Laserfiche WebLink
CNAPTERFOUR Environmental Conseuuences <br />projects' significant impact azea. Background concentrations were also included. The NOz <br />modeling analysis is based on NOx emissions from all sources; however, as stated in the <br />USEPA's Guideline On Air Quality Models, the presence of ozone can retard the formation of <br />NOZ. [In accordance with the Tier 2 screening procedures, a conversion factor o1.' 75 percent is <br />used to estimate N02 impacts from modeled results (EPA 1995).] <br />The conservative dispersion modeling performed for this project indicated that tt~e maximum <br />ground level concentrations (total concentration) predicted for all pollutants (PMto, NOZ and CO) <br />aze well below the applicable standards (NAAQS/CAAQS concentrations) (Tables 4.5-3 and <br />4.5-4). <br />Piceance Site <br />TABLE 4.5-3 <br />SUMMARY OF PICEANCE CUMULATIVE AIR QUALITY STANDAR])S ANALYSIS <br />::::::.:::.:::::::::s-:::.:.•:::::::::;::::.::::::::: ::::::Pltii ::::; : :::.:::::P1V€ ::::::: :::':.::1~0' :>:::`' .:::::CO::<;:r ::•:::C()' :`."; <br />Pollutant/Pai'abieYer:::::';:'::•:::::: <br />::::.::::: <br />::•: -::< :::.: <br />-:: :::;'' :.::.::::::.::::.:.:::::: <br />:::::.29-Lour::::: <br />:: :::::::::::::::.:::. ::::::::::: <br />:-:-:Annusl:::::: ::'::::.,..,.;:.;:;...: ;;; <br />.:,:Aanuai <br />::;.:: .;' ,~ .:'''•::! <br />)E1aur...:.. <br />::::.X :::: ..:...:..,,,,,. <br />.:::;8-;~aur;:::.::: <br />. <br />. . . <br />. . <br />Maximum Modeled 29.1 7.9 18.4 2,478 579 <br />Cumulative Concentration <br />Background Concentration 5] 9 2.0 1,144 1,144 <br />Total Concentration 80.1 16.9 20.4 3,622 1,723 <br />CAAQS/NAAQS 150' S0 100 40,000 10,000 <br />Concentration <br />Percent of Applicable 53.4 33.8 20.4 9.1 17.2 <br />CAAQSlNAAQS <br />a The "highest-second-high" design concentration from the model has been compared to the 24~ hour PM l0 <br />standard, even though the 99th percentile format of the standard could allow for the use of the "highest-fourth- <br />high" concentration. <br />Source: RTP 1998a <br />4-24 Meteorology and Air Quality <br />