Lower rainfall, lower bacteria levels along Shenandoah River

Water quality monitoring at 40% of the locations tested in the Shenandoah Valley this year detected levels of fecal bacteria that made the waters unsafe for swimming, tubing, kayaking, or rafting, according to an environmental policy group’s report released Tuesday.

So far this year, 21 of the 52 water monitoring locations in the valley have had levels of E. Coli bacteria that exceeded the U.S. Environmental Protection Agency’s recommendations for swimming or water contact recreation, according to Virginia Department of Environmental Quality data reviewed by the Environmental Integrity Project.

The percentage of sites with unhealthy bacteria levels was the lowest in the last eight years, in part because the amount of rainfall this year was also the lowest over that period. The 20 inches of rain recorded in Harrisonburg, in the heart of the Shenandoah Valley, from January through August, was a third less than the average of 30 inches. Less rainfall means less manure is washed off farm fields and into streams and rivers.

“The health risks from farm manure runoff were somewhat reduced this summer because of the low rainfall conditions,” said Eric Schaeffer, executive director of the Environmental Integrity Project. “This does not mean the Shenandoah River is cleaned up, or that the problem of farm runoff pollution is solved. Virginia should keep up its efforts to convince farmers to fence their livestock out of streams and reduce their overapplication of manure.”

The Shenandoah Valley has the largest concentration of livestock operations in Virginia, with almost 528,000 cows, 160 million chickens and 16 million turkeys raised annually in Augusta, Page, Shenandoah and Rockingham counties. Most of their manure is spread on surrounding farmland as fertilizer, but it contains far more phosphorus than crops need for growth. The excess manure leaks pollutants into groundwater and is washed by rain into streams.