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Division of Spill Prevention and Response


Updated: Sept. 3, 2014

North Pole Refinery - Project Home



The discovery of sulfolane in drinking water wells in 2009 near the North Pole Refinery, about 15 miles east of Fairbanks, has led to an extensive groundwater investigation. Flint Hills Resources of Alaska, owner of the refinery, responded quickly by providing affected residents with alternate drinking water. Sulfolane is an emerging contaminant, therefore, the long-term health effects from exposure through drinking water are not yet understood. The groundwater plume is approximately 2.5 miles wide, 3 miles long and nearly 300 feet deep, making it one of the largest in the state, with many private properties impacted. Currently nearly 300 alternate drinking water supplies have been installed in the affected properties. For additional details, see Frequently Asked Questions.


North Pole Refinery

Current Issues

    • Cleanup Level Review: The ADEC Commissioner has asked the Division of Spill Prevention and Response to further document the rationale and re-evaluate the information that led to the selection of a site-specific cleanup level for sulfolane. This evaluation is expected to be completed by the end of 2014.

      • An independent, expert panel convened by Toxicology Excellence for Risk Assessment (TERA) will be meeting in Fairbanks to discuss the panel’s review of the available reference doses for sulfolane. A reference dose is a toxicity value, a key component used by DEC in establishing a cleanup level for the groundwater. The technical panel will be meeting September 16th (8 a.m. to 5 p.m.) and 17th (8 a.m. to 4 p.m.) at the University of Alaska Fairbanks (Wood Center-Room EF).

        The panel selected by TERA is comprised of national experts in toxicology, immunology, risk assessment, and contaminated sites. The group will discuss relevant scientific issues and questions related to the reference doses during a two day event. This process and the results will help assure DEC utilizes the most scientifically defensible reference dose when calculating a groundwater cleanup level for sulfolane.

        A report summarizing the panel’s recommendations will be submitted to DEC and considered as part of the decision on a cleanup level for sulfolane. DEC’s decision on a cleanup level is expected by the end of 2014.

        The public is invited to observe the panel during their deliberations. Anyone interested in observing the discussion will need to register in advance, as space will be limited. No audio or video recording or photographs will be permitted. Because the panel review is a scientific meeting, there will be no public comment period during the meeting, however DEC personnel will be available to answer general questions on the sulfolane project after the panel concludes their deliberations each day.

        TERA is an independent non-profit organized for scientific and educational purposes. TERA describes its mission as supporting the protection of public health by developing, reviewing and communicating risk assessment values and analyses; improving risk methods through research; and educating risk assessors, managers, and the public on risk assessment issues. For more information, please visit their website.

        The public may submit technical comments on the reference doses by September 8 at the TERA webpage on this issue. The written comments will be provided to the panel for their consideration.

        To register to observe the TERA meeting visit the registration webpage before September 8. If you plan to attend the meeting and park on campus, please note that UAF parking rules apply.

      • Download the Commissioner's decision on Flint Hills' Request for Hearing - Apr. 4, 2014 (96.5 KB PDF)
      • DEC Update on the adjudicatory hearing (PDF) - April 28, 2014