Under the 1990 federal Clean Air Act, EPA was required to designate as "nonattainment" those areas not meeting air quality standards for airborne particulate, such as Imperial County. Because the county was classified moderate nonattainment in 1990, it was required to reach attainment by Dec. 31, 1994. Since it did not, the county should have been reclassified as serious nonattainment, according to Earthjustice, hence the lawsuit to force the EPA's hand on the issue.
Several calls to EPA and the U.S Department of Justice — EPA's legal counsel — were not returned.
PM-10 is particulate matter less than 10 microns in size. A micron is a linear measurement equal to a millionth of a meter.
In papers filed with the District Court for the District of Columbia, Earthjustice argues "the severity and frequency of PM-10 violations in Imperial Valley are among the most extreme in the nation.
"According to EPA, the area violated PM-10 health standards on 206 days last year," the documents state. "On one day during the year 2000, Imperial Valley recorded PM-10 levels 1000 (percent) over the health standard — more than double the level at which EPA says ‘significant harm' to health occurs."
Baron and Jan Cortez, American Lung Association of San Diego and Imperial counties vice president of research and environmental programs, said they are not aware of any scientific data that shows a direct cause and effect relationship between PM-10 levels in Imperial County and respiratory disease.
Cortez said there are studies from other areas that do show such a relationship and at levels lower than those found in Imperial County.
"There have been a number of studies proving particles less than 10 microns cause lung irritation," Cortez said. "Breathing particles small enough to enter air passages is not good for health."
Cortez said solutions to dust problems include better controls on diesel engines, driving fewer miles and a reduction in the creation of agricultural dust. She also said although the new power plants being built in Mexicali will have additional equipment to reduce nitrogen oxides, they will not have the equipment necessary to minimize PM-10.
In its legal documents filed with the court, Earthjustice included information from the March 2001 indicator of the month bulletin from San Diego State University, Imperial Valley campus' California Center for Border and Regional Economic Studies. The bulletin quotes California Air Resources Board data that shows PM-10 emissions in the Imperial Valley for 1996 were 80,414 tons and 71,323 tons for the Mexicali Valley. The bulletin also says state Department of Health Services data shows deaths from respiratory illnesses from 1995 to 1997 in Imperial County were 15.2 per 100,000 population, compared to a state rate of 6.2 per 100,000.
Locally, county Air Pollution Control Officer Stephen Birdsall said county officials will meet with EPA officials in San Francisco today to discuss the PM-10 matter. He said a bumped-up designation from moderate nonattainment to serious nonattainment would have devastating effects in the Valley.
"That would be a serious economic burden on everybody down here," Birdsall said.
On Tuesday, the county Board of Supervisors approved Aug. 14 as the date for a public hearing on the county's proposed PM-10 plan.
Birdsall said the plan is available for public review at the APCD office in El Centro today, and the plan's attachments will be available Monday.
Meanwhile, a somewhat similar situation took place in the Coachella Valley, where the area was classified as serious nonattainment for PM-10. Through dust control measures the dust levels were reduced enough that the South Coast Air Quality Management District has requested EPA reclassify the area from "serious nonattainment" to "attainment."