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North Pole Refinery - Project Home

Updated: Mar. 12, 2014

Announcement regarding
the Cleanup Level for Sulfolane

See the Public Notice, issued Jan. 17th, 2014

Flint Hills Resources Alaska has filed a request with the Commissioner of DEC for an adjudicatory hearing. This request challenges the establishment of a site-specific alternative cleanup level (ACL) for sulfolane in groundwater of 14 parts per billion (ppb). Flint Hills proposes 362 ppb as the ACL instead. The hearing request is a result of DEC’s Conditional Approval of the Revised Draft Human Health Risk Assessment for the refinery. DEC’s Conditional Approval established 14 ppb as the groundwater ACL acceptable for the protection of human health and the environment. A higher cleanup level as requested by Flint Hills would allow a higher concentration of sulfolane to remain in the groundwater without being cleaned up.


Along with the request for an adjudicatory hearing, Flint Hills has also requested a stay (or hold) on the completion of certain scheduled activities, including the feasibility study and cleanup plan, until the adjudicatory hearing is decided. Related documents are available from the DEC public notice page at the link above or these links below:

This public comment period has ended.



The discovery in late 2009 of sulfolane in drinking water wells near the North Pole Refinery, about 15 miles east of Fairbanks, has led to an extensive investigation of contaminated groundwater. The plume is nearly 2.5 miles wide and 3 miles long, one of the largest in the state. Flint Hills Resources of Alaska, the current refinery owner, responded quickly to offer affected residents an alternate drinking water source. Sulfolane, an emerging contaminant, was at first not officially listed as a hazardous chemical, and its long-term health effects from exposure have not yet been studied. This event has been unprecedented for the Contaminated Sites Program due to the number of properties affected with private drinking water wells and the size of the plume. For an overview in more detail, see Frequently Asked Questions.

State-Directed Priorities Are To:



    • Eliminate exposure to sulfolane.
    • Pursue aggressive on-site remediation.
    • Eliminate off-site contaminant migration.
    • Achieve and maintain source control:
      • Maintain an inspection process that eliminates releases or leaking issues and minimizes the potential for new spills.
      • Aggressively respond to and clean up any new spills.
    • Understand the size and shape of the contaminant plume and its potential for future movement in order to develop a comprehensive and protective cleanup plan.
    • Complete an evaluation of risk that accounts for all exposure pathways and cumulative risk.

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Past newsletters, TPT updates and other information can be found on the Documents page.