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IFIELD METHODS AND PROCEDURES <br /> The following section describes field procedures that are to be used by ENSR personnel <br />' in the performance of the tasks involved with this protect <br />' HEALTH AND SAFETY PLAN <br /> Fieldwork performed by ENSR and ENSR's subcontractors at the site will be conducted <br />' according to guidelines established in a Health and Safety Plan (HASP) The HASP is a <br /> document that describes the hazards that may be encountered in the field and specifies <br />' protective equipment, work procedures and emergency information A copy of the <br /> HASP will be at the site and available for reference by appropriate parties during work at <br />' the site <br />' GROUNDWATER DEPTH ASSESSMENT <br /> A water/product interface probe is used to assess the liquid-phase hydrocarbons (LPH) <br />' thickness, if present, and a water level indicator is used to measure the groundwater depth <br /> in monitoring wells that do not contain LPH Depth to groundwater or LPH is measured <br /> from a datum point at the top of each monitoring well casing The datum point is typically <br /> lie a notch cut in the north side of the casing edge If a water level indicator is used, the tip is <br /> subjectively analyzed for LPH sheen <br /> SUBJECTIVE ANALYSIS OF GROUNDWATER <br />' Prior to purging, a water sample is collected from the monitoring well for subjective <br /> assessment The sample is retrieved by gently lowering a clean, disposable bailer to <br />' approximately one-half the bailer length past the air/liquid interface The bailer is then <br /> retrieved and the sample contained within the bailer is examined for floating LPH and the <br />' appearance of a LPH sheen <br /> MONITORING WELL SAMPLING <br /> Monitoring wells are purged using a pump or bailer until pH, temperature and conductivity <br />' of the purge water has stabilized and a minimum of three well volumes of water has been <br /> removed The purge water is placed in 55-gallon drums and temporarily stored on-site <br /> pending evaluation of disposal options If three well volumes cannot be removed in <br /> one-half an hour's time, the well is allowed to recharge to 80 percent of original level After <br /> recharging, a groundwater sample is then removed from each of the wells using a pump or <br />' disposable bailer The water sample is collected, labeled and handled according to the <br /> 1 <br />