Laserfiche WebLink
Soil Suitability/ Nitrate Loading Study <br /> Schuler Property : Tracy, California Irerracon <br /> May 30, 2019 Terracon Project No. NA197026 <br /> processes within the soil. Based on the presence of silty sandy soils and relatively fast <br /> permeability, there is a potential contaminants may affect groundwater. <br /> 2.2 Groundwater Analysis <br /> 2.2.1 Regional Groundwater <br /> A discussion of regional groundwater, including depth to groundwater and flow gradient is <br /> included in Section 1.4.1. No significant seasonal trends were evident from the sources <br /> consulted. <br /> 2.2.2 Potential Ground Water Contamination Issues <br /> A discussion of issues related to potential groundwater contamination is included in Section 1.4.2. <br /> 2.2.3 Current and Future On-Site Ground Water Uses <br /> As noted in Section 1.4.3., Nitrate as N was reported at 15.0 mg/L in groundwater sample GW-1 <br /> above the MCL of 10 mg/L N. Groundwater sample GW-2 reported below laboratory reporting <br /> limits of 0.010 micrograms per liter(ug/L)for DBCP. The development of an additional residence <br /> and septic system may further increase nitrates in groundwater. <br /> 2.3 Sources and Impact of Nitrate to Groundwater <br /> 2.3.1 Current Off-Site Sources of Nitrate <br /> Agriculture and septic systems in the area may be the most significant sources of nitrate in <br /> groundwater. Septic tank use in the vicinity is discussed in Section 1.3.4. <br /> 2.3.2 Contribution of Rainfall <br /> An estimate of the quantity and quality of rainfall was required for the nitrate loading analysis. <br /> Average precipitation and potential evapotranspiration data was obtained from the California <br /> Irrigation Management Information System (CIMIS)from the Tracy(167)station. The estimate of <br /> deep percolation of rain is based on the average monthly precipitation of rain fall and <br /> evapotranspiration for San Joaquin County, California. The estimate first determines whether the <br /> average monthly precipitation exceeds average monthly potential evapotranspiration. If so, then <br /> the difference is potential deep percolation. This method does not consider runoff, although due <br /> relatively flat nature of the site runoff should be minimal. <br /> Responsive ■ Resourceful ■ Reliable 13 <br />