PFAS (Per‐ and polyfluoroalkyl substances) are man‐made chemicals that have been widely used since the 1940s in consumer products and industrial applications. Due to their widespread use and persistence in the environment, most people in the United States have been exposed to some level of PFAS. Food has been packaged in materials and processed with equipment that uses PFAS. Household products such as stain‐ and water‐resistant fabrics (like clothes, towels, or sheets), along with carpeting, non‐stick cookware, cleaning products and paints, all contained PFAS. Even workplaces like production facilities and industrial settings have used PFAS in their day-to-day operations. Class B Firefighting foam (AFFF) foam is made with PFOA and PFOS due to their extreme effectiveness at quickly extinguishing petroleum‐based fires.
The highest exposure comes from the above consumer products, however drinking water can be an extra source of exposure if contamination has occurred.

PFAS have been found in Maine in a number of places including: agricultural sites, drinking water supplies, surface waters, landfills, wastewater, sludge and septage spreading sites, and remediation and cleanup sites. In general, PFAS can enter the environment through direct releases from specific PFAS-containing products (e.g., certain firefighting foams), from various waste streams (sludge and septage when land applied, leachate from unlined landfills), and other pathways still being researched. In Maine, sludge and septage that may contain PFAS was applied to various “sites” for nutrient value. This activity was licensed because at the time little was known about PFAS as an emerging contaminant. 

Sludge is a solid, semi-solid, or liquid waste generated from a wastewater treatment process as well as from dewatered septage. Wastewater is used water that can include substances such as domestic, commercial, and industrial waste; food scraps; fats, oils, and grease; soaps; and chemicals and can be generated by households, businesses, and industry. Wastewater treatment systems treat this used water so that it can be recycled back into the environment. Sludge is a byproduct that has been spread for decades on agricultural land as a way to supplement farmland with nutrients.

Septage is a fluid mixture of sewage solids, liquids and sludge of domestic origin, which is collected in and removed from a septic tank system. Once a septic system is pumped out the septage must be disposed of.  Land application of septage is the most common and economical way to utilize it. Typically septage is land applied in areas that are more remote, but residential developments can be later built in those areas.