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• Groundwater sampling and analysis plan • Health and safety plan 1. Background Information According to the Soil Conservation Service Soil Survey of San Joaquin County, California, the soils at the CFL land application site consist of well-drained sandy loam, clay loam, and clay, with permeabilities ranging from moderately rapid to slow. The soils are formed in alluvium derived from granitic and mixed rock sources, with slopes ranging from 0 to 2 percent. The average annual precipitation is about 15 inches, most of which occurs during the winter months. Contours for depth to groundwater in the Stockton area are presented in Figure 2. As indicated in Figure 2, the gradient is toward the west, with a slight southerly component. According to the data provided in Figure 2,the depth to groundwater in the vicinity of CFL is approximately 70 to 80 ft. However, according to drillers with experience in San Joaquin County,the water table may be closer to 100 ft below ground surface. 2. Proposed Monitoring Well Locations Three monitoring well locations were chosen to provide both background (upgradient) groundwater quality data and compliance groundwater quality data immediately downgradient of the CFL land application area, as well as providing drill rig access and convenient access for sample collection and groundwater level monitoring. The proposed locations are indicated in Figure 3. As shown in Figure 3,the upgradient well will be located at the eastern extremity of the CFL property, while the downgradient wells are located at the western boundary. By comparing the quality of groundwater samples collected from the upgradient and downgradient wells, it will be possible to determine the impact of land application of wastewater at the CFL pasture and orchards. B. DRILLING DETAILS This selection provides a description of the equipment that will be used to construct the monitoring wells, along with associated drilling activities. 1. Drilling Equipment The wells will be drilled using a hollow-stem auger. The drilling contractor will be required to hold a valid Class C-57 California Contractor's License. A permit for installation of the wells will be obtained from the San Joaquin County Environmental Health Department. The borehole will be drilled to a depth of approximately 80 to 100 feet, depending on the depth at which saturated soil conditions are first encountered. The well borehole will be approximately 12 inches in diameter,to allow for adequate space for the gravel pack and well casing. All cuttings will be disposed of by spreading onsite, as directed by CFL. Drilling equipment will be washed at each monitoring well site to Project Workplan 2 SA1433 July 30,2004 n:lsa01433\gwmwiwp\workplan.doc