Protecting Farmlands & Water from PFAS in Sewage Sludge

The Problem

Sewage sludge (also known as biosolids) is the solid waste produced during the treatment of municipal, human, and industrial wastewater. In Maryland, sewage sludge — including some from out-of-state facilities — is used as fertilizer on farms. However, sewage sludge often contains pathogens and toxic substances, including PFAS chemicals, also known as “forever chemicals.” While existing regulations prohibit immediate grazing, row crop consumption, and public access to treated fields, these measures fall short when sewage sludge contains PFOS and PFOA, two highly toxic PFAS compounds that persist in the environment and pose significant risks to human and ecological health.

During treatment, these chemicals concentrate in sewage sludge, which are then spread on agricultural fields. Alarmingly, Maryland’s sewage sludge permits allow waste from multiple facilities to be applied to single fields, heightening the risk of contamination.

Sewage sludge containing PFAS run off farm fields and filter into groundwater and contaminate drinking water sources. PFAS also bioaccumulates in fish and wildlife, and is stored in milk, fruits and vegetables.

States across the country are working to pass policies that protect human and environmental health from toxic PFAS in sewage sludge. Following their lead, Maryland began testing sewage sludge and found significant PFAS levels. While the state has recommended guidance on PFOS and PFOA levels in sewage sludge, the recommendations are not strong enough and they lack necessary regulatory authority.

The Environmental Protection Agency’s draft Sewage Sludge Risk Assessment, released in January 2025, highlights the severe risks posed by PFOS and PFOA levels as low as 1–5 parts per billion, linking exposure to contaminated water, wildlife, and crops to serious health issues, including immune dysfunction, thyroid disease, and cancer.

Maryland can’t wait for the EPA and must take stronger action to safeguard its drinking water sources, environment and the health of our farmers and communities. While there is no known safe level, this bill takes a significant step to lower health risks, and identify and mitigate sources of PFAS before getting to wastewater treatment plants. Farmers have a right to know what they are putting on their fields.

What the Bill Does

Tiered Protections for Maryland Farms (on or after October 1, 2028):
- > 50 ppb (combined PFOA + PFOS): No land application permitted.
- 25-49 ppb: Utilities must develop a mitigation plan and adhere to certain land application requirements (e.g. setbacks, buffers, reduced application rates).
- < 25 ppb: no restrictions
Stopping Pollution at the Source
- * Source Tracking & Mitigation Plans: If sewage sludge tests over 25 ppb, wastewater treatment plants (WWTPs) must create a mitigation plan that includes a study to identify the source, enabling PFAS to be stopped at the source.
- * Industrial Pretreatment Standards: MDE's and local jurisdictions' authority to set pretreatment standards is clarified and enhanced.
- * Polluter Pays: Local jurisdictions can set rates and fees for industrial users discharging PFAS.
Operational Flexibility for WWTPs:
- * Blending Authority: for a period not more than two years after the date of determination, WWTPs are allowed to blend sludge from multiple sources to dilute PFAS to below 25 ppb.
- * Transitional Application: Facilities with levels of 25-49 ppb can land apply for up to 12 months at a reduced rate and with setbacks while developing mitigation plans.
Farmer Notification: 14 days prior to application of sewage sludge, the land applier will provide notice to farmers, adjacent land owners and local governments of the concentrations of PFAS between 25 ppb and 50 ppb.
Current status: A small number of utilities exceed 25 ppb, and some are already working on mitigation plans.