Maryland finally acknowledged the problem with sewage sludge – now it needs to get the solution right

What Maryland’s new PFAS sewage sludge law does

When Maryland lawmakers took up legislation to address PFAS, or “forever chemicals,” in sewage sludge this year, communities, farmers, and advocates alike were encouraged. For years, they have sounded the alarm about spreading sewage sludge on land. But now that the legislation has become law, one thing is clear: Maryland has not gone far enough to solve the problem.

The new law creates different requirements for managing PFAS in sewage sludge based on the amount detected. Extremely high levels trigger restrictions for spreading sludge on land. Lower levels require wastewater treatment facilities to investigate where the PFAS is coming from and develop plans to reduce its concentration. At these lower levels, contaminated sludge can continue to be spread on land with no additional requirements.

That is where Maryland got the solution wrong.

Why PFAS in sewage sludge is a problem

Sewage sludge is the material left over from the wastewater treatment process. Everything that goes down the drain – from household waste to industrial and commercial discharges – can end up concentrated in this material. Wastewater treatment plants are designed to clean any water that enters the facility before releasing it back into nature. But they are not designed to destroy every toxic chemical that enters the wastewater system. This is especially true for PFAS.

PFAS don’t break down naturally. Instead, these chemicals build up over time. So, when PFAS-contaminated sludge is spread on farmland, those chemicals can become concentrated in the soil and even move into groundwater. Studies show that once in soil, the PFAS can enter crops and livestock, threatening our food system and our health.  

Where Maryland’s PFAS sewage sludge law falls short

Maryland is right to recognize PFAS contamination in sewage sludge. But the framework the state adopted isn’t based on protecting public health. Rather, it’s based on creating as little disruption to wastewater treatment plants as possible.

For starters, the law only measures two types of PFAS chemicals – PFOA and PFOS – in sludge. But sewage sludge doesn’t just contain these two types of PFAS. Studies have detected numerous other members of this chemical group in sludge. Limiting the law to PFOA and PFOS leaves sludge contaminated with other PFAS chemicals unregulated.

If that weren’t bad enough, the law treats 25 parts per billion (ppb) as a dividing line. Below that level, sewage sludge can continue being spread on land without any additional action.  But a number on a page does not make contaminated sludge safe. The U.S. Environmental Protection Agency’s 2025 draft risk assessment on PFAS in sludge found that, under certain conditions, sewage sludge containing just 1 ppb of PFOA or PFOS could result in risks to human health above the EPA’s acceptable thresholds.

Perhaps most troubling, the law allows contaminated sludge containing 25-50 ppb of PFOA and PFOS to be blended with other material. Why? To bring the concentration of PFAS down so that it can continue to be spread on land. But dilution is not destruction. Instead of eliminating the contamination, the law allows it to be spread across more material until it falls below the legal limit.

Reducing PFAS pollution isn’t enough

When PFAS concentrations reach 25 ppb, Maryland’s law requires wastewater treatment plants to investigate where those chemicals are coming from and develop a plan to reduce them. This is a critical step. But reducing PFAS at the source is not enough on its own. The state also need to end the spread of contaminated sludge on land. Combined, these two strategies create a strong system that limits future contamination while ensuring sludge with PFAS is never spread land. In only taking the first approach, Maryland fumbled. But policymakers made the law even weaker through the thresholds they set.

Since January 2025, only two of the 51 facilities that will be regulated under the law reported PFAS concentrations above 50 ppb. Another six reported concentrations above 25 ppb. That means the majority of Maryland’s facilities – reporting less than 25 ppb – can continue spreading contaminated sludge on land as usual.

Unfortunately, Maryland is not alone. Virginia adopted the same three-tiered structure earlier this year, while Michigan has been using the same approach for several years. Though it’s encouraging to see each of these states recognize PFAS in sludge as problematic, all three laws point to a troubling trend: states are opting to mitigate damage, rather than outright ban a practice proven to be toxic to our health and environment. Thankfully, some states are resisting the trend. Both Maine and Connecticut have completely banned the spread of PFAS-contaminated sewage sludge on land.

Maryland needs to go further

Maryland clearly understands PFAS can pose unacceptable risks – it has already restricted PFAS in products like firefighting foam, food packaging, carpets, and rugs. But the state needs to go further. Persistent, toxic chemicals, should not be spread on land where we grow food, raise livestock, and depend on groundwater.

The new law is an important first step. It will help Maryland better understand where PFAS is coming from, reduce some sources of contamination, and bring greater scrutiny to the risks of sewage sludge.

But we should not confuse acknowledging a problem with solving it.

Maryland must build on this progress by investing in safer ways to manage sewage sludge and ultimately ending the practice of spreading PFAS-contaminated sludge on land. The logical conclusion is simple: contaminated sewage sludge does not belong on any land.