North Pole Refinery
- Click on photos or maps for larger versions.
- Contacts updated: 9/30/2020
- Summary updated: 9/30/2020
For background on the history of this site, please see the Project History page
Map above shows the results of annual testing performed in 2019 to determine the approximate extent of sulfolane impacts in the North Pole area. Click on the map to download a larger version.
Contamination associated with historical oil refining activities at the former North Pole Refinery (now Marathon Terminal), located about 15 miles east of Fairbanks, has affected groundwater used as a source of drinking water in the North Pole area. The refinery operated from the late 1970s until it shut down in 2014. In 2009, the industrial solvent sulfolane, which was used in the refining process, was detected in drinking water wells off the former refinery property. In 2018, per- and polyfluoroalkyl substances (PFAS) used in fire-fighting foams on the former refinery were detected in groundwater off the property. The sulfolane groundwater plume is approximately 2 miles wide, 3.5 miles long and over 300 feet deep, and continuing to migrate gradually to the north-northwest. The PFAS plume appears to have a similar footprint, although the boundaries of the plume have not been fully evaluated. The former refinery’s land still contains fuel product trapped in the soil and groundwater, but these petroleum components have not migrated off the property.
Under DEC oversight in 2009, then-owner of the refinery Flint Hills Resources Alaska (FHRA) began providing affected residents and businesses with alternative drinking water solutions. They also began sampling and other activities to find out how far the sulfolane had spread. Sulfolane was found to have impacted approximately 350 drinking water wells. FHRA provided affected properties with either connections to city water (if available), bulk water tanks, bottled water, or point-of-entry (POE) treatment systems to remove sulfolane from their well water. Properties in a “buffer zone” beyond the sulfolane plume were provided interim bottled water to protect against possible migration of the sulfolane. Sampling conducted in 2018 showed that the alternative water solutions that provided for protection from sulfolane were also protecting residents from PFAS in their well water.
In February 2017, the State of Alaska, FHRA, and the City of North Pole reached a settlement agreement to expand the City’s piped water system to all improved properties located within the sulfolane plume or in its anticipated migration path. The expanded piped water system is expected to be complete by the end of 2020 and will provide permanent protection from contamination in groundwater that is used for drinking water. Long-term groundwater monitoring continues off the former refinery property to track the sulfolane plume’s migration and concentrations for protection of properties developed in the future or ones located beyond the expanded piped water area. On the former refinery property, groundwater monitoring is used to track sulfolane and petroleum concentrations.
PFAS were discovered beyond the former refinery’s property boundary in a single 2018 sampling event. Plans are under development for future sampling to be performed under DEC oversight.
Litigation continues between the State of Alaska and the former refinery owner, Williams Alaska Petroleum Inc. The company was not part of the 2017 settlement agreement.
Contamination summary: soil and groundwater on the former refinery property is contaminated with sulfolane, PFAS and petroleum constituents. Sulfolane and PFAS in contaminated groundwater have migrated off the property.
- The National Toxicology Program's sulfolane studies
- Human Health and Toxicology - Sulfolane
- Summary of DHSS health recommendations
- The extent of the sulfolane plume is shown on the 2019 offsite sulfolane plume map.
- The current understanding of PFAS in groundwater, represented by the sum of two PFAS (perfluorooctanoic acid [PFOA] and perfluorooctane sulfonic acid [PFOS]), is shown on the 2018 offsite PFOS + PFOA plume map (PDF)
- The 2018 offsite PFAS sample event is described in this 2019 Fact Sheet
Public Health and Environmental Concerns
Soil and groundwater on the former refinery property are contaminated with sulfolane, PFAS and petroleum. Sulfolane and PFAS in contaminated groundwater have migrated off the refinery property.
- PFAS in Fish in Kimberly Lake
- DHSS fact sheet: Perfluoroalkyl Substances Found in Kimberly Lake. (PDF)
- ADF&G's Emergency Order No. 3-R-U-02-20, Kimberly Lake remains closed to sport fishing. (PDF) (April 11, 2020)
Groundwater Advisory: In November 2018, DEC issued a Contaminated Groundwater Advisory to all property owners within the North Pole piped water expansion area where many private water wells contain sulfolane and/or per- and polyfluroroalkyl substances, known as PFAS.
- The Groundwater Advisory for the North Pole area
- Groundwater Advisory Frequently Asked Questions (FAQs)
The former refinery is currently being operated as the Marathon Terminal. Refining operations ceased in 2014. In 2019, Marathon Petroleum (MPC AlaskaTerminal Company LLC) purchased the property and operations.
- Dept. of Law press release: "Fairbanks Superior Court Decision Finds Former Refinery Owner Must Pay Damages to State for Sulfolane Pollution in North Pole Drinking Water"
- Map showing the extent of the sulfolane plume from the 2019 offsite monitoring report.
- 2019 Offsite sulfolane report (6.8M)
- Map showing Onsite sulfolane monitoring results
- Map showing Onsite benzene monitoring results
- 2019 Onsite monitoring report (8M)