Eastern U.S. water supplies threatened by a legacy of acid rain
http://www.caryinstitute.org/newsroom/eastern-us-water-supplies-threatened-legacy-acid-rain[font face=Serif][font size=5]Eastern U.S. water supplies threatened by a legacy of acid rain[/font]
Monday, August 26, 2013
[font size=3]Millbrook, NY Human activities are changing the water chemistry of many streams and rivers in the Eastern U.S., with consequences for water supplies and aquatic life, so reports a new study in the journal Environmental Science and Technology.
In the first survey of its kind, researchers looked at long-term alkalinity trends in 97 streams and rivers from Florida to New Hampshire. Sites ranged from small headwater streams to some of the nations largest rivers. Over the past 25 to 60 years, two-thirds have become significantly more alkaline.
Alkalinity is a measure of waters 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. This is because
acid rain, acidic 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.
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http://dx.doi.org/10.1021/es401046s