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I. INTRODUCTION This report presents our findings of the Nitrate Loading Study conducted for the subdivision projects referenced as Clements Oakridge Estates. Chesney Consulting was retained by Mr. Wayne Craig of Sandhill Development Company, LLC to complete the studies and soil testi for this project as required by the San Joaquin Coune a eat Department (EHD). Mr. Craig is proposingo evelop the subject propert into 15; approximately 1.5 acre residential lots on approximately 21.2 acres. The project is located at the southern end of the town of Clements and is referenced in the United States Public Land Survey System as Section 22, Township 4 North, Range 8 East. The San Joaquin County Environmental Health Department requires Nitrate Loading Studies for projects in unsewered areas, or for projects which may potentially impact the underlying groundwater with nitrate. This report complies with the San Joaquin County Development Title, Section 9-1105.2 for a"Nitrate Loading Study." Additionally, this proposed project must comply with the Environmental Health Department Sewage Standards, specifically Section 10 - "Requirements for Waste Disposal for New Land Developments." The primary concern of nitrate in drinking water is that high concentrations can cause methemoglobinemia in infants. This disease occurs through a series of complex chemical reactions within the hemoglobin in the blood. Only infants and young children are susceptible. Although this disease is relatively rare, nitrate can also potentially cause other health concerns. There have been scientific studies to suggest that nitrate may produce carcinogenic effects in humans and it can also induce abortion or death in cattle. Nitrate concentrations in water can be expressed in two different terms: 1.) As the weight of the nitrate molecule, which is one atom of nitrogen and three atoms of oxygen for an atomic weight of 62 units. Or, 2.) Nitrate can be expressed as the amount of the nitrogen atom itself. This one atom of nitrogen (N) in a nitrate molecule contributes 14 atomic weight units to the weight of the nitrate molecule. The ratio of weight of the nitrate molecule (NO3) to the atom (N) is 62114 or approximately 4.5. The U.S.E.P.A. has established the Maximum Contaminant Level (MCL) of nitrate in drinking water at 45 mg/l as nitrate. Due to the ratio described above, the MCL is sometimes reported as 10 mg/l as nitrate-nitrogen. The town of Clements does not have a Publicly Owned Treatment Works (POTW) sewer system; therefore, the entire town and surrounding residential and commercial properties are on septic systems, scientifically referred to as decentralized subsurface wastewater infiltration systems (SWIS). Our Study documents that the deep aquifers under the subject property that the Clements Oakridge -- --�-- Estates development will be drawingfrom resentl have not been.im acted b nitrate from surrounding on-site septic sstems or agricultural fertilizer inputs. Page -I- Chesney Consulting