Site Report: MOA - Paratransit Addition
Site Name: | MOA - Paratransit Addition |
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Address: | 3625 A Dr. Martin Luther King Jr. Avenue, Anchorage, AK 99507 |
File Number: | 2100.38.512 |
Hazard ID: | 25424 |
Status: | Non-Qualifying |
Staff: | No Longer Assigned, 9074655229 dec.icunit@alaska.gov |
Latitude: | 61.178140 |
Longitude: | -149.813780 |
Horizontal Datum: | NAD83 |
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We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.
Problems/Comments
In September 2005, a geotechnical investigation was conducted to evaluate the soil and groundwater conditions at the proposed MOA Paratransit Addition. Due to the historical contamination previously identified within the planned footprint of the addition,, environmental sampling of the soil and groundwater was conducted. A diesel range organics (DRO) concentration of 289 milligrams per kilogram (mg/kg) was detected in the soil from Boring B-1 which was collected from about 10 feet bgs. A soil sample from Boring B-2 at 10 feet below ground surface (bgs) contained 0.0336 mg/kg tetrachloroethylene (PCE). These samples exceed the migration to groundwater cleanup levels of 250 mg/kg and 0.024 mg/kg, respectively. Monitoring well MW-1 was installed approximately five feet west of Boring B-2 on to evaluate groundwater for contamination. Sampling results for residual (RRO), diesel (DRO), and gasoline range organics (GRO), and volatile organic compounds (VOCs) were all non-detect. The groundwater was 10.5 feet bgs prior to sampling on 9/7/2005. As of June 2009, the new Paratransit Addition is already completed over the site. The former address was 3650 C East Tudor Road and was changed as of 2009 and confirmed by a site visit.
Action Information
Action Date | Action | Description | DEC Staff |
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10/15/2005 | Document, Report, or Work plan Review - other | Reviewed the Shannon & Wilson, Inc. "Geotechnical Engineering Report, MOA Paratransit Addition, Anchorage, Alaska", dated October 2005, received 7/27/09. Borings B-1 and B-2 were drilled on 9/1-2/05 and monitoring well MW-1 was installed 5’ west of boring B-2. One sample from 10’ bgs from each boring was sent for laboratory analysis of RRO, DRO, GRO, and VOCs. The only detections in the sampling results from boring B-1 were RRO at 239 mg/kg and DRO at 289 mg/kg, the latter above the cleanup level of 250 mg/kg. The only detections in the sampling results from boring B-2 were RRO at 89.7 mg/kg and Tetrachloroethene (PCE) at 0.0336 mg/kg, the latter above the migration to GW cleanup level of 0.024 mg/kg. The borings were filled with Volclay below the water table, topped with bentonite chips, drill cuttings, and then capped with asphalt. Monitoring well MW-1 was sampled for RRO, DRO, GRO, and VOCs on 9/7/05. All results were ND. This action was placed at this date to maintain site chronology despite the report being reviewed on 8/4/09. | Bill Petrik |
1/18/2006 | Cleanup Plan Approved | Reviewed the Shannon & Wilson, Inc. "Environmental Management Plan, MOA Paratransit Addition, 3650 East Tudor Road, Anchorage, Alaska" dated November 2005, received 11/18/05. The document constitutes an Environmental Management Plan (EMP) for handling and remediating/disposing potentially contaminated soil and groundwater that may be encountered during construction of the Municipality of Anchorage (MOA) Paratransit Addition. Sent a letter this date conditionally concurring with the approach. The project is located adjacent to Building C on the facility and consists of constructing an addition to the existing Bus Maintenance Building. The proposed addition will be constructed in the area where two former 10,000 gallon underground storage tanks (USTs) were located (See file 2100.26.045). The former UST's were used for storage of diesel fuel and were removed from the ground in 1992. Investigative work in the vicinity of the former USTs completed to date, indicates that diesel range organic (DRO) levels in soil collected from beneath the USTs were below the most stringent soil clean up level of 250 mg/kg as listed in 18 AAC 75.341 Table B2. Two former 500 gallon waste oil UST's were located in the vicinity of the project area. One located approximately 50 feet south of the project location and one approximately 75 feet to the east. Both UST's were decommissioned by the MOA in 1997. Laboratory results from soil collected from the eastern UST excavation did not indicate any contamination above regulatory levels. Laboratory results of soil collected from the limits of the southern UST excavation identified exceedances of diesel range organics (DRO) of 1,800 mg/kg, gasoline range organics (GRO) of 3,000 mg/kg and Tetrachloroethylene (PCE) of 0.039 mg/kg. No additional soil was removed from the ground due to the proximity to a buried fiber optics and high voltage cables. Geotechnical investigation activities were performed in 2005 in the project area to evaluate the soil and groundwater conditions. Environmental sampling of soil and groundwater was included based on site history. Soil was collected from the project area and laboratory analyzed. Laboratory results identified 289 mg/kg DRO in soil boring B-1 and 0.0336 mg/kg PCE in soil boring B-2, both at 11‘ bgs. A groundwater monitoring well (MW-l) was installed adjacent to soil boring B-2 to evaluate groundwater quality. No contaminants were detected in groundwater collected from MW-1. The project plans do not include excavation to 11’ bgs. The majority of the material to be excavated should consist of clean fill from the backfilled UST excavation. In the event contaminated material is encountered, it is proposed in the EMP that any potentially impacted soil will not be excavated, but moved within the excavation to allow foundation preparation. Based on the data provided, on-site contamination associated with this project is not considered a risk to human health or the environment and DEC approves the EMP. DEC's determination is based on current site conditions. Should site conditions change and/or remaining contamination become a risk to human health or the environment, additional actions may be required. | David Pikul |
5/7/2008 | Document, Report, or Work plan Review - other | Reviewed the Shannon & Wilson, Inc. "Excavation Monitoring and Well Decommissioning, MOA Paratransit Addition, Anchorage, Alaska" dated 4/22/08, received 5/7/08. The report documents field activities performed and results from foundation and utility installation efforts, and decommissioning monitoring well MW-1. During excavation activities during August and November 2007, 141 soil screening samples were collected from the excavations and 8 stockpiles of excavated soil. In accordance with the 1/18/06 ADEC-approved Environmental Management Plan, soil requiring offsite disposal would be characterized for DRO, RRO, and VOCs. Because none of the stockpiles was transported off site, no samples were collected for laboratory analytical testing. Monitoring well MW-1 was located within the foundation area, encased in concrete, and was consequently decommissioned in place. The report was reviewed on 7/17/09 but placed at the date the report was received by the CSP for the sake of maintaining site chronology. | Bill Petrik |
6/12/2009 | Site Visit | Conducted a site visit and confirmed that the addition was completed. Made notes as to the building footprint location and the new building address. The new addition is located atop the former site named "MOA - Bus Transit Facility 2 Former 10,000 Gallon Diesel USTs", file 2100.26.045 but not atop two other separate areas, one due east of the addition by ~60' and the other due south of the addition by ~30', where separate 500-gallon USTs were removed in 1997 (sites not added to the CSP DB). The groundwater at this site may be affected by the site due south but insufficient work has been done at that site to date that to determine any possible affects by that site on this site. | Bill Petrik |
7/7/2009 | Site Added to Database | A new site has been added to the database. | Mitzi Read |
8/10/2009 | Exposure Tracking Model Ranking | Initial ranking with ETM completed for source area id: 78789 name: MOA - Paratransit Addition | Bill Petrik |
9/16/2009 | Update or Other Action | The CSP completed a review of the environmental records associated with this site and based on the information provided to date, the ADEC has determined that further evaluations of site conditions are required. The CSP sent a letter this date and requested a CSM be completed for the site as well as the potential for vapor intrusion related to the VOCs be evaluated. | Bill Petrik |
7/23/2013 | Exposure Tracking Model Ranking | A new updated ranking with ETM has been completed for source area 78789 Borings B-1 and B-2. | Katrina Chambon |
7/26/2013 | Update or Other Action | CSP has reviewed the administrative file for the site and belives that this site has an identified source; which, is a current active site. CSP considers this site as a duplicate site. Please refer to site "MOA - Maintenance Support Division Communications Shop - UST 1448-1"' File Number 2100.26.318 and Hazard ID 25443 regarding any cleanup activities and current actions. This site is considered Non Qualifying | Katrina Chambon |
Contaminant Information
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Requirements
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There are no documents for this site report.
Hazard ID | Site Name | File Number |
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23950 | MOA - Bus Transit Facility 2 Former 10,000 Gallon Diesel USTs | 2100.26.045 |