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Soil Suitability /Nitrate Loading Study Irerracon <br />Munsch Property e Lodi, California <br />January 7, 2022 ■ Terracon Project No. NA217092 <br />1.6.5 Percolation Test Procedure <br />Percolation tests were conducted for the borings on December 21, 2021 in accordance with the <br />requirements of the San Joaquin County EHD. Each percolation test had a duration of four hours. <br />The last half an hour of the test was observed by Mr. Francisco Ruiz from the EHD. Measurement <br />of the water level during the percolation tests was from a fixed reference point on the PVC casing <br />using a calibrated Solinst electric water level detector with a depth accuracy of 0.01 feet. All <br />tabulated values on the field data sheet (Appendix E) are in decimal feet. After water drop was <br />observed, the holes were checked and refilled as necessary to maintain approximately 0.5 feet <br />(6 inches) of water above the top of gravel. The readings were recorded every 30 minutes for a <br />period of four (4) hours." <br />1.6.6 Percolation Test Forms and Results <br />A shallow percolation test is defined by the EHD as being between 36 and 42 inches in depth. <br />While a deep percolation test is defined by the EHD as being between 42 inches and 25 feet in <br />depth. The shallow percolation test must demonstrate a satisfactory percolation rate of less than <br />or equal to 60 minutes per inch drop in water level within the existing septic system disposal field <br />of a parcel to utilize a standard septic system and 30 minutes per inch or less for septic pits. <br />Details of the percolation tests are summarized in the table below. <br />Table 6. <br />Summary of Percolation Test. <br />Test No. <br />Percolation Test <br />Percolation Rate <br />Test Duration <br />Comments <br />Date Tested <br />Depth feet <br />min/in <br />hours <br />see note <br />Pi <br />Satisfactory <br />12-21-2021 <br />3 <br />27'7 <br />4 <br />Percolation Rate <br />P2 <br />Satisfactory <br />12-21-2021 <br />3.5 <br />50 <br />4 <br />Percolation Rate <br />P3 <br />Satisfactory <br />12-21-2021 <br />8.0 <br />6.58 <br />4 <br />Percolation Test <br />Note: H satistactory percolation rate IS bu minutes per Incn or Tess Tor snallow leacn uneS ano 6u minutes per Incn or IesS Tor <br />seepage pits per San Joaquin County Onsite Wastewater Treatment Systems Standards (EHD 42-014), January 2017. <br />1.6.7 Discussion of Percolation Test Results <br />Based on the percolation tests results, percolation test borings at P1-3 feet bgs demonstrated a <br />satisfactory percolation rate for standard shallow leach lines. Likewise, percolation test P2-3.5 <br />feet demonstrated a satisfactory percolation rate for shallow leach lines. P3-8.0 feet demonstrated <br />a satisfactory percolation rate for deep seepage pits or sumps. Table 1. 10.2 of the OWTS manual <br />indicates a minimum 8 -foot soil depth is needed from the bottom of the seepage pit or sump to <br />groundwater. <br />Responsive ■ Resourceful ■ Reliable 11 <br />