ARCHIVED REPORTS_2010_5 - Laserfiche WebLink

Home Browse Search

site and surrounding areas are located in Zone X which is identified as "Areas Outside 500-Year Floodplain". 4.6.3 Design Storm The 100-year, 24-hour precipitation event is estimated to be 3.9 inches, based on data published by the Department of Water Resources (see WDRs, Appendix A). 4.6.4 Evaporation The mean annual pan evaporation for Lodi measured from 1948 to 2002 was 64.92 inches (Western Regional Climate Center). The mean monthly evaporation ranged between 0.06 inches in December and 10.60 inches in July. These values can be adjusted by multiplying by 0.7 or 0.8 to more closely estimate the evaporation from natural surfaces. 4.6.5 Run-on and Runoff Volume and Pattern The natural topography of the Foothill Landfill area controls run-on onto the site, with the refuse fill generally at a higher elevation than the surrounding soil. In addition, the active fill area is a significant distance from the property boundary, providing area for drainage features to channel water away from the landfill. To control runoff, a perimeter ditch surrounding the landfill directs storm water into various storm water basins, the largest which is on the east side of Module "I" of the site (Figure 2). Overflow of this basin has not occurred to the knowledge of the County. Run-on near the active area is diverted to a sedimentation area located southeast of Module 1 (Figure 2). If this sedimentation area overflows, the water flows overland through grassland to the water pond on landfill property. Water leaving the landfill I property along this route is sampled for National Pollution Discharge Elimination System requirements. Foothill Sanitary Landfill Page 9 of 57 Public Works/Solid Waste Joint Technical Document County of San Joaquin—Revised 7/30/10 i I