Skip to content Skip to content

Site Report: Kenai Kachemak Pipeline Project

Site Name: Kenai Kachemak Pipeline Project
Address: Mile 124.5 Sterling Hwy., Near Larissa Avenue, Clam Gulch, AK 99568
File Number: 2307.38.003
Hazard ID: 4011
Status: Active
Staff: Dawn Wilburn, 9072628200 dawn.wilburn@alaska.gov
Latitude: 60.147984
Longitude: -151.500780
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

On March 26, 2003, during trench excavation work for a natural gas pipeline construction project, petroleum and chlorinated solvent contaminated stained soil, crushed 55-gallon drums, and other metal debris were encountered and identified. This natural gas pipeline and this site is located within an Alaska Department of Transportation and Public Facilities (ADOT&PF) easement, approximately 300 feet off the Sterling Highway in the vicinity of Mile 124.5 of the Sterling Highway, south of Clam Gulch. Shannon & Wilson, an environmental consulting firm, visited the site and collected a total of four soil samples for approved laboratory analysis. Diesel range hydrocarbons (DRO), benzene, carbon tetrachloride, trichloroethylene, barium, cadmium, chromium, and selenium exceeded ADEC Method Two 'Migration to Groundwater' soil cleanup levels, in the in-trench soil sample. Trichloroethylene exceeded the ADEC Method Two ‘Outdoor Inhalation’ soil cleanup level, and Arsenic exceeded the ADEC Method Two ‘Direct Contact’ soil cleanup level. Groundwater was not encountered, however the trench excavation was limited to approximately 6 feet in depth. Two stockpiles of visually impacted soil were stored adjacent to the trench excavation. These contaminated soils were returned to the natural gas pipeline trench. No further assessment of the extent or magnitude of the petroleum and hazardous substance soil contamination was completed. The location of this site is poorly documented. The contamination is located in and surrounding the high pressure natural gas pipeline trench, which has been backfilled, re-graded and re-vegetated. The site location is not visually identifiable, and it will be difficult to locate without survey coordinates. Updated 6/12/2013.

Action Information

Action Date Action Description DEC Staff
9/15/2003 Site Added to Database Solvents, metals, petroleum concentrations in soils. Bruce Wanstall
9/16/2003 Site Ranked Using the AHRM Preliminary ranking based on information in initial release investigation. Bruce Wanstall
10/7/2004 Update or Other Action File forwarded to Anchorage office for Project Manager assignment. Bruce Wanstall
11/10/2004 Update or Other Action Letter sent to ADOT/PF requesting additional site assessment to determine full horizontal and vertical extent of remaining contamination. A risk management decision will be made after reviewing the additional assessment data on what additional work may be required. Donald Seagren
8/30/2005 GIS Position Updated Using Figure 1 from a Release Investigation, Mile 124.5 Sterling Highway, Clam Gulch, from Shannon & Wilson, dated April 28, 2003, 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
4/11/2007 Exposure Tracking Model Ranking Donald Seagren
6/12/2008 Update or Other Action Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein. Alyce Hughey
1/4/2011 Update or Other Action ADEC supervisor directed the natural gas pipeline installation contractor to place two stockpiles of visually contaminated soil back into the utility trench without surveying or establishing the location, or assessing the extent of the hazardous substance pollution. The contamination is located in and surrounding the high pressure natural gas pipeline trench, which has been backfilled, re-graded and re-vegetated. Any additional efforts to assess or cleanup the petroleum and hazardous substance contaminated soils are immediately complicated by the fact that the specific location of these impacted soils, and this site, are not known. Because of the chlorinated solvents indentified in the initial soil sample data and the lack of any immediately adjacent development, it would be reasonable to suspect that this pollution was the result of an illegal dumping of solid waste and other hazardous substances by someone who understood the costs associated with proper characterization and disposal of chlorinated solvents. Trichloroethene (TCE) and Carbon Tetrachloride are both contaminants of concern in soil. TCE concentrations detected at 8.25 mg/kg, exceeded the ADEC Method Two, Table B1 'Outdoor Inhalation' soil cleanup level. Paul Horwath
1/5/2011 Exposure Tracking Model Ranking A new updated ranking with the ADEC CSP Exposure Tracking Model has been completed for source area 74985 Unknown. This resulted in an ETM Score of 10, and a High Potential Exposure determination for Groundwater Ingestion, Surface Water Ingestion, and Wild or Farmed Foods Ingestion. Paul Horwath
4/1/2013 Update or Other Action Trichloroethene (TCE) and Carbon Tetrachloride were added to this database as contaminants of concern in soil. TCE concentrations exceeded the ADEC Table B1 'outdoor inhalation' soil cleanup level. Paul Horwath
6/17/2013 Update or Other Action After having reviewed the ADEC project file, it is concluded that it may be difficult to relocate this 'site' in the field. The 'site' isn't within the Sterling Highway road right-of-way, as was originally believed. It was realized that this high pressure natural gas pipeline is buried in a State of Alaska ADOT&PF 'easement' located approximately 300 feet away from the Sterling Highway, in the vicinity of Mile 124.5 Sterling Highway - south of Clam Gulch. The best known course of action to locate this 'site' in the field would be to contact the owner of the natural gas pipeline and see if they have as-built drawings for their pipeline that include construction Station numbers. If so, and if there are permanent Station monuments remaining along the pipeline in the field, a natural gas company employee with the as-built drawings may be able to travel to the gas pipline and identify the 'site' location using the Station number 1479 + 0 location information. Figure 2, Site Map, in Shannon & Wilson's April 28, 2003 letter-report RELEASE INVESTIGATION, MILE 124.5 STERLING HIGHWAY, CLAM GULCH, ALASKA, includes a center line Station number 1479 + 0, and shows this Station number to be located 55 to 145 feet north of this 'site'. If Station number 1479 could be located in the field, then this 'site' would be located south along the pipeline approximately 55 to 145 feet. The easement was reportely landscaped and re-vegetated after the pipeline was buried, leaving no visual evidence at the ground surface. There are also two color photographs on Figure 3 of this S&W report that might be helpful in identifying the 'site' location in the field. Trees visible in these two photographs may still be visually identifiable along the pipeline adjacent to this 'site'. Paul Horwath
6/17/2013 Update or Other Action Cadmium, Chromium, Arsenic, and Barium were added as additional contaminants of concern in soil. Paul Horwath
7/10/2015 Update or Other Action File review completed on this day. Site location, based on field notes is 15 feet south of Pipeline Station number 1479+00. This station number was located based on as-built surveys and GIS placement. See file for up-to-date site location information. Site may be location of former dump site (unknown), but indicated by buried drums and other metal debris and stained soil. Chlorinated solvents remains in soil above cleanup levels. Joshua Barsis
7/20/2015 Update or Other Action Further review of site location on this day. This site has two possible locations; one is the area identified by as-built maps, and the other is based off of aerial imagery. ADEC reviewed aerial imagery dated 1951 though 2004. One area was identified as having fill since 1961 until early 2000. There is soil disturbance and evidence of trenching in 2003 in this location. The site location based off of as-built maps shows an old home that has existed since the 1950s. The as-built information is located in the Anchorage electronic file. The ADEC GIS map has been updated to show the location based on as-built. If further investigation occurs in the future, both locations should be investigated. Joshua Barsis
10/25/2016 Update or Other Action Letter sent on this day with a brief site history and to outline existing data gaps that need to be addressed before this site could be considered for closure. Joshua Barsis
12/1/2021 Update or Other Action Reviewed file for next steps and requested site update from the responsible party, ADOT&PF - Anchorage. Last correspondence on file is the letter that was sent on October 31, 2016, that outlined the existing data gaps at this site. Jessica Hall
12/6/2021 Update or Other Action Per email from Alaska Dept. of Transportation & Public Facilities. DOT &PF is still under a Consent and Final Order with EPA to decommission Class V Injection wells, which is our priority. Also, the state budget has been cut over the past five years, which has forced DOT&PF to prioritize decommissioning the wells under the EPA CAFO first and if possible try to characterize and remediate while staying in the scope of the budget for each well closure. DOT&PF has not further characterized this site due to the CAFO prioritization as well as no State General funds available to fund the vertical and horizontal extent of contamination at this site. Jessica Hall
12/6/2021 Potentially Responsible Party/State Interest Letter Sent ADOT a Potentially Responsible Party/State Interest Letter. Jessica Hall

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

No associated sites were found.

Missing Location Data

Because the GIS location data for this site has not been entered, we cannot direct you to its position on the map. Click "Continue" to proceed to the Contaminated Sites Web Map or "Close" to return to the site report.
Continue     Close