Jul. 25--Ohio's plans to reduce mercury pollution from coal- fired power plants are stronger than the federal government's, but still weak, critics say.

Yesterday, the Ohio Environmental Protection Agency said it will impose rules to reduce mercury emissions 86 percent by 2018.

The Ohio environmental officials had sought more stringent rules - - a 90 percent reduction by 2018 -- but instead followed instructions from Gov. Bob Taft, said state EPA Director Joe Koncelik.

In March 2005, the federal EPA promised to reduce emissions 70 percent by 2020. That would mean cutting current annual emissions of mercury at the nation's more than 450 power plants from 48 tons to 38 tons in 2010 and 15 tons in 2018.

There are 28 coal-fired power plants in Ohio.

But both state and federal agencies will allow companies to trade pollution credits, a process in which dirty power plants can buy credits from clean ones to meet annual limits.

This credit program, critics say, will keep the air dirty in Ohio, which ranks among the top states in mercury emissions.

"The trading of toxins ... creates local hot spots," said Rebecca Stanfield, director of Environment Illinois, one of a number of advocacy groups that hosted a teleconference yesterday to discuss Ohio's plans.

Stanfield said 16 attorneys general and five environmental organizations across the country have filed a lawsuit fighting the system of trading credits.

All states must have a mercuryreduction plan in place by November.

Mercury settles into lakes and streams and becomes more dangerous as it is consumed by fish and moves up the food chain. It can cause severe brain and kidney damage in humans.

Other states, including Illinois, Connecticut, Massachusetts and New Jersey, have implemented more-stringent requirements to reduce mercury emissions by 2010 to 2012, according to environmental groups.

"This ... can be done sooner by what's proposed nationally and in Ohio," said Ted Schettler, science director for the Science and Environmental Health Network in Boston.

Koncelik said the governor's proposal, which must be approved by the state Joint Committee on Agency Rule Review, will produce results.

"The rule reduction package that we're putting out today is (still) going to get significant reductions in Ohio," he said.

Mark Rickel, a Taft spokesman, agreed and said the state was careful not to go too far.

"In the short term, going beyond the federal rule will be seen as Ohio not being business-friendly," Rickel said.

Steve Brash, a spokesman for Duke Energy, which operates three power plants in Ohio, said it's inappropriate for states to develop regulations to control mercury emissions.

"It's very difficult for companies to meet different requirements of different states, especially at a time when the industry is consolidating," he said.

But critics say energy companies need to be pushed to install scrubbers and other equipment on aging power plants to reduce emissions of mercury and other pollutants, including sulfur dioxide.

A similar credit program exists for sulfur dioxide, the main ingredient in acid rain.

"It's disappointing that Gov. Taft would not take this opportunity to protect Ohio's children from toxic mercury pollution," said Erin Bowser, director for Ohio Public Interest Research Group.

pteng@dispatch.com