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r7 INTRODUCTION Chad and Jennifer DeJong are proposing to install a modular(manufactured) four bedroom home on property they own, as referenced on the Title Page. This proposed modular home will be considered the primary dwelling structure on the subject property. The San Joaquin County Environmental Health Department(EHD)required a Soil Suitability Study and Nitrate Loading Study for this project, and all projects where exceedance of nitrate loading standards may occur. These Studies were completed by the engineering geology firm of Petralogix on September 19, 2019, and an Addendum to the Nitrate Loading Study by Petralogix dated May 19, 2020 (Project No. for all three Reports: 2019-00072). The findings from the Soil Suitability Study indicate the soil underlying the property is suitable for the acceptance of onsite wastewater treatment system(OWTS) effluent because of an acceptable percolation rate of 17.86 minutes per inch(min/in)for a shallow 3.42 ft perc test depth. The Study also noted the groundwater in this locale to be 55 ft and 60 ft below ground surface (bgs) in the Spring and Fall of 2016. The Nitrate Loading Study calculations found the resultant nitrate-nitrogen effluent concentration from this proposed project to be 13.53 ppm nitrate-nitrogen(NO3-N), which is 3.53 ppm over the Maximum Contaminant Level of 10 ppm NO3-N. A May 19, 2020 directive from EHD states in Section 1 a. of this document: "the potential impact of the nitrate to ground water shall be mitigated. OWTS shall utilize supplemental treatment and meet performance requirements in Section 10.9 of Regional Water Quality Control Board OWTS policy(Boards Policy)." Section 1 b. states"that a Registered Civil Engineer shall complete engineering design plan to EHD for approval prior to issuance of building permit." Section 1 c. states that"an annual permit is required. Fee for annual operating permit is due at time of OWTS permit application." Section 1d. References a monitoring program"to monitor the effectiveness of the supplemental treatment system, quarterly sampling of the effluent and under the leachfield is required." The first sampling shall be done six (6)months after the OWTS installation. Sampling results shall be submitted to EHD for review. The EHD may reduce the sampling frequency after one year of sampling." This report provides a Monitoring Program for the design of the OWTS to assure compliance with Section 10.9.1 of the Board's Policy. O.W.T.S. DESIGN - OPERATIONAL COMPONENTS AND PARAMETERS To mitigate the excessive nitrate loading(as calculated) from the proposed OWTS,the following design parameters are presented. Although it is debatable as to whether any OWTS within San Joaquin County falls under Tier 3 - Impaired Areas, Section 10.9 from Tier 3 of the State Water Board 0WTS Policy is referenced. The EHD f6llows the directive from Section 10.9.1 "to meet a 50%reduction in total nitrogen when comparing the 30-day average influent to the 30-day average effluent." The OWTS design also incorporates Section 10.9.2 regarding disposal components"used to enhance vegetative nitrogen uptake, [with] the dispersal system having at least six(6) inches soil cover." Pale -]- Chesney Consulting