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North Pole Refinery

Site Location

DEC Contaminated Sites contact: Jim Fish, 907-451-2117  

  • Click on photos or maps for larger versions.
  • Contacts updated: 5/8/2023
  • Summary updated: 5/8/2023

Site Narrative

For background on the history of this site, please see the Project History page

Description

Map above shows the results of annual testing performed in 2020 to determine the approximate extent of sulfolane impacts in the North Pole area. version. See the most recent maps on the Maps page

Contamination from 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 former refinery's land still contains fuel product trapped in the soil and groundwater.

The sulfolane groundwater plume is approximately 2 miles wide, 3.5 miles long and over 300 feet deep, and continuing to migrate gradually northward. The PFAS plume appears to have a similar footprint, although the boundaries of the plume have not been fully evaluated.

In response to the sulfolane contamination, the refinery’s then-owner Flint Hills Resources Alaska (FHRA) began providing affected residents and businesses with alternative drinking water solutions in 2009 under DEC oversight. 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. By the end of 2020, all eligible property owners were offered connection to the service and able to phase out the use of contaminated groundwater wells. Most property owners were eligible to connect at no cost, depending upon the land’s location and improvement status. The expanded system provides permanent protection from contamination in 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.

On the former refinery property, a multi-year investigation to evaluate PFAS levels in soil, groundwater, and surface water began in 2020 under DEC oversight. The investigation is continuing in 2023.

Litigation continues between the State of Alaska and a 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 are contaminated with sulfolane, PFAS and petroleum constituents. Sulfolane and PFAS in contaminated groundwater have migrated off the property.

Sulfolane is an industrial solvent used primarily in natural gas and petroleum refining. Most of what we know about how sulfolane might affect human health comes from studies in which laboratory animals were exposed to sulfolane for periods of time. The National Toxicology Program is currently studying the long-term effects of exposure to sulfolane in water on rodents. For more information on the toxicity of sulfolane and the National Toxicology Program studies, see the following:

Per- and polyfluoroalkyl substances (PFAS) are a large and complex class of human-made compounds which have a wide-range of toxicities. They are found in some firefighting foams and many consumer products.

The links below provide recent information regarding contamination off the former refinery property:

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.

Drinking Water: The public in the affected area was provided access to alternative water solutions and recently has had the opportunity to connect to the North Pole municipal water system. Starting in 2009, alternative, sulfolane-free water or water treatment systems for sulfolane removal were provided to all properties with any detection of sulfolane in the water. In addition to providing protection from sulfolane, the water treatment systems were shown in 2018 to also remove PFAS from 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 municipal water system to all improved properties located within the sulfolane plume or in its anticipated migration path. By the end of 2020, all eligible property owners were offered connection to the service and able to phase out the use of contaminated groundwater wells. Most property owners were eligible to connect at no cost, depending upon the land’s location and improvement status. The expanded system provides permanent protection from contamination in drinking water. For information about municipal water system connections and use of well water within the affected area, see the following:

Gardening: In 2010, produce from North Pole gardens that used sulfolane-impacted well water for watering were sampled. The results were based on the testing of 23 types of plants from seven North Pole gardens. Results affirmed that some edible garden plants retain sulfolane from contaminated well water. Sulfolane levels in produce varied depending on the type of plant and part of the plant tested.

In 2018, DEC evaluated the uptake of PFAS into garden produce irrigated with PFAS contaminated groundwater. Water from a well at a local North Pole farm was found to contain PFOA and PFOS at a total of 16 parts per trillion (ppt). DEC collected samples from 14 types of fruits and vegetables. The study found that some PFAS can be taken up and accumulate in fruits and vegetables irrigated with water containing PFAS. DHSS determined the hazard associated with exposure to PFAS through eating vegetables and strawberries grown at the local farm is negligible.

Fish: Three rainbow trout from Kimberly Lake, north of the former NPR, were collected and submitted to a commercial laboratory for PFAS analysis in 2018. All three fish were found to contain elevated levels of two PFAS: perfluorononanoic acid (PFNA) and perfluorooctane sulfonic acid (PFOS). Kimberly Lake was closed to fishing in April 2019 by the Alaska Dept. of Fish & Game because of PFAS levels found in fish. The ADF&G released an emergency order closing Kimberly Lake to sport fishing at that time. As of May 1, 2023, ADF&G has restricted Kimberly Lake to catch-and-release fishing only for all fish species. More information may be found by following the links below.

In 2013, Badger Slough and seven gravel ponds, including Kimberly Lake, were sampled for sulfolane. Sulfolane was not detected in any of the surface water samples. Sulfolane is known to degrade readily in environments with an adequate supply of oxygen, like gravel ponds.

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 polyfluoroalkyl substances, known as PFAS.

The advisory assists residents in avoiding unintentional contact with, or spreading of, the chemicals present in well water. DEC advises against using untreated, contaminated well water that may cause the spread of pollution. Bringing impacted well water to the surface may expose people or wildlife to the chemicals and/or allow the chemicals to spread onto other properties, sloughs, or ponds. In issuing this advisory, DEC is seeking the community’s assistance in minimizing the future spread of these contaminants. For those wishing to use well water, DEC recommends treatment to remove both sulfolane and PFAS. DEC is available to provide guidance on this question.

If you are concerned you may have sulfolane or PFAS in your well water, DEC has prepared fact sheets to provide step-by-step advice for testing your water. DEC recommends you contact Zuzana Culakova, Chemist, DEC Contaminated Sites Program at 907-465-5346, or the Contaminated Sites Program at 907-451-2143 if you have any questions about testing.

Current Status

The former refinery is currently being operated as the Marathon Terminal. Refining operations ceased in 2014. In 2019, Marathon Petroleum (MPC Alaska Terminal Company LLC) purchased the property and operations.

In October 2019, a trial was held in Fairbanks to settle the litigation between the State of Alaska, Flint Hills Resources Alaska and Williams Alaska Petroleum Inc. Results are discussed in the press release below from the Department of Law.

  • 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"

Long-term groundwater monitoring continues both on and off the former refinery property under DEC oversight. Groundwater monitoring through 2022 has shown no evidence of petroleum compounds migrating off the property above State cleanup levels. For sulfolane, which does not have a cleanup level, offsite migration is not to exceed a concentration of 400 parts per billion. Monitoring indicates sulfolane is migrating off the former refinery property at concentrations below that amount.

The 2020 and 2021 annual offsite and 2022 annual onsite monitoring reports and selected maps may be accessed by the links below.

The 2018 offsite PFAS monitoring report may be accessed by following the links below.

The City of North Pole now provides a permanent source of sulfolane-free water to residents, land owners and businesses in the areas where groundwater has been contaminated by sulfolane. If you have questions, please contact the city’s website.

A May 2023 fact sheet is available to update North Pole residents and others interested in the state’s response to groundwater contamination at and north of the former North Pole Refinery. Recent project milestones are discussed.