Mercury From a Factory Closed Decades Ago

The South River and the South Fork of the Shenandoah look like clean smallmouth water. The fish, though, carry mercury that was dumped there by a factory decades ago, and Virginia’s health department advises limits on eating them. This is the story of where the mercury came from, drawn from a U.S. Geological Survey (USGS) summary and the state’s advisory.

The source

A former DuPont facility in Waynesboro disposed of mercury waste from 1929 to 1950. The USGS page says the contamination extends about 125 miles downstream, from Waynesboro to Front Royal. In 2002 the Virginia Department of Environmental Quality found smallmouth bass with mercury as high as 4 parts per million, with an average of 1.3 against the state’s limit of 0.5.

The Virginia Department of Health placed a consumption advisory on the South River and the South Fork. In July 2005 DuPont signed an agreement for a six-year ecosystem study of the South River watershed.

Why it is remarkable

The river looks unspoiled, and the fishing is good. The mercury came from waste placed decades before anyone tested the fish, and it has stayed in the river’s sediment and food chain since.

Connection to the waterway

The advisory is the part that matters on the water, and it is covered in the Shenandoah River guide. As we last read it, the current table lists mercury at two meals a month for all species in the Port Republic reach and “DO NOT EAT” for all South River fish except trout.

The river today

The Shenandoah is one of Virginia’s best-known smallmouth rivers. DWR calls it one of the top smallmouth rivers in the East, with up to three fish an hour and some over 20 inches. The river also holds stocked muskie, channel catfish mostly of 2 to 4 pounds with some over 10, and rock bass and sunfish. Flathead catfish have been illegally introduced, and DWR’s advice is not to move them.

DWR describes 20 public access points on the river from Port Republic to Front Royal, plus the North Fork to Riverton. Rules between Port Republic and Front Royal include five black bass a day with none kept between 11 and 14 inches, 50 sunfish, 25 rock bass, 25 crappie, one muskie a day of at least 40 inches, and 20 channel catfish.

The advisory in practice

The 2025 VDH advisory for the Shenandoah lists mercury at two meals a month for all species in the Port Republic reach. Carp, channel catfish and white sucker carry a do-not-eat advisory in the Front Royal to West Virginia line reach. The table’s layout was unclear in our extraction, so read the current advisory yourself before you eat any fish.

What anglers can take from it

Read the current advisory for the reach you plan to fish and decide before you go whether you will keep fish. Catch and release is the simplest option on these waters. More stories from Virginia waters are in the Dock Tales index.

Sources and caveats

This tale uses the USGS page on the South River mercury study and the Virginia Department of Health’s Shenandoah River advisory (2025). The USGS page is older and does not give a discovery date. We could not read the USGS page in our last pass, and the advisory table’s alignment was unclear, so check every advisory value against the live health department table before relying on it.