Laserfiche WebLink
MacArthur Project Modification --- Santa Ana - Air Quality Assessment <br />KPC Environmental, Inc., <br />The analysis for the proposed project assumed a schedule for the construction and <br />estimated the project completion in 12- months. Increasing the construction timeline <br />would allow for each task in the construction of the buildings to be completed over a <br />greater timeline which in some cases such as grading /excavation and coatings would <br />decrease the estimated emissions presented in this analysis. This analysis is presenting a <br />"worst- case" construction scenario using a compressed construction schedule to present <br />the construction emissions at the highest anticipated. levels. <br />5.1.1 Mass Grading/Parking Structure Excavation Emissions <br />The proposed project site will require mass grading /excavation to prepare the site for <br />construction. Mass Grading estimates In this assessment are based on a default <br />URBEMIS scenario with PM 10 levels at 20 lbslacrelday utilizing 5- pieces of heavy <br />equipment including 2- excavators, 1- grader, 1 rubber tired dozer, 1 <br />tractorslloaderslbackhoes, and 1 -other (ICE) equipment over a period of approximately <br />40 active work days. Estimated emissions during grading/excavation included export of <br />approximately 200,000 cubic yards of soil from the excavation using 20 -cubic yard dump <br />trucks traveling 1,000 vehicle miles per day. <br />Mitigation measure (Best Management Practice) of watering site 2 -times per day was <br />used for PM 10 & PM2.5. No mitigation or BMP's were used in the URBEMIS model for <br />other emissions constituents. <br />Table 5 -1 Mass Grading /Excavation <br />Pollutant <br />Unmitigated <br />(lbslday) <br />Mitigated <br />(lbslday) <br />SCAQMD <br />Threshold <br />ROG <br />8.36 <br />8.36 <br />75 <br />NDx <br />78.53 <br />78.53 <br />100 <br />CO <br />40.07 <br />40.07 <br />550 <br />PM 10 <br />23.89 <br />15.20 <br />150 <br />S02 <br />0.04 <br />0.04 <br />150 <br />PM 2.5 <br />7.66 <br />5.85 <br />55 <br />CO2 <br />9.797.61 <br />9.797.61 <br />NIA <br />Bold- underline indicates exceedance of SCAQMD Threshold. <br />02/02/11 13 <br />