"The Spill at Dan River"

"Every year coal-burning power plants generate not only electricity, but a staggering amount of leftover coal ash that contains heavy metals unhealthy to humans. Yet due in part to intense industry lobbying, there are no federal regulations on its disposal. It's left to the states to oversee some of the most powerful utility companies in the country.

So coal ash is often just dumped into giant pits that are dug by rivers and lakes, where toxins can leach into nearby water and soil. There are over 1,000 ash pits or ponds dotting the nation, many of them old, poorly monitored, all but forgotten. But every few years we are reminded that the status quo can lead to disaster --like the coal ash spill this past February into North Carolina's Dan River at a power plant owned by Duke Energy, the biggest utility company in the country."

Lesley Stahl reports for CBS' 60 Minutes December 7, 2014.