West Mojave Plan FEIR/S - Desert Managers Group

AIRBASINAIR QUALITYDISTRICTPOLLUTANTSSAB SCAQMD Ozone(federal)Chapter 3 3-53PLANNINGAREA NAMECoachella ValleyFEDERALDESIGNATIONNonattainmentSTATEDESIGNATIONPM 10 (state) SSAB NonattainmentOzone (state) SSAB NonattainmentAll others SSAB Unclassified/attainmentAttainmentRespirable Particulate Matter (PM 10 ): PM 10 is the most important air pollutant in theWest Mojave planning area. PM 10 in the atmosphere can be caused by both environmentalfactors and human activities. Human activities that contribute to the PM 10 emissions includecombustion sources such as stack emissions, diesel exhaust and smoke from prescribed fire andwild fire, fugitive dust sources such as construction and demolition activities, off highwayvehicle (OHV) travel, unpaved public roads and parking lots, industrial activities, OHV openareas and military activities. The combustion sources tend to produce smaller particulates (lessthan 5 µ) while fugitive sources tend to produce larger particulates (larger than 5µ).One of the reasons for the concern with PM 10 emissions is their adverse effect on humanhealth. All of the PM 10 particles are considered respirable particulate because they can beinhaled into the nose, throat and/or lungs. The fine PM 10 particles are the largest threat to healthbecause they tend to deposit in the air sacks. In addition, many of the fine particles are fromprecursor emissions many of which are toxic or carcinogenic. Fugitive dust is primarily coarseparticulate that is not as likely to contain toxic materials. The newest studies report that a 100µgm/m 3 increase in daily PM 10 concentrations would increase mortality by 10%. The state PM 10standards are considered public health goals. The USEPA has established new NAAQSstandards for PM 2.5 emissions. These standards are for particles at or below 2.5 µ. These fineparticles have been implicated as an increased health risk and consist of chemical compoundsthat mostly result from combustion processes.Nearly all of the planning area has recorded concentrations of PM 10 in excess of thenational and state ambient air quality standards for PM 10 emissions. The USEPA has classifiedfive areas within the West Mojave planning area as federal PM 10 nonattainment areas. The fivecurrent federal nonattainment areas are: the Owens Valley PM 10 Planning Area, the CosoJunction PM 10 Planning Area, the Indian Wells Valley PM 10 Planning Area, the Trona PM 10Planning Area and the San Bernardino County PM 10 Area. The Owens Valley planning area isone of five serious federal nonattainment PM 10 planning areas in the nation. Southeast KernCounty and northeastern Los Angeles County (Antelope Valley) are currently listed asunclassified by the USEPA.The Antelope Valley Area has recorded levels above the national threshold, but has notbeen classified as nonattainment by USEPA yet. The air quality management district has beenworking directly with USEPA to successfully reduce the PM 10 concentration levels and avoidhaving the Antelope Valley Planning Area designated as a federal nonattainment area. Part ofthis effort is through the adoption and implementation of rules to control fugitive dust that