ARCHIVED REPORTS_XR0006266 - Laserfiche WebLink

Home Browse Search

i i .4 N U MAI 0 92005 ' ' FIELD METHODS AND PROCEDURE s1H The following section describes field procedures that are to be used by ENSR personnel in the performance of the tasks involved with this protect 1 HEALTH AND SAFETY PLAN ' Fieldwork performed by ENSR and ENSR's subcontractors at the site will be conducted according to guidelines established in a Health and Safety Plan (HASP) The HASP is a ' document that describes the hazards that may be encountered in the field and specifies protective equipment, work procedures and emergency information A copy of the HASP ' will be at the site and available for reference by appropriate parties during work at the site 2 GROUNDWATER DEPTH ASSESSMENT ' A water/product interface probe is used to assess the liquid-phase hydrocarbons (LPH) thickness, if present, and a water level indicator is used to measure the groundwater depth in monitoring wells that do not contain LPH Depth to groundwater or LPH is measured from a ' datum point at the top of each monitoring well casing The datum point is typically a notch out in the north side of the casing edge If a water level indicator is used, the tip is subjectively analyzed for LPH sheen 3 SUBJECTIVE ANALYSIS OF GROUNDWATER Prior to purging, a water sample is collected from the monitoring well for subjective assessment The sample is retrieved by gently lowering a clean, disposable bailer to ' approximately one-half the bailer length past the air/liquid interface The bailer is then retrieved and the sample contained within the bailer is examined for floating LPH and the ' appearance of a LPH sheen 4 MONITORING WELL SAMPLING Monitoring wells are purged using a pump or bailer until pH, temperature and conductivity of fthe purge water has stabilized and a minimum of three well volumes of water has been removed The purge water is placed in 55-gallon drums and temporarily stored on-site pending evaluation of disposal options If three well volumes cannot be removed in one-half • an hour's time, the well is allowed to recharge to 80 percent of original level After recharging, ' a groundwater sample is then removed from each of the wells using a pump or disposable