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Site Report: UNOCAL Granite Point

Site Name: UNOCAL Granite Point
Address: Granite Point, Tyonek, AK 99682
File Number: 2337.38.033
Hazard ID: 1280
Status: Active
Staff: Peter Campbell, 9072623412 peter.campbell@alaska.gov
Latitude: 61.017778
Longitude: -151.421944
Horizontal Datum:NAD83

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, lead, and barium contamination encountered during initial site assessment. In 1993 during a Site Assessment/Remedial Investigation a total of approximately 15,000 cubic yards of contaminated soil was estimated to be located at the Unocal Granite Point Facility within 10 different areas. 1. Amoco Heater Treater Area - Approximatley 3,800 cubic yards. Source Area #72258 2. Diesel Spill Site-(Drum Storage Area)-Approximately 300 cubic yards.Source Area#79463 3. CIPL Valve Standards - Approximately 50 cubic yards. Source Area #79464 4. Amoco Pig Trap - Approximately 150 cubic yards. Source Area #79465 5. Unocal Pig Trap - Approximately 4,500 cubic yards. Source Area #79467 6. Flow Separator - Approximatley 300 cubic yards. Source Area #79466 7. Unocal Heater Treater & Coalescer-Approximatley 2,500 cubic yards.Source Area #79468 8. Unocal Tank Containment - Approximately 1,700 cubic yards. Source Area #79469 9. Old Flare Pit/Impoundment - Approximately 200 cubic yards. Source Area #79470 10. New Flare Pit - Approximately 1,500 cubic yards. Source Area #79471 In 1993 during the Site Assessment/Remedial Investigation analytes testing above the established ADEC soil cleanup levels includes gasoline range organics (GRO) at 301 to 1,300 milligrams per kilogram (mg/kg) at 1 to 6.5 feet below ground surface (bgs), diesel range organics (DRO) at 321 to 18,000 mg/kg at 1 to 9 feet bgs, benzene at 0.05 to 0.32 mg/kg at 4 to 5.5 feet bgs, ethylbenzene at 9.98 mg/kg at 3.5 to 4.5 feet bgs in one sample, xylenes at 99 mg/kg t 3.5 to 4.5 feet bgs in one sample, 2-Methylnaphthalene at 6.5 to 35 mg/kg at 1.5 to 5 feet bgs, Methylene Chloride at 0.018 to 0.34 mg/kg at 1 to 8.5 feet bgs, arsenic at 4.1 to 10.4 mg/kg at 1 to 9 feet bgs, and chromium at 26.5 mg/kg at 7.5 to 9 feet bgs. In 1993 during the Site Assessment/Remedial Investigation analytes testing above the established ADEC groundwater cleanup levels includes DRO at 1.5 to 12.6 milligrams per liter (mg/L), residual range organics (RRO) at 2.0 to 2.5 mg/L, benzene at 0.046 to 0.150 mg/L, Methylene Chloride at 0.005 to 0.035 mg/L, arsenic at 0.0119 to 0.0369 mg/L, barium at 2.03 mg/L, chromium at 0.170 to 0.395 mg/L, and lead at 0.0252 to 0.0936 mg/L. DRO plumes were identified in the areas of the Amoco Heater Treater, the Unocal Heater Treater/Coalescer, the Unocal Pig Trap Building, and the Sludge Tank Area. A RRO plume was identified in the area of the Unocal Heater Treater/Coalescer. Benzene plumes were identified in the areas of the Unocal Pig Trap Building, the New Flare Pit, and the Sludge Tank Area. The groundwater contamination detected in the area of the Sludge Tank area was unusual due to no soil contamination encountered during the drilling of the well. This site also includes spill no. 18239907802; spill date = 3/19/2018; substance = crude oil; quantity = unknown; source = crude oil processing equipment; lat/long (WGS 84, CS web map) 61.017062, -151.421151; description: During excavation activities to investigate a gas alarm at the Granite Point Tank Farm Valve Building, petroleum-contaminated soil was encountered. Approximately 55 gallons of contaminated soil were removed.

Action Information

Action Date Action Description DEC Staff
8/9/1993 Update or Other Action (Old R:Base Action Code = TECH - Technical Assistance). Technical assistance was provided to Unocal by ADEC in development of a Phase 2 Site Assessment Plan. Former Staff
8/9/1993 Update or Other Action (Old R:Base Action Code = SA2 - Phase II Site Assessment (General)). Unocal began implementation of a Phase 2 Groundwater Assessment Plan. Former Staff
8/12/1993 Meeting or Teleconference Held A meeting was held at KDO at the request of Unocal for purposes of submitting and discussing the proposed Phase 2 Site Assessment Plan. Former Staff
8/20/1993 Site Ranked Using the AHRM Initial ranking. Former Staff
8/20/1993 Site Added to Database Former Staff
3/4/1994 Update or Other Action (Old R:Base Action Code = TECH - Technical Assistance). Treatment alternatives were discussed with representatives of Unocal (at Unocal's request). Treatment alternatives are being considered to assist Unocal in locating a gas compressor building in an area identified as contaminated. Former Staff
7/27/1994 Update or Other Action (Old R:Base Action Code = TECH - Technical Assistance). TECH was provided to Unocal for the installation of a generator building at the facility. Problems were encountered when Unocal selected a contaminated area to locate the generator building. Unocal decided to relocate the building in an area believed to be free of contamination, rather than excavate contaminated soils (approximately 300 cubic yards). Former Staff
8/31/1994 Update or Other Action (Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). A remedial action plan for contaminated soils to be excavated in the footprint of a generator/switchgear building and the piping runs associated with this building was reviewed and rejected by departmental staff. Comments for non-acceptance were sent to the RP. Former Staff
5/25/2004 Update or Other Action File number assigned and entered into the Fileroom DB and CS DB. Alyce Hughey
11/1/2005 GIS Position Updated Using Figure 1 from a Groundwater Results for Monitoring Well MW-2 at the Granite Point Tank Farm, from OilRisk Consultants, dated May 24, 2004, in conjunction with TopoZone Pro and the KPB Parcel Lookup, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Maps, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:10,000, Coordinate Datum NAD83. High degree of confidence in accuracy of location. Alyce Hughey
5/29/2008 Exposure Tracking Model Ranking Initial ranking with ETM completed. Don Fritz
11/16/2011 Update or Other Action Site transferred from Don Fritz to Peter Campbell per Paul Horwath. Alyce Hughey
5/23/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 72258 name: AMOCO Heater Treatr Area Alyce Hughey
5/24/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79463 name: Diesel Spill Site (Drum Storage Area) Alyce Hughey
5/24/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79464 name: CIPL Valve Standards Alyce Hughey
5/24/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79465 name: AMOCO Pig Trap Alyce Hughey
5/24/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79466 name: Flow Separator Alyce Hughey
5/28/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79467 name: Unocal Pig Trap Alyce Hughey
5/28/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79468 name: Unocal Heater Treater and Coalescer Alyce Hughey
5/28/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79469 name: Unocal Tank Containment Alyce Hughey
5/28/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79470 name: Old Flare Pit/Impoundment Alyce Hughey
5/28/2013 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 79471 name: New Flare Pit Alyce Hughey
7/10/2013 Update or Other Action Review project file and send a letter to Hilcorp requesting a work plan for surface and ground water monitoring at the site. Peter Campbell
9/5/2013 Document, Report, or Work plan Review - other Received a 2006 ground water sampling report for the Granite Point Tank Farm from Hilcorp via Chevron. Peter Campbell
9/5/2013 Document, Report, or Work plan Review - other Received September 2006 Groundwater Sampling Results, Granite Point Tank Farm, Oil Risk Consultants, prepared for Unocal. Peter Campbell
9/5/2013 Document, Report, or Work plan Review - other Received a work plan for surface and groundwater monitoring to assess current conditions at the site. Peter Campbell
9/6/2013 Update or Other Action Work plan approved. Peter Campbell
8/8/2014 Document, Report, or Work plan Review - other Received Granite Point Tank Farm 2013 Groundwater Monitoring Report.. Peter Campbell
9/16/2015 Site Visit Site walk with Hilcorp representative and consultant to examine monitoring network and site conditions. Many of the existing wells have been destroyed and or lost. Requested a work plan from Hilcorp designed to fill data gaps on the down gradient side of the facility including surface water sampling. Peter Campbell
8/17/2016 Update or Other Action Hilcorp reported that sheen is day lighting at the ground surface after rainfall. The location of the seep is near the north central part of the facility between Tank 104 and a fuel storage area. The contaminated sites program has required that a spill assessment work plan be submitted to assess the extent of contamination and determine what remedial actions are necessary. Peter Campbell
5/18/2017 Document, Report, or Work plan Review - other Work plan approved to assess an area hydrocarbon staining near tank 104. Hand auger boings will be used to determine the extent of surface staining. Up to 20 borings may be used to explore the area. Assessment will include sampling existing groundwater monitoring wells and extending the analytical sampling suite into VOCs and SVOCs. Peter Campbell
12/1/2017 Document, Report, or Work plan Review - other Reviewed Contaminated Soil and Groundwater Management Plan for Cross Inlet Extension Project. Responded with a letter to Hilcorp correcting some of the proposed approaches to soils management, sample methods and parameters required for impacted soils. Peter Campbell
12/1/2017 Document, Report, or Work plan Review - other Reviewed the Road Stain and Seep Investigation Report dated October 2017. The report covered sampling of groundwater seeps south of the property, road staining in the northern portion and monitoring well sampling. Soils impacted at the road staining area were heavily contaminated. ADEC will require cleanup of this area. It appears that ground water seeps and surface water are not being impacted based on testing results. Peter Campbell
1/25/2018 Document, Report, or Work plan Review - other Conditional approval granted for Contaminated Soil Management plan for the Cross Inlet Extension Project. The plans cover the Granite Point Tank Farm, Middle Ground Shoal and East Forelands. Peter Campbell
6/18/2020 Spill Transferred from Prevention Preparedness and Response Program Spill transferred by PPRP staff Mike Evans. Spill no. 18239907802; spill date = 3/19/2018; substance = crude oil; quantity = unknown; source = crude oil processing equipment; lat/long (WGS 84, CS web map) 61.017062, -151.421151; description: During excavation activities to investigate a gas alarm at the Granite Point Tank Farm Valve Building, petroleum-contaminated soil was encountered. Approximately 55 gallons of contaminated soil were removed. Mitzi Read
10/20/2022 Long Term Monitoring Workplan or Report Review Review and approve Draft Groundwater Monitoring and Product Recovery Work Plan. Peter Campbell
11/18/2022 Update or Other Action Approve the disposal of monitoring well purge water into the facility waste stream. Peter Campbell

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

No associated sites were found.

Missing Location Data

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State of Alaska Department of Environmental Conservation

P.O. Box 111800
Juneau, AK 99811-1800
Phone: 907-465-5066
Fax: 907-465-5245
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