In addition to the new standards, power plants will have to install continuous monitoring systems looking for emissions of mercury and other toxic pollutants like arsenic, chromium, cobalt, nickel.

“This is a really important step,” said Paul Billings, national senior vice president for public policy with the American Lung Association, calling the pollutants “really bad for human health.”

In addition, EPA’s rules regulate three types of wastewater generated at coal-fired power plants and address water stored in coal ash ponds – reducing this form of pollution by close to 600 million pounds per year.

Finally, EPA is closing loopholes for toxic coal ash – making sure power plants must safely dispose of coal ash previously dumped at unregulated landfills.

“Any one of [these rules] individually is a monumental achievement,” said Holly Bender, Sierra Club chief energy officer at the Sierra Club. “Collectively, these rules send a very strong signal to the electric power industry that it is no longer okay to contribute to these significant public health harms.”