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For the purpose of the nitrate loading analysis, however, a five-bedroom primary residence and a three-bedroom second unit dwelling are considered for each parcel. These are considered so that, should the owners at some point in the future decide to build on the land, nitrate loading will have been addressed. Crites and Tchobanoglous (1998) list a typical flow rate of 50 to 70 gallons per person per day for an individual residence. In the past, San Joaquin County Environmental Health Department has requested that the flow rate be calculated as 140 gallons per bedroom per day to reflect maximum usage. On March 4, 2020, however, Michael Kith of the San Joaquin County Environmental Health Department dictated a new procedure for calculating residential flow, developed in consultation with Norman Hantzsche (author of the 1992 paper discussed previously). He indicated that wastewater flow from a single-family residence should be calculated as 100 gallons per day (gpd) for the first bedroom and 50 gpd for each additional bedroom; additional residences should be calculated in the same manner (personal communication, March 4, 2020). The first theoretical house on each parcel will have five bedrooms, which results in a flow value of 300 gpd using the new method. The second theoretical house will have three bedrooms, which results in a flow value of 200 gpd using the new method. The maximum daily flow for each parcel is thus estimated to be 500 gpd. The modular home on Parcel D has three bedrooms, and the older home will be demolished in the near future (personal communication with Camillo Leventini, May 12, 2021). Without any additional development, the maximum daily flow for Parcel D is thus estimated to be 200 gpd. A typical residential concentration of 35 mg/L of nitrate as N was selected for the existing modular home and theoretical residences (Crites and Tchobanoglous, 1998). The estimated flow values discussed here should not be used for the design and sizing of the septic system. The design and sizing of the septic system should utilize the San Joaquin County Environmental Health Department On-Site Wastewater Treatment Systems Standards, which incorporates peak and surge flow factors. The estimates used in the On-Site Wastewater Treatment Systems Standards may be greater than those discussed here. Denitrification Reductions Denitrification is a process that occurs in the septic system drain field whereby certain bacteria oxidize the nitrate (NO3) in the wastewater and release nitrogen gas (N2) to the atmosphere. Due to the biologic processes in the shallow soils, nitrogen in the drain field may undergo a reduction between 10 percent to 35 percent. Soils with higher clay content, moist soil conditions, high pH, and organic material denitrify by about 35 LOGE 2062 Page 13