Southern Appalachian Mountain streams are not the cleanest for drinking, study finds

Streams from the mountainous Southern Appalachian region provide clean drinking water to 10 million, but a new study finds this spring water is not as pure as previously believed.

Using more than 40 years’ worth of data, researchers from the University of Georgia found the quality of this water has been reduced by historical events and modern changes, namely sediment from rural roads and agricultural runoff.

The team identified high concentrations of nitrate from farming runoff and sediment from unpaved roads cutting through the range.

However, in areas with both mountain and valley development, the researchers found sediment concentrations four to six times higher.

In the densely populated southeastern US, forested watersheds are particularly important to drinking water supplies, according the the Southern Research Station. 

The new study found large amounts of sediments traveling through the so-called pure mountain water, which not only costs cities and towns more money to filter out, but also impacts animals and fish that rely on the streams to survive.

Rhett Jackson, a professor at UGA’s Warnell School of Forestry and Natural Resources and the paper’s lead author, said in a statement: ‘We had access to studies from 1976 to last year that encompassed both stream and terrestrial studies.

‘Some streams in Macon County have very high sediment concentrations, four times greater than found in forested streams.’

Jackson also notes that water quality issues in the Appalachian Mountains is not a new problem, as European settlers from more than 100 years ago first began changing the water’s chemistry.

Streams from the mountainous Southern Appalachian region provide clean drinking water to 10 million, but a new study finds this spring water is not as pure as previously believed

He continued to explain that prior to English settlers, the land was farmed by native Cherokee Indians who took care of the land.

But the new settlers cut the forests and even tried to farm the hills, causing erosion and sediment to move into the streams. 

Today, stream beds continue to show evidence of sediment deposited more than a century ago, even as new sediment pushes through the waters, Jackson explained.

A typical southern Appalachian forest stream contains sediment amounts—calculated as total suspended solid concentration—of about 8 to 10 milligrams per liter. 

But in areas with both mountain and valley development, the researchers found sediment concentrations four to six times higher. 

Along with sediment from roads and development, the team also identified high nutrient concentrations and particularly nitrate. 

This is due to waters from pastures, which are contaminated with fertilizer, running into the streams.

Streams without shade also have higher water temperatures. In Appalachia, where mountain trout and other wildlife thrive in cold waters, even a few extra degrees in the summer can kill trout or reduce their competitiveness against warm water fish. 

Jackson said about 40 percent of streams in the study area aren’t buffered, but notes that buffering runoff from a gravel road or planting trees near an open stream, can go a long way.

‘Because the water in streams comes from the whole landscape, everything we see on the land has some effect on streams,’ he said. 

‘But streams are resilient, and as long as we intelligently modify our actions a little bit, we can farm and live near streams while protecting their water quality. Maintaining the quality of our landscape requires a little thought and work on our parts.’