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II. SOIL SUITABILITY STUDY SUBJECT SITE AND STUDY AREA BACKGROUND INFORMATION The subject property and surrounding area is zoned AG-40 with the General Plan designation as agriculture. Acreage directly to the northeast was previously used as feedlot operation with one lane of stanchions. The subject parcel is currently used for pasture for horses, a Quonset type building for storage, and a single family residence. To the north of the residence is a bullfighting arena. The actual dairy site has also been used for pasture. The topography of the future dairy site is flat; therefore, it will not be necessary to accommodate slopes in the septic system design. The fall of the dairy site parcel was originally to the south, however, it has been graded to now fall to the north where the holding pond will be located. The surrounding study area is predominately agricultural production, primarily dairies. Pasture (alfalfa), rice, row and orchard crop are also found within the study area. The surrounding housing to the south of the property is low density, single family ranchettes on five(+) acre parcels. The new dairy facility will contain septic systems for the Borba's residence, two farm worker residences and a bathroom in the milk barn. It can be assumed that City of Escalon water and sewer will not be installed in this area for decades, if ever. A review of Application Permits on file at the San Joaquin County Environmental Health Department reveals there have been 5 Applications for Repairs/Additions in the one-mile diameter study area. Most of these applications for system modifications were for additional drainage to existing systems,primarily as seepage pits or sumps. This number of repair applications can be considered upper medium for the study area, thus indicating the surface soils are not overly conducive for shallow effluent percolation. SOIL PROFILE AND PERCOLATION TESTING Due to indigenous surface and subsurface clay soil properties, it was decided to proceed with the soil profiling and percolation testing by using a backhoe. The backhoe test pit provides greater evaluation of the soil characteristics than with an augered boring. In addition to strata delineation, a backhoe trench pump-in test was done in lieu of the traditional eight-inch diameter augered boring. Since there will be seepage pits or sumps installed for effluent management, the trench pump-in test is more indicative of predicting percolation under anticipated design conditions. The attached Log of Boring illustrates the surface and subsurface soil characteristics under the facility. The soil type from existing grade to two feet consists of a silty clay (ML-CL). From 2.5 feet to 5.5 feet exists a severe cemented silts/clays hardpan which is prevalent throughout much of the Escalon area. The underlying soil types continue to consist primarily of silts and clays until 18 feet below grade where a black/white fine-to-medium sand with some silt(SM-SP) is encountered. The test pit was excavated another two feet through this sand stratum to a terminated depth of 20 ft. 2 Vaffey Ag Pfsearck