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CA ARNG Field Quality Assurance Project Plan • Sample truck; • Teflon® sample bailer, point source check valve and flow control bottom emptying assembly; • Plastic buckets; and a Hand reel with Teflon® coated stainless steel line or disposable monofilament line. Portable Submersible Pump Pre -Sampling Procedures 9.1.5.6 Prior to initiating well purging, all sampling equipment that may come in contact with well water are decontaminated following the procedure described in Section 9.3 of this field QAPP. Once decontamination is complete, the following steps are followed prior to purging the well. Measure static water level in the well casing to determine the minimum volume of water needed to be purged from the well prior to collection of groundwater samples. Water level measurements are measured to the nearest 0.01 foot using an electronic water level sounder. Water levels are recorded on the groundwater sampling data sheet. 2. Position the purge pump reel system over the wellhead (hard hats are required for all work involving overhead equipment). 3. Attach the control converter box to the pump and power supply, and start the generator. 4. Attach a garden hose to the Port -a -Reel and place it opposite the wastewater container. To prevent siphoning, make sure that hose is not submerged in water in the wastewater container. 5. Attach the power cable to the plug on the power cable reel. Plug the power cable into the generator. 6. Remove a minimum of three times the volume of water initially standing in the well casing during purging of the well using a submersible pump; purge volume is calculated as follows: Minimum Purge Volume (gallons) — 3 x V (Equation 16) V = 3.142 L x 7.48 gallons/ft3; V = One wetted casing volume (gallons); R = Inside radius of casing (feet); and L = Height of water column in well (feet). The following formula can be used: Minimum purge volume = (total depth — water level) x (gallons per feet)' x 3 (Equation 17) 'Depends on casing diameter: for 2 -inch well — 0.163 for 4 -inch well — 0.65 for 6 -inch well — 1.46 field QAPP.DOC 9-5 May 2000