AgdaPkt 2017-04-03 Joint SA PFA - Laserfiche WebLink

Browse Search

Jonathan Hayes - Greystar Updated March 15, 2017 - Page 5 Roadway Community Risk Impacts Traffic on high volume roadways is a source of TAC emissions that may adversely affect sensitive receptors in close proximity to the roadway. BAAQMD’s Google Earth Highway Screening Analysis Tool was used to estimate the screening TAC impacts from El Camino Real traffic. The project is located adjacent to El Camino Real, with the closest dwelling units approximately 25 feet west of the nearest traffic lanes. BAAQMD provides a Google Earth Highway Screening Analysis Tool that can be used to identify screening level impacts from State Highways.2 This tool was used to identify screening community risk levels. TAC impacts were estimated using Link 26, Elevation 20 feet (2nd story) at a distance of 25 feet as follows: Roadway/Setback Cancer Risk (per million) PM2.5 Concentration (µg/m3) Acute Hazard (HI) Chronic Hazard (HI) El Camino Real (25 ft) at the 20- foot high receptor position 10.50 0.147 0.01 0.03 For local roadways, the BAAQMD has developed a Roadway Screening Analysis Calculator to assess whether roadways with traffic volumes of over 10,000 vehicles per day may have a potentially significant effect on a proposed project. The screening calculator is based on simple worst-case modeling for either north-south or east-west roadway segments, in San Mateo County. Two adjustments were made to the cancer risk predictions made by this calculator: (1) adjustment for latest vehicle emissions rates and (2) adjustment of cancer risk to reflect new OEHHA guidance described above. The BAQAMD calculator uses older EMFAC2011 emission rates for the year 2014. Overall, emission rates will decrease by the time the project is constructed and occupied. The project is not likely to be occupied prior to 2018. In addition, a new version of the emission factor model, EMFAC2014, is available. This version predicts much lower emission rates than EMFAC2011 and the rates for 2018 are lower than the rates for 2014. Using a fleet mix typical of local roadways operating at 30 mph, EMFAC2014 predicts diesel (DSL) PM2.5 aggregate emission rates in 2018 that are 46 percent of EMFAC2011 rates for 2014.3 TOG for gasoline-powered vehicle rates are 56 percent of EMFAC2011 year 2014 rates. An adjustment factor of 0.5 was applied to the Roadway Screening Analysis Calculator results. The adjusted predicted cancer risk was then adjusted using a factor of 1.3744 to account for new OEHHA guidance (see discussion above regarding cancer risk calculation methodology in 2Available at http://www.baaqmd.gov/Divisions/Planning-and-Research/CEQA-GUIDELINES/Tools-and-Methodology.aspx 3 Comprised mostly of light- and medium-duty vehicles. 8.A. - Page 88