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6.2.5 Surveying of Deep SVE Wells and Groundwater Monitoring Well <br /> Following completion of drilling and completion of the SVE wells and single groundwater <br /> monitoring well the northing and easting horizontal coordinates, ground surface elevation, and <br /> top of casing (TOC) elevations will be surveyed by a Certified Engineering Geologist. <br /> Horizontal coordinates will be reported in California State Plane Zone 2, (NAD83) and will be <br /> based on a minimum of two local survey monuments. The vertical control of the elevations will <br /> be related to the NVGD29 and referenced to the City of Lodi bench marks and published by the <br /> City of Lodi Department of Public Works. <br /> 6.2.6 Groundwater Monitoring Well Sampling Procedures <br /> Groundwater at the newly installed monitoring well will be monitored and sampled no sooner than <br /> 24 hours after development of the well. Depth to groundwater will be measured from the top of <br /> casing (TOC) to the nearest 0.01-foot using a Solinst water level meter. The monitoring well will <br /> be sampled using low-flow purging and sampling techniques. A bailer will be slowly lowered to a <br /> depth approximately at the bottom of the wellbore to collect a representative water sample within <br /> the casing. Water will be purged from the wellbore using a bailer at least three well volumes will <br /> be removed prior to sampling. <br /> Periodically during purging the pH, temperature, and electrical conductivity parameters will be <br /> measured. Groundwater will be considered stabilized and representative of the aquifer when three <br /> consecutive measurements are within=1:0.1 for pH,f 3%for electrical conductivity, and± 10%for <br /> temperature. <br /> After purging, a groundwater sample will be collected with a bailer into four 40-milliliter VOA <br /> vials. Care will be taken to verify that headspace or bubbles do not exist and each VOA vial will be <br /> sealed using a Teflon®-lined lid. The samples will be labeled and placed in an iced cooler <br /> maintained at 4° Centigrade, and accompanied with a chain- of-custody document for transport to <br /> the analytical laboratory. <br /> M ain\D:AEnvironmentaI\LN CV\10152007.wpd 39 <br />