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Site Report: Alyeska MP400 Bullet Hole Spill

Site Name: Alyeska MP400 Bullet Hole Spill
Address: Pipeline MP 400.9, Adjacent - Check Valve 66, Central, AK 99730
File Number: 330.38.104
Hazard ID: 3853
Status: Cleanup Complete - Institutional Controls
Staff: IC Unit, 9074655229
Latitude: 65.438889
Longitude: -148.583333
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.


On October 4, 2001, a bullet ruptured the Trans Alaska Pipeline System (TAPS) near pipeline milepost 400.9, releasing an estimated 285,600 gallons of crude oil beneath and to the west of the pipeline. The release was contained to an area of approximately 2.5 acres by excavation of a perimeter and containment pits into the permafrost. Trenching, product recovery, soil excavation/removal/backfilling, fertilization, and re-vegetation efforts were conducted in 2001 and 2002. As of November 16, 2001, 173,400 gallons of crude oil had been recovered. Ongoing visual monitoring shows that the revegetation efforts have been successful, and the site lacks evidence of contaminant migration or sheen on surface water bodies.

Action Information

Action Date Action Description DEC Staff
3/14/2002 Update or Other Action Release Response and Environmental Site Assessment Report date. Mentions a corrective action plan submitted to DEC in December 2001. This report summarizes results of October and November 2001 site assessment. One of the goals was to define remediation efforts required. In most locations, contamination did not extend beyond 2 ft bgs due to the presence of permafrost silt. However, where pockets of coarse-grained material were present, contamination extended further in depth. Test pits were advanced and soil removed from the pipeline ROW. This removal effort removed much of the surface contamination but it was determined that further excavation was warranted when corrective actions resumed. Keather McLoone
4/10/2002 Update or Other Action Right of Way Assessment and Oil Recovery Program Report date. This subsurface assessment was conducted in the pipeline right of way (ROW) and initially identified the presence of a subsurface, separate phase crude oil lens at ~ 19 ft bgs. The lateral extent of this lens was found to be associated with a lens of suprapermafrost groundwater and bounded on all sides and at depth by permafrost. This initiated installation of product recovery wells and monitoring wells in the ROW. Due to concerns of maintaining the structural integrity of the pipeline, it was deemed impractical to excavate this lens of contamination. Soil samples collected from borings contained concentrations up to 4,240 mg/kg GRO, 24,200 mg/kg DRO, 10,500 mg/kg RRO, 67.5 mg/kg benzene, 187 mg/kg toluene, and 279 mg/kg xylenes. Keather McLoone
12/1/2002 Update or Other Action Corrective Action Report submitted for the TAPS Milepost 400.9 spill. The report summarizes the work that was completed at the site. Alyeska successfully excavated and remediated over 27,000 tons of lightly oiled soil and vegetative mat and 2,491 cubic yards of heavily oiled vegetative mat and soil from the spill site. The closure soil samples met the ADEC Method One, Category D cleanup levels. The excavation was backfilled with approximately 18,500 cubic yards of soil which was graded, contoured, and revegetated by planting grasses, willows, and black spruce. Alyeska will monitor the revegetation efforts for three additional years. A lens of contaminated soil beneath (15 to 22 feet bgs) the right-of-way could not be excavated due to the pipeline structural integrity concerns. Recovery wells were installed in the ROW in 2002, the combined systems removed a total of 452 gallons of crude-oil-impacted water and 291.5 gallons of separate-phase crude oil (hand bailing, peristaltic pumps and belt skimmers). The plume is confined to a linear expression within the ROW and discontinuous in extent controlled by the irregular morphology of the meltwater lens. The plume is bounded by permafrost below and to the northeast and southwest. There is no indication that the crude oil plume or the dissolved plume is migrating off the pipeline ROW. Deborah Williams
12/31/2002 Site Added to Database Some crude contamination left in a lens of contaminated soil beneath (15 to 22 feet below ground surface) the right-of-way of the Trans Alaska Pipeline. Deborah Williams
12/31/2002 Site Ranked Using the AHRM Preliminary ranking. Deborah Williams
3/8/2004 Update or Other Action ADEC received SLR's report on 2003 Water Monitoring and Remedial Action Report Milepost 400 Crude Oil Release site. Although detectable levels of hydrocarbons still exist at certain surface water sampling locations and within monitoring wells in the ROW, it is apparent that the concentrations have greatly decreased over the past year. No surface water quality violations occurred in 2003. It is recommended that recovery of the free-phase crude oil continue in 2004, as soon as weather permits. It is also recommended that water monitoring continue through 2004 to include surface water sampling sites and the monitoring wells, with three scheduled comprehensive sampling events, in the spring, mid-summer and fall. Deborah Williams
1/21/2005 Update or Other Action Receipt of MP 400 Revegetation Report for 2004 prepared for APSC by Lazy Mountain Research Company. Concludes that revegetation goal for the site is being realized. Keather McLoone
3/8/2005 Update or Other Action Review of 2004 Water Monitoring and Remedial Action Report received 02/25/2005. Detectable levels of hydrocarbons were noted in surface water from locations SW-11 and SW-12, but at levels below ADEC cleanup standards. Hydrocarbon concentrations in groundwater remained relatively stable at monitoring wells within the ROW. Although benzene exceedances occurred in wells MW-5, MW-6, and MW-8, the magnitude was similar to concentrations detected in 2003 samples, and notably less than detections in 2002 samples. Deborah Williams
2/6/2006 Update or Other Action ADEC received the 2005 Water Monitoring and Remedial Action Report for the MP 400 Release site. According to the report, hydrocarbon concentrations in the groundwater remain relatively stable (ranged up to 184 ppb benzene) at monitoring wells within the ROW. SLR recommends sampling of the groundwater wells and continuation of the surface water sampling at locations SW-1, SW-2, SW-8, SW-9, SW-11 and SW-12. Product recovery over the 3 previous seasons has decreased with approximately one quart recovered in 2005 - all from RW-3 (max. thickness 0.16 inches). No other wells contained sufficient product to allow recovery using a skimmer or a peristaltic pump. Deborah Williams
2/16/2007 Update or Other Action ADEC received the SLR report - 2006 Water Monitoring and Remedial Action Report for MP 400 Crude Oil Release Site. According to the report, MW-5, MW-6 and MW-8 still have benzene contamination above ADEC cleanup levels but they appear to be relatively stable. Petroleum hydrocarbon concentrations in surface water remain below ADEC surface water quality criteria (TAH and TAqH). No product was recovered in 2006 due to low levels. Deborah Williams
3/15/2007 Exposure Tracking Model Ranking Initial ETM ranking by Deb Williams Keather McLoone
7/19/2007 Update or Other Action ADEC and Alyeska Pipeline (and their consultant SLR) conducted a field visit of the bullet hole site. The area that had been disturbed during the response efforts was in various stages of revegetation. It was evident that the black spruce area had been cleared in the response and now had willows and other vegetation growing. The wetland area downgradient did not have visual evidence (ie sheening) of contamination. The monitor data was discussed and DEC recognizes there may be impacts in the pipeline corridor but the data indicates it is not migrating. Closure issues were discussed and Alyeska may request a closure decision in the future. Jim Frechione
3/21/2008 Update or Other Action Receipt of Milepost 400 Crude Oil Release Site 2007 Water Monitoring and Remedial Action Report. Multiple site visits were conducted in 2007 to observe re-vegetation development, water levels, product levels, stream conditions etc. Planned collection of groundwater was not possible due to dry and frozen wells. No sheen was observed on surface water; therefore, no surface water samples were collected. No measurable product was observed in recovery wells. Recovery and monitoring wells were decommissioned. APSC requests site closure. Keather McLoone
5/1/2008 Conditional Closure Approved The Alaska Department of Environmental Conservation (ADEC), Contaminated Sites Program, reviewed the environmental records associated with site MP400 Bullet Hole Spill. This site had been contaminated by the release of a hazardous substance; however, based on the information provided to date, ADEC has determined that no further remedial action is required, and that MP400 Bullet Hole Spill site can be closed subject to the conditions outlined in this document. The hazardous substance contamination has been adequately addressed and does not pose an unacceptable risk to human health or the environment. Keather McLoone
5/1/2008 Institutional Control Record Established ADEC has determined that the cleanup action employed at the Alyeska MP400 Bullet Hole Spill were effective in removing a majority of the contaminant source material. 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 is required at Alyeska MP400 Bullet Hole Spill. This determination is subject to the following conditions: 1. An institutional control will be recorded on the ADEC database that identifies the nature and extent of the contamination remaining on the site. 2. Any proposal to transport soil off site requires ADEC approval in accordance with 18 AAC 75.370 (b). 3. Visual monitoring and reporting of surface water observations for potential offsite migration of contaminants to be addressed on an annual basis. Keather McLoone
6/25/2009 Site Visit CS staff conducted a site inspection along with Alyeska Pipeline Services Company and their consultant, SLR, to the Milepost (MP) 400 Bullet Hole Spill site. The MP 400 Bullet Hole Spill Site visit included a walk to the downgradient edge of the excavated area to observe the few locations where surface water occurs. The area was successfully revegetated, with the vegetation now nearly 6 feet tall, using willow cuttings. No petroleum sheening was observed. Locations of former monitoring wells were also pointed out. Spill response history was also discussed. Keather McLoone
5/23/2011 Report or Workplan Review - Other Date of receipt of Valdez Marine Terminal 2011 Tanks 51 and 52 Water Monitoring Workplan. Alyeska proposes a single groundwater and surface water sampling event. Keather McLoone
6/10/2011 Update or Other Action Email communication on this date regarding the visual surface water monitoring requirement agreed to by Alyeska as part of the earlier decision letter's conditions. Alyeska indicated that while this had been overlooked in the past, it would be added to their commitments so that it would not be overlooked in the future. 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
9/6/2012 Report or Workplan Review - Other Received & reviewed Alyeska's annual visual inspection report. Transplanted vegetation continues to thrive, and the site is being recolonized by natural processes, resulting in the presence of additional species, such as alder trees that weren't introduced by Alyeska. Moose frequent the area, and there isn't any evidence of sheen on surface water bodies. Therefore, Alyeska petitioned for removal of the reqirement for annual visual inspections from the list of ICs at this site. Richard Bernhardt
9/7/2012 Institutional Control Update Removed the institutional control requirement to conduct annual visual monitoring at this site. Annual visual monitoring of surface water bodies was designed to identify potential ecological impacts and offsite migration of contaminants. Details from these inspections have shown that Alyeska’s trenching, product recovery, soil excavation, backfilling, fertilization, and re-vegetation efforts in 2001 and 2002 were successful, and there is no evidence of ongoing contaminant migration or continued surface impact. The other two institutional controls (documentation of contamination within the CSP database and requirement of approval to transport soil from this site) remain in effect. Richard Bernhardt
11/12/2013 Update or Other Action Staff changed from Linda Nuechterlein to IC Unit. Kristin Thompson
11/20/2013 Institutional Control Compliance Review IC review conducted. The Task Tracker application was updated to document the need for an IC reminder letter to be sent to the RP. Evonne Reese
6/20/2018 Institutional Control Compliance Review IC compliance review conducted. Closure/IC Details updated. ICs Verification letter issued. Reminder system set to follow-up every five years. Kristin Thompson
6/22/2018 Institutional Control Periodic Reporting Alyeska reported there have been no changes at the site. Kristin Thompson

Contaminant Information

Name Level Description Media Comments
BTEX 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
RRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
GRO Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil
Naphthalene Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation Soil

Control Type

Type Details
CS Database Notation And Letter To Landowner/RP


Description Details
Excavation / Soil Movement Restrictions The remaining contaminated soil is located below the fiber optic cable and pipeline structural support members and not readily available to typical receptors. However, if excavation activities were to occur, receptors such as construction workers could come in contact with contaminated soil. Therefore, the ADEC should be notified prior to any excavation activities occurring so that receptor exposure can be evaluated and management conditions applied as needed.
Advance approval required to transport soil or groundwater off-site. Standard condition.
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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