Montana Department of Environmental Quality About Us Permitting & Operator Assistance Public Participation


Program Overview

Per and Polyfluoroalkyl Substances

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that includes PFOA, PFOS, and many other chemicals. PFAS have been manufactured and used in a variety of industries around the globe, including in the United States since the 1940s. PFOA and PFOS have been the most extensively produced and studied of these chemicals. Both chemicals are very persistent in the environment and in the human body – meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects.


PFAS Contacts


To sign up for email updates related to PFAS.


36% of Montana’s population served by public water supplies drink from systems tested during 2013-2015 under the Unregulated Contaminant Monitoring Regulation (UCMR3). All systems tested below the method reporting limit (MRL).

More information can be found at:

MT0000235 City of Hardin HARDIN
MT0004313 Pipkin Commercial Subdivision BELGRADE
MT0004392 Cherry Creek Manuf. Home Park BILLINGS
MT0000328 City of Shelby SHELBY
MT0000590 Leisure Village MHP HLNA HELENA
MT0000165 Town of Bridger BRIDGER
MT0000155 County Water District of Billings Heights BILLINGS
MT0000161 City of Bozeman BOZEMAN
MT0000170 Butte Silverbow Water Department BUTTE
MT0000241 Helena Water System HELENA
MT0000259 Kalispell Public Worksn KALISPELL
MT0004204 University of Montana - Missoula MISSOULA
MT0000294 Mountain Water Company MISSOULA
MT0000525 City of Great Falls GREAT FALLS
MT0000153 City of Billings BILLINGS
Contaminants Tested (UCMR3) MRL μg/L
PFOS - Perfluorooctanesulfonic acid 0.04
PFOA – Perfluorooctanoic acid 0.02
PFNA- Perfluorononanoic acid 0.02
PFHxS- Perfluorohexanesulfonic acid 0.03
PFHpA- Perfluoroheptanoic acid 0.01
PFBS- Perfluorobutanesulfonic acid 0.09

Disposal of PFAS and PFAS-containing materials is informed by EPA’s interim guidance released in 2020. Be sure to consult with any landfill before attempting to deliver bulk PFAS materials to them or contact DEQ for specific guidance.

  • Contaminated media – Incineration or landfill. Incineration would likely take place outside of Montana and may need to be coordinated by a hazardous waste transporter service (see list). Not all landfills will accept PFAS-contaminated soils or wastewater residuals. Be sure to contact the landfill directly before hauling to them.
  • Consumer products – PFAS-containing consumer products can be disposed of like any other Group II waste; therefore, they may be disposed of at any licensed Class II landfill. Items like mattresses and carpets may be managed separately. Class II landfills typically have liners which collect leachate and allow chemicals like PFAS to be managed.
  • Bulk PFAS (like leftover Aqueous Fire Fighting Foam)
    • Disposal of solidified material in a lined unit at a licensed Class II landfill. Verify with the landfill first. Not all landfills will accept given the uncertainties.
    • Contracting with a hazardous waste transporter service. Though not a characteristic hazardous waste, AFFF is being transported by some of these companies to facilities that accept it. A transporter might manage the PFAS in one of the following ways:
      1. Delivering to an incinerator in another state for thermal destruction.
      2. Delivering to a hazardous waste landfill or storage facility until more research on disposal technologies is conducted.
      3. Deep well injection.
      4. Solidifying the material and landfill at a licensed Class II landfill.

What is PFAS?

“PFAS” in an acronym that stands for “per- and polyfluoroalkyl substances.” PFAS encompasses a wide universe of substances with very different physical and chemical properties, including gases, liquids, surfactants, and solid material high-molecular weight polymers (ITRC 2018).

What kind of products contain PFAS?

PFAS are present in many different commercial products, such as non-stick coatings, stain and water-resistant products, protective coatings, personal healthcare products, firefighting foams, and architectural resins (ITRC 2018).

How is PFAS different than a PFC?

The acronym “PFC” is poorly defined in scientific literature, but typically refers to “perfluorinated compounds.” it does not include polyfluorinated substances, which are increasingly recognized as important contaminants at many PFAS sites (ITRC 2018).

What are PFOS and PFOA?

PFOS and PFOA are acronyms that stand for “perfluorooctane sulfonate and perfluorooctanoic acid,” respectively. PFOS and PFOA are two common PFAS used in many industrial and consumer products. PFOS and PFOA have been found in soil and groundwater throughout the country. PFOS and PFOA have also been found in some public drinking water systems.

Does the US Environmental Protection Agency (EPA) regulate PFAS?

PFAS are not currently regulated by EPA under the Safe Drinking Water Act (SDWA), the Resource Conservation and Recovery Act (RCRA), or the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), known as Superfund. However, EPA is evaluating the need to establish drinking water standards (maximum contaminant levels or MCLs) for select PFAS under the SDWA and listing certain PFAS as hazardous substances under CERCLA.

Has the EPA developed any PFAS Water Quality Standards?

No; however, the EPA has adopted a lifetime drinking water health advisory of 70 nanograms/liter ((ng/L) or parts per trillion (ppt)) for PFOS and PFOA. When both PFOS and PFOA are found in drinking water, the combined concentrations of PFOS and PFOA should be compared against the 70 ppt health advisory (EPA 2016).

Does the State of Montana regulate PFAS compounds?

Yes; the Montana Department of Environmental Quality (DEQ) recently added PFOS and PFOA to Circular DEQ-7 Montana Numeric Water Quality Standards for groundwater at the EPA Health Advisory level of 70 ppt. Also, the State’s environmental requirements, criteria, or limitations (ERCLs) (referred to as ARARs under CERCLA) provide that concentrations of parameters for which human health standards are not listed in DEQ-7 must not exceed levels that render the waters harmful, detrimental, or injurious to beneficial uses (See Administrative Rule of Montana 17.30.1006 for groundwater classification, beneficial use, and specific standards).

Have any Public Water Systems in Montana been sampled for PFAS?

Yes; between 2013 and 2015, EPA sampled medium-size Montana public water systems as part of the third unregulated contaminant monitoring rule (UCMR 3). Samples were analyzed for six PFAS: perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), and perfluorobutanesulfonic acid (PFBS). No detections were found above the laboratory reporting limits.

What Montana Public Water Systems were sampled for PFAS under the Unregulated Contaminant Monitoring Rule (UCMR 3)?

A number of public water systems have been sampled in Montana, including but not limited to systems in Billings, Bozeman, Butte, Helena, Kalispell, Hardin, Belgrade, Shelby, and Bridger. For more detailed information on EPA’s monitoring between 2013 and 2015, please see the UCMR 3 Occurrence Data:

Should I test my private water supply well for PFAS?

DEQ recommends that you contact the department prior to sampling your private water supply well for PFAS to discuss if it has the potential to be impacted. If you choose to sample your private water supply well, DEQ recommends that you hire an environmental professional to assist you. Special care needs to be taken during sampling to ensure collection of representative samples.

Where have PFAS been found in Montana?

To date, PFAS have been detected in soil, groundwater, and surface water (storm water outfalls) above screening levels at two active military installations in Montana: the Montana Air National Guard and Malmstrom Air Force Base in Great Falls. In addition, PFAS have also been detected above groundwater screening levels at Fort Harrison in Helena and at the former Glasgow Air Force Base in Saint Marie. Further investigation is ongoing.

What steps is Montana DEQ taking with Respect to PFAS?

DEQ is currently providing on-going regulatory oversight for the identified PFAS sites in Montana. DEQ has developed a PFAS working group and is coordinating with other state agencies and local governments to develop a potential PFAS site list. The list will include locations where PFAS may have been stored, used, disposed of, or otherwise released to the environment. DEQ is also evaluating potential funding sources to conduct soil and groundwater sampling at or near identified or potential PFAS sites and to expand sampling of public and private drinking water systems at or near identified or potential PFAS sites.

What kind of sites might be considered a "potential PFAS site"?

Potential PFAS sites include, but are not limited to: industrial sites, dumps or landfills, wastewater treatment biosolids application sites, and fire training areas or airplane crash sites where aqueous film forming foam (AFFF) was used for fire suppression.

What are the best treatment alternatives for PFAS-impacted drinking water?

Viable PFAS water treatment options include activated carbon treatment, ion exchange treatment, or high-pressure membranes. More information is available at:

Where can I find information on PFAS health effects?

Please see ATSDR’s website for current information on PFAS health effects.

Where can I find more information on PFAS?

Please see below links for more PFAS information:

Hi, I can help answer your questions!