State officials are writing costly and controversial regulations the toughest in more than 15 years that are designed to crack down on emissions from coal-burning power plants and other industrial sources.

The new limits, which are expected to cost industry more than $1 billion, will affect a suite of pollutants that are responsible for everything from respiratory illnesses to making fish unhealthy to eat.

Once in place, four different sets of regulations mandated by the federal government will cut ozone, particle pollution, visibility- reducing haze and mercury.

The Clean Air Interstate Rule, perhaps the most important, slaps new pollution controls on utilities and some factories to fight ozone and particle pollution, both of which cause health problems.

Another measure would rewrite the state's new mercury reduction law so it would mirror a new federal law.

All of the measures need to go to the state Natural Resources Board and the Legislature later this year and during 2007.

The changes are the "most significant since passage of the 1990 Clean Air Act," said Kathleen Standen, an environmental and regulatory manager with We Energies of Milwaukee.

Environmentalists say the regulations are overdue, and they are pressing the Department of Natural Resources for greater reductions, especially from the state's fleet of coal-burning power plants.

"Whatever problem we are trying to fix, a lot of it is attributable to coal plants," said Bruce Nilles, an attorney for the Sierra Club.

The changes won't affect a large source of air pollution automobiles, according to Al Shea, the DNR's top air regulator.

With the help of emission-reducing reformulated gas and southeastern Wisconsin's vehicle inspection program, "we think that we have done as much as possible," Shea said.

The new regulations should make air easier to breathe, especially in southeastern Wisconsin. Air quality is improving in the region, but it continues to violate federal ozone standards. Ozone creates smog and poses serious health risks.

Wisconsin is required to meet federal ozone standards by summer of 2009, but the DNR is mulling whether to ask federal regulators to push back that date.

Air getting cleaner

Ironically, the changes come as Wisconsin's air is getting cleaner. Measures of most major pollutants have fallen over the last 20 years, DNR figures show, because of regulations now in place.

Wisconsin Manufacturers & Commerce, the state's largest business group, says its own data of air quality show that southeast Wisconsin is within a hair's breadth of meeting federal ozone standards.

"We are not there yet, but we are so close," said Scott Manley, director of environmental policy for the group.

But even though the emissions picture is improving, state and federal officials insist Wisconsin's air must get cleaner.

"There is a human health cost to living with polluted air," Henry Anderson recently told a group being briefed on the regulations.

Asthma hospitalizations, for instance, increase when air quality declines, said Anderson, chief medical officer of the Wisconsin Division of Public Health.

In defending the new controls, state officials say dirty air costs money. It carries health costs from illness, lost productivity and death that are three to 10 times higher than the cost of compliance, officials say.

But cleaning up pollution also comes with a price: The pending rules will force Wisconsin utilities and some large manufacturers to install new pollution-control equipment.

Standen says We Energies should be able to comply with most of its obligations because of a 2003 settlement with the federal Environmental Protection Agency over air violations. The settlement, which included $3.2 million in penalties, requires the company to spend $600 million in pollution upgrades.

Wisconsin Manufacturers & Commerce and other business interests have told the DNR that they fear the agency will overreach and try to cut more pollution than required by the EPA.

The DNR says it's too early to make that assessment.

Slashing emissions

The Clean Air Interstate Rule is perhaps the most significant regulation of the four new air pollution measures. The rule would fight ozone and particle pollution by cutting emissions of sulfur dioxide by 61% and nitrogen oxides by 57% in 28 states east of the Mississippi River by 2015.

Some of the cuts will come as soon as 2009.

Ozone is a noxious cocktail that can cause respiratory problems. It is formed from sunlight, heat, nitrogen oxides and volatile organic compounds.

Particle pollution, especially microscopic bits of soot, can be inhaled deep into the lungs and enter the bloodstream.

The interstate rule puts the 28 states and the District of Columbia together to fight pollution.

That should help states such as Wisconsin that inherit bad air from other states.

More than half of all ground-level ozone in Milwaukee comes from industrial sources in Illinois, DNR figures show.

The backbone of the rule is an optional pollution trading program, which business embraces, that will let companies buy out of their obligations rather than install equipment.

Environmentalist Nilles says the trading system could work between utilities in a region, but not if it allows Wisconsin companies to buy credits from another region and pollute at home.

A second rule will fight haze at 156 national parks and wilderness areas. This will require two dozen power plants and factories in Wisconsin to install controls called the "best available retrofit technology" so air is cleaner in places such as Isle Royal National Park in Lake Superior.

A third rule takes further steps to fight ozone. Utilities and factories in 10 counties stretching from Kenosha to Door will have to make additional pollution reductions using what regulators call "reasonable available control technology."

And finally, Wisconsin must rewrite regulations controlling mercury pollution.

In 2004, Wisconsin became one of the first states to enact a mercury law. The state called for cutting emissions by 40% in 2010, 75% in 2015, and, as a goal, by 80% in 2018.

Water contaminated

But a key provision required Wisconsin to copy any regulations that the federal government might eventually pass. That's what's happening now as Wisconsin seeks to rewrite its mercury law to piggyback with federal regulations.

Mercury, much of it from coal-burning power plants, has polluted every body of water in Wisconsin. It falls on water bodies where it converts to a more toxic form and contaminates fish.

A 2005 study of hair samples of more than 2,000 men and women in Wisconsin by the state Department of Health and Family Services found that 29% of men and 13% of women had mercury exposure that exceeded safe levels.

At a glance

-- Wisconsin is required to meet federal ozone standards by the summer of 2009.

-- New state regulations would cut ozone, particle pollution, visibility-reducing haze and mercury from coal-burning power plants and other industrial sources.

-- The state also is rewriting the mercury reduction law so it will mirror federal law.

Copyright 2006, Journal Sentinel Inc. All rights reserved. (Note: This notice does not apply to those news items already copyrighted and received through wire services or other media.)