Results from sampling of waste streams, identification of potential treatment options and presentation of the framework for surface water quality standard development
Montpelier, Vt. - The Vermont Department of Environmental Conservation (DEC) released several per- and polyfluorinated substances (PFAS) reports today. The reports will help DEC continue to investigate PFAS in landfill leachate, to evaluate the impact of landfill leachate on PFAS concentrations at wastewater treatment facilities, and to evaluate treatment alternatives for PFAS leachate. The reports will also help DEC begin to evaluate other potential sources of PFAS releases into the environment from residential, industrial and wastewater treatment facilities and how to manage sludges and biosolids produced by these facilities.
The first report, a continuation of the state’s investigations since 2016, includes testing results from 19 wastewater treatment facilities (WWTFs), select industrial discharges, and landfill leachates. The second report, obligated by the solid waste permit to open new cells at the NEWSVT landfill facility and required by Act 21, presents landfill leachate management options. The third report includes a plan to develop water quality standards for Vermont’s lakes and rivers.
To expand understanding of the PFAS within landfill leachate and at WWTFs, DEC conducted sampling studies throughout 2019. This included sampling WWTF influent (waste coming into the facility), effluent (discharge from the treatment facility), and solid byproducts produced by WWTFs. Nearly 400 samples were tested for 24 PFAS chemicals. Detectable PFAS was found in influent, effluent and solid byproducts collected at all facilities, including at WWTFs that do not accept industrial wastewater, indicating that residential materials can also contribute PFAS to WWTFs. The report also found that facilities accepting large volumes of landfill leachate have higher concentrations of PFAS in their effluent when compared to facilities that do not accept this leachate. The sampling results are outlined in Weston and Sampson: Poly- and Perfluoroalkyl Substances at Wastewater Treatment Facilities and Landfill Leachate
In two reports: PFAS Waste Source Testing Report and Conceptual Leachate Treatment Scoping Study for New England Waste Services of Vermont (NEWSVT) Landfill Report, NEWSVT summarizes its sampling work and presents landfill leachate management and treatment options to reduce or eliminate the discharge of PFAS from leachate at WWTFs. After taking over 100 PFAS samples from waste at the NEWSVT landfill, NEWSVT found PFAS in all landfill waste materials sampled. These materials included WWTF and industrial sludges, contaminated soils, bulky waste, textiles, carpeting and commercial customer wastes. The report concludes that the most significant contributors of PFAS are residential materials, such as textiles, furniture and carpets.
Treatment options are available and continue to evolve for reducing or eliminating contaminants of emerging concern, including PFAS, from landfill leachate and WWTF effluent. However, these treatment options create a concentrated waste residual that also must be disposed of or destroyed. The science and technologies available for managing the waste residuals and potential air emissions from these treatment options are still developing. The DEC is contracting with an independent third party to advance our understanding of the treatment options presented in this report.
DEC is reviewing landfill leachate treatment options and will be evaluating alternatives to address the risk of PFAS contamination when implementing regulatory programs responsible for permitting industrial and commercial discharges, such as leachate, to municipal wastewater collection systems and treatment facilities, and when permitting the discharge of effluent from WWTFs.
PFAS concentrations in NEWSVT leachate will continue to be tested as part of the semi-annual monitoring required by the facility’s Solid Waste Facility Certification. At this time, DEC does not recommend initiating a pilot landfill leachate treatment system independent of the regulatory processes.
Knowledge gained from these reports and DEC’s site investigations will help inform 2020 sampling plans and will assist in evaluating alternatives for addressing PFAS. All three reports, as well as additional technical information, can be found at https://dec.vermont.gov/pfas. For more information on Vermont’s PFAS Sampling Plan, visit https://dec.vermont.gov/content/pfas-sampling-report