DEC's Community Survey regarding information on sulfolane

The Department of Environmental Conservation has formed a Technical Project Team (TPT) that includes experts in environmental investigations and cleanup, state and federal regulatory agencies, University of Alaska, and the responsible parties to direct the response to the contaminant releases on the North Pole Refinery.

In October 2009, sulfolane was detected in the groundwater outside of the facility’s property boundaries to the north and in drinking water wells. This was considered an immediate public health concern and changed the focus of environmental compliance at the refinery. Sulfolane, or tetrahydrothiophene 1, 1-dioxide, is a solvent developed by Shell Oil Company in the early 1960s and is used at the North Pole Refinery for the extraction of aromatic components from petroleum. Gasoline is the only produced fuel at the North Pole Refinery which currently undergoes and requires the sulfolane™ extraction process. The primary source of sulfolane in the groundwater at the refinery is believed to be historic releases of fuel that contained sulfolane. Spills of pure sulfolane were likely to have occurred over the years of the refinery’s operation that were not identified or recorded because sulfolane was not regulated as a hazardous chemical. A sulfolane extraction unit has been in operation since it was installed in 1985.

In 2010, DEC requested from facilities that distribute or store gasoline produced from the North Pole Refinery and have had reported gasoline releases to determine if sulfolane™ is a contaminant of potential concern. To date, all facilities that have sampled for sulfolane have shown that it is not a contaminant of potential concern and therefore, DEC considers sulfolane to be specific to the North Pole Refinery historic operations.

This website contains a complete record of the ongoing investigation and work by the Technical Project Team. The navigation bar on the right links to the following information:

• The Project Status & Updates page summarizes the most recent activities under this investigation.

• The Maps page provides links to numerous maps showing the groundwater concentrations and estimated plume area.

• The Background page provides the history of the site and general background information related to this project.

• The Drinking Water page contains information about sulfolane contamination levels in drinking water and well monitoring data and results.

• The Site Characterization and Remediation page contains information about the delineation of the sulfolane plume and ongoing activities to contain and cleanup the contamination.
  

• The Human Health and Toxicology page contains information about the human health effects of sulfolane.

• The Frequently Asked Questions page answers common questions about the North Pole Refinery site and sulfolane contamination.

• The Documents page contains downloadable files of all documents and reports generated during the life of this project.

• The Technical Project Team (TPT) page presents TPT subgroups and their affiliations and a record of past meeting summaries and related documents.

• The Feedback & Public Involvement page includes information on how to provide DEC with feedback on the Project, as well as points of contact for additional information on various topics.