SU0004916 - Laserfiche WebLink

Home Browse Search

Particulate Matter Respirable PM of 10 micrometers,or less,in diameter is referred to as PMIo(1 micrometer is equal to 1-millionth _ of a meter). PM10 consists of particulates directly emitted into the air, such as fugitive dust, soot,and smoke from mobile and stationary sources, construction operations,fires and natural windblown dust,and particulates formed in the atmosphere by condensation and/or transformation of SO2 and reactive organic gases(EPA 2002). PM,o _ includes a subgroup of finer particle called PM2.5,which has an aerodynamic diameter of 2.5 micrometers or less. The adverse health effects associated with PMro depend on the specific composition of the PM. For example, health effects may be associated with metals,polycyclic aromatic hydrocarbons, and other toxic substances adsorbed onto fine particulates,which is referred to as the piggybacking effect,or with fine dust particles of silica or asbestos. Generally,adverse health effects associated with PMro may result from both short-and long-term exposure to elevated PMro concentrations and may include breathing and respiratory symptoms, aggravation of existing respiratory and cardiovascular diseases,alterations in the body's immune system,carcinogenesis, and premature death(EPA 2002). PM2.5 poses an increased health risk because it can deposit deep in the lungs and contains substances that are particularly harmful to human health. As a result,the EPA promulgated national PM2.5 standards in 1997; however,these standards have yet to be implemented. Toxic Air Contaminants A records search monitored by the SJVAPCD was conducted for stationary sources of TACs near the College Park site. No stationary sources of TACs were found within 0.25 mile of the project site(ARB 2004b; San Joaquin County 1991; EPA 2004b). Sources of TACs within the project study area are heavy-duty diesel vehicles,primarily on Interstate 205 (I-205) and Interstate 580(I-580). The ARB identified particulate emissions from diesel-fueled engines(diesel PM)as a TAC in August 1998. The ARB has since developed the Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fueled Engines and Vehicles(2000)and the Risk Management Guidance for the Permitting of New Stationary Diesel-Fueled Engines(2000). Both documents were approved by the ARB on _ September 28,2000.The ARB is developing regulations designed to reduce diesel PM emissions from diesel- fueled engines and vehicles. The goal of each regulation is to make diesel engines as clean as possible by establishing state-of-the-art technology requirements or emission standards to reduce diesel PM emissions. These regulations will require substantial reductions in diesel PM beginning with the 2004 model year. Additional more stringent standards will apply to engines starting in the 2007 model year. Off-road vehicles came under more stringent regulation beginning with the 2005 model year. Each set of regulations will serve to significantly reduce diesel PM emissions and long-term human health risks attributable to diesel-fueled vehicles and equipment. EXISTING AMBIENT AIR QUALITY The EPA has established primary and secondary national ambient air quality standards(NAAQS)for the following criteria air pollutants: 03,CO,NO2, SO2,PMro,PM2.s,and lead. The primary standards protect public health,and the secondary standards protect public welfare. In addition to the NAAQS,the ARB has established California ambient air quality standards(CAAQS) for the criteria air pollutants, sulfates,hydrogen sulfide,vinyl chloride,and visibility-reducing PM. In most cases,the CAAQS are more stringent than the NAAQS. The NAAQS and CAAQS as listed in Table 4.12-1. EDAW College Park at Mountain House Specific Plan III Draft EIR Air Quality 4.12-4 San Joaquin County