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Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Air Actions, California

Owens Valley Particulate Matter Plan: Fact Sheet

Final Approval for the Owens Valley PM-10 Planning Area Demonstration Of Attainment State Implementation Plan (SIP) For Attaining Clean Air in the Owens Valley

Summary of Action:

Particulate matter is a serious air pollutant that may cause severe respiratory illness. In California's Owens Valley, particulate matter has been measured at the highest levels found in the United States. EPA is finalizing its approval of the Owens Valley PM-10 Planning Area State Implementation Plan (SIP) submitted by the State of California for attaining clean air in the Owens Valley Planning Area. The SIP was submitted by the State to show that the Owens Valley will meet Federal PM-10 requirements of the Clean Air Act for clean air by applying certain control measures. EPA is also approving the State's request for an extension to December 31, 2006, to attain this requirement.


Air pollutants called "particulate matter" include dust, dirt, soot, smoke, and liquid droplets directly emitted into the air by sources like factories, motor vehicles, construction activity, fires, and windblown dust. Strong winds over the Owens Valley dry lake bed blow high levels of dust into the air containing a variety of particulates. The dust from the lake bed contains carcinogens such as nickel, cadmium, arsenic, as well as sodium, chlorine, iron, calcium, potassium, sulfur, aluminum, and magnesium. Fine particulates are so small that several thousand of them could fit on the period at the end of this sentence. Particulates can harm human health and the environment. They can affect breathing and cause lung damage, increased respiratory disease and possibly premature death. Children, the elderly, and people suffering from heart and lung disease, like asthma, are especially at risk. Particulates also damage paint, soil clothing and reduce visibility. Air monitoring of the Owens Valley during the past 18 years has measured the highest particulate matter ("PM-10") pollution in the United States. EPA classified Owens Valley as a "serious nonattainment area" for PM-10 in January 1993, and established February 8, 1997, as the submittal deadline for a State Implementation Plan (SIP) demonstrating quick attainment of the PM-10 health standard. The SIP submitted by the State is the result of the City of Los Angeles and the Great Basin Unified Air Pollution Control District working together to resolve the PM-10 emissions from Owens dry lake bed. The Plan, for the first time, applies control measures on the dry lake bed to reduce PM-10. The three control measures are shallow flooding, managed vegetation, and gravel cover. In 2003, the District will reevaluate the air emissions and make corrections necessary to attain the standard by 2006.

For more information:

Please contact Larry Biland of the Air Planning Office at (415) 947-4132 or biland.larry@epa.gov.

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