Conferees Near Clean Air Accord : Environment: A breakthrough compromise on acid rain leaves only a handful of minor issues to be settled. Bill takes aim at smog and ozone depletion.

House and Senate negotiators Sunday neared agreement on a sweeping revision of the Clean Air Act that aims to cleanse the nation’s skies of smog, acid rain and cancer causing pollutants by the early part of the 21st Century.

Working around the clock, the negotiators were expected by late Sunday night to break a decade-long deadlock and approve what congressional leaders have called the most important piece of regulatory legislation to be passed this year.

A breakthrough compromise on acid rain controls, reached just before dawn on Sunday, left only a handful of relatively minor issues to be settled.

“It is the most far-reaching and aggressive program to clean up pollution anywhere in the world,” said Rep. Henry A. Waxman (D-Los Angeles), one of the legislation’s principal authors.

The omnibus legislation, which President Bush is expected to sign as soon as the House and Senate give their final approval, would reduce urban smog through tougher controls on automobile pollution and the use of cleaner burning fuels and would expand the regulation of toxic emissions from factories to lessen cancer risks. It also would combat acid rain by making utilities cut sulfur emissions and would seek to safeguard the Earth’s protective ozone layer by phasing out the use of ozone-depleting chlorofluorocarbons by the year 2000.

The bill would:

--Phase in new tailpipe standards for cars and light trucks intended to reduce emissions of hydrocarbons and nitrogen oxides and mandate the use of cleaner-burning gasolines.

--Tighten controls on industrial pollution, for the first time extending them to small sources, such as dry cleaners.

--Expand to 189 the number of airborne toxins regulated by the Environmental Protection Agency.

--Require 107 utility plants in the Midwest and the Southeast to cut emissions of sulfur dioxide by 10 million tons in 10 years.

Both houses of Congress must approve the final agreement and a few conservative senators have hinted that they may try to mount a filibuster. But supporters have said that they are confident of enough votes to block any last-minute attempt to kill the bill.

Its impact will be enormous, as will its price.

While there is disagreement over its cost, $20 billion a year is a conservative estimate for legislation that imposes a complex web of regulations on everything from giant steel mills and Midwestern utility companies to corner gas stations and neighborhood dry cleaners.

Industry spokesmen warned that the price may be far higher. But clean air advocates and health officials have said that the benefits--in both lower health care costs and in the lives that will be saved by taking poisons out of the air Americans breathe--will be incalculable.

“We have finally put in place policies for the next decade that are going to clean up the pollution that harms people’s health and threatens the ecosystem of our planet,” Waxman said.

Inevitably with a bill this broad, the legislation that finally emerged from more than a year of committee hearings, floor debates and in recent weeks nearly around the clock conference negotiations was a compendium of compromises crafted by lawmakers representing the various industries, regions and other special interests affected by the regulations.

The result is a patchwork of provisions that, while described as very strict by industry lobbyists, falls short of what some environmentalists and state air quality officials said is necessary to meet new turn-of-the-century deadlines for cleaning up the air in America’s most polluted cities.

“Overall, this bill is a net plus for the environment, but it also contains unnecessary delays and the auto standards are not as tight as they could have been,” said Gene Karpinski, an environmentalist with the Public Interest Research Group.

Backed by the White House and key allies such Rep. John D. Dingell (D-Mich.), chairman of the House Energy and Commerce Committee, oil and auto industry lobbyists succeeded in getting the conferees to stretch out some deadlines and to adopt the generally more lenient motor vehicle provisions of the House-passed version of the bill. But industry officials declined to portray these compromises as victories for their side.

“There were no clear winners and no clear losers here. Everybody gave a pound of flesh,” said Tim MacCarthy, a lobbyist for the Motor Vehicles Manufacturers Assn. “We’re not totally happy either, but then we did not expect to be.”

The bill sets deadlines, ranging from three to 17 years, for cities to eliminate smog by lowering the ozone level in their areas to the national standard of 0.12 parts per million. Los Angeles, with the worst smog in the nation, will have an additional three years, until 2010, to attain the standard.

To achieve these goals, the legislation tightens federal controls on major sources of industrial pollution and for the first time extends them in severely polluted areas to small sources, such as dry cleaners, printing plants and automobile paint shops.

To control the largest single source of smog-forming pollution--the automobile--the bill takes a triple-track approach. It tightens tailpipe emission standards, mandates the use of cleaner-burning “reformulated gasoline” in the nation’s nine smoggiest cities and establishes in California a pilot program for ultra-clean cars and fuels--a plan that other states may use and that eventually could set standards for the entire nation.

The tailpipe standards for new cars and light duty trucks will be phased in starting in 1994, with the aim of reducing emissions of hydrocarbons and nitrogen oxides, main ingredients of smog, by nearly 40% and 60%, respectively, by 1998.

A second round of 50% emission cuts will go into effect after the year 2000, unless the EPA determines that they are not needed or are prohibitively expensive.

California has already adopted these standards for cars sold in the state. But extending them to the rest of the nation means that the one in four cars in California that come from out of state now will also have to be cleaner.

For the first time, the bill also tackles the problem of acid rain and dramatically expands federal regulation of airborne toxins that can cause cancer, birth defects or other serious diseases. Only seven of these hazardous pollutants emitted by the chemical, oil and steel industries are currently regulated. The bill expands that number to 189, leaving it up to the EPA to set specific limits for each industry, with the aim of achieving a 90% overall reduction in toxic emissions by early in the next century.

To curb acid rain, the bill requires 107 dirty utility plants clustered in the Midwest and the Southeast to cut their emissions of sulfur dioxide by almost 10 million tons by the year 2000. Emissions thereafter would be capped at 1980 levels, but an innovative trading system will let utilities that cannot meet the limits to buy “pollution credits” from utilities that make extra reductions.

The last major piece of the legislation to be put in place, the acid rain agreement, was reached just before dawn Sunday after a nightlong argument over whether the Midwest, which bears the brunt of the reductions, was being treated fairly. In the end, the negotiators agreed to delay some of the reductions that Midwestern utilities must make until the year 2000.

Although environmentalists had hoped for an even stronger bill, they conceded that the legislation represents a major breakthrough in a decade-long deadlock in Congress over revising the 1977 Clean Air Act.

Bush helped to break the logjam last year when, reversing the Ronald Reagan Administration’s opposition to environmental regulation, he proposed a clean air package. It later became the basis for negotiations with clean air advocates in Congress, led in the House by Waxman and in the Senate by Majority Leader George J. Mitchell (D-Me.) and Environment and Public Works Committee Chairman Max Baucus (D-Mont.).