| Action Date |
Action |
Description |
DEC Staff |
| 9/21/1993 |
Update or Other Action |
A.G. letter (Breck Tostevin) to Tamela J. Tobia, OS Judge Advocate for the Army. Letter states that a separate petroleum site compliance agreement should be separate from the CERCLA federal facility agreement. The petroleum site restoration agreement would function as a "two-party agreement" under the FFA. It would track the basic provisions of the UST Agreement but be tailored to the State's contaminated site regulations and would interface with the FFA. All petroleum sites addressed under the Two Party agreement would be reviewed in the final operable unit of the FFA and actions taken would be memorialized in a Record of Decision (ROD) under the FFA. |
Louis Howard |
| 11/15/1993 |
Enforcement Agreement or Order |
State-Fort Richardson Underground Storage Tank Compliance Agreement signed by ADEC and U.S. Army. Purpose of the agreement is to bring Fort Richardson into compliance with Underground Storage Tank (UST) regulations and avoid the expense of formal enforcement proceedings. The Army agrees to perform the necessary inventory, record keeping, registration, upgrading or closure, tightness testing, site assessment, release reporting, release investigation, and corrective action (remediation) associated with USTs at Fort Richardson (excluding Alaska Department of Military and Veterans Affairs and Army National Guard USTs). |
Janice Adair |
| 2/15/1996 |
Site Characterization Report Approved |
Circle Loop Road Release Investigation Building 914 UST #37 received.
This document presents the findings of Shannon & Wilson's Release Investigation of a former UST site located along Circle Loop Road on the Army's Fort Richardson facility, Alaska. The former UST, designated Tank 37, was a heating oil tank which supplied fuel to Building 914, located along Circle Loop Road.
The RI for Building 914 was completed as part of a larger assessment addressing a total of eleven former UST sites along Circle Loop Road. Each of the eleven tank sites was associated with a warehouse structure, including Buildings 914, 920, 926, 932, 934, 936, 944, 946, 950, 962, & 968.
The primary objective of the RI was to define the horizontal & vertical extent of petroleum hydrocarbon contamination at each of the eleven tank sites. Information obtained from the RI was incorporated into Jeachability assessments in order to evaluate the potential for the hydrocarbons to impact the sites' GW.
A total of eight soil borings, with one completed as a monitoring well, were drilled at the Building 914 location. The borings were positioned within & adjacent to the former Tank 37 excavation in order to evaluate the vertical & lateral extent of contamination. Samples with DRO exceeding the 1,000 ppm cleanup guideline were collected from three of the eight borings drilled at the Building 914 site. The highest DRO concentration of 6,910 ppm (PID 270 ppm) was reported in sample 339SL, collected from a depth of 10 to 12 feet bgs in boring AP-3535.
Same boring different depths:
15-17’ bgs 340SL 2,810 mg/kg (PID 360 ppm) 2-Methylnaphthalene 15 mg/kg (MGW 6.1 mg/kg),
20-22’ bgs 341SL 3,270 mg/kg (PID 300 ppm),
25-27’ bgs 342SL 3,930 mg/kg (PID 220 ppm),
30-32’ bgs 343SL 4,700 mg/kg (PID 230 ppm),
35-37’ bgs 344SL 1,460 mg/kg (PID 170 ppm),
40-42’ bgs 345SL 1,560 mg/kg (PID 21 PPM which throws the theory of LESS THAN 25 PPM on PID = “CLEAN SOIL”).
B-60/AP-3541
452SL 20-22’bgs DRO 1,400 mg/kg (PID 21 PPM which throws the theory of LESS THAN 25 PPM on PID = “CLEAN SOIL”),
453SL 20-22’ bgs 932 mg/kg (PID 21 PPM which throws the theory of LESS THAN 25 PPM on PID = “CLEAN SOIL”).
Sixteen of the samples contained detectable levels of semi-volatile organic compounds (SVOCs) including up to 0.13 ppm of di-n-butyl phthalate, 0.8 ppm ofbis(2-ethylhexyl) phthalate, 4.7 ppm of naphthalene, 15 ppm of 2-methylnaphthalene, 0.4 ppm of phenanthrene, & 0.26 ppm of 2,4-dimethylphenol.
Based on the reported concentrations of DRO detected in the soil boring samples, the estimated extent of soil contamination exceeding the Level C cleanup guideline of 1,000 ppm; DRO measures approximately 25 feet by 35 feet, or 875 square feet, laterally. The soils containing DRO greater than the Level C cleanup guideline extend vertically about 43 feet below ground surface at the point directly beneath the former Tank 37 excavation. These estimated contaminant plume dimensions indicate that approximately 900 cubic yards of soil exceeding the applicable DRO cleanup guideline are present in the subsurface.
Modelling of the site using the Seasonal SOIL compartment model (SESOIL) indicates that the target compounds migrate vertically at constant rates ranging from an estimated 0.04 7 meters/year (0.155 feet/year) for naphthalene to an estimated 0.364 meters/year (1.2 feet/year) for toluene. These rates are shown in the leaching assessment to be independent of the initial contaminant concentrations & instead depend on the hydraulic loading in conjunction with the specific chemical & soil properties.
None of the four modelled hydrocarbon plumes reached GW within the 99 year model simulation. Based on these surrogate results, the slower-migrating DRO hydrocarbons are likewise not anticipated to intercept the site's GW in the next 99 years. Therefore, it is our opinion that no further action is required at this site & we recommend that the USACE request closure for the Tank 37, Building 914 site. Site-specific ACLs were not developed for this site, however, since the model predicts that the contaminant plumes will not reach GW within the 99 year run time, regardless of initial soil concentrations.
Following a minimum of 24 hours after development, each well was purged using a dedicated, disposable Voss Teflon bailer to remove a minimum of 3 well volumes. NOTE TO FILE: Bailers are not recommended for volatile organic compounds (e.g. BTEX, GRO). |
Louis Howard |
| 3/7/1996 |
Update or Other Action |
DECISION DOCUMENT FOR NO FURTHER REMEDIAL ACTION PLANNED AT THE CIRCLE LOOP ROAD WAREHOUSES,
HEATING OIL UNDERGROUND STORAGE TANKS, FORT RICHARDSON, ALASKA
1. PURPOSE OF REMEDIAL ACTION
This decision document describes the rationale forNo Further Remedial Action Planned (NFRAP) at the Circle Loop Road Warehouses, Fort Richardson, Alaska. This action has been chosen in accordance with the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) as amended by the Superfund Amendments and Reauthorization Act (SARA), the National Contingency Plan (NCP), the Resource Conservation and Recovery Act (RCRA) and Army Regulation 200-1, as applicable.
The sites addressed by this document include Bldg 914 underground storage tank (UST) 137, Bldg 926 UST 96, Bldg 932 UST 97, Bldg 934 UST 98, Bldg 936 UST 99, Bldg 944 UST 100, Bldg 946 UST 101, Bldg 950 UST 102, Bldg 962 UST 105, and Bldg 968 UST 34. These USTs were removed during the summer 1994 to meet the requirements of the Fort Richardson-State of Alaska, Department of
Environmental Conservation (ADEC) UST Compliance Agreement. During removal, soil contamination was found at each site at levels exceeding the State of Alaska level D clean-up standards, 2000 parts per million (ppm) Diesel Range Organics (DRO) and 2000 ppm residual range organics (RRO), specified in 18 Alaska Administrative Code (AAC) 78.
A release investigation was conducted which averaged 4 soil borings per site. The borings were drilled to approximately 50 feet below ground surface (bgs), and found DRO concentrations ranging from 3,010 ppm to 16,000 ppm.
The Directorate of Public Works, Environmental Compliance and Restoration Branch developed this decision document. Attached is a letter of concurrence from the Alaska Department of Environmental Conservation (ADEC) South-Central Regional Office, Contaminated Site Program Defense Facilities Oversight Office
2. SUMMARY OF SITE RISK
Circle Loop Road warehouses is an industrial complex. Due to limited acess it is not expected to pose a risk to the general public or other pathways. Contamination is not expected to impact groundwater, based up on a soil leaching potential assessment conducted during the release investigation. Therefore, contamination poses no risk to the potential drinking water supply in the area.
3. SUMMARY OF REMEDIAL ALTERNATIVES
An evaluation of remedial alternatives was not conducted forthis site. Previous experience indicated that these sites could be closed through development of alternative clean-up levels(ACL) using a soil leaching potential assessment. This work was conducted concurrently with the release investigation.
4. PUBLIC/COMMUNITY INVOLVEMENT
Information concerning investigations and remediation of underground storage tank sites is incorporated in both fact sheets and public meetings developed for Fort Richardson's on-going community relations program.
5. DECLARATION
Because this remedy will result in hazardous substances remaining on-site above levels that allow for unlimited use and unrestricted exposure, a review will be conducted within five years (2001, 2006, 2011, 2016) to ensure that there is adequate protection of human health and the environment. |
Louis Howard |
| 3/22/1996 |
Update or Other Action |
Level "D" cleanup criteria applies. However, after a peer review, the leachability study was accepted which showed that the petroleum contaminated soils for numerous buildings at the Circle Loop area would not impact the groundwater beneath any of the sites. These buildings are as follows: 914 UST 137, 920 UST 95, 926 UST 96, 932 UST 97, 934 UST 98, 936 UST 99, 944 UST 100,
946 UST 101, 950 UST 102, 962 UST 105, and 968 UST 34.
No further assessment or remediation of the sites is requested by ADEC at this time based upon the data submitted by the Army. However, these closures do not preclude future remediation or site investigation if new information indicates there is previously undiscovered contamination or exposures which cause unacceptable risk to human health or the environment. Future investigation and/or remedial actions may be required if contamination exceeding these risks are detected or if the contamination is excavated.
ADEC reserves all of its rights under Title 46 of Alaska Statutes and 18 AAC 78 to request additional activities in the future if necessary to address these risks. ADEC requests any monitoring wells installed as a part of these investigations be added to the Post-wide monitoring network established under the CERCLA Federal Facility Agreement. The Army must maintain institutional controls on the sites which limit access to the soils and that anytime they are dug up they must be properly handled and disposed of.
Because this remedy will result in hazardous substances remaining on-site above levels that allow for unlimited use and unrestricted exposure, a review will be conducted every five years to ensure that there is adequate protection of human health and the environment. |
Louis Howard |
| 3/22/1996 |
Update or Other Action |
ICs are required since level of soil contaminated with petroleum is above those levels which would allow for unrestricted use. Circle Loop Road warehouse is currently an industrial complex. Due to limited access it is not expected to pose a risk to the general public or other pathways. Contamination is not expected to reach groundwater, based on a soil leaching potential assessment conducted during the release investigation. Therefore contamination poses no risk to the potential drinking water supply in the area. A dig permit required for any soil activity in area managed by Public Works Environmental staff. Area noted on Post Management plans and maps as an area requiring ICs and waste management and disposal at a permitted facility if soil were to be excavated at any time in the future.
ADEC requests any monitoring wells installed as part of these investigations to be added to a "Post-wide" groundwater monitoring well network established under CERCLA FFA (or the Two-Party Agreement).
The buildings covered by this decision are: 914 UST 137, 920 UST 95, 926 UST 96, 932 UST 97, 934 UST 98, 936 UST 99, 944 UST 100, 946 UST 101, 950 UST 102, 962 UST 105, and 968 UST 34.
This decision requires the Army to control digging or any excavation in area and that institutional controls will be in place to control access to contaminated soils. |
Louis Howard |
| 2/17/1997 |
Site Added to Database |
Diesel fuel contamination. |
Louis Howard |
| 4/21/1998 |
Site Ranked Using the AHRM |
Ranking action added now because it was not added when the site was originally ranked. |
Bill Petrik |
| 9/14/2001 |
Update or Other Action |
Institutional controls report received for several sites which include this building. DRO was detected up to 6,900 mg/kg, a leachability study was used to obtain site closure (NFA actually). This closure does not preclude future remediation or site investigation if new information indicates there is previously undiscovered contamination or exposures which cause an unacceptable risk to human health or the environment. ADEC requests any monitoring wells installed as a part of the investigation be added to the Post-wide monitoring network established under the CERCLA Federal Facility Agreement. ICs tracked under Fort Richardson Master Plan (GIS). |
Louis Howard |
| 12/12/2001 |
Update or Other Action |
1. All organizations conducting activities on United States Army Alaska (USARAK) controlled land are responsible for complying with established institutional controls (ICs). ICs are administrative, procedural, and regulatory measures to control human access to and usage of property. They are applicable to all known or suspected contaminated sites where contamination has been left in place.
2. These controls have been established to implement the selected remedial actions agreed upon by the U.S. Army (Army), the U.S. Environmental Protection Agency (USEPA), and the Alaska Department of Environmental Conservation (ADEC) in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) as amended by the Superfund Amendment Reauthorization Act (SARA). These controls also apply to remedial actions agreed upon under Two-Party Compliance Agreements. These agreements are concluded between USARAK and ADEC and apply to petroleum/oil/lubricants- (POL) contaminated sites.
3. ICs such as limitations on access, water use, excavations, and property transfers will supplement engineering controls as appropriate for short-term and long-term management to prevent or limit human and environmental exposure to hazardous substances, pollutants, or contaminants. Specific ICs include, among other things: limitations on the depth and location of excavations, prohibition of or restrictions on well drilling and use of ground water, requirements for worker use of personal protective equipment, site monitoring, and prohibition of certain land uses, types of vehicles, etc.
4. Organizational units, tenants, and support/contractor organizations must obtain an Excavation Clearance Request (ECR) for all soil disturbing activities impacting soils six inches or more below the ground surface. The review process for approval of an ECR begins with the identification of the current status (known or suspected hazardous waste site or “clean” site) of a work location. ECR’s for work in known or suspected hazardous waste sites:
a. will include specific limitations and controls on such work;
b. will include specific IC procedures, and notification, monitoring, reporting, and stop work requirements;
c. may include procedures for management, characterization, and disposal of any soil or groundwater encountered or removed;
d. will identify “project managers” for both the unit/contractor requesting the work and DPW Environment Resources.
5. The DPW project manager will conduct on-site inspections of each work site (at which ICs apply) to determine continued compliance with the terms and conditions of the approved ECR. DPW has the authority to revoke ECR approval if the specified terms and conditions are not being met. ECR forms are available at the Customer Service Desks at: a. Building 730 at Fort Richardson; b. Building 3015 at Fort Wainwright; c. Building 605 at Fort Greely.
6. USARAK has negotiated (with USEPA and/or ADEC) decision documents and/or Records of Decision (RODs) that mandate the implementation of ICs USARAK Directorate of Public Works, Environmental Resources Department (PWE), maintains copies of all decision documents and RODs requiring ICs in its real property files. PWE provides regularly updated post maps showing all areas affected by ICs. These maps can easily be accessed by using an approved intranet mapping interface application. Copies of these maps will be available to each directorate, activity, and tenant organization. To ensure the effectiveness of ICs, all organizational units and tenant activities will be informed on an annual basis of ICs on contaminated soils and groundwater in effect near their facilities.
7. ICs are enforceable by the U.S. Environmental Protection Agency (USEPA) and the Alaska Department of Environmental Conservation (ADEC). Failure to comply with an IC mandated in a decision document or ROD will violate the USARAK Federal Facility Agreement and may result in stipulated fines and penalties. This does not include the costs of corrective actions required due to violation of an established IC.
|
Louis Howard |
| 8/30/2007 |
GIS Position Updated |
61.2723 N latitude -149.7113 W longitude Figure 2 S&W Inc. Location map developed from Corps of Engineers master plan of Fort Richardson |
Louis Howard |
| 6/6/2012 |
Update or Other Action |
Draft Project Management Plan received for review and comment.
Performance Objective
Site Closure resulting in unrestricted future land use, or closure with land use controls, monitoring of long term management sites, and implementation of strategies that reduce the Air Force’s long-term environmental liabilities at JBER.
Potential Risk
The nature and extent of soil contamination in the upper 25 feet is greater than anticipated.
Groundwater impacts are discovered during site characterization.
Risk Mitigation
Will excavate soil as needed (estimate 250 yd3) to achieve SC. Monitoring wells will be installed, and groundwater contamination will be addressed with a technology that is appropriate to the nature and extent of the plume to achieve SC within the Period Of Performance. |
Louis Howard |
| 8/1/2013 |
Update or Other Action |
Draft UFP-QAPP received for review and comment.
The overall objective for the site is to meet “unrestricted or residential site use” criteria and achieve a “cleanup complete without institutional controls (ICs)” determination. To meet this objective, soil samples will be collected to characterize risk to human health and the environment within the framework of the ADEC site cleanup process (Title 18 Alaska Administrative Code Chapter 75 [18 AAC 75] Sections 325 to 390, and 18 AAC 78 Section 600) (ADEC, 2012a; ADEC, 2012b).
If 18 AAC 75 Method Two criteria are exceeded, the Hydrocarbon Risk Calculator (HRC) approach under Method Three will be used to assess whether site conditions meet ADEC risk criteria (in which case, a “cleanup complete without ICs” determination will be requested) or whether the site poses unacceptable risk (in which case, further remediation may be required).
If unacceptable risk is indicated by the HRC or if vadose zone soils exceed maximum allowable concentrations, then remedial options will be evaluated that address the contaminants of concern and associated exposure routes that contribute enough risk to cause the cumulative
risk estimate to exceed the risk standard.
One boring will be drilled at former boring AP-3535 to resample the soil at the location and
depth where previous sampling showed exceedances of the migration to groundwater criteria
for DRO and to collect source area soil samples for polycyclic aromatic hydrocarbons (PAHs), volatile petroleum hydrocarbons (VPH), and extractable petroleum hydrocarbons
(EPH) analysis.
One boring will be drilled in the area west of former UST 37 to assess the lateral extent of
contamination. Samples will be analyzed for gasoline-range organics (GRO), DRO,
petroleum-related volatile organic compounds (VOCs) (benzene, toluene, ethylbenzene,
xylenes, and naphthalene [BTEXN]), and PAHs.
Up to approximately 15 new primary soil samples will be collected and analyzed for GRO, DRO, RRO, petroleum-related VOCs (BTEXN), and PAHs. Three of the soil samples will also be analyzed for EPH and VPH. One of the soil samples will be analyzed for soil bulk density, grain size distribution, specific gravity, and soil moisture content. One of the soil samples will be collected from below the contaminated soil source and analyzed for fraction of organic carbon (foc).
If monitoring well AP-3542 exists and is able to be sampled, a groundwater sample will be
collected and analyzed for GRO, DRO, RRO, petroleum-related VOCs (BTEXN), and PAHs. |
Louis Howard |
| 8/13/2013 |
Document, Report, or Work plan Review - other |
Staff provided comments on the draft UFP-QAP WP.
Site-Specific Background
The text states: “Two environmental site investigations were conducted at TU083. A groundwater sample was collected from AP-3542 and analyzed for DRO, BTEX, and SVOCs. A groundwater sample collected from the onsite monitoring well contained DRO at a concentration well below its 18 AAC 75 groundwater cleanup level; concentrations of BTEX and SVOCs were not detectable.”
Actually more than one water sampling event occurred at the three monitoring wells (AP-3542, AP-3547, AP-3591) at Building 914. “Water samples collected from the three monitoring wells in March 1995 contained DRO ranging from 0.4 ppm to 0.5 ppm.. The initial groundwater sampling event was conducted on May 9 and 10, 1995, for the three new monitoring wells. Following a minimum of 24 hours after development, each well was purged using a dedicated, disposable Voss Teflon bailer to remove a minimum of 3 well volumes. The samples were collected directly from the bailer in the following order: volatiles, semi-volatiles, and DRO.
… the second sampling event was conducted using nitrile gloves instead of plastic surgical gloves, and stainless steel bailers were substituted for the disposable Teflon bailers. (Circle Loop Road Release Investigation Building 914 Underground Storage Tank 37 February 21, 1996 (Executive Summary and 3.3.3 Water Sampling)
Please note the use of bailers is not recommended for collection of VOC (e.g. BTEX, GRO) samples from monitoring wells. The use of bladder pumps, positive pressure submersible pumps, gear pumps, passive diffusion bag samplers, or samplers like HydraSleeve or Snap Samplers are preferred to reduce the loss of volatiles during sampling.
Page ES-7
Figure 2 Site TU083 Historical and Proposed Sample Locations – Building 914
Add the 15 mg/kg 2-Methylnaphthalene exceedance at 15-17’ bgs for boring AP-3535 (Table 2 Summary of Soil Analytical Results Circle Lp Rd 1996 RI) to Figure 2.
Page 34
The text states: “Groundwater samples will be collected using low-flow sampling techniques as described in SOP-13, and groundwater quality parameters will be collected.” This statement is not correct.
Low-flow sampling techniques are detailed in SOP-08 “Groundwater Well Sampling”.
SOP-08 states: “Low-flow sampling is typically conducted using positive displacement pumps, submersible pumps, or peristaltic pumps.”
ADEC does not recommend peristaltic pumps for collection of volatiles. ADEC May 2010 Field Sampling Guidance (draft): “Peristaltic pumps (section D2 of Groundwater Sample Equipment) and bailers (section D1) are not the preferred method for the collection of volatiles or other air sensitive parameters.”
SOP-13 “Water Quality Measurements and Calibrations details in one sentence that is relevant to low-flow sampling: “Continue pumping and begin low-flow purging of the monitoring well at a flow rate of approximately 1 liter (0.25 gallons) every 3 minutes or 0.1 gal/min.”
The actual intent of SOP-13 is to describe general methods for calibrating, maintaining, and operating water quality meters and probes used for groundwater sampling.
Please correct reference to SOP 08 as follows in this site-specific UFP-QAPP and all future and current draft UFP-QAPPs for JBER-Elmendorf/JBER-Richardson as follows (or some similar text for SOP-08 and SOP-13:
“Groundwater samples will be collected using low-flow sampling techniques as described in SOP-08 and the collection of groundwater quality parameters as described in SOP-13.”
Soil Excavation (If Required)
The text states: “If potential risk is indicated by the HRC or if vadose zone soils exceed maximum allowable concentrations (12,500 mg/kg for DRO), then remedial options that address the contaminants of concern and associated exposure routes that contribute enough risk to cause the cumulative risk estimate to exceed the risk standard will be evaluated.”
Not necessarily correct, remedial options that address the contaminants of concern which exceed maximum allowable concentrations will be also evaluated regardless of HRC risk calculation results. See comment #1 regarding MAC. Indications of risk or no risk by the HRC is not the sole criteria on whether action will take place at a site on JBER-Richardson or JBER-Elmendorf.
|
Louis Howard |
| 8/26/2013 |
Document, Report, or Work plan Review - other |
ADEC has reviewed JBER's responses to ADEC's comments for TU073, TU083 and TU085. The responses to comments are acceptable and the documents may be finalized. |
Louis Howard |
| 6/2/2014 |
Update or Other Action |
Draft SC report received for review and comment.
Conclusions
The following conclusions were made regarding TU083:
Based on previous investigations and the 2013 site characterization field investigation, DRO was detected in soil at concentrations above project screening levels.
DRO in soil at concentrations above the screening level (250 mg/kg) covers an area approximately 60 feet long and 30 feet wide extending primarily west from the former tank location, and starting near the ground surface and reaching a total depth of approximately 37 feet bgs (2,470 cubic yards).
Using the HRC for contaminated soil with the source area, the cumulative carcinogenic risk and noncarcinogenic HI estimates, based on both industrial and hypothetical residential exposure scenarios, are below the regulatory risk standards for soil direct contact/ingestion, outdoor air inhalation, and groundwater ingestion.
Using the HRC for contaminated soil with the source area, potential risks posed by the GRO, DRO, and RRO aromatic and aliphatic fractions are below the regulatory risk standard of 1 for direct contact, outdoor inhalation, and groundwater ingestion pathways.
The potential future indoor air exposure pathway is considered incomplete because there are no petroleum-related contaminants present that exceed the most stringent of ADEC’s 18 AAC 75.341 Table B1 cleanup levels.
No potential risks to the ecological receptors were observed, and petroleum hydrocarbon contamination in surface soil is considered insignificant (less than 0.5 acre). The site achieved the “off-ramp” in Part 3 Habitat of the Ecoscoping form (see completed Ecoscoping form in Appendix D).
Recommendations
The following are recommended for TU083:
No further investigation or cleanup of soil or groundwater.
Decommission monitoring well AP-3542.
ADEC designation of “Cleanup Complete” because the site meets the criteria established for site closure. |
Louis Howard |
| 6/25/2014 |
Cleanup Complete Determination Issued |
Cleanup complete determination made.
Site Description and Background
TU083 is the location of a former 1,000-gallon underground storage tank (UST 37) that stored
heating oil for former Building 914. The UST was removed in 1994 from a single excavation,
and Building 914 was demolished sometime between September 1993 and October 1994.
Contaminants of Concern
Diesel Range Organics (DRO)
Cleanup Levels
The cleanup level for soils at TU083 containing DRO contamination is 10,250 mg/kg in the Under 40-inch Zone based on the ingestion pathway within the 0 to 15’ interval below ground surface (bgs).
Based on the analytical data for soil and groundwater samples, modeling using the Hydrocarbon Risk Calculator (HRC), residual petroleum in soil at the site does not pose a migration to groundwater concern.
The estimated rounded cumulative cancer risk at TU083 for the current industrial and hypothetical residential exposure scenarios, across all exposure pathways, (7 x 10-7 and 8 x 10-6 respectively) is below the regulatory risk standard of 1 x 10-5 for petroleum hydrocarbons.
The estimated cumulative noncancer HI at TU083 for the current industrial and hypothetical residential exposure scenarios, across all exposure pathways, (0.01 and 0.03 respectively) is below the regulatory risk standard of 1. TU083 meets the ADEC risk criteria [18 AAC 75.325(g)] for petroleum hydrocarbons. The risk posed by the DRO aromatic and aliphatic surrogate fractions meets the risk standard for each exposure pathway, assuming a residential land use scenario.
An ecoscoping form was completed for TU083 and no observed surface soil staining, no impacted vegetation, no surface water or sediment runoff from the site. The ecoscoping form indicates that a more in-depth risk evaluation is not needed and that the TU083 site conditions are protective of the environment.
Based on a review of the environmental records, ADEC has determined that TU083 has been adequately characterized and has achieved the applicable requirements under the site cleanup rules. ADEC is issuing this written determination that cleanup is complete, subject to a future department determination that the cleanup is not protective of human health, safety, welfare, or of the environment [18 AAC 75.380(d)]. A “cleanup complete” designation will be entered for TU083 in the Contaminated Sites Database. |
Louis Howard |
| 6/26/2014 |
Institutional Control Record Removed |
Institutional Controls have been removed. |
Louis Howard |
| 10/6/2014 |
Update or Other Action |
Well decommissioning report received by ADEC.
Well decommissioning was completed by GeoTek, Alaska, on August 11, 2014, and was documented by CH2M HILL. Table 1 provides information about the decommissioned well. Well decommissioning was conducted in accordance with the Final Joint Base Elmendorf-Richardson, Monitoring Well Decommissioning Work Plan, TU083 – Building 914 (United States Air Force [USAF], 2014), and in accordance with procedures described in ADEC’s Monitoring Well Guidance (ADEC, 2013), as well as procedures described in Standard Operating Procedure (SOP)-12 presented in the approved Final Joint Base Elmendorf-Richardson, Basewide Uniform Federal Policy-Quality Assurance Project Plan, Alaska (USAF, 2013 |
Louis Howard |
| 10/7/2014 |
Document, Report, or Work plan Review - other |
Well decommissioning report approved. |
Louis Howard |
