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Site Report: Alyeska PS 01 Former Baseline Shop


Site Name: Alyeska PS 01 Former Baseline Shop
Address: Spine Road, Pump Station 01, 4.5 Miles S of Prudhoe Bay, Deadhorse, AK 99734
File Number: 330.38.114
Hazard ID: 4447
Status: Cleanup Complete
Staff: ,
Latitude: 70.257186
Longitude: -148.618522
Horizontal Datum:WGS84

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

Petroleum contamination from three historical spills discovered in 2004, in the vicinity of the Former Baseline Shop. Included in this site are: 1) Alyeska Spill No. 2004-IR-6948 (Northern Trench); reported on 9/17/2004; located in a trench that contained abandoned piping on the northeast corner of a concrete foundation that was scheduled for removal; maximum concentrations were gasoline range organics (GRO) at 3.86 milligrams per kilogram (mg/kg), diesel range organics (DRO) at 332 mg/kg, and residual range organics (RRO) at 49.2 mg/kg, 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene were both detected below cleanup levels. 2) Alyeska Spill No. 2004-IR-7013 (Scraper Building); reported on 10/1/2004; located ~30 feet northeast of the Scraper building on the western edge of the drive lane; the exposed area contained abandoned piping and corrugated piping; maximum concentrations were GRO at 255 mg/kg, DRO at 1,900 mg/kg, and RRO at 133 mg/kg. 3) Alyeska Spill No. 2004-IR-7062 (Southern Trench); reported on 10/9/2004; located along the edge of the concrete foundation east of the former Hazardous Waste Connex, ~40 feet south of spill 2004-IR-6948; one sample was analyzed for petroleum components and was non-detect. Soil results listed above and in 2007 report all below arctic zone cleanup levels.

Action Information

Action Date Action Description DEC Staff
8/10/2007 Exposure Tracking Model Ranking Initial ranking completed. Mitzi Read
8/10/2007 Site Added to Database Site added to the database. Mitzi Read
3/14/2008 Update or Other Action Receipt of Pump Station 1 2007 Former Baseline Shop Contamination Assessment Report. Eight borings were advanced to address historic contamination and attempt to delineate to the extent practical. Soil samples did not contain contaminants greater than the most conservative of arctic zone cleanup levels. Two monitoring wells were installed but only MW-2 contained sufficient water for sample collection. GRO, DRO, and RRO results were 1.84, 12.7, and 2.09 mg/L respectively. VOCs were detected but not above Table C levels. Groundwater monitoring will continue in 2008. Review of report including lab QA/QC conducted 3/25/08. Keather McLoone
3/4/2009 Report or Workplan Review - Other Date of receipt of Pump Station 1 Former Baseline Shop 2008 Ground Water Monitoring Report by SLR. Two monitoring wells were sampled. DRO/RRO above Table C. Cleanup criteria for 1,2,3-dichloropropane lowered with new regs released recently. This compound was reported in MW-2 below the PQL (considered estimated) and above the current Table C level. PQL greater than current Table C level. Monitoring to continue in 2009. Keather McLoone
5/22/2009 Report or Workplan Review - Other Review of Pump Station 1 Former Baseline Shop 2009 Groundwater Monitoring Work Plan. A single groundwater event is planned for late summer/early fall. MW-1 and MW-2 will be sampled and analyzed for GRO, DRO/RRO, and VOCs. Keather McLoone
5/7/2010 Report or Workplan Review - Other Review of Pump Station 1 Former Basline (Shop) 2009 Groundwater Monitoring Report. Two wells were sampled for GRO/DRO/RRO and VOCs in July 2009. Both wells had DRO/RRO above Table C and MW-1 had GRO above Table C. MW-2 also had methylene chloride above Table C. Several issues with lab analysis of VOCs were determined to not have a significant impact on data usability. Keather McLoone
6/18/2010 Report or Workplan Review - Other Review of Pump Station 1 Former Baseline Shop 2010 Groundwater Monitoring Workplan received June 15,2010. A single groundwater event including the 2 onsite wells is planned for when the PS 01 gravel pad is thawed. Keather McLoone
3/24/2011 Report or Workplan Review - Other Date of receipt of Pump Station 1 Former Baseline 2010 Ground Water Monitoring Report. Groundwater exceedances for GRO, DRO, and RRO exist at this site. 1,2,3-trichloropropane was detected above Table C in the duplicate sample at 0.00227 mg/L but the primary sample was non-detect at 0.001 mg/L. Keather McLoone
3/24/2011 Report or Workplan Review - Other Date of receipt of Pump Station 1 Former Baseline 2010 Ground Water Monitoring Report. Groundwater exceedances for GRO, DRO, and RRO exist at this site. 1,2,3-trichloropropane was detected above Table C in the duplicate sample at 0.00227 mg/L but the primary sample was non-detect at 0.001 mg/L. Keather McLoone
6/27/2011 Report or Workplan Review - Other Date of receipt of Pump Station 1 Former Baseline Shop 2011 Groundwater Monitoring Work Plan. Alyeska plans to conduct a single suprapermafrost ground water sampling event in 2011. Keather McLoone
2/14/2012 Report or Workplan Review - Other Date of receipt of 2011 Groundwater Monitoring report. Two wells were sampled and both wells contained DRO and RRO above groundwater cleanup levels. Review included laboratory data review checklist. Followup being conducted via email regarding LOQs not meeting cleanup levels for 1,2,3-trichloropropane and EDB. Keather McLoone
6/13/2012 Site Characterization Workplan Approved 2012 Work Plan approved for conducting soil borings, soil sampling, installing and sampling new monitoring wells. Commented on potential site closure. DRO remains approx 40x higher than ADEC cleanup levels, GRO is near cleanup levels and largely static, and RRO is 4-6x higher than cleanup levels. Data for other analytes (1,2,3-trichloropropane and Methylene chloride) were elevated but may represent sample "noise" due to lack of repeatability. Compare to levels next time. Richard Bernhardt
2/26/2013 Report or Workplan Review - Other SLR installed, developed and sampled 4x new monitoring wells (MWs 3,4,5,6) in 2012 for a total of six MWs onsite. Water samples were collected on 1 Aug (one day after the wells were installed). MWs 1,2,4,& 5 exceeded ADEC cleanup levels for DRO, but concentrations in MW-1 were roughly 1/3 of their previous concentration a year prior. The DRO concentration in MW-2 was reduced by a factor of 2.1. This drastic reduction may reflect a greater than expected radius of influence from the sulfate injection pilot study that was conducted approximately 380 ft. to the south southeast. Alternatively, external factors may have affected sample results this year. Future results will help to resolve this uncertainty. Maximum DRO concentrations were noted in MWs 1,2,4,& 5 with concentrations of 18.6, 14.8, 1.88, and 1.96 mg/L, respectively. No other exceedances were noted. ADEC requested for VOCs to be sampled by EPA Method 504.1 before entertaining a closure request to confirm that 1,2,3-Trichloropropane and 1,2-Dibromoethane are below regulatory criteria. Limits of detection are above regulatory criteria using EPA Method 8260B. Richard Bernhardt
3/14/2013 Update or Other Action Coordinates verified by comparing 2012 work report to Google Earth imagery. Richard Bernhardt
5/24/2013 Site Characterization Workplan Approved On this date, the Pump Station 1 Former Baseline Shop 2013 Groundwater Monitoring and Investigation Work Plan was recieved. In 2013, a single suprapermafrost GW sampling event will occur following the installation of additional soil borings and wells to further delineate soil and GW Impact. Richard Bernhardt
1/2/2014 Site Characterization Report Approved On this date, ADEC received the 2013 Groundwater Monitoring Report PS 1 Former Baseline Shop submitted by SLR dated December 31, 2013. Groundwater samples were collected from MW-1 to MW-6, in the vicinity of the former baseline shop. All the samples were analyzed for SW8260B and USEPA 504.1. The detection limit for the compound 1,2,3-trichloropropane, analyzed by method SW8260B, was 0.00062 mg/L, which is above the Table C groundwater cleanup level of 0.00012 mg/L. MW-1, MW-2, MW-4, and MW-5 contained DRO up to 31.5 mg/L. MW-1, MW-2, and MW-5 contained RRO up to 2.4 mg/L. PCE was detected in MW-4 at 0.00579 mg/L The GW gradient at the Former Baseline is relatively flat, with a trend towards the south. The 2013 GW elevations were from 1.17 to 1.40 feet higher than in 2012. Grant Lidren
5/27/2014 Risk Assessment Workplan Approved On this date, ADEC approved the 2014 Groundwater Monitoring Work Plan Pump Station 1 Former Baseline Shop submitted by SLR, dated May 2014. Grant Lidren
1/9/2015 Site Characterization Report Approved On this date, ADEC received the 2014 Groundwater Monitoring Report PS 1 Former Baseline Shop submitted by SLR dated December 2014. Groundwater samples were collected from MW-1 to MW-6, in the vicinity of the former baseline shop. Method 504.1 results for EDB and 1,2,3-trichloropropane contain a low bias due the temp blank received by the Network Denver lab at a temp of 12.8 C. MW-3 did not contain detectable concentrations of contaminants. MW-1, MW-2, MW-4, MW-5, and MW-6 contained detectable concentrations of DRO up to 19.3 mg/L. MW-1, MW-2, MW-5, and MW-6 contained detectable concentration of RRO up to 1.61 mg/L. PCE was only detected in MW-2 and MW-4 at 0.0011 mg/L and 0.00646 mg/L respectively. The GW gradient at the Former Baseline is relatively flat, with a trend toward the southwest then to the south. The 2014 GW elevations were from 0.58 to 1.72 feet lower than in 2013. Grant Lidren
7/6/2015 Site Characterization Workplan Approved The Alaska Department of Environmental Conservation (ADEC) Contaminated Sites Program (CSP) has received and reviewed the 2015 Groundwater Monitoring Work Plan Pump Station 1 Former Baseline Shop submitted by SLR and dated June 2015. ADEC has no objections to the Work Plan and SLR may proceed with the following comment: groundwater samples analyzed by AK 102; AK 103; and SW8260B will be preserved with HCL. Grant Lidren
3/29/2016 Site Characterization Report Approved On this date, ADEC received the 2015 Groundwater Monitoring Report PS 1 Former Baseline Shop submitted by SLR dated February 2016. Groundwater samples were collected from MW-1 to MW-6, in the vicinity of the former baseline shop. EDB and 1,2,3-trichloropropane, analyzed by USEPA Method 8260B-SIM, were ND. MW-1, MW-2, and MW-5 contained petroleum constituents above cleanup levels with DRO at 27.4 mg/L and RRO at 2.93 mg/L (MW-1). PCE was only detected in MW-2, MW-4, and MW-6 up to 0.00645 mg/L (MW-4). The GW gradient at the Former Baseline is relatively flat, with a trend toward the southwest then to the south. The 2015 GW elevations were from 0.81 to 1.71 feet higher than in 2014. Grant Lidren
2/15/2017 Update or Other Action On this date, ADEC received the 2016 Groundwater Monitoring Report PS 1 Former Baseline Shop submitted by SLR dated February 2017. Groundwater samples were collected from MW-1 to MW-6, in the vicinity of the former baseline shop. EDB and 1,2,3-trichloropropane, analyzed by USEPA Method 8260B-SIM, were ND. MW-1, MW-2, and MW-5 contained petroleum constituents above cleanup levels with DRO at 16.2 mg/L and RRO at 1.68 mg/L (MW-1). PCE was only detected in MW-2, MW-4, and MW-6 but below the DEC 2016 cleanup levels. The GW gradient at the Former Baseline is relatively flat, with a trend toward the southwest then to the south. The 2015 GW elevations were lower than in 2015 except for MW-2. Grant Lidren
7/19/2017 Site Characterization Workplan Approved On this date, ADEC received and approved the Pump Station 1 Baseline Shop Well and Equipment Shop Well Decommissioning Work Plan submitted by SLR and dated July 19, 2017. Grant Lidren
12/5/2017 Update or Other Action The six onsite monitoring wells were decommissioned during the summer of 2017. Grant Lidren
12/5/2017 Cleanup Complete Determination Issued The Alaska Department of Environmental Conservation, Contaminated Sites Program (ADEC) has completed a review of the environmental records associated with Alyeska Pump Station (PS) 01 Former Baseline Shop. Based on the information provided to date, it has been determined that the contaminant concentrations remaining on site do not pose an unacceptable risk to human health or the environment and no further remedial action will be required unless new information becomes available that indicates residual contaminants may pose an unacceptable risk. Grant Lidren

Contaminant Information

Name Level Description Media Comments
DRO > Method 1 (Arctic only) Soil
GRO > Method 1 (Arctic only) Soil

Control Type

Type Details
No ICs Required

Requirements

Description Details
Advance approval required to transport soil or groundwater off-site.
Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70)

Missing Location Data

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