A Google Earth image that the Sierra Club on Monday, saying it shows illegal coal-ash dumping into the Ohio River by Louisville Gas & Electric. Sierra Club handout/Google Image

Environmental groups announced their intent to sue a Kentucky coal-ash plant for “unabated” dumping into the Ohio River on Monday, after a hidden camera they set up captured alleged illegal discharges of chemicals by the company.

“We deserve clean water,” Thomas Pearce, regional organizer for the Sierra Club in western Kentucky, told Al Jazeera. “We’re calling on the Environmental Protection Agency to put forward more stringent guidelines for coal ash because states aren’t policing it. Look at North Carolina and the Duke spill.”

The allegations against Louisville Gas & Electric (LG&E) are the latest in a series of controversies over coal-ash dumping. Last month, Duke Energy, the country’s largest electricity provider, spilled 35 million gallons of toxic coal-ash slurry into the Dan River in Eden, N.C. Coal ash contains high levels of arsenic, lead, selenium and other heavy metals that the EPA says can cause cancer, birth defects and respiratory problems.

The Sierra Club and EarthJustice say their soon-to-be-filed lawsuit against LG&E is based on time-lapse photography from a camera they strapped to a tree. The camera captured a year’s worth of images showing “dangerous” coal ash wastewater being dumped continuously into the Ohio River.

A representative for LG&E said Monday the company hasn’t received the environmental groups’ notice of intent (NOI) and won’t comment on pending litigation.

The photos, along with Google Earth satellite images from 1993 to the present collected by the groups, will be used to support the environmentalists’ claims that LG&E has violated the federal Clean Water Act and the terms of the utility’s permit — which allows for only “occasional” discharge into the river.

“It’s a violation of their permit under the Clean Water Act … Our photos were taken every three seconds for a year,” Pearce said. “If you look at the photos, it’s not an occasional discharge. It’s a steady stream coming out of the coal-ash containment pond … every day, all day, all night.”

Now that the groups have filed an NOI, LG&E has 60 days to remedy the problem. If, at the end of that period, the problem remains, Pearce said the lawsuit will go forward.

The Kentucky Division of Water, responsible for protecting and managing local water resources, told local media Monday that it doesn’t believe the company’s discharges violated the company’s permit.

“The discharge reflected in photos contained in news stories today and as referenced in the NOI is a legally permitted discharge. While the permit description and narrative of the fact sheet describe the direct discharge component of outfall 002 to the Ohio River as ‘occasional,’ the permit effluent requirements do not restrict the frequency of the discharge. Consequently there is no violation of the permit,” the department said.

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