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URS Greiner Woodward1 <br /> C yde <br /> I <br /> Ms, Carol Oz, R.E.H.S.- Page 3 <br /> LOP/Site Mitigation Unit <br /> San Joaquin County—Public Health Services <br /> Environmental Health Division <br /> March 13,2000 <br /> The equipment used in the drilling of the wells will be thoroughly cleaned using a high temperature,high pressure <br /> steam cleaner before commencing work and between each borehole. The waste water generated during the <br /> equipment cleaning will be stored in labeled 55-gallon DOT- approved steel drums pending disposal. <br /> A summary of the well installation activities will be included as part of the first quarterly groundwater monitoring <br /> report prepared for the Site. <br /> Following well installation the groundwater monitoring wells will be surveyed to a common datum by a <br /> professional land surveyor. Horizontal locations and vertical elevation for each well will be recorded to an <br /> accuracy of 0.01 feet. <br /> A summary of the well installation activities, surveying, and well construction specifications will be included as <br /> part of the first quarterly groundwater monitoring report prepared for the Site. <br /> Groundwater Monitoring Well.Development <br /> F <br /> A minimum of 72 hours following monitoring well installation the wells will be developed by purging <br /> approximately 10 well casing volumes of water from each well. During well development, temperature, pH, <br /> specific conductivity and turbidity will be monitored to evaluate development results. Well development will be <br /> stopped prior to removing 10 well casing volumes of water'if the monitored readings have stabilized (three <br /> consecutive readings with less than 10% fluctuation). <br /> Quarterly Groundwater Monitoring Well Sampling and Report Preparation <br /> The three newly installed groundwater monitoring wells will be sampled on a quarterly basis for two quarters to <br /> assess the lateral extent of the impacted groundwater at the Site. The groundwater monitoring activities at the <br /> Site will be conducted as follows. <br /> .Prior to approaching each well, VOC field measurements will,be taken from the well head area, inside of the <br /> vault,and inside the well casing. These field measurements will be used in the evaluation of the proper personnel <br /> protection equipment for each well location. Following URSGWC's standard operating procedures for l <br /> groundwater sampling, field personnel will purge and sample wells beginning with those having the least potential <br /> for contamination and proceeded to wells having a greaterpotential for contamination. F <br /> Before purging,the groundwater level and total depth of each well will be measured to an accuracy of 0.01 feet <br /> to a]mown surveyed point at each well location with an electronic water level indicator. These measurements <br /> will be used to calculate the purging volume for each well and the groundwater gradient and flow direction at the <br /> Site. <br /> I:I l 4214102_Tracyl Workplan.doc <br />