Laserfiche WebLink
TABLE 4 <br /> PRECIPITATION AND ETo DATA FOR MANTECA CIMIS STATION#70 <br /> I <br /> Month Monthly Precipitation ETo Average Potential Deep <br /> (Avg.2015-2019) (Avg.2015-2019) Percolation(in/mo) <br /> (in/mo) (in/day) <br /> January 2.65 1.12 0.04 1.53 <br /> February 1.12 2.11 0.08 -- <br /> March 1.79 3.55 0.12 -- <br /> April 1.43 4.28 0.14 -- <br /> May 0.49 6.67 0.22 -- <br /> June 0.18 7.87 0.26 -- <br /> July 0.00 8.26 0.27 -- <br /> August 0.01 7.12 0.23 -- <br /> September 0.06 5.23 0.17 -- <br /> October 0.56 3.67 0.12 -- <br /> November 1.44 1.88 0.06 -- <br /> December 1.95 1.28 0.06 0.67 <br /> TOTALS(in.) 1 11.68 53.0 ------ 2.21 <br /> The Table illustrates that evapotranspiration far exceeds precipitation. Only in the months of <br /> December and January would deep percolation potentially occur. This data illustrates a relatively <br /> high potential for there to be significant evapotranspiration from my wastewater disposal system <br /> design that takes advantage of evapotranspiration during the favorable months of March through <br /> October. <br /> III. NITRATE LOADING STUDY FINDINGS <br /> A. WASTEWATER FLOW VOLUME PROJECTIONS AND CHARACTERISTICS <br /> Wastewater Flow Volume Projections <br /> To determine nitrate-nitrogen loading from any project, wastewater flow volumes must be <br /> determined as accurately as possible. Domestic flow volume projections are typically approximated <br /> from the USEPA Onsite Wastewater Treatment Systems Manual, Pg. 3-4. <br /> However, the EHD now specifies residential (domestic) flow volumes to average 75 <br /> gallons/person/day. As referenced, the existing house has three bedrooms and the proposed second <br /> unit dwelling will also have three bedrooms. Therefore, total flow volume projection= 6 bedrooms <br /> i <br /> x 75 gals ADF =450 gallons wastewater/day for the entire project. <br /> Page -6- <br /> Chesney Consulting <br />