Stroud Science on NPR: Road Salt Boosts Safety But Threatens Fresh Water

800 600 Stroud Water Research Center

That’s not snow in the photo, it’s a thick layer of road salt. Salt levels in streams have increased dramatically as more and more road salt is applied in an attempt to enhance safety during the winter months. Photo: Jessica Provinksi

Map of the United States with Salt Belt states highlighted in red.
The Salt Belt states. By Randommapmaker – Own work, CC BY-SA 4.0, Link

When National Public Radio’s StateImpact Pennsylvania wanted to understand how our addiction to road salt is impacting the environment, they came to Stroud Water Research Center.

Stroud Center senior scientist John Jackson, Ph.D., has been studying the health of Pennsylvania’s streams for decades and sees a worrisome trend: increasing road salt usage is leading to higher salt levels in groundwater and streams.

Stroud Center scientists see mayflies as the “canary in the coal mine” for stream health: their presence indicates a relatively healthy stream, and their absence signals that a stream may be polluted. What happens to sensitive species like mayflies as salt levels rise in streams?

“There are measurable impacts, negative things, they grow more slowly, their survivorship decreases, they come out smaller — so physiologically they’re stressing, and in some cases, they’re dying,” Jackson said. And when mayflies die, the stream’s whole food chain is affected, including fish, insects, and birds.

Jackson also spoke about how the Stroud Center is providing sensor stations to watershed groups working in the Delaware River Basin, and how the sensor data is improving our understanding of the issue of salt pollution in streams and rivers. Listen to the broadcast story below.

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