The public health concerns about the “forever chemical” — PFAS, or per and polyfluoroalkyl substances — will not be subsiding in 2021.

Because PFAS are water soluble, over time these chemicals from firefighting foam, manufacturing sites, landfills, spills, air deposition from factories and other sources can seep into surface soils. From there, PFAS can leach into groundwater or surface water, and can contaminate drinking water.

Last Oct. 2, the Department of Environmental Protection amended its drinking water regulations to establish a maximum contaminant level (MCL) of 20 parts per trillion (or ppt) for the sum of six PFAS compounds, known as PFAS6. This drinking water standard is set to protect against adverse health effects for all people consuming the water. The regulations detail the sampling requirements and corrective actions that approximately 1,600 public water systems must take when the MCL is exceeded, as well as the provisions for public education and notice of violations of the MCL.

The schedule set by MassDEP’s new regulations for public water systems to test for PFAS began this year. Large public water systems, serving more than 50,000 people, began compliance monitoring on Jan. 1. Public water systems serving between 10,000 and 50,000 people are to begin monitoring on April 1, with smaller systems, serving 10,000 or fewer people, starting on Oct. 1. Transient non-community public water systems (e.g., hotels and restaurants) must collect, analyze and report sampling results by Sept. 30, 2022.

The big concern, of course, is that many public water systems will detect PFAS and need to install costly treatment at the expense of other necessary system upgrades. The state has made funding available for limited sampling as well as reimbursement for the design of PFAS treatment. The Drinking Water State Revolving Fund, administered by the Clean Water Trust, also has funding to address PFAS contamination via low-interest loans.

Based on experiences in other states, the MassDEP does not expect to find widespread PFAS contamination, but acknowledges that the cost to an individual public water system will depend upon the extent of PFAS contamination at that system. If PFAS detections are widespread and at elevated levels, new state funding to support municipal capital infrastructure and other financial and technical assistance associated with PFAS testing, monitoring and remediation will be necessary.

The concerns of municipal leaders about PFAS, however, should not stop with their own public water system. Private wells provide drinking water to more than 500,000 Massachusetts residents. The MassDEP is encouraging PFAS sampling of residential wells, especially if a well is located near potential sources or near other water supplies where PFAS has been detected.

Private drinking water wells are not regulated by the MassDEP, however. Un-permitted releases of oil and hazardous materials, including PFAS6, into the environment are regulated under Chapter 21E and by the Massachusetts Contingency Plan, which has a “reportable concentration” of 20 ppt for PFAS6 in groundwater used as drinking water. As a result, homeowners who test their private well and find that PFAS6 exists in groundwater in concentrations equal to or above 20 ppt are required to notify the MassDEP, undertake MCP response actions, and may find themselves subject to significant legal and financial responsibilities under Chapter 21E. For municipalities, this means potentially more MCP “disposal sites” in their communities, and where the PFAS6 source is not known, at-risk and frustrated residents.

PFAS has also been identified in discharges from wastewater treatment plants. In Massachusetts, such discharges are regulated by the federal National Pollutant Discharge Elimination System permit program. The MassDEP runs a parallel surface water discharge permitting program. Both programs control water pollution by regulating “point sources” that discharge pollutants to surface waters.

Last summer, the U.S. Environmental Protection Agency began issuing draft NPDES permits for several Massachusetts wastewater treatment plants, with requirements to monitor influent, effluent and sludge for PFAS6. The MassDEP has also been setting conditions in its Massachusetts Surface Water Discharge Permits to monitor discharges for PFAS and to monitor its significant industrial users’ discharges for PFAS. Finally, the MassDEP has concerns regarding the levels of PFAS produced from wastewater treatment and other processes residuals.

In Massachusetts, the water infrastructure — drinking water, wastewater, and stormwater systems — is primarily a local responsibility. The financial burden for PFAS compliance at public water supplies and wastewater treatment plants will inevitably lead to higher water and sewer rates — and public pushback on rate increases. More significant are the risks stemming from permit requirements that cast wastewater treatment plants as “sources” of PFAS or as “polluters,” even though operations do not add PFAS during treatment and only receive PFAS from upstream dischargers (including residential users), that could set back years of effort to educate the public on the true costs and high value of clean water.

Written by Robert D. Cox Jr., environmental attorney and managing partner at Bowditch & Dewey LLP