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Pacific Southwest, Region 9

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

Air Actions, Nevada

NOTE: This content is no longer being updated. The most up to date information can be found in Federal Register Notices and Approved Air Quality Implementation Plans in Region 9.

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Particulate Matter in Las Vegas, Nevada Fact Sheet on Proposed Disapproval

June 5, 2000


Proposed Disapproval of the State Implementation Plans for PM-10 for Clark County

SUMMARY OF ACTION Particulate matter is a serious air pollutant that may cause severe respiratory illness. The Particulate Matter (PM-10) State Implementation Plans (SIPs) for the Las Vegas Valley do not show that the area will attain healthful air and therefore, EPA is proposing to disapprove the Moderate Area and Serious Area SIPs submitted by the State of Nevada for attainment of the 24-hour and annual PM-10 standard in the Las Vegas Valley. EPA is also proposing to deny the State's request to extend the PM-10 attainment deadline for the Las Vegas Valley from December 31, 2001 to December 31, 2006. EPA is proposing disapproval of the SIPs because they fail to meet Clean air Act (CAA) requirements, including requirements for an approvable emissions inventory, attainment demonstration, and control measures. EPA is disapproving the request for an attainment date extension because the State did not demonstrate that it meets the CAA criteria for an extension. This action starts a process that if finalized by a separate EPA notice, will trigger the 18-month time clock for mandatory application of sanctions and 2-year time clock for promulgation of a federal implementation plan (FIP) unless the State submits, and EPA approves, a revised SIP before that time. The Clark County Department of Comprehensive Planning (CCDCP) and the Clark County Health District (CCHD) are the agencies responsible for addressing PM-10 pollution in the Las Vegas Valley. A new plan is already well underway. Staff from CCDCP, CCHD, Regional Transportation Commission and the Nevada Division of Environmental Protection are meeting semi-monthly with EPA staff to discuss the corrective actions Clark County will take with a new PM-10 SIP. The County also provided us with a time line as to when we will receive a new PM-10 SIP which is to occur in late summer 2000. Despite this effort, violations of the PM-10 NAAQS continue in the Las Vegas Valley and therefore EPA must take action on the submitted SIP to ensure healthful air for all residents of the Las Vegas Valley. We encourage the Clark County Department of Comprehensive Planning and the Clark County Health District to continue working on a new SIP addressing all the requirements of the CAA.

BACKGROUND Particulates can harm human health and the environment. Recent research has linked exposure to relatively low concentrations of particulate matter with respiratory illness and premature death. Those at greatest risk are children, the elderly, and those with pre-existing respiratory or heart 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. Exposure to particulate air pollution can trigger asthma attacks and cause wheezing, coughing, and respiratory irritation in individuals with sensitive airways. Fugitive dust during high wind events is largely responsible for exceedances of both the 24-hour and annual PM-10 air quality standards in the Las Vegas Valley. Fugitive dust is particulate matter suspended in the air either by mechanical disturbance of the surface material or by wind action blowing across surface areas which have been mechanically disturbed. Human activities associated with increasing urbanization are the major source of fugitive dust emissions within the Valley. These sources of fugitive dust include entrained paved and unpaved road dust, construction activities, and disturbed vacant land.

Reasons forDisapproval Emissions Inventory: The Serious plan does not include a complete emissions inventory for either the 24-hour or annual PM-10 standard. For example, the inventories do not include emissions of condensible particulate or PM-10 precursors, including volatile organic compounds (VOC), nitrogen oxides (NOx), sulfur dioxide (SO2), and ammonia (NH3). Additionally, there are no emission estimates for airport activities, agricultural activities, various commercial cooking methods, off-road vehicle exhaust, and lawn care equipment.

Reasonably Available Control Measures/Best Available Control Measures (RACM/BACM): The Moderate and Serious plans failed to demonstrate that the control measures in the plans are RACM or BACM. The plans contain no control measures at all for disturbed vacant lands which are significant sources of PM-10 in the Las Vegas Valley. Also, some control measures in the plans are not fully enforceable.

Attainment Demonstration: The Las Vegas Valley Serious Area plan as submitted just barely shows attainment of the annual standard by 2001. Due to deficiencies in the emissions inventories (see above), the attainment demonstration for the annual standard is questionable. The Las Vegas Valley Serious Area plan does not demonstrate attainment of the 24-hour standard by 2001. The modeled result predicts a post-control concentration above the 24-hour standard. The air quality modelling and attainment demonstration contained in the plan are not consistent with existing EPA guidelines.

Reasonable Further Progress (RFP)/Quantitative Milestones: Both the Moderate and Serious Area plans for the Las Vegas Valley do not contain annual emission reductions for milestone years or a commitment to submit reports on compliance with the quantitative milestones.

Extension of the Attainment Deadline: The State did not show that it meets the CAA criteria for an extension of the attainment date. For example, the Serious plan did not demonstrate that the most stringent measures would be implemented in the Las Vegas Valley to allow the area to attain as expeditiously as practicable. Therefore, we are denying the State's request for an extension and the area's attainment deadline remains as soon as practicable but no later than December 31, 2001.

The proposed disapproval is available on the EPA Region 9 Web site at https://www.epa.gov/region09. A 60-day public comment period will begin when EPA publishes the proposed disapproval in the Federal Register. For additional information, please contact Larry Biland of the air Planning Office at (415) 947-4132.

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