PFAS-contaminated sewage sludge is spreading across Tennessee land. The state could step in.

Farmers, landowners and government agencies have been using treated wastewater to fertilize land in Tennessee for decades, but the practice is coming under increasing scrutiny: Sewage sludge may be contaminated with toxic chemicals known as PFAS.

The latest evidence comes from northeast Tennessee.

Earlier this year, the Sierra Club tested soil, groundwater and drinking water in Sullivan County near sites of historic or current use of sewage sludge, also called “biosolids,” and found PFAS at each location, according to a new report.

“It’s a complicated problem,” said Dan Firth, a waste expert with the Tennessee chapter of the Sierra Club and an author of the report. “One immediate step we can take is to stop applying biosolids now.”

How wastewater can cause drinking water to become contaminated with PFAS

Once wastewater or industrial waste travels through pipes, it ends up in wastewater treatment plants. These plants will treat the waste, and the solids can be turned into biosolids and spread as fertilizer. Many farmers and landowners spread this product on their fields: in the U.S., about 60% of biosolids are used on land as fertilizer.

Facilities test for pathogens and heavy metals such as lead, but most states do not test sludge for PFAS, which can come from industrial waste or even toilet paper.

When landowners spread sludge, PFAS can wash off fields into nearby rivers, leach into groundwater, be absorbed by plants and contaminate local drinking water.

“As we continue to apply these contaminated biosolids to land, we are putting our water resources at risk as well as the land,” Firth said. “PFAS flow into the water.”

And these pollutants can contaminate resources far from the original application sites.

PFAS are linked to cancer and reproductive problems

PFAS, or per- and polyfluoroalkyl substances, are a class of about 15,000 synthetic chemicals found in numerous industrial and consumer products, from dental floss and lipstick to ink and waterproof clothing. The compounds do not break down or degrade once present in the environment, and they accumulate in soil, water, animals and people. PFAS, often dubbed “forever chemicals,” are linked to many health problems, including some cancers and reproductive issues.

The Sierra Club collected soil and water samples in Sullivan County from a field where sludge was historically applied, a field adjacent to a field where sludge is currently applied, and a drinking water well near fields where sludge is applied. Wastewater treatment plants in Bristol, Tennessee, and Bristol, Virginia, produce sludge from local wastewater and discharges from two local landfills, and this sludge is being spread in eastern Sullivan County.

PFAS were detected at every site tested, the report said.

But this is just one example.

“Biosolids are being applied across the state,” Firth said.

Locally, Metro Water Services in Nashville makes a fertilizer called “Music City Gold” at its wastewater treatment plant. In 2022, the Sierra Club detected PFAS in this product, which meets current EPA requirements for a “Class A” biosolid and is sold as a household fertilizer to Nashville residents. (Only “Class B” biosolids are reported for use.)

PFAS levels in Tennessee may be higher than early tests show

This type of testing only reveals part of the problem. Typical testing methods look for 40 PFAS compounds, Firth said, among the estimated 15,000 compounds currently in existence. To fill in some gaps in the latest round of sampling, the Sierra Club looked at total organic fluoride to better reflect overall PFAS levels.

“By comparing the fluoride that arises from measured PFAS compounds to the total, we get an idea of ​​how much PFAS we are not measuring,” Firth said.

Fluoride analysis indicated that undetected PFAS compounds are potentially hundreds to thousands of times higher than detected concentrations.

“We know they are there and that many of them will break down into toxic compounds and leach into soil, groundwater and surface water,” Firth added.

Some states are banning the use of biosolids on land

Maine banned the use of sewage sludge as fertilizer in 2022, citing concerns about PFAS. Connecticut became the second state to do so this year with legislation that also phases out products with “intentionally added” PFAS, such as firefighting equipment and menstrual products.

Maine is the only state to have systematically tested agricultural land for PFAS, which samples have shown have contaminated more than 70 farms and disrupted people’s livelihoods, sometimes from sludge spread decades earlier.

Firth said companies need to stop using PFAS, but until then, Tennessee should also ban sewage sludge as fertilizer.

The Tennessee Department of Environment and Conservation will hold a public hearing on September 5 at 1:00 p.m. to discuss the permit authorizing the land application of biosolids. Any member of the public may submit written comments to John Newberry at [email protected] through September 20.