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indicators for assessing sufficient purging The purging parameters are measured to <br />' observe stabilization to a range of values typical for that aquifer and well. Stable field <br /> parameters are recognized as indicative of groundwater aquifer chemistry entering the <br />' well Specific conductance (conductivity) meters are read to the nearest ±10 umhoslcm <br /> and are calibrated daily. pH meters are read to the nearest ±0 1 pH units and are <br /> calibrated daily Temperature is read to the nearest 0.1 °F Calibration of physical <br />' parameter meters will follow manufacturer's specifications Collected field data during <br /> purging activities will be entered on the Well Sampling Field Data Sheet <br /> Following purging, the well is allowed to recharge prior to sampling. When recovery <br /> to 80% of the static water level is estimated or observed to exceed two hours, a sample <br /> will be collected when sufficient volume is available to fill all sample containers. The <br /> well will be purged slowly enough to minimize the volatilization of organic <br /> contaminants during well recharge <br /> In wells where free-phase hydrocarbons are detected, the free-phase portion will be <br /> bailed from the well and its volume recorded. Generally, if free-phase hydrocarbons <br /> persist through bailing, a groundwater sample will not be collected unless requested by <br /> the client. <br /> Volatile organic groundwater samples are collected so that air passage through the <br /> sample does not occur or is minimal (to prevent volatiles from being stripped from the <br /> samples). Sample bottles are filled by slowly running the sample down the side of the <br /> bottle until there is a positive convex meniscus over the mouth of the bottle. The teflon <br /> side of the septum (in cap) is then positioned against the meniscus, the cap is screwed on <br /> tightly, the sample is inverted, and the bottle is lightly tapped. If a bubble is evident, <br /> the cap is removed, more sample is added, and the bottle is resealed. <br />` Chain-of-Custody <br /> Groundwater sample containers are labeled with a unique sample number, location, and <br />` date of collection. All samples are logged into a chain-of-custody form and placed in a <br /> secure, chilled ice chest for shipment to a laboratory certified by the State of California <br /> Sample Storage <br />' Groundwater samples collected in the field are stored in an ice chest cooled to <br /> approximately 4 °C while in transit to the office or analytical laboratory. Samples are <br /> stored in a refrigerator overnight and during weekends and holidays The refrigerator <br /> is set to 4 °C and is locked with access controlled by a designated sample custodian. <br />` RESNA INDUSTRIES INC. <br /> Groundwater Sampling Protocol <br /> Latest Revision September 18, 1992 <br />