North Pole Refinery Contamination Response At A Glance 2024

November 2024

Contents

• New to Town?
• Brief History
• Water System Update
• Groundwater Advisory
• Addressing PFAS on the Former Refinery
• Continued Oversight
• NTP Studies Continue
• Recent Sampling Results
• Map of the sulfolane plume
• Key Contacts

See the PDF version of this fact sheet

This is an update for North Pole residents and others interested in the state’s response to groundwater contamination from the former North Pole Refinery. These recent project milestones are discussed.

• Although all eligible and willing property owners were connected to the City of North Pole’s expanded piped water system by 2020, it is possible that other properties may now be eligible to receive water. In summer - fall 2024, former refinery owner Williams Petroleum Alaska (Williams) is contacting property owners not connected to municipal water for possible alternative water supplies. Properties with sulfolane in their well water may be eligible for connection to municipal water or alternative water.
• DEC’s Groundwater Advisory informs affected community members about impacts from the remaining groundwater contamination.
• In summer 2024, DEC received Williams’ evaluation of potential remedies and a work plan for interim remedial actions to address per- and polyfluoroalkyl substances (PFAS) remaining in soil and groundwater on the former refinery property above allowable levels.
• Annual (or more often) groundwater monitoring, under DEC oversight, continues to track movement and concentrations of the sulfolane plume both on and off the former refinery.
• On the national level, the National Toxicology Program continues research regarding the toxicity of sulfolane.
• On April 10, 2024, the U.S. Environmental Protection Agency (EPA) adopted a National Primary Drinking Water Regulation (NPDWR) establishing Maximum Contaminant Levels for six PFAS and a cumulative risk level for the sum of four PFAS. The Division of Spill Prevention and Response (SPAR) is reviewing the EPA’s recently adopted NPDWR for PFAS and evaluating the potential impacts to PFAS-contaminated sites throughout the state. For more information on EPA's announcement, please visit EPA's PFAS website.

New to Town?

• DEC encourages you to see where you live relative to the sulfolane plume. If you live within it, you are urged to find out the source of your water supply (see map at the end of this fact sheet).
• Check out these North Pole Refinery pages for updated Frequently Asked Questions (FAQs), maps, and detailed information about the contamination.
• Go to the City of North Pole's utility website for information about the municipal water system.

Brief History

The North Pole Refinery operated from 1977 until 2013. During that time, many spills and leaks of industrial chemicals and wastewater contaminated the soil and groundwater on the refinery property. Spilled substances included petroleum products, sulfolane, and per- and polyfluoroalkyl substances (PFAS). Over time, sulfolane and PFAS in the groundwater migrated off the refinery property, eventually extending 3.5 miles to the north-northwest.

In 2009, sulfolane was detected in drinking water wells north of the refinery. Under DEC oversight, then-owner of the refinery, Flint Hills Resources Alaska (FHRA), provided new water wells for the city of North Pole and alternative water supplies to affected residents. They also completed intensive characterization activities to investigate the source and extent of the sulfolane contamination.

In 2017, FHRA, the City of North Pole, and the State of Alaska agreed to expand the city’s water system to allow city water connections to properties impacted by the sulfolane contamination.

In 2018, PFAS were detected in water wells north of the former refinery. In drinking water wells tested, the treatment systems provided by FHRA for sulfolane removal also removed PFAS.

In 2020, the Fairbanks superior court issued a decision holding Williams Alaska Petroleum, Inc., a previous owner of the refinery, liable for releasing large quantities of sulfolane into the groundwater. The Court also found that FHRA was responsible for contamination but had responded appropriately to the State’s demands for action. As a result of the court action, Williams took over some of the sulfolane monitoring and began PFAS characterization activities on the former refinery.

More detailed Project History

Water System Update

In July 2024, DEC approved Williams’ work plan to evaluate properties near the former refinery for alternative water supplies (AWS). Owners of properties that are not connected to municipal water are being contacted by Williams or their consultants this summer and fall. Wells with detectable levels of sulfolane may be eligible for AWS.

In 2018-2020, the City of North Pole expanded its water system to include properties impacted by the sulfolane plume, within and outside the city limits. 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. Of 730 eligible properties, 652 connections were made.

The piped water system is a comprehensive way to eliminate exposure to sulfolane in drinking water. The City of North Pole's public water system is regulated by the State's Drinking Water Program, which requires compliance with state and federal drinking water regulations. The Program reviewed and approved the design of North Pole’s water expansion project.

Groundwater Advisory

In November 2018, DEC issued a Contaminated Groundwater Advisory to all property owners within North Pole’s water expansion area, where many private water wells contain sulfolane and/or PFAS.

The advisory helps residents avoid unintentional contact with, or spreading of, the chemicals present in well water.

DEC advises against using untreated, contaminated well water for all use, including but not limited to drinking, cooking, bathing, or household uses, as well as gardening, lawn watering, car and equipment washing and other outdoor uses. Bringing contaminated well water to the surface may expose people and animals to chemicals in the water. Using contaminated well water may also allow chemicals in the water 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.

• More on the Groundwater Advisory

Addressing PFAS on the Former Refinery

Sampling performed in 2020 and 2022 showed PFAS above DEC’s soil cleanup level on the refinery and PFAS in groundwater above DEC’s action level migrating off the former refinery property. In 2024, soil and groundwater sampling continued on the former refinery, and Williams evaluated potential remedies to address the PFAS. In July - October 2024, DEC approved Williams’ evaluation of potential remedies and work plan for interim remedial actions to address some of the PFAS contamination remaining on the refinery property. DEC expects the interim remedy to be initiated before the end of 2024.

Continued Oversight

DEC continues to oversee responses to contamination at the former North Pole Refinery to protect human health and the environment and ensure compliance with regulations.

• Annual monitoring of the sulfolane plume continues to track movement of the plume boundaries and show where contamination levels are increasing and decreasing. The sampling includes “buffer zone” wells beyond the known extent of the sulfolane plume.
• In 2023, DEC received Five-Year reviews of monitoring results on and off the former refinery from FHRA and Williams. DEC reviewed the monitoring results; monitoring will continue at a similar level both on and off the former refinery for another five years. The Five-Year reviews are available on the website.
• In the event the sulfolane plume migrates beyond the expanded municipal water service area, an agreement is in place to supply clean alternative water if sulfolane in a private drinking water well exceeds a protective level, currently set at EPA's Regional Screening Level of 20 parts per billion. Monitoring through 2023 has not shown sulfolane plume expansion beyond the municipal water service area.
• For PFAS, Williams sampled some monitoring wells, a few private wells, and surface water in 2023 and early 2024, in the first offsite PFAS sample event since DEC’s 2018 sampling. This evaluation found PFAS present in groundwater above the DEC action level in some monitoring wells north of the former refinery. PFAS were also detected in lakes and ponds northwest of the former refinery at concentrations below the DEC action level and at low concentrations in Badger (Chena) Slough samples. The DEC action levels apply to groundwater and surface water used as drinking water.
• DEC continues to monitor research conducted at the federal level addressing gaps in the understanding of sulfolane and PFAS toxicity.

More on cleanup and monitoring

NTP Studies Continue

The National Toxicology Program (NTP), a federal interagency organization, is conducting toxicology studies for sulfolane to look at effects from long-term exposure to the chemical and other research gaps. Specifically, a two-year study on rats and mice is evaluating the effects of long-term exposure to sulfolane in drinking water and the effects on pregnancy, development and the immune system.

More on health and the NTP

Recent Sampling Results

Off the former refinery: Based on samples collected annually through 2023, the sulfolane plume continues to expand slowly towards the north-northeast but shows no evidence of migrating beyond the area served by municipal water. See map below.

On the former refinery: Based on samples collected at least annually through 2023, there are no indications of contamination migrating off the former refinery property above allowable limits. In samples from wells near the property boundary, petroleum concentrations are below Alaska cleanup levels, and sulfolane concentrations are below the allowable limit.

• In addition to the map below, other maps of the site are available

Map showing approximate boundaries of the sulfolane plume

The map shows the approximate boundaries of the sulfolane plume based on results of groundwater sampling done from 2017 to 2023. It also shows the municipal water supply lines. Additional maps showing sampling results and indication of the plume boundary over time are available from the Maps page. Larger size of map

Key Contacts