SU0006343 SSNL - Laserfiche WebLink

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r777ounding Analyses of the water table underlying the proposed disposal area location was calculated for this project. • Depth to groundwater was measured both in the sounding of the domestic well and in a backhoe test pit. Standing water in the well was measured at three feet below the top of the well casing, and at 4.5 feet below grade in the backhoe test pit. In compliance with EHD requirements,nitrate and the agrichemical dibromochloropropane(DBCP)was analyzed, in addition to chloride and total alkalinity. • From the Site Plan prepared by Mr. Paul Bagha,P.E. it has been determined that the primary disposal area and the required 100%reserve/replacement/addition areas may have to be enlarged and/or reorientated to serve both Phase I and Phase II of the project. • Although ultimate wastewater flow volumes emanating from the completed project are unknown, average daily flow(ADF)volumes were formulated for both Phase I and Phase II using all available parameters acceptable to EHD. Average daily flow volumes of domestic sewage are expected to be comparatively small. However, since there will be a kitchen associated with the Temple,the wastewater is anticipated to potentially possess a comparatively higher strength. In summary,the soils testing and investigation has found the indigenous soils under the proposed domestic wastewater disposal area to contain a predominately fine-grained clay material with acceptable infiltration and percolation capabilities. Infiltration test results indicate the surface soils where the native soil-effluent interface elevation is anticipated possesses greater infiltration capacity than what is commonly perceived to be in this locale. Although the test results show acceptable permeability, long-term acceptance rates of wastewater effluent by the indigenous soils can be positively assumed to decrease substantially over time. This premise is based on the number of septic system failures that have occurred,particularly those witnessed by EHD in the Larch-Clover area of Tracy. The water table underlying the proposed disposal area has been impacted with nitrate to more than double the Maximum Contaminant Level. Calculations show that the percolating effluent will produce a dilution effect to the current nitrate concentration in the water table. II, SOIL SUITABILITY STUDY FINDINGS A. SUBJECT PROPERTY AND SURROUNDING STUDY AREA INFORMATION ' 1 SSS§ 1.1. Surrounding land use to the north is rural residential with agricultural production north of the Larch-Clover area. To the east and west contains the referenced Larch-Clover area of Tracy,and Interstate 205 is directly south of the southern property line. a use referenced is illustrated on the San Joaquin County Parcel Viewer Maps. The property is zone R-L, Lo Density Residential. SSS§3.1,3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 6.8. App ications on microfiche file with the EHD reveal that # there have been in excess of 25 permits issued for repairs/replacements/additions to existing systems on Clover Road exclusively. Not all of these permits are found in this Report due to the sheer number of permits. The first three permits encountered in the microfiche files are attached, in, accordance with the request of the Unit II Program Manager. The Larch-Clover area has always had a significantly high number of repair permits due to the clayey soil and shallow groundwater, and may also be due to inadequate systems originally installed. I 2 Chesney Consulting