SR0084795_SSNL - Laserfiche WebLink

Home Browse Search

groundwater, directional flow and gradient are referred to in Section 4 of the Soil Suitability Report prepared by Dillon & Murphy that is attached in the Appendix. 4.2 Description/discussion of any existing and/or potential groundwater contamination issues in the general location of the site: Description of existing or potential groundwater contamination issues in the general location of the site are referred to in Section 4.2 of the Soil Suitability Report prepared by Dillon & Murphy that is attached in the Appendix. 4.3 Description of the current use of groundwater at the site and of the future expected use of groundwater as related to the proposed development project: The depth to ground water in this area is approximately 140+ feet according to the map of "Lines of Equal Depth to Groundwater" published Spring, 2018, by the San Joaquin County Flood and Water Conservation District. The gradient descends from east to west. This was verified with the California Department of Water Resource's Water Data Library. The results of the historic depth to ground water show that the relative depth has not changed drastically throughout the years. The proposed improvements will not have a negative effect on the current depth to ground water. See appendix for the site's depth groundwater tables and diagrams. 5.0 SOURCES AND CALCULATED IMPACT OF NITRATE TO GROUNDWATER 5.1 Description of all current off-site sources of nitrate to soil and groundwater in the general tip gradient area and the contribution of nitrate load from these sources to the project site: Current off-site source of nitrate to soil and groundwater in the general up gradient area and the contribution of nitrate loads are agriculture and neighboring sites with septic systems with minimal to no current impact to the site. The neighboring sites are all residential/agricultural with no major sources of pollution that could affect this project site. 5.2 Description of impact of rainfall contribution of nitrate load to the project site: The impact of rainfall contribution on the project site was completed to determine the nitrate load. The average monthly precipitation and evotranspiration are required to calculate the site nitrate load. These two values are used to estimate the deep percolation. The deep percolation is estimated by analyzing the difference between the monthly average precipitation and the evotranspiration, when the evotranspiration exceeds the monthly average precipitation. These calculations are attached in the Appendix. The data for the potential evotranspiration water was obtained from the California Irrigation Management Information System (CIMIS). The project is located within an area designated as Zone 12. Based on the values for this area along with the average monthly precipitation values obtained from the Western regional Climate Center for the Lodi region an estimate of the deep percolation of rain for the project was determined. Station 262 in Liden had the most similar weather and soil conditions to our project site. L