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I. INTRODUCTION Presented herein, are the results of our soil and groundwater study for the proposed Southwinds Church of Tracy project. This project is currently in the early stages of planning, and this investigation was a requirement imposed by the San Joaquin County Department of Environmental Health. San Joaquin County Ordinances, specifically Section 9-1105.2D stipulates that a Nitrate Loading Study be conducted when significant nitrogen loading may take place from a project in unsewered areas. _ The purpose of this investigation was to quantify the potential for environmental degradation from nitrate contamination of the underlying groundwater and to assess the viability of the proposed traditional septic system. Additionally, alternate treatment methodologies for on-site wastewater treatment are discussed. Our investigation includes historical agricultural considerations, on-site soil physical testing and chemical analyses, groundwater sampling and testing, surface water information, wastewater loading projections, septic system designs, and potential nitrate loading for the project. Nitrates are one of the most problematic and widespread of the vast number of groundwater contaminants. The concentration of nitrates in groundwater is of primary concern because of the possible human and animal health effects from excessive nitrate consumption. In human infants, excess nitrate can cause methemoglobinemia or"blue-baby" syndrome. In ruminants, abortion may be induced. It is important to recognize that not only is the issue of nitrate and nitrogen contamination highly r complex within the environment, the method in which nitrate is analyzed and reported can be equally confusing. Nitrate test results can be expressed as either nitrate-nitrogen (NO3-N) or as _ nitrate(NO). The drinking water standard (Maximum Contaminant Level, MCL) in the U.S. is 10 milligrams per liter (mg/1) for nitrate-nitrogen, or 45 mg/1 for nitrate. Drinking water is normally expressed in terms of nitrate. In summary, our findings confirm the on-site soils consist of a high clay content soil with low infiltration and percolation capabilities. The groundwater is comparatively high, which is characteristic of this locale. High clay content soil and shallow groundwater can adversely affect the proper operation of septic systems. 2 Naffey ly-1koearck