SU0005874 SSNL - Laserfiche WebLink

Home Browse Search

February 15, 2006 NOA Project Number: E06006A Based on this method, an estimate for the deep percolation of rain for the Site is 11.68'inches. The deep percolation of rain is based on 90 percent of the long-term average total rain fall for the Manteca area (www.cimis.wate_r.ca.gov): 12.98 inches x 0.9 11.68 inches. The nitrate concentration of rainfall was estimated to be Img/L-N (Har tzsche and Finnemore, 1992). 3.3 -Current On-Site Sources of Nitrate Current on-site sources of nitrate include domestic waste water from the existing three-bedroom residence, domestic waste water from a potential second dwelling unit that could be placed on the property, and rainfall. 3.3.1 Existing Septic System Based on permits reviewed at the EHD (Section 3.5 of the SSS), two residential septic systems exist on the'Site; only one is currently in use.` 3.3.2 'Agricultural Contribution - No agricultural contribution was considered since the Site is not used for agriculture, according to Ms. Del Rio. 3.4 Future On-Site Sources of Nitrate 3.4.1 Quantity and Quality of Domestic Wastewater From Proposed Project The following discussion is for determining the long-term waste water flow generated from the proposed agricultural store for the nitrate loading analysis and.should not be used for septic system design purposes. Typically; use estimates for the sizing of septic systems include a peak use factor, whereas the numbers discussed here are based on long-term averages. According to project information on file at the San Joaquin County Planning Department, employees at the proposed agricultural store will work in two:shifts, the first from 7:00 to 3:30 five days per week, and the second from 10:00 to 8:00 seven days per week. Two employees will work eachshift. An estimated 30 customers.per shift are anticipated. The existing three-bedroom residence has the potential to be occupied by up to four people over the long term. A second dwelling unit,which could be constructed on the parcel, could be occupied by up to three people. Therefore, a total of seven people will be used to calculate the residential septic tank usage. The estimated.sewage flow rates for use categories are available from a number of references. The uses presented below were guided by the San Joaquin County On-Site Wastewater Disposal Standards (2003), Crites and Tchobanoglous (1998),-and EPA (1980). The text from Crites and