The Rachel Maddow Show, 3/19/14, 10:45 PM ET

Activists catch power plant on hidden camera

Rachel Maddow reports on a hidden camera set up by the Sierra Club that they claim shows a power plant regularly discharging coal ash pond water into the Ohio River, apparently permitted via a very liberal interpretation of the meaning of "occasional."

Company allegedly caught on film dumping coal ash into Ohio River

The Sierra Club is taking legal action against Louisville Gas & Electric (LG&E), claiming that footage from a hidden camera shows the Kentucky energy company dumping toxic coal ash into the Ohio River.

This week, the environmental activist group filed a notice of intent to sue LG&E for alleged violations of the Clean Water Act. In a statement released Monday, Thomas Pearce—the Sierra Club organizer who installed the camera—compared the coal ash dumping to recent water contamination incidents in North Carolina and West Virginia. The difference, he said, is that this particular spill at the company’s Mill Creek Generating Station is occurring “in slow motion.”

The Mill Creek Station has a permit with the Kentucky Department of Environmental Protection (KPDES) which allows it to discharge coal ash into the Ohio River at “occasional” intervals. The Sierra Club notice of intent alleges that the energy company  has instead been discharging into the river “on an almost daily basis.”

LG&E spokesperson Chris Whelan said the company would not comment on pending litigation. However, she directed msnbc to a statement from KPDES’s umbrella agency, the Kentucky Energy and Environment Cabinet (EEC), which describes the coal ash dumping as “permitted discharge.”

“Discharge data submitted to the agency by LG&E Mill Creek as required by their permit indicates that the discharge is in compliance with permit requirements,” according to the statement.

In response, Pearce told Al Jazeera, “We are not surprised by the Kentucky Division of Water’s response, and we’ll take that up in court.”

Coal ash is a waste byproduct produced when energy plants burn coal for fuel. In sufficient quantities, the ash can cause cancer and other chronic ailments. LG&E has already been fined multiple times in recent years for alleged coal ash contamination infractions.

Coal and Kentucky

Company allegedly caught on film dumping coal ash into Ohio River