EPA Issues Long-Awaited PFOA/PFOS Risk Assessment

EPA Issues Long-Awaited PFOA/PFOS Risk Assessment

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The U.S. EPA has long supported the land application of biosolids regulated under Section 503 regulations for sewage sludge disposal. However, increasing attention and questions have been raised on what to do with biosolids containing trace amounts of per- and polyfluoroalkyl substances. This week, EPA issued a pre-published version of the agency’s draft risk assessment for PFOA and PFOS involving biosolids land application and surface disposal. Over 50 percent of the biosolids in the U.S. are land applied, with 31 percent being used for agricultural fertilizer. The assessment modeled the potential impacts involving several scenarios, including an agricultural farm, a food crop farm, soil reclamation, disposal in sludge landfill, and incineration.

EPA concluded that for all scenarios involving land application, biosolids containing PFOA or PFOS at concentrations exceeding 1 part per billion (ppb) – akin to one drop in a swimming pool – pose on unacceptable risk to humans from consumption of dairy products (milk, eggs, beef, chickens, etc.), fish and drinking water impacted by PFOA or PFOS. In characterizing these risks, EPA stated,

Not all farms or disposal sites where sewage sludge containing PFOA or PFOS have been used or disposed of are expected to pose a risk to human health. For example, human health risks are expected to be lower where sewage sludge is applied to areas with protected groundwater, sites that are distant from surface waters used for fishing or as a drinking water source, and when applied to non-food crops, such as grain, fuel, or fiber crops.

EPA’s draft assessment will only continue to heighten concerns over the land application of biosolids. While EPA stressed the importance of source reduction to wastewater treatment plants through industrial pretreatment, the assessment raises serious questions regarding the viable options and costs for sewage disposal. Some states may follow Maine’s lead who, in 2022, banned land application of biosolids, creating a hardship for many communities faced with biosolids disposal. More likely, however, EPA and the states will adopt new requirements for land application and disposal suitable for areas and uses where human exposure is limited.

For more details, readers can view the draft assessment and docket materials here. EPA is accepting comments for 60 days from publication in the Federal Register.

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