Who Should Bear Burden When L.A. Exports Smog?

When residents of San Diego County found themselves under siege from heavy smog 55 days last year, they had more than themselves to blame.

A report released this week by the San Diego County Air Pollution Control District blamed smog blown down from Los Angeles for three out of every four days that San Diego exceeded the federal clean air standard for ozone, a health-threatening air pollutant.

“This is not smog that kind of comes in and mixes with San Diego smog and the two add and go over the health standard,” said R.J. Sommerville, San Diego County’s air pollution control officer. “This is a . . . smog cloud that rolls into San Diego (from Los Angeles). It’s characteristically quite intense. You can watch the monitoring stations in Del Mar and along the coast. They’ll just go up in a very short period of time.”

Trans-boundary pollution--the tainted air that travels from one region to another--is not a new phenomenon.

But the worsening impact of the traveling pollution underscores the dilemma many air pollution authorities are facing in trying to clean up their skies. Local and regional plans to return blue skies to smoggy areas may not be enough to fight someone else’s pollution.

The problem goes far beyond San Diego.

San Bernardino, Riverside and Palm Springs all have been victims of pollution generated along the Los Angeles County coast.

To the north, the Air Force has long complained that space shuttle landings and flight testing at Edwards Air Force Base may be jeopardized by reduced visibility brought on by Los Angeles smog.

In western Colorado, 15% of reduced visibility was attributed by one study to pollution from California.

Los Angeles smog has even been measured by scientists at Death Valley and the Grand Canyon, two of America’s premier natural wonders.

Using sensitive instruments, scientists proved that air pollution in Los Angeles and the Grand Canyon were linked by releasing trace gases in Los Angeles that subsequently were detected in the national park. In the case of areas such as San Diego, scientists know the origin of the pollution because of well-documented wind current patterns.

As the trans-boundary pollution problem spreads, individual air pollution control districts--which are mandating increasingly stringent and costly emission controls in their areas--are finding that even their most energetic efforts are not enough.

The issues are complex and not easily solved. Congress is finding that trans-boundary pollution is among the stickier problems it confronts in attempting to come up with amendments to the federal Clean Air Act.

Who is to blame for air pollution in a given area? Who is to pay for the cleanup? Should residents and businesses in an area burdened by imported smog be required to pay for even tougher controls to hold the line? Should smog-producing regions such as the Los Angeles Basin be required to take tougher steps to reduce how much of their smog goes elsewhere?

Officials with the South Coast Air Basin, which includes Los Angeles, Orange, Riverside and San Bernardino counties, are quick to acknowledge that the region’s smog does not honor boundary lines drawn on a map.

“I think we would concur that there are meteorological conditions where we contribute unhealthy air to San Diego County,” concedes James M. Lents, executive officer of the South Coast Air Quality Management District.

But San Diego also gets some smog from Mexico. And smog originating in San Diego winds up in Imperial County. There are even times--few to be sure--when San Diego’s smog blows north into the Los Angeles Basin, the state Air Resources Board said.

For the most part, however, the direction smog takes between Los Angeles and San Diego is one way--headed south.

Typically, Santa Ana winds carry the smog to sea where it stagnates for a day or two. More often than not, it blows right back into Los Angeles.

But there are times when the pollutants blow out to sea and are picked up by prevailing onshore winds that carry them into San Diego County, coming ashore at Del Mar, San Diego and Chula Vista, according to Chung Liu, planning manager with the AQMD.

“When the San Diego area generates enough pollution to come very close to the health standards, then emissions from the South Coast Air Basin are enough to push it over the top,” said state Air Resources Board spokesman Bill Sessa.

But Sommerville, the San Diego air pollution control officer, insists that most of the time Los Angeles smog is solely to blame for incidents of excessive smog in San Diego.

The federal health standard is exceeded when ozone concentrations exceed the federal standard of 0.12 parts of ozone per million parts of air for one hour.

Ozone is a major health threat that can cause respiratory illness, reduce lung capacity in even healthy adults during exercise, and weaken the body’s immune system. It also can damage crops, trees and building materials. Ozone is formed when hydrocarbons, such as gasoline fumes, react with oxides of nitrogen, such as tailpipe emissions, in the presence of sunlight. Ozone makes up about 95% of what is commonly called smog.

There is little doubt that growth and development in San Diego County is a major contributor to the city’s worsening air pollution. Gains made against air pollution during the past five years in San Diego are being offset by population increases, which bring more cars and increased development.

A little more than 10 years ago, all of the high ozone days in San Diego were laid at the door of Los Angeles. A more recent study examining 158 days in 1985 and 1986 when maximum ozone concentrations equaled or exceeded the federal standard showed that was no longer the case.

“About half the time (49%), ozone or precursor emissions were transported from the South Coast Air Basin, and a little over a quarter of the time (28%) no transport was found to impact San Diego,” a study by the state Air Resources Board found. It could not be determined where the remaining 23% originated.

The same study indicated that Mexico also may contribute to San Diego’s pollution problem. During 31 of the 158 days when ozone levels exceeded the federal standard in San Diego, researchers said pollution from Tijuana may have been a contributing factor.

All of this raises questions about how effective regional air pollution control plans are and whether they should be merged to fight the problem.

Lents, of the AQMD, and Sommerville, of the San Diego district, think not. Sommerville agreed with AQMD officials, saying San Diego will benefit as the Los Angeles Basin implements its tough new air pollution control plan.

“There’s really no good purpose served by having one huge agency,” Sommerville said, adding that the tough regulations needed in Los Angeles are not necessary in San Diego.

But the California Clean Air Act nonetheless requires one region to take another region into consideration when implementing smog-reducing regulations. The regional districts are asked to be good neighbors and impose extra controls, if necessary, to keep their pollution out of someone else’s back yard.

In fact, Tom Eichhorn, an AQMD spokesman, said the district’s new 20-year plan to reduce air pollution in the Los Angeles Basin by 80% to 90% “will significantly reduce our contribution to San Diego.”

In San Diego and other spots where smog imports are of concern, residents and businesses have argued against stricter local air pollution controls on the grounds that the biggest share of pollution comes from outside the area.

The San Diego County Air Pollution Control District, for instance, is urging Congress to amend the federal Clean Air Act to take San Diego’s situation into account. If the federal government does not give San Diego credit for the fact that some of its air pollution originates in Los Angeles, San Diego will be forced to impose far more stringent local controls. “If we have to do more because of things we can’t control, it doesn’t seem quite fair,” said Bob Goggin, spokesman for the San Diego district.

The argument is familiar to federal authorities, who hear the same from states affected by trans-boundary pollution.

“There is a lot of doubt how one might try to force a state to do something,” Brock Nicholson, chief of the U.S. Environmental Protection Agency’s ozone and carbon monoxide policy development, said in a telephone interview from North Carolina. “There’s always a tendency of a downwind state to say don’t make me do as much. Upwind states say, wait a minute, it’s not all me.”

California is not alone in having an impact outside its boundaries. In the Northeast, air pollutants from Virginia to Rhode Island are finding their way to New Hampshire and Maine, including President Bush’s retreat at Kennebunkport.

An amendment proposed for the federal Clean Air Act calls for creating an “interstate (air pollution) transport commission” to study the scientific and technical aspects of the problem and then make recommendations to affected states.

Whatever the result of the clean air negotiations, California authorities say that trans-boundary pollution should not become an excuse to ease up on local controls.

“What our studies show is that all air basins inherit some pollution from some other region and also contribute pollution to other regions. But, by and large, the pollution in any given region is locally generated,” said Sessa.

Times staff writer Amy Wallace in San Diego contributed to this story.