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February 2,2006 <br /> NOA Project Number: E05058B <br /> 3.4 Future On-Site Sources of Nitrate <br /> 3.4.1 Quantity and Quality ofDomestic Wastewater From Proposed Project <br /> The following discussion is for determining the long-term waste water flow generated from the <br /> proposed residences for the nitrate loading analysis and should not be used for septic system design <br /> purposes. Typically,use estimates for the sizing of septic systems include a peak use factor,whereas <br /> the numbers discussed here are based on long-term averages. <br /> For the purposes of the NLS,we will assume that a three bedroom home could be built on each <br /> parcel.A three bedroom house is presumed to be occupied by up to four people over the long term. <br /> A second dwelling unit, occupied by a potential three people, could be placed on the lot as well. <br /> Therefore,a total of seven people per parcel will be used to calculate the residential septic tank <br /> usage for each of the vacant parcels. <br /> The estimated sewage flow rates for use categories are available from a number of references. The <br /> uses presented below were guided by the San Joaquin County On-Site Wastewater Disposal Standards <br /> (2003),Crites and Tchobanoglous (1998),and EPA (1980). The San Joaquin County On-Site <br /> Wastewater Disposal Standards does not provide a flow rate for residential use. The San Joaquin <br /> County On-Site Wastewater Disposal Standards are based 9nA e 1963 Manual of Septic Tank Practice. <br /> The text from Crites and Tchobanoglous (1998)�(Table 4-24dicates that the typical residential use <br /> rate is7 ons per day. The EPA (1980) Design-Manual (Table 4-6) indicates the typical use rate <br /> is 45 gallo s per day for a resident. <br /> Since the Crites and Tchobanoglous (1998) information is the most current available, our office <br /> believes it provides the best estimate of waste water flow for the residential category. <br /> The following tables presents the septic waste water uses associated with the Site. The rates <br /> presented from the references provide general guidance but do not always reflect a match in usage. <br /> Careful examination,professional judgement, and experience are necessary to select a reasonable <br /> flow rate estimate. The flow rates selected for the uses associated with this project are presented in <br /> the following table. <br /> 4 "044 <br />