What's in your drinking water?

I'm glad I don't get my drinking water from the Schuylkill River. The same can't be said for millions of Pennsylvania residents, mostly in the Philadelphia area.

For the past five years, Exelon Nuclear, which operates the nuclear plant in Limerick, Montgomery County, has been taking hundreds of millions of gallons of water from the Schuylkill River to cool its nuclear reactors and has been replacing the water with coal mine water from Schuylkill County.

It's all legal. Exelon has permission from the proper authorities, but I'm not sure how many people know about the arrangement.

Evan Brandt of The Mercury writes that Exelon now wants the five-year test project to become permanent.

That means Exelon can take 56 million gallons a day from the Schuylkill River as long as it replaces it somewhere else along the watershed. But as Brandt points out in his story, the water from coal mines is extremely acidic because it comes into contact with the mineral pyrite, which forms sulfuric acid and iron hydroxide with it comes into contact with air or water.

"It is the most common form of water pollution in Pennsylvania and about half of the coal mine discharges in the state have some level of acidity. The vast majority of that pollution is in western Pennsylvania," Brandt writes. "The pH level in this discharge is often toxic to fish and the insects that fish eat."

Read more about the situation in The Mercury.