On Shenandoah River, algae and bacteria continue to plague recreation — and human health

State moves toward new environmental standards
Algae in the North Fork of the Shenandoah in August 2021.
Algae in the North Fork of the Shenandoah in August 2021.(Matt Kowalski/Chesapeake Bay Foundation)
Published: Aug. 31, 2021 at 10:10 AM EDT|Updated: Sep. 1, 2021 at 7:13 AM EDT
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On the rolling river of old song, new growth is troubling the waters.

When summer temperatures rise and waters slow, long strands of algae emerge in many parts of the Shenandoah and its North and South Forks. Thick and dense enough to form floating mats, they catch kayakers’ paddles and fishermen’s rods and deter swimmers and waders.

This so-called filamentous algae isn’t just unsightly. One report from Shenandoah Riverkeeper Mark Frondorf this July described an outbreak in the North Fork near Mine Mountain as resembling “purple jelly” and smelling bad.

“People will say, you know, ‘I brought my friends, I go here all the time through the years, but it was so nasty this time or these two months or this summer that I’m not coming back,’” said David Sligh, conservation director for environmental nonprofit Wild Virginia during a meeting on the Shenandoah this spring. “You’ve got testimony from outfitters and fishing guides that say, ‘After I take somebody there and it’s really horrible, I can’t take them back there. They don’t want to go.’”

For more than a decade, filamentous algae problems have been mounting. In 2016, the Potomac Riverkeeper Network, which includes the Shenandoah Riverkeeper, sued the EPA over its approval of DEQ’s decision to not list the Shenandoah as impaired due to algae. The distinction would have required Virginia to enforce pollution limits for the waterway, but the group lost its suit in D.C. Circuit Court.

Complaints have continued. In 2019 alone, the Virginia Department of Environmental Quality received 53 complaints about nuisance algae on the Shenandoah and its two forks. In 2020, there were 30 complaints. As of mid-August this year, there had been 20.

“The vast majority of them are from just a few constituents, but with the level of attention and scrutiny on the North Fork of the Shenandoah … we are receiving more calls, more reports,” said Tara Wyrick, a water monitoring and assessment manager with DEQ’s Valley Region office. “We generally see algae growing all the way through the end of October.”


The Virginia Mercury is a new, nonpartisan, nonprofit news organization covering Virginia government and policy.

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