Analysis of Existing and Emerging Biosolids Beneficial Use Regulations

Background
Biosolids management in the United States is shaped by evolving federal and state regulations, which influence wastewater solids processing technologies, marketing, distribution, and overall management costs. Recent regulatory revisions have been driven by environmental stressors such as climate change and Contaminants of Emerging Concern (CECs), particularly per- and polyfluoroalkyl substances (PFAS). PFAS compounds have become a primary focus local, state, and federal regulatory agencies, reshaping biosolids beneficial use and disposal practices nationwide.

A Risk Assessment for PFOA and PFOS in Biosolids has been conducted by the United States Environment Protection Agency (USEPA), with draft results having been released in January, 2025. The Risk Assessment process is a scientific, multi-stage process to evaluate the need for regulatory guidance on these compounds in biosolids. This analysis examines the recently released draft results, their implications, and their influence on new state regulations.

In anticipation of formal USEPA guidance, key states such as Michigan, California, Maine, and New York have adopted significant policy changes that have had far-reaching impacts. These state-level regulatory frameworks have influenced regional policies and created unique opportunities and challenges for utilities as they develop long-term strategies for managing wastewater solids. As regulations evolve, the landscape for biosolids beneficial use and disposal will continue to shift.

Objective
This analysis focuses on the USEPA Risk Assessment process and recent state regulatory changes, with the following objectives:

USEPA Risk Assessment
1. Review the standard Risk Assessment process used to develop Part 503 biosolids guidance.
2. Analyze the draft results for PFOA and PFOS, highlighting the risk ratios and their implications.
3. Outline next steps in the Risk Assessment process.

State Regulations
1. Identify states implementing PFAS reduction strategies, including sampling and limits for PFAS in biosolids.
2. Evaluate PFAS reduction efforts in Maine, Michigan, California, and New York.
3. Compare USEPA draft results to existing state standards and practices.

Methodology
Research for this analysis included:
1. A detailed review of the USEPA Risk Assessment process to provide historical context and its application for PFAS in biosolids.
2. An in-depth review of the draft Risk Assessment results released by the USEPA in January, 2025.
3. Analysis of state biosolid regulations, validated through surveys with state regulators to assess recent updates and their impacts.

Findings and Current Status
USEPA Risk Assessment
1. Traditional Risk Assessment processes include a Risk Management analysis to weigh cost-benefit impacts before releasing draft results. The process utilized by USEPA for the Biosolids Risk Assessment did not follow the standard process, releasing draft results ahead of completing the Risk Management process. This approach results in limited context provided for results and may lead to reactionary legislation at the state level.
2. The USEPA's assessment of PFOA and PFOS present in biosolids, the USEPA used a deterministic approach, producing a single worst-case risk value focused on farm family exposure. This approach does not reflect typical conditions and resulted higher risks for lower concentrations of PFOA and PFOS in biosolids.
3. Draft results will provide a starting point for determining regulatory limits for PFOA and PFOS in biosolids, with revisions to Part 503 unlikely in the next year. The Risk Assessment results will be reviewed internally by the USEPA and externally by third parties to verify accuracy and approach. This process may lead to further delays in regulatory changes due to USEPA's initial approach for conducting the Assessment.

State Regulations
1. California emphasizes source control, requiring PFAS monitoring to track reductions in biosolids. Results will be compared to USEPA draft numbers.
2. Michigan's 'Michigan Model' set a precedent for PFAS monitoring and limits, influencing neighboring states and earning USEPA recognition.
3. Maine and New York implemented unique strategies for biosolids management, showcasing varied regulatory approaches.

Comparative analysis reveals diverse strategies among states, driven by unique regulatory frameworks. These efforts provide a roadmap for adapting to USEPA guidance while addressing region-specific challenges.