Maryland has enacted limits on how much PFAS can be present in sewage sludge spread as fertilizer on farm fields, and a new round of local reporting has surfaced a criticism that has followed the law since it passed. The threshold may sit above the level most treatment plants already produce.
Governor Wes Moore signed Senate Bill 719 and House Bill 925 on April 28. According to a summary from the law firm Beveridge and Diamond, the measures restrict or prohibit land application of sewage sludge containing specified concentrations of regulated PFAS, defined in the legislation as PFOA, PFOS or a mixture of the two.
PFAS are called "forever chemicals" because they persist in the environment rather than breaking down. When sludge containing them is spread on farmland, the compounds can migrate into soil, crops, livestock, groundwater and surface water. Roughly half of the biosolids generated by Maryland wastewater treatment facilities are currently used in agriculture.
The Structure the Law Creates
The framework is tiered. Sludge containing 25 parts per billion or more of regulated PFAS may still be land applied, but only under alternate management measures, with the source of the PFAS tracked and a state-approved mitigation plan in place. Material containing 50 parts per billion or more is prohibited from agricultural use beginning October 1, 2027. Measurements are averaged over 12 months rather than taken from a single sample.
The law also directs the Maryland Department of the Environment to develop monitoring protocols and strengthens the state's authority to control industrial discharges of PFAS at the source, before they reach wastewater treatment plants.
That upstream provision matters because treatment plants do not manufacture PFAS. They concentrate what arrives in the sewer. The department's own analysis of the bill notes that testing requirements for PFOS and PFOA in land-applied sludge already began in January 2025 under earlier state guidance, and that more than 500 biosolids samples were evaluated in 2025.
Maryland is not alone, and the timing was coordinated. Virginia's governor signed a comparable measure the same day Maryland's legislature acted, an approach Waste Dive reported was designed to create similar requirements across the Potomac River watershed. Maine and Michigan moved earlier, after PFAS contamination turned up in farm soils and dairy operations.
State activity has accelerated in part because the EPA released a draft risk assessment on PFOA and PFOS in sewage sludge in 2025 but has not finalized federal limits, leaving individual legislatures to set their own thresholds.
The Objection from Advocates
The criticism is specific and testable, which is what makes it worth reporting.
"They've essentially greenlit contamination," Peter Blair, policy and advocacy director at the national nonprofit Just Zero, told Spotlight on Maryland in reporting published this week by Fox Baltimore and the Baltimore Sun.
The argument rests on where the limit lands relative to current practice. Biosolids produced at the Blue Plains Advanced Wastewater Treatment Plant in Washington, D.C., which are distributed to Maryland farms, contain 14 parts per billion of PFAS, well below both thresholds. Six other facilities exceeded 25 parts per billion and will be required to examine their PFAS sources and blend material to lower concentrations.
Blair objects to that blending provision most directly, arguing that dilution does not destroy PFAS and instead spreads the same quantity of contamination across a larger area. His broader concern is framing: he told the outlet he does not want the law treated as having solved the problem.
During committee testimony earlier in the session, advocates had pushed for stricter numbers, proposing limits of 20 parts per billion for PFOS and 10 for PFOA.
The Response from Operators and Farmers
The utilities and farmers on the receiving end make a different argument.
Chris Peot, director of resource recovery for DC Water, which manages Blue Plains, said he is not sure where the line should be drawn on safe levels of PFAS in biosolids, and that ideally there should not be any. He disputes the contention that PFAS is taken up by crops grown in fertilized fields, and notes that annual rainfall deposits more PFAS on land than the biosolids his plant produces. His position is that destruction of PFAS is prohibitively difficult at a plant the size of Blue Plains and that the real solution is source control.
"It really has to do with the products that residents are using," Peot told Spotlight on Maryland. "So I would like there to be an educational campaign, maybe at the state level, to educate people about the products that they use every day and the alternatives."
Blair rejects the rainfall comparison. PFAS falling from the sky, he said in an email to the outlet, is a reason to eliminate PFAS wherever possible rather than a reason to spread more of it on farmland.
Charles County farmer Steve Walter, who fertilizes his crops with Blue Plains biosolids, makes a structural objection that overlaps with Peot's: treatment plants can only process what arrives in the sewer, so a law aimed at the sludge is aimed at the wrong end of the chain.
Whether PFAS moves from biosolids into crops is the scientific crux of the disagreement, and it is genuinely unsettled rather than one side ignoring evidence.
The Practical Picture for Maryland Households
Nothing in this law requires an individual action, and no state agency has advised residents to avoid Maryland produce.
The exposure pathways that regulators are tracking are drinking water and groundwater rather than the grocery aisle, and the concentrations involved are measured in parts per billion. Maryland officials have been monitoring PFAS detections in drinking water and groundwater sources across the state, including elevated levels in some Frederick County wells that prompted local utilities and schools to switch to alternative sources.
Households on private wells near agricultural land have the most direct reason to pay attention, because private wells are not covered by federal drinking water testing requirements and no one tests them unless the owner arranges it. Certified laboratories offer PFAS well testing, and the state environment department maintains guidance on sampling. Households on public water systems can request their utility's most recent PFAS results, which utilities are now required to monitor under federal drinking water rules.
The measurable question the next two years will answer is whether reported PFAS concentrations in Maryland biosolids actually fall once testing and source-control requirements take effect, or whether they stay roughly where they already are. That data will exist, and it will settle the argument more definitively than either side's current claims.
Frequently Asked Questions
What does the new Maryland law do? Senate Bill 719 and House Bill 925, signed April 28, 2026, set concentration limits for regulated PFAS in sewage sludge applied to farmland, require monitoring, and strengthen state authority over industrial PFAS discharges.
What are the specific limits? Sludge at 25 parts per billion or more of PFOA, PFOS or a mixture may be land applied only under alternate management measures with a state-approved mitigation plan. Material at 50 parts per billion or more is barred from agricultural use starting October 1, 2027.
Why do critics say the law falls short? Because many treatment plants already produce biosolids below the threshold. Blue Plains material measures 14 parts per billion, so advocates argue the cap codifies current practice rather than reducing contamination.
What do utilities and farmers say? DC Water's resource recovery director disputes that properly applied biosolids are taken up by crops and argues the fix is source control at the manufacturer level. A Charles County farmer makes a similar point: treatment plants cannot control what enters the sewer.
How does PFAS move from sludge into food or water? When biosolids are spread on fields, PFAS can migrate into soil, be taken up by some crops, be consumed by livestock, and leach into groundwater or run off into surface water. The extent of crop uptake remains scientifically contested.
Should Maryland residents avoid local produce? No agency has issued that advice. Regulators are focused on drinking water and groundwater pathways rather than retail food.
Who should consider testing their water? Households on private wells near farmland, since private wells are not covered by federal drinking water monitoring. Households on public systems can request their utility's most recent PFAS results.
