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Site Report: Alyeska PLMP 734 Pipe Leak

Site Name: Alyeska PLMP 734 Pipe Leak
Address: Mile 65 Richardson Hwy., Pipeline Mile 734, Copper Center, AK 99573
File Number: 330.38.096
Hazard ID: 20
Status: Cleanup Complete - Institutional Controls
Staff: IC Unit, 9074655229
Latitude: 61.487228
Longitude: -145.156862
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.


PLMP 734 is the location of a structural failure of the pipeline discovered on June 15, 1979. The volume of the historical spill was estimated to be between 126,000 and 168,000 gallons. Alyeska indicates that crude oil was recovered at the time and re-injected into the pipeline, sorbents used to recover crude oil were incinerated, and excavated gravel was spread on an access road in the vicinity. In preparation for the 2001 sleeve inspection and repair, Alyeska determined by using test pits that soil contamination still existed above ADEC cleanup levels. The excavation was extended to a maximum depth of 14.5 feet below ground surface. Approximately 400 cubic yards of impacted soil were excavated and transported to the soil stockpile at PS 12. The final dimensions of the excavation at ground surface were approximately 50 feet x 37 feet. SLR estimates the volume of impacted soil to be approximately 25 to 100 cubic yards.

Action Information

Action Date Action Description DEC Staff
3/14/2002 Update or Other Action Date of PLMP 734 Sleeve Repair Report cover letter received 3/19/2002. Following excavation of approximately 400 cubic yards of contaminated soil (stockpiled at PS 12), confirmation samples contained up to 0.98 mg/kg benzene and 1,910 mg/kg DRO. GRO, RRO, and other BTEX compounds were below Method Two levels. Keather McLoone
6/27/2002 Site Added to Database Crude oil contamination. Deborah Williams
6/27/2002 Site Ranked Using the AHRM Preliminary ranking. Deborah Williams
4/9/2003 Conceptual Site Model Submitted Date of receipt of Pipeline Milepost 734 Conceptual Site Model submitted by SLR on behalf of Alyeska. Three surface water locations were sampled on 8/23/2002. TAH and TAqH results were below water quality criteria. Keather McLoone
5/7/2004 Site Number Identifier Changed Changed Region from 31 to 24. No Longer Assigned
1/15/2008 Exposure Tracking Model Ranking Initial ranking with ETM completed. Keather McLoone
3/8/2011 Cleanup Complete Determination Issued Contaminated Sites staff has completed a review of the environmental records associated with Alyeska PS 03 Fire Training Area located Mile 311.8 Dalton Highway. 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 as long as the site is in compliance with the established institutional controls (ICs). Keather McLoone
3/10/2011 Institutional Control Record Established Institutional Controls established and entered into the database. Keather McLoone
12/1/2011 Update or Other Action The current project manager chose to retain management of this site with the Cleanup Complete Determination that has Institutional Controls. Kristin Thompson
12/16/2013 Update or Other Action On this date, ADEC received the CC-IC agreement page from Alyeska Grant Lidren
12/19/2013 Institutional Control Compliance Review IC compliance review conducted and staff changed from Grant Lidren to IC Unit. Reminder system set-up for follow-up with the responsible party in 2017. Kristin Thompson
5/12/2017 Institutional Control Compliance Review IC compliance review conducted. ICs Verification letter issued. Reminder system set to follow-up every five years. Kristin Thompson
6/12/2017 Institutional Control Periodic Reporting Received a letter verifying that land use conditions remain unchanged. Kristin Thompson

Contaminant Information

Name Level Description Media Comments
Benzene Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
DRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil

Control Type

Type Details
Signed CS Determination


Description Details
Advance approval required to transport soil or groundwater off-site. Standard condition.
Other Required every five years.
When Contaminated Soil is Accessible, Remediation Should Occur Soil contamination is located in the area of PLMP 734. When the soil in this area becomes accessible, such as during pipeline decommissioning, the soil must be evaluated and contamination addressed in accordance with an ADEC approved work plan.
Groundwater Use Restrictions Installation of groundwater wells will require approval from ADEC.
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) Standard condition.

Missing Location Data

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