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r ' CALIFORNIA GEOPHYSICAL GROUP, INC WATER SAMPLING PROTOCOLS .� Water Sampling Procedures ' The equipment used to withdraw water from the well will be a PVC or stainless steel bailer or an electric Pump All equipment including the bailers, bailing cord, water depth measunng dev<se, pump electric lines and hose must be decontaminated prior to entering any well They will be decontaminated by washing with ' non-phosphate detergent and rinsed with tap water The well will be measured, purged remeasured and a water sample will be taken immediately after remeasuring ' MEASURING The depth to groundwater will be measured from the highest point on the top of the casing to the surface of the water table This point is marked with black on the casing The measuring devise used will be an electric conductivity devise which tnps a red light and/or a buzzer when the probe touches water A minimum of three measurements will be made at each well, the final reading will be noted after 2 or more ' readings do not vary by more than 0 01 feet The total depth of the well will also be measured This information along with water parameters mentioned later will be entered onto the sampling sheet The casing volume will be calculated according to the formula supplied on the sampling sheet ' FLOATING FREE PRODUCT The presence of floating free product will be checked by recording the depth of the water and marking that ' level on the probe wire The probe and wire will be withdrawn from the well and dried liquid paste of chalk will be placed on the probe and up the side of the wire for 2 feet(could be higher depending on the depth of the plume) The probe is then carefully lowered into the well so that the probe lust touches the water table, liwre will be taken not to lower the probe below the water table Once the probe has buzzed at the water table it is withdrawn quickly from the well and the liquid level above the water level point on the probe is recorded This differential behveen the liquid level and the probe water sensing point is the floating product thickness and will be recorded cn the sampling sheet Water samples will be obtained as follows ' A) First, one casing volume of water will be withdrawn from the well, ' B) The parameters of pH, conductivity, temperature and oxygen will be measured The color, odor and presence of sheen of the purged water will be noted, C) A 2nd and 3`d casing volume of water will be withdrawn and the parameters remeasured, if the results from the third measuring vary by more than 10% for the conductivity or temperature or 0 1 on the pH reading then step C is repeated until the readings are within the limits ' D) The well will be allowed to recover to 80% of its original volume or 2 hours have passed(remeasured) then a sample will be withdrawn and placed in the appropriate sample bottle supplied by a California ' Certified Analytical Laboratory The Labs supply the sample vials with the proper amount of Hydrochlonc Acid in each bottle, so no further acid or any other chemical should be added to the water The bottles will be placed on ice in a cooler and kept on ice until delivered to the lab or turned over to their couner within 48 ' hours of the sampling time 0