Our activities are changing the water chemistry of many streams and rivers in the Eastern U.S., with consequences for water supplies and aquatic life.
In the first survey of its kind, researchers looked at alkalinity trends in 97 streams and rivers from Florida to New Hampshire. Over the past 25 to 60 years, two-thirds have become significantly more alkaline.
Alkalinity is a measure of water’s ability to neutralize acid. In excess, it can cause ammonia toxicity and algal blooms, altering water quality and harming aquatic life. Increasing alkalinity hardens drinking water, causing pipe scaling and costly infrastructure problems. And, perhaps most alarming, it exacerbates the salinization of fresh water.
In what may seem like a paradox, human activities that create acid conditions are driving the problem. Acid rain, mining waste, and agricultural fertilizers speed the breakdown of limestone, other carbonate rocks, and even concrete and cement. The result: alkaline particles are washed off of the landscape and into streams and rivers.
Gene Likens, an ecologist at the Cary Institute and a co-discoverer of acid rain, was on the research team…
“We discovered acid rain in North America in our work in the White Mountains of New Hampshire 50 years ago. Acid rain first acidified small streams, but now it’s increasing the outputs of alkalinity from watersheds – and this is 20 years after the federal legislation was enacted to reduce the airborne pollutants.”
Impacted rivers are widespread, including those that provide water for Washington, D.C., Philadelphia, Baltimore, and Atlanta.
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Web Extra
Full interview with Gene Likens, an ecologist at the Cary Institute and a co-discoverer of acid rain
[audio:http://wamcradio.org/EarthWise/wp-content/uploads/2013/09/Likens_full_web.mp3|titles=Likens_full_web].
Web Links
Increased river alkalization in the Eastern U.S.
http://pubs.acs.org/doi/abs/10.1021/es401046s
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.