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9.0 Introduction <br /> On September 20, 1996 groundwater monitoring and sampling was performed at the San Joaquin <br /> ' Catholic Cemetery The site is located approximately one mile north of downtown Stockton, <br /> ' California (Figure 1) <br /> 2.0 Groundwater Gradient <br /> ' Depth-to-groundwater measurements were taken in all five groundwater monitoring wells and <br /> ' two of the four vapor extraction wells (VW-I and VW-2) to evaluate groundwater flow and <br /> gradient characteristics (Figure 2 - Site flan) The depth-to-groundwater at the site ranged from <br /> 50 92 to 51 90 feet below ground surface The elevation of the groundwater surface beneath the <br /> ' site ranged from a high of 33 57 feet below mean sea level (msl) in MW-5 to a low of 33 93 feet <br /> below msl in MW-2 and MW-4 Groundwater levels have dropped an average of 3 65 feet since <br /> the last monitoring event on April 26, 1996 Groundwater monitoring data are summarized in <br /> I <br /> Table 1 <br /> 1 <br /> The groundwater flow direction and gradient are illustrated on the groundwater surface map <br /> (Figure 3) The maximum groundwater gradient was calculated at 0 003 ft/ft in an easterly <br /> direction Groundwater flow and gradient characteristics may be unreliable due to groundwater <br /> ' levels above monitoring well screen intervals <br /> I <br /> I <br /> ' 3.0 Groundwater Sampling and Analyses <br /> In the past, the five on-site monitoring wells have been sampled during quarterly groundwater <br /> ' monitoring Due to the rise in the groundwater surface elevation of approximately 19 06 feet <br /> since May of 1992, the screen intervals of these wells are below the groundwater surface and <br /> ' may not provide an accurate representation of groundwater table conditions In order to collect <br /> groundwater samples representative of groundwater table conditions, only two vapor extraction <br /> ' wells with screen intervals coinciding with the groundwater table (VW-I and VW-2) were <br /> sampled this quarter <br /> Vapor extraction wells VW-1 and VW-2 were purged of at least three well volumes using a <br /> decontaminated Teflon bailer Groundwater Sampling Forms documenting well monitoring, <br /> purging and sampling data are included as Appendix A <br /> 1 <br />