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APPENDIX D. METHODS AND PROCEDURES, QA/QC This Appendix documents the speczfic methods, procedures, and materials used to collect and analyze groundwater samples and monitoring the vapor recovery system Gaugincr and Measursng Monitor Wells Prior to sampling a well, WEGE personnel obtain three measurements : the depth to groundwater (DTW) and the product thickness using a battery powered depth to water-product interface probe and or by using a specially designed bailer. And the vacuum influence at the well head, using a water manometer that is attached to a sample port in the well head The DTW probe is lowered into the well casing until the instrument signals that the top of water has been reached The distance from the top of water to the top of casing is read from the tape that is attached to the probe The tape is calibrated in 0 . 01 foot intervals for accuracy to 0 01 foot The measured distance is subtracted from the established elevation at the top of casing to determine the elevation of groundwater with respect to mean sea level The probe is washed with TSP (Tri Sodium Phosphate) and rinsed in distilled water before each measurement WEGE has designed and built bailers that will collect a sample of the contents of a well to show the exact thickness of any floating product Some of the abbreviations used in water sampling and or measuring or monitoring are DTW, Depth to Water (from surface reference ie usually TOC) , TOC, Top of Casing, MSL, Mean Sea Level, AMSL and BMSL, Above and Below MSL, BS, Below Surface, TOW, Top of Water, TSP, Tri Sodium Phosphate Purging Standing-Water from Monitor Wells If no product is present, WEGE personnel purge the well . This is accomplished by removing groundwater from the well until the water quality parameters (temperature, pH, and conductivity) stabilize, or until the well is emptied of water Periodic measurements of groundwater temperature, pH, and conductivity were taken with a Hydac Monitor or other meter and recorded along with the volume of groundwater removed from the well Purging is done by one or more methods singularly or in combination Bailers, pneumatic or electric sample pumps, or vacuum pump tanks or trucks may be used The usual amount of water removed is three well volumes The water collected during purging is either safely stored onsite for later disposition, transported to an approved onsite or offiste sewer discharge system, or an approved onsite or offsite treatment system 1 R603 APPEND D