Sewage Sludge Can Spread the Harm of Many Toxic Chemicals

Sewage sludge containing toxic chemicals is finding its way onto farm fields. Above, a sewage sludge treatment tank in Scottdale, Pennsylvania. Photo: USDA/Lance Cheung via Flickr Creative Commons (Public Domain).

TipSheet: Sewage Sludge Can Spread the Harm of Many Toxic Chemicals

By Joseph A. Davis

There was a time when the U.S. Environmental Protection Agency renamed toxic sludge as “biosolids,” and journalists went along with it.

Today, as we are becoming aware of more and more toxic chemicals, it is hardly a surprise that we are finding them in sewage sludge. The surprise is that some farmers are spreading them on their fields.

 

The sad part is that we

have dodged the problem in

one way or another for decades.

 

You will find a deeper look in Hiroko Tabuchi’s recent New York Times piece (may require subscription) on the subject. The sad part is that we have dodged the problem in one way or another for decades.

PFAS (which headline writers style “forever chemicals”) are only the latest such chemicals. There are many others. They are toxic. You do not want them in your vegetables.

But there they are. Everything has to go somewhere. Environmental journalists can find a local story just about anywhere. There is one near you.

 

Why it matters

The toxic contaminants of sewage sludge can potentially be harmful to human health and the environment.

And there are a great many of them — not just PFAS, but heavy metals like lead, other toxic organics like dioxins, PCBs, pharmaceuticals whose names you can’t even pronounce and unknown chemicals that did not go into rusty barrels.

The degree of harm is hard to calculate. Toxicologists remind us that the dose makes the poison. Sometimes the concentrations are in parts per trillion.

It is hard to know how much PFAS is in your vegetables, or exactly how much will harm a vulnerable person. The problem gets much harder when you realize that there are thousands of individual PFAS chemicals. Not to mention all the other chemical families.

 

The backstory

It’s a long tale that goes back to 1972, when the Clean Water Act passed in its modern form.

At the time, the immediate problem was to get raw sewage out of the rivers. The EPA later set a rule requiring companies discharging waste into municipal sewers to pretreat their wastewater.

 

Originally, the biggest worry was

whether the sludge had been

disinfected. Calling it biosolids

did not make the problem go away.

 

Eventually, the EPA even issued rules about the disposal of sewage sludge — what’s left over after bacteria have digested all that brown stuff. Originally, the biggest worry was whether the sludge had been disinfected. Calling it biosolids did not make the problem go away.

Those rules may not be good enough or up to date. They allow — some say encourage — sterilized, dried sludge to be spread on fields, golf courses, etc. The big question is whether harmful chemicals are getting into people’s food and water.

 

Story ideas

• Where does your sewage go when you flush the toilet? Talk to your local sewage treatment agencies and ask them what they do with their sewage sludge.
• Ask who takes the bulk of processed sludge from your local agencies? There may be companies who distribute it in large quantities to farmers, golf courses, etc., who apply it to land. Talk to them. Talk to their customers.
• The EPA has to review its “biosolids” rules every two years to see whether they should be updated as new contaminants come to light. What do local sewage officials and environmental advocates think about the EPA’s performance?
• Some disposal of sewage sludge on land requires a National Pollutant Discharge Elimination System (water pollution) permit. Check the permit database for permittees. Check the EPA’s ECHO enforcement database for violators. Talk to permittees and permitting agencies.
• Does your local sludge go into the retail market? What companies and brands sell it? Ask for their test results on chemical contamination. Figure out what they didn’t test for.
• Go to local hardware, home improvement and feed stores. Do they sell sludge products to consumers (as “soil conditioner” or “compost”)? Hang around that area of the store, talk to customers and ask if they use it on home vegetable gardens.
• Talk to groundskeepers or managers at local golf courses. Do they use sludge products on their courses? What can you learn about the runoff situation?
• Go to meetings of local garden clubs and community gardens. Or visit on-site. Ask members what they do, especially with vegetable gardens.

 

Reporting resources

• U.S. Environmental Protection Agency: The agency sets the standards for land application of sludge.
• Local Sewage Treatment Agencies: You can find them in the EPA’s ICIS-NPDES database using SIC code 4952.
• National Association of Clean Water Agencies: The NACWA is a lobby and professional group of municipal sewage treatment agencies.
• Center for Food Safety: A nonprofit group that advocates for food safety.
• Regional Biosolids Groups: Find some listed here.
• Food & Water Watch: A nonprofit environmental advocacy group that follows the sludge-agriculture issue.
• Water Environment Federation: A professional and scientific organization whose members work in the sewage and water industries.

[Editor’s Note: For more on the topic of PFAS in sewage sludge, read our Feature, “For Waste Industry, PFAS Disposal Leads to Controversy, Regulation, Mounting Costs” and our Issue Backgrounder primer on PFAS. Plus, see our Topics on the Beat pages on agriculture and the food system, which include top SEJournal stories and EJToday headlines.]

Joseph A. Davis is a freelance writer/editor in Washington, D.C. who has been writing about the environment since 1976. He writes SEJournal Online's TipSheet, Reporter's Toolbox and Issue Backgrounder, and curates SEJ's weekday news headlines service EJToday and @EJTodayNews. Davis also directs SEJ's Freedom of Information Project and writes the WatchDog opinion column.

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* From the weekly news magazine SEJournal Online, Vol. 9, No. 38. Content from each new issue of SEJournal Online is available to the public via the SEJournal Online main page. Subscribe to the e-newsletter here. And see past issues of the SEJournal archived here.