Monday, September 9, 2013

Two thirds of eastern US rivers are alkaline

Futurity: Human activities are changing the basic chemistry of rivers in ways that could have major consequences for urban water supplies and aquatic ecosystems.

In the first survey of its kind, researchers looked at long-term records of alkalinity trends in 97 rivers from Florida to New Hampshire. They found that over time spans of 25 to 60 years, two-thirds of the rivers had become significantly more alkaline.

Increased alkalinity complicates drinking water and wastewater treatment, encourages algae growth, and can hasten the corrosion of metal pipe infrastructure. At high alkalinity levels, ammonia toxicity can also harm irrigated crops and fish in rivers.

 “The change across so many larger rivers of the eastern U.S. is a big surprise,” says study co-author Michael Pace, an environmental scientist in the University of Virginia.

Among the rivers affected are those that provide water for Washington, DC, Philadelphia, Baltimore, Atlanta, and other major cities, the researchers report. Also affected are rivers that flow into water bodies already harmed by excess algae growth, such as the Chesapeake Bay....

Susquehanna River at sundown, shot by fishhawk, Wikimedia Commons via Flickr,  under the Creative Commons Attribution 2.0 Generic license

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