PFAS: per- and polyfluoroalkyl substances

Per- and polyfluoroalkyl substances (PFAS) are a class of over 4,000 man-made chemicals that are stable and persistent in the environment, accumulates in the body, toxic at low concentrations, and can contaminate groundwater and soil.

Last Page Update: 08/22/2023

PFAS molecule

Please be advised that the Town of Orono is not categorized by the Maine Department of Environmental Protection as a top tier evaluation site for PFAS because it has no historical records of sludge spreading within the area and 2022 Orono drinking water tests did not detect any PFAS.

Quick Facts: 

  • PFAS have triple carbon fluorine bonds that makes them one of the strongest compounds in organic chemistry. Therefore they do not break down easily and persist in the environment.
  • PFAS were invented in 1930, and were known as C-8 for the creation of Teflon.
  • PFAS were mass produced to create materials that had an oil and water repellency, temperature resistance, friction reduction, and resistant to stains. Thus PFAS compounds are in a tremendous amount of products (e.g. carpets, non-stick cookware, clothing, food containers).
  • Because PFAS are in many things, it persists in waste water sludge from treatment plants and leachate from landfills.
  • The main way humans are exposed to PFAS is through contaminated drinking water and food consumption. 
  • PFAS have been linked to a list of health concerns (e.g. thyroid disease, immune system disorders, pregnancy complications and birth defects, increased risk of kidney or testicular cancer).
A picture of someone filling up a glass of water from the sink faucet.

PFAS in Orono's Drinking Water 

Public Drinking Supply

The Orono-Veazie Water District has completed testing the area's drinking water supply (3/30/2022) for PFAS and results show that all PFAS analyzed were not detected.

With the passage of S.P. 64 (Resolve, To Protect Consumers of Public Drinking Water by Establishing Maximum Contaminant Levels for Certain Substances and Contaminants), the Maine legislature has mandated that Public Water Systems that are either community water systems (C) or non-transient, non-community (NTNC) schools and child care facilities sample their finished drinking water for PFAS.  

EPA Drinking Water Standards: There is a non-enforceable standard of 70 parts per trillion (ppt) for two common PFAS chemicals, PFOA and PFOS. 

Maine Drinking Water Standards: An interim standard of 20 parts per trillion (ppt or ng/L) for six PFAS (alone or in combination) is immediately in effect.

Private Wells 

If you would like to know more about testing a private well for PFAS, please view this PDF. If you are concerned about whether these chemicals are in your well water, please contact one of the state toxicologists to discuss whether testing your well water makes sense. 866-292-3474 (toll-free in Maine), 207-287-4311, or Maine Relay 711.

At-Home Water Filtration

While the nondetectable levels of PFAS reported in Orono wells don’t require treatment, we often get questions about at-home filters for additional purity. A scientific study has shown that certain home water filters will effectively filter out PFAS from your drinking water. 

  • Under-the-sink reverse osmosis and dual-stage (activated carbon-based) filters were able to reduce all analyzed PFAS compounds to below detection.
    • Dual-stage filters are under-the-counter filters that start with a sediment filter, followed by a granular activated carbon (GAC) filter.
    • Reverse osmosis relies on membranes with microscopic pores to filter out water impurities. The process can waste up to 3 times as much water as it filters. Therefore, on top of the costs to purchase and maintain these filters, households that use this type of filter will also be using more water.
  • Whole house granular activated carbon (GAC), fridge filters, single-stage GAC, and pitcher filters (e.g. Brita) were not effective at reducing PFAS concentrations consistently.
  • Faucet-mounted filters seemed to be the most reliable out of all common household filters but were still not as effective as reverse osmosis or dual stage filters.  

If you want additional purity of your water, the right filter for your home and family will depend on your specific circumstances and budget. Any filter used should be operated and maintained according to manufacturer’s recommendations. You should change cartridges at the recommended intervals, and never put hot water through the filter.


A sink showing an under the sink three stage water filter

PFAS in the Orono Waste Water Treatment Plant

The operators at the Water Pollution Control Facility (WPCF) in Orono have completed the Maine Department of Environmental Protection (MDEP) trainings on PFAS in waste water treatment plants. The WPCF does not, and has never, spread sludge on to fields, but instead transfers all of their biosolids to Juniper Ridge, which is the most viable option at this point. 

The WPCF is required to test plant discharge, water that has been through the treatment process and is expelled into the Penobscot River (Outfall 001-A), for PFAS once per month for 10 months to give MDEP background data. The WPCF has completed the required testing and summary results are below. The Maine Drinking Water interim standard is 20 ng/L (or ppt) for six PFAS (combined or individual). 

Average = 16.6 ng/L sum of 6 total PFAS

Minimum = 12.9 ng/L sum of 6 total PFAS

Maximum = 19.5 ng/L sum of 6 total PFAS

PFAS in Orono's Municipal Landfills

1) Municipal Solid Waste Landfill (closed) 

Maine Department of Environmental Protection (MDEP) has begun targeting special waste and municipal solid waste landfills to monitor PFAS in leachate.The Town of Orono owns a municipal solid waste (MSW) landfill which has been closed since the early 1990s. This landfill was used for all municipal waste, wastewater sludge disposal, and was commonly on fire as a result of coal or wood ash being disposed of. So along with the municipal waste and wastewater sludge that contains PFAS, it is possible that fire suppressant foam was used on this property that contained PFAS chemicals. The Town of Orono recognizes that these materials and practices may have led to elevated levels of PFAS within the closed landfill. Therefore, the Town proactively reached out to the MDEP to voluntarily sample the closed landfill’s groundwater monitoring wells as part of the statewide effort to collect baseline PFAS data, even though this landfill does not collect and manage leachate.  

Read the Summary Results Here

2) Maine DEP licensed Construction Demolition and Debris (CDD) Landfill (operating)

This disposal site is for wastes generated within the Town of Orono only. Only certain materials are allowed including scrap metal, non-freon-containing white goods (ovens, microwaves), leaves and brush, clothing, towels, bedding, footwear, carpets, furniture, mattresses. The landfill accepts materials known to contain PFAS, like couches, carpet, and mattresses, but does not have a leachate. Groundwater monitoring at the Orono landfill is the most practical way to determine PFAS presence and concentration. 

PFAS in Deer - Attention Hunters

In the 1970s, Maine DEP started to allow permits for spreading of municipal sludge (biosolids) to be used as fertilizer on farm fields. They did not realize this sludge contained PFAS and in 2017, it was identified that PFAS contaminated sludge spreading on a nearby field is what contaminated a drinking well in Arundel, ME. When PFAS contaminated municipal waste water sludge gets spread on farm fields it can contaminate the soil and crops with PFAS. Thus, if deer or wildlife eat the crops they can bioaccumulate (uptake a contaminant into their tissues) PFAS. 

Maine Department of Inland Fisheries and Wildlife, in conjunction with the Maine Center for Disease Control and Prevention (Maine CDC), has detected high levels of PFAS in some deer harvested in the greater Fairfield area and is issuing a do not eat advisory for deer harvested in that area.

At this time, there are no advisories against eating venison from any of the other Maine locations being investigated for PFAS contamination. If you are a hunter and are concerned about PFAS in your deer, you can view the sludge spreading map to see if you harvest deer near an area where sludge may have been spread. Please be advised that just because a location was permitted to spread sludge does not mean that they actually did spread sludge in that area. 

Please contact MDIFW at 207-287-8000, or at IFW.PFAS@maine.gov with any additional questions. 

White-tailed deer standing in a field.

PFAS in Fish - Attention Anglers 

PFAS found in freshwater fish are typically connected to sites associated with historical use of PFAS containing products like spreading of sludge and industrial sites that used or processed PFAS. PFAS may have either entered surface waters directly, been transported during heavy rains, or by leaching into ground water. Fish that live in contaminated waterbodies accumulate PFAS in their tissues. Perfluorooctane sulfonate (PFOS) is the predominant, and sometimes only, PFAS detected in fish tissue. Typically, PFOS levels were significantly less in brook trout compared to species like bass, perch, and pike when comparing species within the same waterbody. 

Maine Department of Inland Fisheries and Wildlife (Maine IFW), in conjunction with the Maine Center for Disease Control and Prevention (Maine CDC) has been sampling fish species in waterbodies throughout the state. For results on specific waterbodies please view the Maine CDC Scientific Brief: PFOS Fish Consumption Advisory. Please visit the State of Maine's FAQ insert on PFAS in recreationally caught freshwater species for answers to common questions regarding this issue. 

In 2020 study of PFAS in fish from the Penobscot River above and below former or current industrial treatment plants found primarily PFOS at barely measurable levels. Levels of PFOS in smallmouth bass from the Penobscot River were all near background levels ranging from roughly 1.5 ppt to 2.5 ppt. 

penobscot river sampling results for pfaspenobscot river sampling sites for pfas


Current (2022) Bills in Maine that Address PFAS - all passed by the House

LD 1875: Addresses perfluoroalkyl and polyfluoroalkyl substances pollution from state-owned solid waste disposal facilities.

  • This bill provides that a solid waste disposal facility owned by the State may not be licensed or otherwise authorized to transfer leachate from the solid waste disposal facility to a wastewater treatment plant unless prior to the transfer the leachate is treated to reduce the concentration of perfluoroalkyl and polyfluoroalkyl substances or the facility receiving the leachate employs technology to reduce the concentration of perfluoroalkyl and polyfluoroalkyl substances.

LD 1911: Prohibits the contamination of clean soils with PFAS chemicals. 

  • This bill prohibits the land application or distribution of sludge or sludge-derived compost unless it is tested for all perfluoroalkyl and polyfluoroalkyl substances

LD 1891: Provides one-time funds for grants to eligible owners of single-family homes or landlords with private well water that shows evidence of contamination.


LD 2013: Establishes the Fund To Address PFAS Contamination within the Department of Agriculture, Conservation and Forestry and the corresponding Advisory Committee on the Fund To Address PFAS Contamination to make recommendations to the department regarding the administration of the fund. 

LD 2019: Requires the registration of adjuvants in the State and regulates the distribution of pesticides with perfluoroalkyl and polyfluoroalkyl substances.

Educational Media Links

Maine Public Radio - PFAS