The discovery of sulfolane in drinking water wells in 2009 near the North Pole Refinery, about 15 miles east of Fairbanks, led to an extensive groundwater investigation. Flint Hills Resources Alaska, owner of the refinery, responded quickly by providing affected residents with alternate drinking water. Sulfolane is an emerging contaminant, and the possible effects of long-term exposure to this chemical through drinking water are not yet fully understood. The groundwater plume is approximately 2 miles wide, 3.5 miles long and over 300 feet deep, making it one of the largest in the state, with many private properties impacted. For additional details, see Frequently Asked Questions and Project History. Currently:
- Alternative water supplies: approximately 1,500 people receive alternate drinking water supplies from Flint Hills, under the Alternative Water Solutions Management Plan.
- Onsite Cleanup Plan implementation: the onsite groundwater extraction and treatment system was upgraded and is operating as planned; onsite soil excavation and disposal was completed in summer 2015; and quarterly groundwater monitoring continues on the refinery property. More on Onsite Cleanup.
- Offsite quarterly groundwater monitoring continues: periodic sampling tracks migration of the sulfolane plume off the refinery property. More on plume monitoring.
- The National Toxicology Program (NTP) continues toxicology studies: this important research on sulfolane will address questions regarding long-term exposure to the solvent. More on the NTP studies.
- Cleanup Level Review: currently there is no cleanup level for sulfolane. The Spill Prevention and Response Division (SPAR) is continuing to review an appropriate cleanup level while waiting for information from research being conducted by the National Toxicology Program. The August 2015 newsletter describes the sulfolane cleanup level situation.
August 2015 newsletter (1.5MB)
- (Dated April 29, 2016) Public Notice on a Hearing on the Existing Agency Record and Written Briefs on ADEC’s Denial of a Petition to Modify Groundwater Extraction System Performance Standard, Flint Hills North Pole Refinery.