PFAS is the acronym for Perfluoroalkyl and polyfluoroalkyl substances. PFAS are a large group of human-made chemicals that have been used in industry and consumer products worldwide since the 1950s. These chemicals are used to make household and commercial products that resist heat and chemical reactions and repel oil, stains, grease, and water. PFAS chemicals include PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonic acid).
PFAS chemicals from household and commercial products may find their way into water, soil, and biosolids. As a result, PFAS have been found in people, fish, and wildlife all over the world. Some PFAS do not break down easily and therefore stay in the environment for a very long time, especially in water. Some PFAS can also stay in people’s bodies for a long time.
In response to the contamination of private wells in Bennington and North Bennington discovered in 2016, the Vermont Department of Health (VDH) issued health-based standards for two PFAS compounds, PFOA and PFOS, to guide drinking water remediation efforts. Since that time, the VDH has updated those standards to include three additional PFAS compounds. In 2019, the Vermont General Assembly passed and the Governor signed into law Act 21 that directs DEC to use the health advisory level as an interim drinking water standard and to develop a final standard, known as a Maximum Contaminant Level (MCL). DEC adopted rules in February 2020 to regulate 5 PFAS compounds in all public drinking water systems. As part of Act 21, public water systems around the state began testing for the presence of PFAS. The following systems tested above standards and the locations in bold are located in the WRNRCD and ONRCD Districts:
- Killington Mountain School (Killington)
- Thetford Academy (Thetford)
- Mount Holly School (Mt Holly)
- Killington Village Inn (Killington)
- Fiddlehead Condominiums (Waitsfield)
In 2019, DEC continued with a broader PFAS investigation, including testing of all biosolids (i.e., sludge meeting pollutant limits and treated for pathogens prior to recycling to the land) produced in Vermont. PFAS was detected in all influent, effluent, and solids samples from these facilities with PFAS in sludges and biosolids averaging 83 ppb (sum of 24 PFAS compounds analyzed) across the facilities tested. With the observation of PFAS contamination in biosolids from Vermont wastewater treatment facilities, DEC then conducted soil and groundwater testing at four agricultural sites permitted for the land application of biosolids and stabilized septage during the late summer/early fall of 2019. In addition, any water supplies within ¼ mile of these sites were tested for PFAS. Based on results from initial testing at land application sites, Vermont DEC directed all land application permittees (18 permittees at the time) to conduct soil and groundwater testing at all permitted sites. Testing began in late 2019 and continued through 2020. Average concentrations of total PFAS in soil across 23 unique land application sites was 16 ppb. Groundwater testing results varied, with approximately 20% of all (downgradient) monitoring wells tested indicating PFAS exceeding the Vermont groundwater enforcement standard. Permittees with sites associated with PFAS above the groundwater enforcement standard were directed to halt land application, retest groundwater to confirm results, and identify and test any water supplies within a quarter mile of the site. PFAS testing of drinking water supplies adjacent to these sites confirmed no detections at or above the groundwater enforcement standard to date from land application.
In February 2020, ANR released the report, Deriving Ambient Water Quality Standards for the Emerging Chemicals of Concern: Per- and Polyfluoroalkyl Substances (PFAS). The report describes the framework ANR uses to establish surface water quality standards, and how this framework may apply to the development of state-specific water quality standards to protect both human health and aquatic life from PFAS. Developing water quality standards for PFAS would represent ANR’s first undertaking to establish water quality standards for a group of chemical contaminants that currently are not included in the Environmental Protection Agency’s (EPA) Clean Water Act Section 304(a) National Recommended Water Quality Criteria.