Submitted by Greg Alderete.
The use of biosolids—treated human sewage sludge—as fertilizer is often promoted as an eco-friendly way to recycle waste. However, spreading biosolids in or near residential areas poses serious medical and environmental risks that are too often ignored.
Even after treatment, biosolids can contain harmful pathogens like E. coli, Salmonella, and viruses such as norovirus and hepatitis A. These microorganisms can become airborne or seep into local water supplies, creating direct exposure risks for nearby residents. In addition to biological hazards, biosolids frequently contain toxic heavy metals—such as lead, mercury, and cadmium—that accumulate in soil and can contaminate crops or groundwater.
Perhaps most alarming is the presence of PFAS, or “forever chemicals,” which are increasingly found in sewage waste. These substances are linked to cancer, thyroid disorders, immune suppression, and developmental delays. Biosolids can also carry antibiotic-resistant bacteria, increasing the spread of superbugs in the environment.
Residents near biosolid-treated areas have reported nausea, rashes, respiratory problems, and eye irritation—especially in children and those with existing health issues. Until more rigorous testing and regulation is implemented, using biosolids near homes, schools, and waterways is an unacceptable gamble with public health.
Does this apply to Sound Grow and Tagro? I thought the soil supplements are sanitized somehow and approved for application.
Maybe the waste facility manager could reply
I would also like to know the answer to this.
I appreciate Greg Alderete’s encyclopedic scope and writing interests, but it would seem incumbent upon any of us authoring sweeping claim or one of alarm do the research ahead of publication. And while your at it, Greg, how about those mountains of artificial fertilizer dissolving from Lowes, Home Depot and Lakewood Hardware parking lots into the Chambers-Clover Watershed annually? Haven’t seen Chum in Flett for several years. Could THAT be a problem for discussion?
I think we are in agreement! There is solid evidence emerging around contaminants in biosolids, and it’s a conversation worth having. States and counties are banning its use. At the same time, we shouldn’t overlook the cumulative impact of other sources of contamination. Several states, including Maine and Michigan , have found high levels of PFAS in sludge and taken action. For example, Maine has prohibited the use of sludge on farm fields. Nearly 70 million acres of U.S. farmland could be contaminated by the toxic “forever chemicals” known as PFAS, according to estimates from biosolids industry groups. This contamination stems from the widespread use of sewage sludge as fertilizer.
The practice remains largely unregulated, despite mounting evidence it could contaminate food and water, creating public health risks. State and federal policymakers need to tackle this threat with steps such as banning the use of PFAS-contaminated sewage sludge on farm fields. The Environmental Protection Agency began regulating biosolids in 1993 under the Clean Water Act. Are we truly comfortable exposing ourselves, our families, pets and our ecosystems to potential bio-contaminants just to green up a lawn?
So misguided. You are pretending like decades of research and regulations don’t exist.
The practice of biosolids production and application to soil is very tightly regulated. For pathogens and bacteria that you mention, Class A biosolids carry less than the soil they are put on. Class B biosolids are comparable to animal manure.
The heavy metals you mention are regulated to levels that prevent them from “contaminating” the soil. Again, in biosolids they are often present in levels that are lower than the soil carries naturally.
As for PFAS, are you eating your lawn?
PFAS chemicals are a legitimate concern. A little bit of research on the issue would show you that PFAS is entering your body from products in your household that you use every day. Cookware. Food wrappers. Personal care products – skin care, makeup, dental floss – these products can carry PFAS and are applied directly to our bodies.
We can recycle the nutrients in biosolids or we can do… what, exactly? Dump them into rivers? Shoot them into space? Burn them? Bury them in giant holes in the ground? Do you have a sustainable solution that I’m not aware of? (You don’t)
Greg, Bob Warfield makes some important points about responsible journalism. Biosolids have been used in landscaping for non-farming purposes in the US for over 75 years in my personal experience. I have not heard of any outbreaks of the problems you mentioned from actual biosolid origin. Untreated, raw sewerage is well documented as causing outbreaks of infectious diseases. In what ways should current testing be more rigorous?
It’s true that biosolids have been used in landscaping for decades, but it’s also true that our understanding of long-term exposure and cumulative effects has evolved. Several U.S. states—and a number of scientifically informed countries—have determined that land application of biosolids can pose risks and should be regulated with greater caution.
The concern isn’t necessarily with immediate outbreaks, but with the presence of PFAS, heavy metals, pharmaceuticals, and other contaminants that current testing may not fully capture—or that may not be monitored frequently enough. As our science progresses, it seems only responsible to reassess what levels of exposure are truly safe over time.
For decades, we were told that atomic testing in the Nevada desert posed no danger. The same assurances were made about Agent Orange. It wasn’t until years later that the devastating health effects became undeniable. We’ve seen this pattern before—downplay, delay, then damage.
Now we’re applying biosolids and lawn products that may contain glufosinate ammonium, PFAS, heavy metals, and pharmaceutical residues—chemicals with known or suspected links to long-term health issues. Many of these substances can be absorbed through the skin, inhaled, or persist in our environment for decades. Yet current testing is often outdated, incomplete, or shaped by industry standards, not independent science.
We should be sounding the alarm. Vigilance isn’t fear-mongering—it’s what responsible societies do when history has already shown us the cost of complacency. Testing must be accurate, innovative, and rooted in the science of today, not the blind assurances of yesterday.
So what about Sound Gro and Tagro? Are they safe to use?
Depends on what you mean by safe. For your lawn? Maybe. For long-term soil health, water quality, and bioaccumulation in the food chain? That’s a much murkier answer. SoundGro (King County) and Tagro (Tacoma) are both municipal biosolid products marketed as safe, sustainable fertilizers. They’re heavily promoted as eco-friendly, “Class A” biosolids, meaning they meet EPA standards for pathogen reduction and can be used without restriction. But—and it’s a big but—“Class A” does not mean free of contaminants. It just means they don’t contain infectious bacteria or viruses at levels considered hazardous. Here’s the real issue:
PFAS (“forever chemicals”): These are not removed during standard wastewater treatment. Both SoundGro and Tagro may contain PFAS, pharmaceuticals, microplastics, and heavy metals—residues from industrial, medical, and household waste streams. Testing is limited, and regulations lag far behind what current science is discovering.
Washington’s awareness is growing: In 2022, Maine banned biosolids after PFAS from sludge contaminated soil and groundwater. That prompted Washington state to begin looking more closely. Some lawmakers and researchers are calling for tighter regulation, better testing, and in some cases, an end to land application altogether.