Air quality and local leaders today called on cities, builders and residents in the Coachella Valley to join in a renewed effort to control blowing dust created by activities such as construction, farming, and motor vehicles use.

"We have the ordinances, methods and technologies already at hand to prevent unhealthful levels of dust," said Roy Wilson, a Riverside County Supervisor and member of the South Coast Air Quality Management District Governing Board. "But we need to do a better job of putting them into practice."

The call came with the release of 2000 air monitoring data showing that the valley has slipped out of attainment of the federal standard for fine particulate matter, known as PM10 because it consists of particles smaller than 10 microns in diameter, less than one-eighth the diameter of a human hair.

These small particles evade the upper respiratory system’s defenses and enter deep into the lungs. Exposure to unhealthful levels of PM10 is associated with exacerbation of chronic respiratory disorders, increased hospitalizations, and even premature deaths.

After seven years of PM10 levels below the health standards, an unhealthful level of PM10 occurred in 1999, as well as 2000. Combined, the two years raise the three-year annual average for PM10 above the 50 microgram per cubic meter of air benchmark the federal Environmental Protection Agency uses to judge whether an area is meeting the health standard.

"Coachella Valley has a history of being able to work locally to meet the health standard," said Corky Larson, executive director of the Coachella Valley Association of Governments. "Local governments are aware of the situation and are working with CVAG and AQMD to redress the problem quickly."

Specifically, the leaders called for local governments, contractors, farmers, and residents to do their part by renewing their efforts to carry out dust control measures in Coachella Valley, including:

• Increased enforcement of existing dust control ordinances and regulations by city and county code enforcement staff (Effective May 15, AQMD has dedicated a full-time inspector to the Coachella Valley to enforce regional dust control regulations and to educate those with the potential to generate dust on control measures. AQMD will work with local governments to further enhance their enforcement efforts.);
• Requiring more detailed dust control plans from builders in the valley that specify the use of more aggressive and frequent watering, soil stabilization, wind screens, and phased as opposed to mass grading by builders to minimize dust;
• Use of existing federal funds earmarked for local governments for such work as installing wind fences that block blowing dust, quickly cleaning up roads and streets after dust storms, and stabilizing dirt roads;
• Improved procedures in planting winter rye grass, known as turf overseeding, by both homeowners and golf course operators to minimize dust; and
• Improved soil conservation methods by farmers.

AQMD and CVAG adopted a comprehensive dust control plan in 1990 and updated it in 1994. Under that plan, local governments adopted dust control ordinances and implemented extensive dust control programs. In 1996, AQMD asked EPA to redesignate Coachella Valley as a PM10 attainment area when its three-year PM10 average dropped below the 50 microgram per cubic meter annual average standard.

However, an upsurge in the economy and population growth has resulted in more land development projects in recent years. In response to increased public complaints and fugitive dust and public nuisance violations at building and development sites and farms during the last two years, local governments are now working closely with AQMD to require more detailed dust control plans. Local farmers and builders support these efforts.

"We’re looking at a year of great opportunity," said Wilson. "We can quickly reverse the situation and reattain the PM10 standard by more closely following the measures we carried out so well in the past."

AQMD measures PM10 levels at air monitoring stations in Palm Springs and Indio. Typically, Indio has higher readings because it is downwind of many of the valley’s dust sources.

Last year, Indio had an annual average concentration of PM10 that was 51.9 micrograms per cubic meter and in 1999 a concentration of 52.7 micrograms per cubic meter. In 1998, the concentration was 47.2 micrograms per cubic meter. The average annual concentration for the three-year period was 50.6 micrograms per cubic meter.

At the Palm Springs monitoring station, the annual average concentrations were 24.4, 28.8, and 26.4 micrograms per cubic meter in 2000, 1999, and 1998, respectively.

As the wind blows down the valley, the air picks up fine PM10-sized dust from the desert floor, as well as dust entrained by cars traveling on dirt and paved roads, construction sites, agricultural tilling, and other activities.

The reported annual PM10 levels do not include the impact from blow sand dust storms that occur on days when winds exceed 25 miles per hour. EPA excludes these conditions if man-made dust sources are controlled and a system for notifying the public of high wind forecasts is in place.

"We can’t do anything about the nature of the valley, but we can control our own contributions," said Larson.

AQMD is the air pollution control agency for the Coachella Valley, as well as Orange County and the metropolitan portions of Riverside, San Bernardino, and Los Angeles County.

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This page updated: March 03, 2004
URL: http://www.aqmd.gov/news1/Coachella_non_attain.htm