EPA’s Draft Risk Assessment: Key Impacts on Maine’s PFAS Regulations

By: Kat Joyce, Jack Woodcock, Richard Qualey

In mid-January the EPA released its “Draft Sewage Sludge Risk Assessment for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonic Acid (PFOS).” Translation: the EPA conducted a scientific analysis to determine the potential risks to human health and the environment posed by the presence of forever chemicals in sewage sludge that is used as fertilizer, surface disposed, or incinerated. They are seeking comments, particularly on scientific and technical issues on the draft assessment.

Clear as sludge? Perhaps some background.

Recent Federal PFAS Rulemaking

PFOA and PFOS are part of a large group of lab-made chemicals known as perfluoroalkyl and polyfluoroalkyl substances (PFAS). In the past year, PFAS has been the subject of substantial rulemaking:

• In February 2024, the EPA proposed to add nine particular PFAS compounds to the definition of hazardous constituents.
• In April, the EPA announced a final rule designating PFOA and PFOS as “hazardous substances” under CERCLA.
• Also in April, the Biden Administration announced a nationwide standard for PFAS in drinking water.

The drinking water standard set a “non-enforceable health-based goal” and a “Maximum Contaminant Level Goal” for PFOA and PFOS of zero.  The final regulations also set enforceable Maximum Contaminant Levels at 4.0 parts per trillion for PFOA and PFOS, individually.  For GenX chemicals, the final regulation set a Maximum Contaminant Level at 10 parts per trillion.  Both final rules have been challenged and are currently pending in the Court of Appeals for the District of Columbia.

The EPA’s Draft Sewage Sludge Risk Assessment for PFOA and PFOS

The EPA capped a year of substantial regulatory activity surrounding PFAS by releasing the Draft Sewage and Sludge Risk Assessment.  In the U.S., there are generally three options for use or disposal of sewage sludge as reported in the draft risk assessment:

(1) approximately 56% of the nation’s sewage sludge is land applied as fertilizer (roughly 31% is applied to agricultural land and 25% is applied to other lands, such as reclamation sites, home lawns and gardens, or golf courses),

(2) approximately 27% is disposed of in landfills, and

(3) approximately 16% is incinerated.

The draft risk assessment focuses solely on the land application and incineration of sewage sludge.

EPA’s Fertilizer Push

For decades, the EPA has encouraged the use of sewage sludge from wastewater treatment plants as fertilizer for agricultural land. The concept is simple—wastewater treatment facilities need a way to dispose of the sludge, the sludge is rich in nutrients, so what better way to dispose of the sludge than to repurpose it as fertilizer? Facilitating this policy, in 1993 the EPA issued regulations providing for management practices and pollutant limits to protect human health in the land application and disposal of sewage sludge.  The Clean Water Act also requires the EPA to review sewage sludge regulations every two years to assess whether additional pollutants should be regulated.

Key Findings of the Risk Assessment

The Draft Risk Assessment concluded that, in various land-application scenarios, sewage sludge must contain less than 1 part per billion to be within the EPA’s acceptable threshold for human health risk.  The Risk Assessment noted that the presence of and magnitude of human health risks from the land application of sewage sludge may vary greatly depending on site-specific conditions.

The risk assessment did not include qualitative risk assessments for the incineration of sewage sludge.

Have Your Say: Public Comments

These are only a handful of takeaways from the draft risk assessment, which spans more than 200 pages and presents a plethora of assumptions, conclusions, data, and source citations, all accessible for public review. Publication of the EPA’s draft risk assessment in the Federal Register on January 15th started the 60-day public comment period, after which the EPA will review all submitted comments, make adjustments to the draft risk assessment based on those comments, and publish a final report to follow.

Implications of the EPA’s Draft Risk Assessment in Maine

The Risk Assessment has vast implications in Maine, which has identified hundreds of sites upon which sewage sludge was permitted to be spread by Maine’s Department of Environmental Protection. While Maine has been on the forefront of PFAS regulation, testing, and remuneration for those impacted by the past spreading of sewage sludge, any federal action on this issue will have clear impact in Maine given the state’s efforts to identify sites across the state that received the land application of sewage sludge.

The draft risk assessment thus falls in Episode One of what likely will be a long series in assessing and regulating the presence of PFAS in biosolids, both at the State and Federal levels.