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FIELD METHODS AND PROCEDURES <br /> i <br />' The following section describes field procedures that are to be used by ENSR personnel in <br /> the performance of the tasks involved with this project <br />' 9 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 HASP <br />' will be at the site and available for reference by appropriate parties during work at the site <br />' 2 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 in <br /> monitoring wells that do not contain LPH Depth to groundwater or LPH is measured from a <br /> datum point at the top of each monitoring well casing The datum point is typically a notch cut <br /> in the north side of the casing edge If a water level indicator is used, the tip is subjectively <br /> analyzed for LPH sheen <br /> 3 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 /> 4 MONITORING WELL SAMPLING <br /> Monitoring wells are purged using a pump or bailer until pH, temperature and conductivity of <br /> 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 one-half <br /> an hour's time, the well is allowed to recharge to 80 percent of original level After recharging, <br /> a groundwater sample is then removed from each of the wells using a pump or disposable <br />