Bills setting limits on contamination from per- and polyfluoroalkyl substances in sewage sludge, or biosolids, were approved in Maryland and Virginia on Monday. The policies set similar limits and are the latest example of regional action on contamination amid continued federal inaction.
Gary Feldon, a partner at law firm Hollingsworth, said the approach taken by both states ensures similar requirements across the Potomac River watershed. He noted that harmonizing policies across neighboring states around the country has taken on added importance as companies that straddle state lines face growing restrictions.
“Where you have these really interconnected water systems and wastewater management policies, you're going to see states hopefully come up with consistent approaches to PFAS in biosolids,” Feldon said. “If you have two states that have inconsistent policies, then that burdens companies that are trying to comply.”
Maryland and Virginia are among a growing group of states passing restrictions, though not always in relative harmony. Maine and Connecticut are so far the only two states to pass total bans on the land application of sludge, and those restrictions have come with challenges. In Wisconsin and Michigan, regulators have taken a similar approach to monitoring requirements and industrial pretreatment requirements, Feldon noted.
Maryland and Virginia share a waterway, but they also share disposal capacity. A study conducted by the Potomac Riverkeeper Network found that 35% of the sludge land applied in Virginia came from out of state, almost entirely from Maryland and Washington, D.C.
David Flores, vice president and general counsel of the Potomac Riverkeeper Network, said information sharing and collaboration on regulations are important to protect farmers and residents across the region.
“The regulatory requirements in Maryland, particularly as it concerns what [treatment plants] they might need to do to identify sources of PFAS contamination and control them, is consequential to the amount of PFAS that's in the sludge that crosses state lines and ends up on farmlands in Virginia,” Flores said.
Virginia lawmakers sent their PFAS bills to the governor in March. Gov. Abigail Spanberger signed SB386/HB1443 on Monday, which would require wastewater treatment plants to test for PFOA and PFOS in their sewage sludge monthly starting next year. Starting in July 2027, the sludge cannot be land applied if PFOA or PFOS concentrations are greater than or equal to 50 parts per billion on a 12-month rolling average. Between 25 and 50 ppb, the amount of land applied sludge is limited until concentrations drop below 25 ppb.
A bill proposed in Maryland last year would have set more restrictive limits on PFAS in sludge, but it did not advance after wastewater treatment plant operators engaged with its sponsors.
Maryland's legislature passed SB 719/HB925 on Monday, the final day of the state’s legislative session. The bills would prevent the land application of sewage sludge if concentrations of PFOA and PFOS are above 50 ppb starting Oct. 1, 2028. If the concentration is above 25 ppb, the sludge must be commingled to reduce contamination and generators must develop a monitoring and mitigation plan.
The bills also require wastewater treatment plants to identify and study the source of PFOA and PFOS entering their system when PFAS levels rise above 25 ppb. Once identified, the plants must also develop a mitigation plan that could include pretreatment control for industrial users or "system-scale solutions" developed by the plant.
Potomac Riverkeeper Network President Betsy Nicholas testified in support of the bill in the Maryland legislature in February. But she called the 25 ppb threshold “a necessary interim step” based more on technology and cost than on science.
"A truly health-protective level for PFAS in biosolids is likely closer to 1 part per billion or even lower. But waiting for systems to reach that level before taking action would mean allowing continued contamination in the meantime," Nicholas testified.
Maryland Sen. Sara Love, who sponsored the bill, also said the measure was just one step in ensuring greater reduction of PFAS. “Because these toxic chemicals do not stop at state lines, Maryland’s action is critical to protecting our shared waters and driving accountability across the region,” Love added in a statement.
The Maryland bill builds on previous requirements issued by the state's Department of the Environment. Beginning last year, wastewater treatment plants are required to sample for PFOS and PFOA if they distribute biosolids for land application. The state also enacted a bill in 2024 requiring regulators to look upstream for significant industrial PFAS polluters and develop monitoring and mitigation measures.
Other environmental organizations had pushed for stronger regulation in the state. Just Zero testified against the Maryland bill, saying it “risks creating a false sense of safety and progress while perpetuating the very harms it seeks to address.”
Maryland Gov. Wes Moore has 30 days to sign the bill. If he takes no action, it will become law.
