RES 06035 - Laserfiche WebLink

Chapter 4 Environmental Setting, Impacts, and Mitigation Measures C. Air Quality Table 4 Project Regional Emissions in Pounds Per Day Phase II SpecificPlan BAAQM D Significance Threshold Particulates PM,O 37.5 80,0 Source: Donald M. Ballanti, Certified Consulting Meteorologist, December, 2005 Guidelines for the evaluation of project impacts issued by the BAAQMD consider emission increases to be significant ifthey exceed 80 pounds per day for regional pollutants," Project emissions shown in Table 4 would not exceed the criterion for any of the three pollutants, so the project is considered to have a less-than-significant effect on regional air quality, (4) Potential to Expose Sensitive Receptors to Substantial Pollutant Concentration. On the local scale, the project would change traffic on the local street network, changing carbon monoxide levels along roadways used by project traffic, Carbon monoxide is an odorless, colorless, poisonous gas whose primary source in the Bay Area is automobiles, Concentrations of this gas are highest near intersections of major roads, Carbon monoxide concentrations under worst-case meteorological conditions have been predicted for the intersections most impacted by project traffic and/or operating at the lowest Level of Service, PM peak traffic volumes were applied to a screening form of the CALlNE-4 dispersion model to predict maximum l-and 8-hour concentrations near these intersections under the worst-case assumption that project traffic changes would occur in 2006, This is an extremely conservative assumption, as full project buildout is expected to take many years, Appendix C provides a description of the model and a discussion of the methodology and assumptions used in the analysis, The model results were used to predict the maximum 1- and 8-hour concentrations, corresponding to the 1- and 8-hour averaging times specified in the state and federal ambient air quality standards for carbon monoxide, The results of the CALlNE-4 analysis for the peak l-hour and 8-hour traffic periods in parts per million (PPM) are shown in Table S. The l-hour values are to be compared to the federall-hour standard of 35 PPM and the state standard of 20 PPM and the 8-hour values are to be compared to the state and federal standard of 9 PPM, As shown in the table, car- bon monoxide concentrations with existing and approved traffic meet the l-hour and 8-hour standards, Traffic from the proposed project would increase concentrations by up to 0,7 parts per million (PPM), but concentrations would remain below the most stringent state or federal standards, 11 BAAQMD, Air Quality and Uroan Development - Guidelines, 1985, 53