Conference Agenda

Per- and Poly-Fluoroalkyl Substances (PFAS) are a large family of organic compounds, including more than 4,500 synthetic fluorinated organic chemicals used in commercial, consumer and industrial products since the 1940s. Conventional sewage treatment methods do not efficiently remove PFAS which are resilient to degradation and tend to sequester to the treated solids produced and the resultant biosolids. In its most recent (2021) review of pollutants in biosolids, the US EPA identified eight PFAS in biosolids, and is undergoing a problem formulation process which will serve as the basis for determining whether regulation of PFOA and PFOS in biosolids is appropriate. If EPA determines that a regulation is appropriate (currently expected in 2024), biosolids producers will be required to meet certain standards. This potential outcome of EPA’s review underscores the importance of understanding technical solutions available to treat PFAS in biosolids if required based on EPA’s review process.

To assist utilities and biosolids producers understand options available to mitigate potential PFAS contamination in biosolids, Jacobs has tested several biosolids products including dried biosolids, pyrolyzed dried biosolids and composts, all produced with non-industrially impacted biosolids to assess the concentration of PFAS compounds in the finished products and the ability of these processes to reduce and or remove PFAS compounds. Samples of input and output solids, bulking agents and finished products were analyzed for 24 PFAS compounds utilizing Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS). Data will be presented on three dried biosolids facilities, two pyrolyzed dried products including output solids, gas and oil, and six compost products.

This presentation will provide information regarding the measured concentrations of PFAS in wastewater solids, dried biosolids, pyrolyzed biosolids and biosolids based compost products. PFAS precursor analyte presence and concentrations in the input solids as well as the wastewater treatment process used to generate these products will also be presented. This information will be useful for those considering methods to reduce or eliminate PFAS in their own wastewater solids or other input wastewater solids at existing or planned biosolids management operations to ensure the lowest feasible PFAS concentrations in end products can be achieved.

Federal and state regulatory agencies—and the public—have growing concerns about public health and environmental wellbeing associated with per- and polyfluoroalkyl substances (PFAS). As of this writing, the United States does not yet have federally enforceable PFAS standards for drinking water, wastewater, or biosolids. This has left states to develop their own regulations to address PFAS contamination, creating a diverse regulatory patchwork across the country. State regulations on PFAS in drinking water are becoming common, but now a few states are also enacting regulations on PFAS in surface water and biosolids as well. For example, Michigan has developed screening levels for PFAS in biosolids, and Maine has effectively banned biosolids land application due to concerns about PFAS.

The EPA plans to complete a risk assessment for two PFAS [perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)] in biosolids for land application by Winter 2024. PFOS is commonly detected in biosolids at a concentration around 10 ppb, even without any industrial sources. A biosolids PFOS limit below that level could widely restrict land application, having a large impact on our industry. This risk assessment requires knowing many parameters for PFAS toxicity, occurrence, fate, and transport. This presentation will walk through the risk assessment process, what parameters are known, and which are not, along with proven methods utilities can use to keep stakeholders and customers informed.

Elected officials, stakeholders and the public are interested in actions utilities are taking to protect public health and the environment. Having a response plan in place to monitor, assess and respond to emerging regulations can “calm the waters” while the regulatory process unfolds. One topic of interest is how to treat PFOS. Ongoing research on PFAS-destroying technologies includes investigations into incineration, pyrolysis, gasification, supercritical water oxidation (SCWO), hydrothermal liquefaction, and hydrothermal alkaline treatment. This presentation will compare the latest known PFAS destruction efficiencies, market readiness, and other considerations that impact the feasibility of these technologies for widespread use. A regulatory update on proposed legislation in the Pacific Northwest will also be provided.