Environment

Louisville Gas and Electric will seek regulatory approval to shut down coal ash ponds in Louisville and Trimble County, at a cost of $311 million to ratepayers.

The company announced this week it will file documents with the Public Service Commission later this month to close the ponds at the Mill Creek and Trimble County power plants. The ponds are one way the company disposes of coal ash, which is a byproduct of burning coal. The ash is also placed into dry landfills, and the company said a quarter of the waste is recycled into products like concrete and wallboards.

LG&E spokeswoman Natasha Collins said the company estimates that the $311 million cost to cap and close the two ponds — lumped in with another $5 million for updated mercury controls — at its peak will increase the average LG&E ratepayer’s bill by $2.26 in 2020.

The monthly surcharge will increase gradually until 2020, and then decline.

“This is the direction that we’ve been going in,” Collins said. “And ultimately, in studying our compliance options as it relates to the new rule, we determined that the lowest reasonable-cost option would be capping and closing our coal ash ponds while also continuing to beneficially reuse the byproducts.”

The coal ash pond at Mill Creek is currently the subject of a lawsuit filed by environmental groups, who claim the pond’s direct discharges into the Ohio River violate LG&E’s state permit. LG&E is also in the process of capping and closing the coal ash pond at the Cane Run plant. The coal-fired Cane Run was retired last year, and a natural gas power plant now operates on the site.

Coal ash ponds came under scrutiny in 2008, when a billion gallons of slurry was released from an impoundment in Kingston, Tennessee. The Environmental Protection Agency finalized the nation’s first-ever federal standards for coal ash in 2014; the rules allow existing coal ash ponds to continue operating, unless they’re causing problems to water quality.