be changed from semi-annually to a frequency determined by the Decision Guide.
ROD: Seep water and surface water will initially be sampled on a quarterly basis. Water will be monitored near the exit of the constructed wetland to ensure reducing concentrations to below the Alaska water quality standards.
Revised Remedy: Sampling for groundwater, seep water and surface water will be changed from quarterly to a frequency determined by the Decision Guide.
The changes to the sampling frequency will continue to provide sufficient data to assess contaminant migration and timely reduction of contaminant concentrations by intrinsic remediation as required by the ROD. The revised monitoring frequency will also streamline the groundwater reporting process and reduce monitoring costs. The Department requests the Air Force Provide an estimate of the cost savings estimates for reduced monitoring.
|
Louis Howard |
| 1/27/2004 |
CERCLA ROD Periodic Review |
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). Alaska Water Quality Standards (AWQS) no longer specify the analytical methods TFH-Diesel and TFH-Gas, a minor change was made to the hydrocarbon cleanup levels agreement with ADEC and EPA in 1998. TFH-diesel and TFH-gas (groundwater) and TFH-gas, TPH and "no-sheen" (surface water) in the sampling program were replaced with Total Aromatic Hydrocarbons (TAH) and Total aqueous hydrocarbons (TaQH).
The revised methods and cleanup levels provide equivalent protection of human health and environmental receptors and bring the cleanup levels in line with current ADEC regulations. Detection levels for the new methods are lower and provide data that can be compared to cleanup levels.
Risks above target health goals were found only from the hypothetical use of groundwater as a drinking water source. LUCs prevent groundwater use as a source of drinking water and no significant land use changes have occurred at the site. Some groundwater plume areas may be under existing commercial buildings and vapor intrusion into buildings was not a pathway that was evaluated in the original risk assessment. However, cleanup levels specified for groundwater in the ROD are protective at the OU, concentrations protective of drinking the water would also be protective of human health due to vapor intrusion (a less intensive exposure than drinking water at this site.). Other exposure assumptions, cleanup levels or RAOs used at the time of the remedy selection remain valid at this time and are still protective to the current regulatory cleanup levels. |
Louis Howard |
| 3/3/2005 |
Update or Other Action |
Memorandum to the Site File OU 5. The purpose of the document 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 OU5 selected remedy will not be significantly affected by this minor change; this change is required to ensure protectiveness of remedy.
Basis for this document: This minor revision to the ROD changes the quantity of seep water treated by the WRS by routing additional seeps to the Wetland Cell. Seeps 9, 10, 11 were routed to the Wetland Cell in August 2004; Seeps 17, 18 were identified flowing directly into the Wetland Cell, so no additional modification is recommended based on existing concentrations. Seeps 9-11 have been sampled regularly since identified in 2001. Results show that TCE continues to exceed cleanup levels at the seeps, but TCE is present at concentrations below cleanup levels immediately downgradient of the seeps, and still upgradient of Ship Creek.
The elevated TCE concentrations identified in Seeps 9, 10, and 11 are likely associated with elevated TCE concentrations found in the upgradient source area of the Kenney Avenue plume, monitored as part of the Basewide Groundwater Monitoring program. Seeps 17 and 18 are monitored for additional contaminant loading to the Wetland Cell. Seeps 17 and 18 are located on the northwest edge of the Wetland Cell and TCE levels in Seep 17 slightly exceed the 5 micrograms per liter (µg/L) cleanup level. Flows from Seeps 17 and 18 have not been directly quantified due to the broad flow paths of the seeps.
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. This change in the ROD does not significantly change or fundamentally affect the remedy selected in the ROD; therefore, no public comment is required. |
Louis Howard |
| 3/21/2005 |
Update or Other Action |
2004 Phase I RPO Annual Report (Draft Final) Groundwater Performance Optimization Monitoring Program received. An evaluation of COC results for the Early Warning Line did not reveal any significant trend. Current and historical data do not indicate the presence of elevated TCE contamination at these well locations. TCE concentrations have remained either undetected or less than 0.52 µg/L since 1992. Evaluation of the Early Warning Line by using modeling software is not recommended because no significant contamination is present.
The locations of the Early Warning Line wells should be reviewed. There are no plumes upgradient of wells OU5MW-05, OU5MW-11, and 76WL-01. Because Site ST76 is upgradient of well 76WL-01, this well should be retained. Well OU5MW-05 should also be retained because it is between Early Warning Line wells 76WL-01 and SP4/11-03 and immediately south of a substantial housing development on Elmendorf AFB. However, well OU5MW-11 should be removed from the Early Warning Line monitoring network because there are no plumes or sites immediately upgradient of this location.
It is recommended that well OU5MW-45 become part of the Early Warning Line monitoring network. This well was installed in 2004 to help delineate the Fairchild Avenue and SP1-02 plumes. Details about this well are currently presented with the Fairchild Avenue Plume in Section 5.7. TCE was not detected above the reporting limit of 0.18 µg/L during its one sampling event. Well OU5W-45 is properly positioned to monitor contaminant migration from upgradient sources.
As summarized in Section 5.11.2.1, well OU3MW-04 is damaged and should be abandoned. A replacement well is not required at the current location of this well; however, installation of another Early Warning Line well is warranted south of the OU5MW-02 Plume. This plume was expanded and redrawn based on sampling results from 2004, and there is no downgradient well to monitor potential contaminant migration from this location. To fill this void, it is recommended that a new Early Warning Line well be installed directly between wells OU5MW 45 and 403WL-01.
It is recommended that COC monitoring continue on a semiannual basis at the Early Warning Line monitoring network.
The majority of Zone 3 sentry wells have not detected TCE contamination since sampling first occurred in 1992. However, four of the Zone 3 sentry wells have exhibited low, but consistently detectable concentrations of TCE. Each of these four wells appears to be associated with existing TCE plumes upgradient of the Zone 3 sentry wells. Only one sentry well, NS3-02, has ever exceeded the cleanup standard of 5 µg/L for TCE. A TCE concentration of 5.49 µg/L was detected in this well during the spring 1996 monitoring event.
Sentry well OU5MW-33, which is downgradient from the LF59MW-03 Plume, has contained detectable TCE levels less than 1 µg/L since 1995. Evaluation of the COC trend plot from this well does not indicate a discernable trend. Sentry well OU5MW-13 is downgradient of the Kenney Avenue Plume and has also indicated detectable TCE levels less than 1 µg/L since it was first sampled in 1992. The TCE concentration in this well has been steadily decreasing since 1999.
Two wells downgradient of the Slammer Avenue Plume, NS3-02 and OU5MW-31, have consistently contained TCE levels between about 1 and 5 µg/L. These wells and their relationship with the Slammer Avenue Plume and the Beaver Pond are discussed in more detail in Section 5.10.2.6, which contains an evaluation of groundwater characteristics in this vicinity. Evaluation of the COC trend plots from NS3-02 and OU5MW-31 was inconclusive; no significant trends are apparent. It is recommended that monitoring at the Zone 3 sentry wells continue on a semiannual basis to track TCE concentrations and detect any resultant trends.
|
Louis Howard |
| 3/22/2005 |
Update or Other Action |
2004 Phase I RPO Annual Report (Draft Final) Groundwater Performance Optimization Monitoring Program received. Remedial activities at the OU 5 WRS are ongoing. The 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.
Additionally, the variability of benzene concentrations identified at seep 2 is 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 an investigative boring be installed upgradient of seep 2 and downgradient of the former pipeline source in attempt to identify the source for possible additional remedial action.
Lastly, 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.
|
Louis Howard |
| 4/1/2005 |
Document, Report, or Work plan Review - other |
The Alaska Department of Environmental Conservation (ADEC) received the 2004 Phase I RPO Annual Report (Draft Final) Groundwater Performance Optimization Monitoring Program 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 |
| 3/10/2006 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on the Draft Annual Report Wetlands Remediation OU 5, Elmendorf AFB February 2006.
4.4 Recommendation Page 4-39 The text states Seep 2 is continuing to exceed cleanup levels for benzene, TAH and TAqH. It was recommended that an investigative boring be installed or test pits excavated upgradient of Seep 2 to attempt to identify the source and determine if a more aggressive remedial action can be taken. ADEC concurs with these recommendations and requests the Air Force consider other rapid screening techniques as in addition to the ones recommended in this document (i.e. Rapid Optical Screening Tool and Site Characterization and Analysis Penetrometer System).
8.0 Wetland Program Recommendations WRS Evaluation Components Page 8-1 ADEC supports re-evaluating the existing decision guides for review by the agencies to allow for program optimization. ROD modification is proposed to indicated separation of the existing OU 5 treatment system into three treatment systems. ADEC supports this effort and the Air Force is requested to identify how the proposed changes affect the remedy selected for OU 5. See “A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy Selection Decision Documents” which states:
Scope. Does the change alter the scope of the remedy (e.g., type of treatment or containment technology, the physical area of the response, remediation goals to be achieved, type and volume of wastes to be addressed)?
Performance. Would the change alter the performance (e.g., treatment levels to be attained, long-term reliability of the remedy)? Cost. Are there significant changes in costs from estimates in the ROD, taking into account the recognized uncertainties associated with the hazardous waste engineering process selected? (Feasibility Study cost estimates are expected to provide an accuracy of +50 percent to -30 percent.)
Remedy changes should fall along a continuum from minor to fundamental. Similarly, an aggregate of non-significant or significant changes could result in a fundamental change. The type of documentation required for a post-ROD change depends on the nature of the change. Changes that significantly or fundamentally affect the remedy selected in the ROD will require more explanation and/or opportunity for public comment than those that do not. Each type of post-ROD change is associated with one of three documentation procedures: (1) a memo or note to the post-ROD file for an insignificant or minor change; (2) an explanation of significant differences (ESD) for a significant change, and (3) a ROD amendment for a fundamental change.
WRS Protectiveness Issues Pages 8-2 and 8-3 The text states various actions for ensuring the protectiveness of the OU5 Wetland Program and ADEC supports these actions. |
Louis Howard |
| 4/27/2006 |
Document, Report, or Work plan Review - other |
Contaminated Sites staff reviewed and approved the United States Air Force’s draft work plan for the Kenney Avenue Plume at Operable Unit 5 on Elmendorf Air Force Base. The Kenney Avenue Plume lies in the central portion of the OU 5 program area at the intersection of Kenney Avenue and 5th Street. The COC at this plume is the chlorinated solvent TCE. During investigation activities in 2003, the source of the Kenney Avenue Plume— the former Diesel Maintenance Shop (Building 5332)—was found. This plume is currently being monitored by the following OU 5 wells: 403MW-01, OU5MW-36, OU5MW-41, and OU5MW-42.
A treatability study will be conducted to evaluate enhancing bioremediation of the chlorinated solvents in the shallow aquifer using pilot test cells of three injection wells each.
Specific objectives of the treatability study are: to assess the feasibility of enhancing the natural attenuation by adding organic carbon in the form of sodium lactate, to determine if bioaugmentation can be successfully used to stimulate complete dechlorination within a treatment cell reactive zone, to determine if abiotic dechlorination can be achieved by addition of sulfate to form reactive metal sulfides under anaerobic conditions and to determine optimal design parameters for potential full-scale application
The site is mildly aerobic to mildly anaerobic, and anaerobic
conditions should be induced with addition of an organic substrate.
Concentrations of manganese and ferrous iron measured under anaerobic conditions at other sites within glacial deposits at Elmendorf AFB indicate that manganese reduction and iron reduction will be a significant competing electron acceptor process at the site.
Adequate substrate should be applied to overcome this potential electron acceptor demand. Consideration should be given to adding sulfate to the substrate amendment. Reduction of
sulfate has the potential to lower the groundwater redox state, forming hydrogen sulfide. Hydrogen sulfide will precipitate with soluble iron and manganese, removing them from
solution and potentially forming reactive metal sulfides that may degrade TCE abiotically.
Hydraulic conductivity and rates of groundwater flow are suitable for applying enhanced bioremediation, although special consideration should be given to the frequency and loading rate of substrate addition when using soluble substrates. More frequent injection (e.g., monthly) or addition of a slow release substrate to the soluble substrate mixture (e.g., a vegetable oil microemulsion that may sorb to the aquifer matrix) may be necessary to sustain the reaction zone.
In addition, the hydraulic conductivity of the formation is suitable for the use of recirculatory injection methods to increase the radius of influence of injected substrate and to increase injection well spacing. The width of the plume, inferred to be approximately 300 feet in the vicinity of well 403-WL-01, suggests that enhanced bioremediation should not be cost prohibitive if a full-scale application for plume containment in a biobarrier configuration was desirable. Compliance levels for groundwater at the Kenny Avenue plume are based on the 1995 OU 5 ROD for trichloroethene (TCE) at 5.0 ug/L and MCLs: cis-1,2-Dichloroethene 70 ug/L, 1,1-Dichloroethene at 7.0 ug/L, and vinyl chloride at 2.0 ug/L (40 CFR 141.61). |
Louis Howard |
| 4/30/2009 |
Document, Report, or Work plan Review - other |
Staff provided comments on the Draft 2008 Zones 2 and 3 Management Areas Work Plan, March 2009
for Elmendorf Air Force Base, Alaska.
2.4.5 Seep and Surface Water
The text states PAH and VOC concentration data will be used to calculate total aromatic hydrocarbons (TAH) and total aqueous hydrocarbons (TAqH) concentrations to evaluate results against Alaska’s water quality standards presented in 18 AAC 70. ADEC concurs. Typically at other contaminated sites where TAH and TAqH concentrations are calculated, ADEC requests the responsible party to use one-half (1/2) of the practical quantitation limit (PQL) and not the method detection limit (MDL) for non-detects (NDs) in the calculation of TAH and TAqH.
2.9.3.2.2 Pump Station #1
Background Data Supporting Proposed Optimizations Page 2-39
The text states results for target analytes that were detected above the reporting limit were used to calculate the maximum TAH concentration. Typically at other contaminated sites where TAH and TAqH concentrations are calculated, ADEC requests the responsible party to use one-half (1/2) of the practical quantitation limit (PQL) and not the method detection limit (MDL) for non-detects (NDs) in the calculation of TAH and TAqH.
Proposed PS #1 Optimization Study Activities for 2009 Page 2-41
The text states if the cleanup standards for benzene, TAH, or TAqH are exceeded in any effluent samples from the PS #1 SCA, PS #1 will be restarted and this portion of the optimization test will be terminated. Typically at other contaminated sites where TAH and TAqH concentrations are calculated, ADEC requests the responsible party to use one-half (1/2) of the practical quantitation limit (PQL) and not the method detection limit (MDL) for non-detects (NDs) in the calculation of TAH and TAqH.
Pumphouse PS #2 Optimization Study Activities for 2009
Contingencies Page 2-44
The text states that one of the conditions that would lead to a re-start of the pumping include COC concentrations in annual samples collected from OU4SP-03 that exceed applicable cleanup standards. Typically at other contaminated sites where TAH and TAqH concentrations are calculated, ADEC requests the responsible party to use one-half (1/2) of the practical quantitation limit (PQL) and not the method detection limit (MDL) for non-detects (NDs) in the calculation of TAH and TAqH.
Proposed WTC Optimization Study Activities Page 2-45
The text states if concentrations of TCE and all other COCs in the WTC effluent remain below applicable standards... the USAF may seek concurrence from USEPA and ADEC to continue bypassing the OFC indefinitely. Typically at other contaminated sites where TAH and TAqH concentrations are calculated, ADEC requests the responsible party to use one-half (1/2) of the practical quantitation limit (PQL) and not the method detection limit (MDL) for non-detects (NDs) in the calculation of TAH and TAqH.
SOP #13 Groundwater Sampling
Passive Diffusion Bag Sampling Attachment 1-31
ADEC concurs with the tasks and approach outlined in this section. There are some limitations regarding passive diffusion bag (PDB) sampling. Passive samplers do not provide direct or real-time data. PDB samplers cannot be used for all contaminants; metals and other inorganic compounds will not diffuse through the membrane. The general target is non-polar VOCs with a molecule size of less than 10 angstroms. Biofouling can make PDBs less effective. PDB sampling in monitoring wells relies on the presence of an uninhibited horizontal water flow.
Other factors, such as vertical flow, biofilms, or iron fouling may negatively affect the quality of PDB sampling data. Well stratification can be an issue even in wells with small screened intervals. If PDB samplers are used to identify the highest potential concentration in a well, numerous linked samplers may be needed to decide on the optimal placement of the final sampler.
SOP # 14 Subsurface Soil Sampling Attachment 1-34
ADEC requests the Air Force clarify text in the second paragraph regarding VOC/GRO samples collected concurrently will not be emptied into a stainless steel bowl for homogenization prior to filling the sample jars. |
Louis Howard |
| 2/10/2011 |
Update or Other Action |
Staff received the Draft Zone 3 Mgt. Area Annual Report. Ten seeps, ten surface water locations, one control point (OU5CP-01), & one sediment location (WCSD-09) were sampled in 2010 at varying frequencies. Samples from all locations were submitted to a fixed-based lab for analysis of VOCs & PAHs. Surface water was sampled at four locations in the Beaver Pond, two locations in Ship Creek, three locations at the Wetland Treatment Cell, & one location outside of the Pump Station #1 seep collection area. The single sediment sampling point was in the Wetland Treatment Cell near the outfall of the discharge points for seeps OU5SP-09, OU5SP-10, & OU5SP-11. Benzene, TAH, & TAqH concentrations measured at seeps OU5SP-01 & OU5SP-02 22 exceeded the cleanup criteria of 5 µg/L for benzene, 10 µg/L for TAH, & 15 µg/L for TAqH during at least one sampling event in 2010.
TCE concentrations measured at seeps OU5SP-07, OU5SP-10, & OU5SP-11 exceeded the cleanup level of 5 µg/L during at least one sampling event in 2010. No other VOCs or PAHs were detected above cleanup levels at the remaining seep sampling locations. Levels of VOCs, TAH & TAqH were below cleanup levels in the surface water samples (WCSW-02 through WCSW-04) & sediment sample (WCSD-09) collected from the Wetland Treatment Cell. COC concentrations in surface water samples from OU5CP-02 were also below cleanup levels for all sampling events in 2010. TCE concentrations measured in Beaver Pond Area surface water samples from locations BPSW-03, BPSW-04, & BPSW-05 exceeded the cleanup level of 5 ug/L at least once during 2010. Levels of other VOCs, TAH, & TAqH were below cleanup levels in the surface water samples collected from the Beaver Pond Area. All VOC, TAH, & TAqH, levels were below cleanup levels at surface water sample point BPSW-01, located at the Beaver Pond Area discharge point. All VOC, TAH, & TAqH concentrations were below cleanup levels in surface water samples collected from Ship Creek (SC-01B & SC-08) in 2010.
No samples were collected at WCSW-01 in 2010 because there was no water entering the Wetland Treatment Cell due to shut-down of all pump stations. Surface water sample location OU5CP-02 was established & added to the sampling program in May 2010 to monitor COC concentrations in the drainage ditch immediately downstream of the outlet for the Pump Station #1 seep collection area. 8 One additional round of samples was collected at seep OU5SP-01 in December 2010 to confirm the results from the samples collected at this location in June 2010, which indicated that benzene, TAH, & TAqH concentrations were significantly higher than those measured historically.
Samples were not collected at surface water point BPSW-03 in December because this location was dry as a result of freezing conditions limiting access to available surface water below the ice. Final analytical data for the December 2010 sampling event were not received from the laboratory prior to the publication of this draft report. The December data presented in this report are preliminary data submitted by the laboratory & that have not been validated. Final, validated data for December 2010 will be presented in the final version of the Zone 3 Management Area Annual Report.
Sampling at seep & 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 & surface water sampling frequency would suffice to demonstrate protectiveness. As discussed in the 2007 RPO evaluation, a LTM optimization evaluation should be conducted for these locations to develop a revised sampling program (USAF, 2008a). The benzene, TAH, & TAqH exceedances detected at seep OU5SP-01 in June 2010 were the first noted at this location since sampling began in 1999.
Levels of these three COCs were well below their respective standards in samples collected in December 12 2010. In accordance with the Decision Guide for Increased Remedial Activity (Appendix H of USAF, 2005c), seep OU5SP-01 should be sampled quarterly in 2011. The source of petroleum hydrocarbon contamination detected in seeps OU5SP-01 & 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 & appropriate approach for reducing or eliminating COC levels in seeps that flow into the Pump Station #1 seep collection area.
The results of visual inspection & assessment of analytical data collected over 16 months demonstrate that pumping is not required for the Wetland Remediation System to reduce influent COC levels in seeps to levels that are below applicable cleanup levels. Based on these data, continued operation of the Wetland Remediation System in a passive configuration is recommended. |
Louis Howard |
| 5/30/2013 |
Update or Other Action |
Draft Annual Field Activities report received for review & comment.
In June and October 2012, Early Warning and Sentry Wells were sampled using PDBS. All groundwater samples from these wells were submitted to an analytical laboratory for analysis of VOCs.
In 2012, TCE concentrations in all of the Early Warning and Sentry Well samples were below the groundwater cleanup level of 5 µg/L. No other VOCs were detected at concentrations above cleanup levels. Table 12-6 presents current and historic analytical results for sampling event at Early Warning and Sentry wells where TCE has been detected. Analytical results for other locations and sampling events did not have TCE above laboratory detections levels.
Site Summary
Analytical samples collected from Early Warning and Sentry wells in 2012 were all below the OU5 ROD cleanup criterion for TCE. No changes are being proposed for the Early Warning and Sentry well remedial activities.
|
Louis Howard |
| 6/4/2014 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft CERCLA GW annual report.
Early Warning and Sentry Wells Site Summary
See comment regarding 1,4-dioxane analysis in groundwater contaminated with TCE. This comment applies to JBER-E and JBER-E upgradient sites with current or past TCE or TCA contamination which the Early Warning and Sentry wells are supposed to detect before the upgradient sources impact Ship Creek. Also, PFCs are still recommended for sampling at all early warning and sentry well locations located downgradient of fire training areas/pits which were historically used, and locations where AFFF was also stored for firefighting purposes or demonstration purposes such as near runways in tanker trunks, aboveground tanks, underground storage tanks and/or fire stations. |
Louis Howard |
| 8/10/2015 |
Document, Report, or Work plan Review - other |
Staff commented on the Annual CERCLA Field Activities Report.
ST037
Staff concurred with recommendations: Optimize the groundwater monitoring network at OU5 as recommended in the ST37 TCE Plume and Source Area Investigation Report (USAF, 2011b). It is recommended for sample frequency to remain quarterly at the Beaver Ponds. An update to the sample frequency will be provided in the 2015 CERCLA report following the OU5 Memorandum to Site File- Well Sampling Frequency Decision Guide.
|
Louis Howard |
