Air Pollution

County would fail new rules for ozone

EPA’s proposed tougher standards for emissions could force many local businesses to step up control efforts

By David Sneed

San Luis Obispo County would have to significantly step up its air pollution control efforts if the federal government adopts new, stricter smog standards.

The federal Environmental Protection Agency is considering toughening its standards for ozone pollution from 80 parts per billion to 70 parts per billion, a step that would put Paso Robles and other communities north of the Cuesta Grade in violation.

Ground-level ozone is a severe lung irritant, commonly called smog, and is formed when sunlight strikes automobile tailpipe emissions containing nitrogen oxides and other pollutants. Industrial emissions and open burning are other sources of ozone precursors.

A tightening of air pollution standards—by lowering the number that is allowable—could mean that businesses in the county such as oil refineries, gas stations, wineries and industrial plants could be required to take additional steps to reduce their emissions, said Larry Allen, county air pollution control officer.

Allen said the county has already done a lot to reach current standards.

“It’s going to be more expensive” to reach lower limits, he said, “because we’ve picked the low-hanging fruit, to be sure.”

Tougher air pollution standards would likely affect most industries in the county because federal officials consider an entire county to be out of compliance even if only one or two locations fail to meet standards.

County air pollution officials would concentrate on industrial businesses because stationary sources of air pollution are the only ones over which they have jurisdiction. Sources such as cars, trucks and buses fall under state and federal jurisdiction. Vehicles produce about three-quarters of the ozone pollutants.

Finding out where additional air pollution cuts from stationary sources can be made requires a complicated process of modeling and examining lists of feasible measures issued by the state to determine which would apply locally.

“It’s very difficult to say at this point in time what we would do,” Allen said. “The cost-effective options have already been looked at.”

The state already has a limit of 70 parts per billion for ozone established in 2005. However, a lower U. S. standard is much more significant because the federal government has more sanctions it can levy on counties that do not meet the standard.

Specifically, the EPA can withhold lucrative transportation grants from counties that do not take appropriate steps to reduce air pollution.

Under current federal standards, only the Carrizo Plain and other locations in the eastern part of the county exceed the standard of 80 parts per billion. Smog there is caused by ozone precursors wafting in from the San Joaquin Valley. An air monitoring station at Red Hills, near the Kern County line east of Paso Robles, also records high ozone levels.

If the federal standard drops to 70 parts per billion, Paso Robles and Atascadero would be in violation, particularly during the sunny summer months.

Ozone in those two areas is produced by local sources of pollution and is not blown in from other parts of the state, Allen said.

The tougher air standards are the result of studies by the EPA that show that lowering ozone levels would reduce the number of heart attacks, asthma and bronchitis and missed work days. The elderly, young children and those who work outdoors are considered the most vulnerable.

The EPA is expected to announce its new ozone standards in coming weeks. Allen expects that the standard will be either 70 or 75 parts per billion.

“The evidence is overwhelming that a lower level is needed to protect public health,” he said.

San Luis Obispo County is one of 533 counties in the nation that would be in violation if the standard is lowered to 70 parts per billion. Many of the others are in Southern California and the Central Valley.

San Bernardino County is the worst, with ozone levels reaching 127 parts per billion.



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