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North Pole Refinery Frequently Asked Questions

Updated: September 30, 2020

What is DEC doing about contaminated groundwater in the North Pole area?

DEC continues regulatory oversight of the former North Pole Refinery, in particular the groundwater plumes contaminated with sulfolane, petroleum and per- and polyfluoroalkyl substances (PFAS). Groundwater monitoring is performed under DEC oversight every year to track changes in the sulfolane plume off the former refinery property and also in the sulfolane and petroleum plumes on the property. Results are reported annually and posted on this website on the Documents page. Plans are under development for future PFAS sampling to be performed under DEC oversight.

Off the former refinery property: The sulfolane contamination extending off the property is expected to remain in the groundwater for many years. The sulfolane plume continues to gradually migrate towards the north-northwest, and concentrations in water wells may change over time. To protect North Pole residents and businesses, monitoring is to continue until the plume reaches a cleanup level to be set by the State of Alaska.

In 2018, DEC investigated PFAS in the North Pole area groundwater. PFAS were present in fire-fighting foams used historically on the former refinery and have been found in soil and groundwater on that property. In 2018, DEC collected groundwater samples from monitoring wells and water wells both within and outside of the city’s piped water expansion area. Sample results showed a PFAS groundwater plume migrating off the former refinery property. Plans are under development for future sampling to be performed under DEC oversight.

On the former refinery property: Sulfolane and petroleum contamination are expected to remain in soil and groundwater on this property for many years. Petroleum contamination is contained on the property, while sulfolane continues to migrate beyond the property line, below levels allowed under the 2017 settlement agreement (400 parts per billion [ppb]). Contingencies are in place to resume active groundwater treatment if petroleum is found to be migrating off the property above DEC cleanup levels or sulfolane above 400 ppb.

PFAS contamination is also present in soil and groundwater on the former refinery property, and plans are under development for future sampling to be performed under DEC oversight.

How can I find out if there is PFAS or sulfolane in the groundwater under my property, and if so, what the concentrations are?

Maps of groundwater sulfolane concentrations are updated annually and posted on this web page. The most recent (2019) sulfolane groundwater map may be found at the following:

The extent of PFAS contamination in groundwater off the former refinery property has not been fully characterized. Plans are under development for future sampling to be performed under DEC oversight. The current understanding of PFAS in groundwater, represented by the sum of two PFAS (perfluorooctanoic acid [PFOA] and perfluorooctane sulfonic acid [PFOS]), is shown on the 2018 offsite PFOS + PFOA plume map (PDF).

Contact DEC at 907-451-2117 or james.fish@alaska.gov for further assistance.

Is the sulfolane plume still being monitored?

DEC continues regulatory oversight of the former North Pole Refinery sulfolane, petroleum, and per- and polyfluoroalkyl substance (PFAS) plumes. Groundwater monitoring is performed under DEC oversight every year to track changes in the sulfolane plume off the former refinery property and in the sulfolane and petroleum plumes on the former refinery property. Results are reported annually and posted on the this web page.

I live in the sulfolane and PFAS plume and recently connected to city water. Why does DEC advise against using my well water for watering my yard or washing my car?

Using your well for purposes such as watering your lawn or washing your car brings contaminated water to the surface and can disperse the chemicals, allowing them to run off your property and on to uncontaminated areas or nearby surface water.

To avoid spreading contamination to places where people or wildlife might be exposed, DEC is seeking community assistance in stopping the spread of contamination from untreated, contaminated groundwater use.

What is sulfolane and what do we know about its health effects?

Sulfolane is an industrial solvent used primarily in natural gas and petroleum refining.

No studies have looked for health effects in people who have been exposed to sulfolane. Most of what we know comes from studies in which laboratory animals were exposed to high levels of sulfolane for short periods of time. High levels of sulfolane (much higher than what has been measured in the groundwater off the former refinery in North Pole) were shown to affect the central nervous system, immune system and the liver, kidneys, and spleen of test animals. Animal studies suggest that sulfolane at very high levels may cause developmental and reproductive problems in mice.

No long-term, or chronic, studies in animals to determine if sulfolane might cause cancer have been published. Research began in May 2015 by the National Toxicology Program (NTP) to evaluate the effects of long-term exposure to sulfolane. The NTP is an expert interagency program, housed within the United States Department of Health and Human Services, that evaluates the toxicity of chemicals of public health concern.

What is PFAS and what do we know about the health effects?

Per- and polyfluoroalkyl substances (PFAS) are a large and complex class of human-made compounds that have a wide-range of toxicities. They are found in some firefighting foams and many consumer products. Some animal studies show health effects from PFAS exposure, but human health studies are less conclusive.

Scientists are still learning about the health effects of long term PFAS exposure. Although more research is needed, studies conducted in highly exposed communities have shown that certain PFAS may have effects on the:

  • Gastrointestinal System - Ulcerative colitis (an inflammatory bowel disease that causes inflammation in the digestive tract)
  • Liver - Liver damage, abnormal fat metabolism, high cholesterol
  • Kidney - Kidney cancer and chronic kidney disease
  • Cardiovascular system - High blood pressure in pregnant women
  • Reproductive system - Testicular cancer and decreased fertility
  • Endocrine system - Thyroid disease
  • Development - Reduced birth weight

For more information on the toxicity of PFAS, see the following:

How is the public protected from potential exposure to contaminated groundwater?

The public in the affected area has been provided access to alternative drinking water solutions and recently has had the opportunity to connect to the North Pole municipal water system. Starting in 2009, alternative water supplies were provided to all properties with any detection of sulfolane in the water. Sampling conducted in 2018 showed the alternative water solutions provided for protection from sulfolane were also protecting residents from PFAS in their well water. In February 2017, the State of Alaska, FHRA, and the City of North Pole reached a settlement agreement to expand the City’s piped water system to all improved properties located within the sulfolane plume or in its anticipated migration path. Implementation of the expanded piped water system is expected to be complete by the end of 2020 and will provide permanent protection from contamination in drinking water. For more information about the piped water expansion project and use of well water within the expansion area, see the following:

Should I use my well water for fruit or vegetable gardening?

Within the sulfolane plume, DHSS recommends using a clean, alternative water source for growing fruits and vegetables. In addition, DEC issued a Contaminated Groundwater Advisory to all property owners within the North Pole piped water expansion area where many private water wells contain sulfolane and/or PFAS. In its Groundwater Advisory, DEC advises against using untreated, contaminated well water after a property is eligible for connection to the water utility service to reduce spreading pollution and eliminate human exposure.

Plants irrigated with contaminated water or grown in contaminated soil have been shown to take up some PFAS from the surrounding environment. The amount of PFAS taken up by fruits and vegetables will vary based on the severity of the PFAS contamination, the type(s) of PFAS in the water and/or soil, and the type of produce grown. Ultimately, the Alaska Department of Health and Social Services has indicated exposure to PFAS through produce is not likely to be substantial compared to other exposure routes, like drinking contaminated water. Furthermore, the health benefits of eating fresh produce generally outweigh the risks associated with PFAS exposure from plants.

Two studies have been conducted to look at the uptake of contaminants in fruits and vegetables grown in the North Pole area:

  • Uptake of PFAS in Locally Grown Produce – In 2018, DEC evaluated the uptake of PFAS into garden produce irrigated with PFAS contaminated groundwater. Water from a well at a local North Pole farm was found to contain PFOA and PFOS at a total of 16 parts per trillion (ppt). DEC collected samples from 14 types of fruits and vegetables. The study found that some PFAS can be taken up and accumulate in fruits and vegetables irrigated with water containing PFAS. DHSS determined the hazard associated with exposure to PFAS through eating vegetables and strawberries grown at the local farm is negligible.
  • Uptake of PFAS in Locally Grown Produce – In 2018, DEC evaluated the uptake of PFAS into garden produce irrigated with PFAS contaminated groundwater. Water from a well at a local North Pole farm was found to contain PFOA and PFOS at a total of 16 parts per trillion (ppt). DEC collected samples from 14 types of fruits and vegetables. The study found that some PFAS can be taken up and accumulate in fruits and vegetables irrigated with water containing PFAS. DHSS determined the hazard associated with exposure to PFAS through eating vegetables and strawberries grown at the local farm is negligible..
Is it safe to eat fish caught in Kimberly Lake?

Three rainbow trout from Kimberly Lake, north of the former former-NPR, were collected and submitted to a commercial laboratory for PFAS analysis in 2018. All three fish were found to contain elevated levels of two PFAS: PFOS and PFNA. Kimberly Lake has been closed to fishing since April 2019 by the Alaska Dept. of Fish & Game (ADF&G) because of PFAS levels found in fish. The ADF&G released an emergency order closing Kimberly Lake to sport fishing.

No other gravel ponds in the North Pole area have been investigated for the presence of PFAS in surface water or fish.

In 2013, Badger Slough and seven gravel ponds, including Kimberly Lake, were sampled for sulfolane. Sulfolane was not detected in any of the surface water samples. Sulfolane is known to degrade readily in environments with an adequate supply of oxygen, like gravel ponds.

What is the status of the City of North Pole’s expanded public water system?

The City of North Pole expanded their piped water system to provide permanent protection from contamination in drinking water. By the end of 2020, all affected community members will have been able to connect to the service, phasing out the use of contaminated groundwater wells. DEC considers a public water system to be the best way to provide clean drinking water to those affected by contamination in groundwater, now and into the future, and encourages eligible residents to connect to piped water.

  • The latest information available from the City about the piped water expansion project, including maps of the expansion area, may be found on the City of North Pole's website.
How can I find out if the home or apartment I am renting is connected to city water?
  • The latest information available from the City about the piped water expansion project, including maps of the expansion area, may be found on the City of North Pole's website
  • For more information, contact the City of North Pole Utilities, Bill Butler, at 907- 488-8593
I have recently connected to the City of North Pole’s expanded piped water system. What am I advised to do with my water well?

DEC advises against using untreated, contaminated well water after a property is eligible for connection to the water utility service.

To avoid spreading contamination to places where people or wildlife might be exposed, DEC is seeking community assistance in stopping the spread of contamination from untreated, contaminated groundwater use.

If you wish to use your well water, treatment is an option to remove both sulfolane and PFAS from well water. DEC is available to provide guidance on this question.

I live outside the area served by the City of North Pole’s piped water system. What should I do if I am concerned about contamination in my water well?

Sulfolane groundwater monitoring is performed under DEC oversight every year to track changes in the sulfolane plume. Maps of groundwater sulfolane concentrations are updated annually and posted on the project web page. The most recent (2019) sulfolane groundwater map may be found at the following:

For PFAS, plans are under development for future sampling to be performed under DEC oversight. The current understanding (2018) of PFAS in groundwater is shown on the 2018 offsite PFOS + PFOA plume map (PDF).

If you are concerned you may have sulfolane or PFAS in your well water, DEC has prepared Fact Sheets to provide step-by-step advice for testing your water. DEC recommends you contact Brian Englund at (907-269-7526) or the Contaminated Sites Program at (907-451-2143) if you have any questions about testing.

How can the public stay informed?

DEC’s website on contamination from the former North Pole Refinery, now Marathon Terminal, remains the best way to learn about the extensive investigation, monitoring, and cleanup efforts at this site. The City of North Pole now provides a permanent source of sulfolane-free water to residents, land owners and businesses in the areas where groundwater has been contaminated by sulfolane and/or PFAS. If you have questions, please contact those listed below.

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