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1. INTRODUCTION This report presents the results of our studies and investigations of the soil and groundwater under the proposed St. Bernard's Catholic Church Complex. Physical and analytical test results from the surface and subsurface soils, and analytical testing of the underlying groundwater and comparable septic tank effluent, have produced data for the preliminary wastewater disposal system design criteria for the project. The San Joaquin County Environmental Health Department(EHD) requires Soil Suitability and Nitrate Loading Studies with corresponding septic system design criteria under Community Development Title 9-1105.2 (d) for projects in unsewered areas, in areas currently impacted with nitrate, or for projects that may adversely affect the underlying groundwater with nitrate. The EHD has been at the forefront of nitrate impact investigations and promoting the prevention or mitigation of environmental contamination from various sources of nitrate, particularly septic systems. A summary of the findings of these studies reveal that 1.)The surface soils to two feet are highly fractured and initially accept large volumes of water until they become saturated and seal over, 2.) Subsurface soils from two to three feet are dense and compact,probably due to tillage compaction, and impermeable under saturated conditions, 3.) Soils below three feet are permeable, 4.) Significant clayey gravel strata exist below 12 feet and extend to the water table, and 5.) There has been nitrate impact to the groundwater table under the subject property, which may be attributed to past agricultural production, along with natural influences under and upgradient to the property. Subject Site and Surrounding Area Description The project is in an area referred to as the South Schulte Specific Plan, which is currently adjacent to the Tracy City limits. This area is anticipated to be annexed to the City at some time in the future. Consequently,this project is currently considered a San Joaquin County project. The subject property is in the southwest corner of Valpico Road and Corral Hollow Road. Low density rural residential housing exists around the property,with a higher density housing on the east side of Corral Hollow Road. The Church of Latter-day Saints is located one-eighth mile to the west of the subject property. History of the Property and Surrounding Area The subject property has been in agricultural production for the past number of decades. Crops grown in this locale include row, grain and tree crops. The 1971 USDA aerial photo map appears to show the property to be in a grain crop. The history of the property and surrounding land use is important in explaining the environmental conditions within the soil and underlying groundwater. Before irrigation, the parcel and entire region were dry-land farmed. Plainview Irrigation District has supplied irrigation water to the subject parcel since 1951. Furrow irrigation was the water conveyance method over the parcel, which was done for row crops until the time the property was acquired by St. Bernard's Church. A tailwater basin was excavated next to the south side of Valpico Road to receive excess irrigation water flowing in a northward direction. Page -2- Chesney Consulting