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Stockton Verde Mobile Home Park, LLC - 2 - 27 April 2021 <br /> Stockton Verde Mobile Home Park WWTF <br /> (MRP) 2014-0153-DWQ-R5356. The Discharger is responsible for all the applicable <br /> requirements that exist in the General Order and this NOA. <br /> FACILITY AND DISCHARGE DESCRIPTION <br /> The Facility is located at 4900 N. Highway 99 in Stockton, San Joaquin County as <br /> shown on Attachment A, which is attached hereto (Assessor Parcel Number 087-040- <br /> 150-000). The Facility is located in an area without a regional wastewater collection <br /> system; therefore, wastewater is collected and treated on-site. The site plan is shown <br /> on Attachment B, which is attached hereto and is made part of this NOA by reference. <br /> The WWTF was recently constructed, replacing an old treatment system permitted <br /> through San Joaquin County. The new system is not yet operational and is expected to <br /> be operating by May 2021. The new system consists of a gravity collection system, a lift <br /> station (LS-2), and an extended aeration treatment system. Average daily influent flow <br /> is 23,000 gallons per day (gpd) with peak flows up to 28,000 gpd. Raw wastewater <br /> flows into the LS-2 via gravity and is pumped through a screen prior to entering the <br /> treatment plant. <br /> The new WWTF has a design capacity of 35,000 gpd and is comprised of a biological <br /> nutrient removal (BNR) treatment system with membrane bio-reactors (MBRs), a sludge <br /> press, and a backup generator. The biological treatment system consists of anoxic, <br /> aerobic, and MBRs, as shown on Attachment B. The MBRs serve as physical <br /> separators and secondary clarifiers while providing the anoxic bioreactors with highly <br /> concentrated nitrified mixed liquor (ML). A portion of this ML is waste activated sludge <br /> (WAS) and a portion will be recycled back to the anoxic basin. The wastewater will be <br /> disinfected with a UV system and then pumped directly to the discharge point for <br /> subsurface disposal. Expected effluent quality is summarized below. <br /> Table 1. Effluent Quality <br /> Constituent Influent Concentrations Effluent Concentrations <br /> (mg/L) (mg/L) <br /> BOD5 300 2 <br /> TSS 400 1 <br /> Nitrate not available 0 <br /> Total Nitrogen 60 2.1 <br /> WAS will be pumped from the MBR tank to a screw press for processing, and the <br /> resulting dry cake will be hauled to a local landfill for final disposal. <br /> Treated wastewater is discharged to 40 existing dry wells, 18 feet deep and filled with <br /> gravel (the previous system also discharged to these wells). Based on groundwater <br /> monitoring data collected from the neighboring MHP (Shadow Lake MHP), depths to <br /> groundwater range from 72 to 74 feet below ground surface (see Attachment B for well <br /> locations). Analytical data collected from the three monitoring wells indicate <br /> groundwater quality is poor with respect to nitrate as nitrogen. In groundwater samples <br /> collected in 2017, nitrate as nitrogen concentrations ranged from 13 to 50 milligrams per <br />