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Air Actions, California

Owens Valley Particulate Matter Plan Q & A

Owens Valley Particulate Matter (PM-10)
State Implementation Plan (SIP) Approval
Great Basin Unified Air Pollution Control District

1. What does today's action mean for Owens Valley? The Great Basin Air Pollution Control District and the City of Los Angeles will now work together to ensure that the Owens Valley will meet the Clean Air Act requirements for clean air.

2. What's in this plan? What does this plan require? The Plan describes the cause of the PM-10 violations and is a blueprint for how these emissions will be controlled to the level required under the CAA. The Owens plan contains three control measures, each of which is designed to reduce emissions from the Owens Lake bed. They are shallow flooding, managed vegetation, and gravel cover.

3. Why is there another SIP due in 2003 when this one is just being approved now? The District commits to revise the SIP in 2003 to incorporate new knowledge and to ensure attainment of the PM-10 NAAQS by December 31, 2006. If the District determines that additional or fewer controls are required to meet the NAAQS by December 31, 2006, the 2003 SIP will provide for implementation of the appropriate control measures for the final step of the control strategy.

4. How did the Great Basin District get the City of Los Angeles to agree to do these measures? By working together, the District and the City developed this Plan.

5. Did EPA cut a deal with the City of Los Angeles on this plan? NO! EPA was a silent observer during the negotiations. If the negotiations failed, EPA would have imposed a Federal Implementation Plan (FIP).

6. What are the health effects of PM-10? Recent research has linked exposure to relatively low concentrations of particulate matter with premature death. Those at greatest risk are the elderly and those with pre-existing respiratory or hear disease. Particulate matter air pollution is especially harmful to people with lung disease such as asthma and chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. Lung disease is the third leading cause of death in the United States. Exposure to air pollution can trigger asthma attacks and cause wheezing, coughing, and respiratory irritation in individuals with sensitive airways.

7. What is the standard? The annual PM-10 standard is 50 micrograms per cubic meter (ug/m3) and the 24-hour standard is 150 ug/m3. The attainment demonstration in the Owens Valley area applies only to the 24-hour standard, since the area does not violate the annual NAAQS. The 3-year annual arithmetic mean for the most recent period (1996-1998) is 37.0 ug/m3.

8. How do the new air quality standards affect this process? The new air quality standards did not affect this process. The opinion issued by the U.S. Court of Appeals for the D.C. Circuit in American Trucking Assoc. Inc., et al v. USEPA No. 97-1440 (May 14, 1999), among other things, vacated the new standards for PM-10 that were published on July 18, 1997, and became effective on September 16, 1997, but left in place the old PM-10 standard. The Owens Valley Plan was negotiated under the old (existing) PM-10 standard.

9. How bad is the PM-10 problem in the Owens Valley? What are the PM-10 levels in Owens Valley? Owens Lake emits about 300,000 tons of PM-10 per year: 30 tons of this is arsenic and 9 tons is cadmium. Owens Lake is the largest single source of PM-10 pollution in the United States. It has caused on average about 19 violations of the standard every year at Keeler during the 18 years that the Great Basin Unified Air Pollution Control District has been measuring particulate matter. It is not a natural source, and the wind speeds (20 to 40 mph) that cause the dust events are not unusually high.

10. Since the air is so bad in the Owens Valley, why has it taken so long to adopt a plan? In 1987, EPA designated the Owens Valley Planning Area as non-attainment for the Federal PM-10 standard. In 1988, 1991, and 1994, the District submitted to EPA committal SIPs describing control studies to determine the most effective measures and how the District would develop and order the City to implement PM-10 control measures on Owens Lake. Each of those SIPs projected that the measures would be developed at least by 1997 and the standard by 2001. The Owens Valley PM-10 problem is atypical since the problem is not based on traditional industrial emissions. Therefore, determining what would control PM-10 emissions has been difficult. Over the last decade, research was conducted on the lake bed to find the most effective control measures.

11. Are there any significant PM-10 sources besides Owen’s Lake that can be controlled enough to make a difference? No. Particulate matter is a combination of fine solids such as dirt, soil dust, pollens, molds, ashes and soot; and aerosols that are formed in the atmosphere from gaseous combustion by products such as volatile organic compounds, sulfur dioxide and nitrogen oxides. Particulate pollution comes from such diverse sources as factory and utility smokestacks, vehicle exhaust, wood burning, mining construction activity, and agriculture. The Great Basin Unified Air Pollution Control District and the California Air Resources Board have independently calculated the emissions in the Owens Valley planning area from industrial facilities, entrained pave road dust, mobile source tail pipe emissions, unpaved road dust, residential wood burning, prescribed burning and agricultural operations. These emissions total less that 1% of the annual inventory. Direct emissions from Owens Lake comprise 94% of the inventory and reentrained Owens Lake dust emissions deposited on the surrounding area comprise 5% of the inventory.

12. Isn’t the whole problem caused naturally? No. The dry lake bed was caused by the complete diversion of water from the Owens River, the source of the lake. As a result, the particulate matter emissions on the dry lake bed are considered man-made and must be controlled to healthful levels. The Desert Research Institute of the University of Nevada at Reno has prepared a model to demonstrate what the elevation of the water would have been in Owens Lake from 1913 to 1995 if the water that the City has diverted to Los Angeles would have instead flowed into the Lake. The model shows that absent the City’s diversions, the natural water level of Owens Lake would have averaged 3,594 feet between 1979 and 1995, and covered all but 28 acres of the lake bed areas that the District has identified as dust sources. Based on the above discussion the District concludes that the City’s water diversions, by uncovering essentially all of the dust source areas on the dry lake bed, have caused or contributed to the measured particulate matter violations in the Owens Valley PM-10 Planning Area.

13. What about CAA sanctions? No sanctions will happen. On February 2, 1999, EPA sent to the State of California a completeness review of the Owens Valley PM-10 SIP. The SIP submittal satisfied the completeness requirements of the Clean Air Act. This letter “shut-off” the clock that would have imposed an offset sanction on major new industrial sources on February 20, 1999, and a highway funding sanction that would have gone into effect on August 20, 1999. The FIP clock will be “shut-off” when EPA approves the SIP.

14. How seriously would the sanctions have affected the region if they did apply? Because there are currently no major new industrial sources or new highway projects in the valley, the sanctions have had no immediate, practical effect on the people or business of Owens Valley.

15. Why impose sanctions if they have no effect? The Clean Air Act gives EPA a non-discretionary responsibility to impose sanctions. The sanctions would, as indicated above, impact any new sources wishing to locate in the Valley.

16. Does EPA still need to do a FIP? No; today’s approval of the SIP fills the gap and eliminates the need for EPA to do a FIP.

17. Is there any way to solve the PM-10 problem without having LA return some of its water? The approved plan is based on a combination of measures, only one of which is the application of water via a drip pipe irrigation system over a portion of the dry lake bed. The water needed can be obtained from any available source and does not have to come from the City’s supply.

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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