Ponds, Creeks and Rivers

By Robert O'Neal. A 6-part series on PFAS in groundwater, ponds, creeks, rivers and lakes, and what it means for swimming, fishing, hunting, wells and livestock.

Part 1 of 6: Where the water goes

PFAS doesn't stay where it's spread.

When it rains on a field that got sludge, some of the PFAS washes off into ditches, creeks and farm ponds. Some soaks down into the groundwater. From there it can move into wells, springs and streams.

The short-chain PFAS move the fastest. They dissolve in water easily, so they travel farther than the old ones.

Factory and sewer plant discharges add more. Here in South Carolina, a national study by the Waterkeeper Alliance found the Pocotaligo River near Sumter had the highest PFAS level of any river it tested, up to 228 parts per trillion. The safe level EPA set for drinking water is 4. State samples there in 2023 ran over 7,000.

So the question people ask is fair. Is it safe to swim? To fish? To water cattle?

The next parts take those one at a time.

Part 2 of 6: Can you swim in it?

Here's the good news. For most water, swimming is considered low risk.

Most PFAS gets into people by swallowing it, in drinking water and food. A swim is a short visit, not a daily dose.

On the Pocotaligo, the river with the highest level in that national study, the local riverkeeper said she doesn't consider swimming or boating dangerous.

But low risk isn't no risk. As we covered in Dust, Skin and Other Ways In, a 2024 study found PFAS can get through human skin, and the short-chain ones get through easier. So use some sense:

• Try not to swallow the water. Watch the kids on this one.
• Shower after you swim.
• Wash your hands before you eat.
• Stay out of the foam. That's the next part.

Part 3 of 6: Stay out of the foam

You've seen it. White or tan foam piling up below a dam, in a creek bend, or along a pond bank.

Not all foam is PFAS. Some is natural. But PFAS likes to collect at the surface of water, and foam can hold it at much higher levels than the water underneath.

Michigan has dealt with this for years. Its health department tells people to stay out of foam on lakes, rivers and streams.

• If you touch it, rinse it off as soon as you can and shower.
• Don't let kids play in it.
• Wash your hands before you eat or put them near your mouth.
• Keep dogs and other animals out of it. They lick it off their fur and swallow it. If your dog gets in it, rinse it off with clean water.

You can't tell by looking which foam has PFAS. So treat it all the same.

Part 4 of 6: The fish we catch

The bigger worry isn't swimming. It's eating what you catch.

PFAS builds up in fish. When you eat fish from the same water week after week, it adds up in you.

South Carolina found PFAS in fish from about 18 waterways. Some of them close to home: the Great Pee Dee near Florence, Lake Marion, the Wateree, the Congaree, the Pocotaligo and the Waccamaw.

As of 2026, the state advises limiting four kinds of fish:

• Largemouth bass
• Bluegill
• Redear sunfish
• Black crappie

Eat only the fillets, not the whole fish.

Take extra care if you're pregnant or nursing, feeding children under 14, or if fish you catch is a regular part of what your family eats.

PFAS was also found in catfish, redbreast, warmouth, bowfin and white perch. Those aren't named in the advisory yet. The state says it's still testing to set clear limits.

Reporters found PFAS was showing up in South Carolina fish for years before the public was told. Keep an eye out for updates.

Part 5 of 6: Deer and wild game

Deer graze the same fields cattle do. If a field got sludge, the deer feeding on it can pick up PFAS too.

Maine found this out in 2021. The state tested eight deer taken near farm fields in Fairfield that had sludge spread on them. All of them had PFOS in their meat. Their livers had about 4 to 50 times more than the meat.

For the worst of those deer, even one meal of liver a year was over the safe limit.

Maine told hunters not to eat any deer taken within about five miles of those fields. Hunters who already had one in the freezer were told to throw it out. The state gave them an extra deer permit the next season.

In Wisconsin, near a plant that made firefighting foam, the state told hunters not to eat deer liver. In the 20 deer tested there, PFAS in the meat and heart was low.

The liver gets the most because it filters the blood. That's where PFOS collects, in deer the same as in cattle.

We could not find any testing of deer for PFAS in South Carolina.

If you hunt near fields that got sludge:

• Skip the liver and other organs.
• If you want to know for sure, a lab can test the meat.

Part 6 of 6: Farm ponds, wells and livestock

For those of us on farms, this is where water matters most.

A farm pond downhill from a field that got sludge can collect PFAS from every rain. So can a creek running through a pasture. Remember Wilbur Tennant from The DuPonts. His cattle drank from a creek that ran out of a landfill.

Where creeks and ponds carry PFAS, shallow wells nearby can too. The riverkeeper on the Pocotaligo pointed out that even though the river isn't a town water source, private wells near it could be affected.

Livestock drink a lot of water, every day, for years. In Maine, a dairy farm had high PFAS in its water as well as its soil, hay and milk.

What you can do:

• Test your well, and ask the lab to include the short-chain PFAS.
• If your cattle drink from a pond or creek near sludge-treated land, test that water too.
• If you use a filter, know what it's rated to remove. Carbon filters miss a lot of the short-chain ones.

Swimming once in a while is one thing. Drinking it every day is another.