A court decision sends a 2010 pollution permit for the Louisville Gas and Electric Trimble County Generating Station back to the state for review because of steps missed during the permit process.

Franklin Circuit Court Judge Phillip Shepherd issued a ruling that the Kentucky Energy and Environmental Cabinet was required to and failed to conduct a required "Best Professional Judgment" analysis - a method using all reasonable and relevant data - for scrubber wastewater required by the Clean Water Act for the plant's permit.

LG&E applied for a permit application in 2007 while the new Unit 2 was being constructed. The plant's pollution permit needed to be renewed to reflect changes in the system.

A permit is required for the coal-fired plant in Trimble County because the site uses flue gas desulfurization devices to reduce sulfur emissions at the plant, often referred to as "wet scrubbers," court documents said. The wet scrubbing process creates wastewater that is pumped into gypsum storage basins where some pollutants settle before the wastewater moves to the Ohio River through a submerged diffuser.

The review by state authorities should determine that environmental standards set by the Clean Water Act are met before approval of the permit. The permitting process in that the state cabinet oversaw, Shepherd ruled, did not comply with all current Clean Water Act obligations.

Several groups who petitioned the courts for judicial review of the permit - including the Kentucky Waterways Alliance, Sierra Club, Valley Watch and Save the Valley - believed the 2010 permit allowed more pollutants to go into the water than allowable by law. The petition was filed in Trimble County in 2010 before being transferred to Franklin Circuit Court in 2011 on jurisdictional grounds.

The environmental groups consider the ruling a major victory for clean water and public health.

"This is wonderful news for Kentucky's rivers and means that LG&E will now have to put in place controls for toxic pollutants like arsenic and mercury," Judy Peterson, executive director of the Kentucky Waterways Alliance, said in a release.

Valley Watch President John Blair said he hoped that the ruling helps to protect the health and environment of the lower Ohio River Valley from pollutants.

"Valley Watch is thrilled that after all this time, the Kentucky Division of Water is having to deal with toxins like mercury and arsenic from a power plant," Blair said. "Most of our members live downstream and drink water from the Ohio River, which has been referred to as 'an open sewer' for too long."

Louisville Gas and Electric spokeswoman Chris Whelan said the ruling calls for the permit to be sent back to the Energy and Environment Cabinet to be reviewed, but the plant will continue to operate as usual during that time. She said LG&E believes the plant currently meets all environmental requirements set by the Clean Water Act.

"This current permit is still in effect," Whelan said. "We will continue to operate the plant in a safe and environmentally responsible manner."

The document noted the ruling issued by Shepherd on Tuesday could be superseded by any forthcoming rulings on the reduction of toxic pollutants from power plants into waterways by the U.S. Environmental Protection Agency.