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The subject property has well and septic system records dating back to 1963. The existing septic system for the residence located in Parcel Two of the included Tentative Map has its latest records dating back to 1976 when a 70 foot leach line and a 33 inch diameter drain pit were added as a repair measure. Prior to this repair,a seepage pit with a diameter of 46 inches at a depth of 25 feet were the means of disposal. The earliest record of a septic system notes the addition of a single 100 foot long leach line,but no records indicate a septic tank size,age or the type of septic system. The residence located in Parcel One of the above mentioned Tentative Map was built in 2017. The online records from San Joaquin County reference said Parcel One has a septic tank with a capacity of 1,200 gallons composed of two compartments. The septic system includes three leach lines each with a forty foot length. The septic system is approximately seventy-five feet from the property line and more than one-hundred feet from the well. The on-site wastewater treatment system permit also calls out as the system having three seepage pits, thirty-six inches diameter at a depth of twenty five feet. This permit had a final inspection date of July 14, 2017. There are no records of any repairs to this system. The system has been in constant usage for a primary residence,therefore confirming the installed system is functioning properly. 5.4 Discussion of all proposed future on-site sources of nitrate to soil and groundwater and the contribution of nitrate load from these sources to the project site: The future use of the site, if the rezone is approved, will continue to be residential. The existing lot would be divided into two equal lots, with each lot containing 5 acres. The project 10 acres will be used for rural residential purposes. For residential use,the approximate flow rate that is expected to be generated is between 100 gallons per person per day (San Joaquin County Standards). Calculating the site's nitrate loads, a conservative value of 100 gallons per person per day was used. This method is conservative as it does not include lateral dispersion or mixing of groundwater. The residential homes both contain 3 bedrooms. The residential dwelling is assuming 3.5 people per dwelling at 100 gal/day/person for an approximate generated flow rate of 350 gals/day. The average total nitrogen concentration of domestic wastewater is about 20-85 mg/L-N, although 35-45 mg/L-N is a better approximation(Crites and Tchnobanglous). The value selected for this site was 35 mg/L-N. The site will experience a process of denitrification as the soil naturally treats surface material through natural forms. Denitrification is a process that occurs when bacteria uses oxygen in the nitrate (NO3)and release nitrogen(N2) into the atmosphere. Denitrification can be variable to the type of soils,chemical properties,moisture content and other variables. Based on the sandy loams on site and the high percolation rates,this site's soil has low levels of denitrification. It is expected that a site with soil of these characteristics shall have approximately about 10-15% of denitrification. The value used for this site was 15%. 5.5 Calculate mass balance of nitrogen loading considering all potential sources identified using Hantzsche/Finnemore equation: Using the data mentioned within this report and the attached Soil Suitability Report the mass balance of nitrogen loading for this site was calculated,this was done using Hantzsche/Finnemore formula. Based on the Hantzsche/Finnemore equation each 5-acre parcel would contain a Nitrate Load (Nc) of 7.01 mg/L-N for a flow of 350 gal/day. Each parcel would be able to sustain flow 5