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lC c' Csituations we carry backups for the dedicated units in the field. rDuring the purging of the well the sample integrity is always considered. We attempt to purge the 1� well without stressing the subsurface static conditions. As each well casing volume is removed the pH,temperature,conductivity,turbidity and odor is monitored.A laboratory grade Y.S.I.556 muli- probed meter is used by Del-Tech to insure the highest level of field monitoring of the parameters C described. If requested dissolved oxygen and oxidation redox potential will be also included At a minimum three well casing volumes will be attempted to be removed If at this time the well stabilization has not occurred then additional well volumes will be purged until a variance of less than 101/e is indicated or a N.T.U.turbidity reading of less than 15 is recorded(if possible). All purge water is discharge and contained in 60 gallon polyethylene drums. Each ofthese drums are sealed and labeled at the end of the monitoring event. They are then dollied to the most logical storage location on site,as to not cause a traffic hazard. Dnmm counts are completed each time the site is sampled and the inventory is recorded on the first page ofthe Del-Tech field monitoring log. L Next, the well is re-sounded to assure that a minimum of 80%water column recharge has been achieved. Once well stabilization has occurred,the well is sampled through the dedicated discharge tubing on dedicated well heads or with a clean stainless steel or disposable PVC bailer. The bailer is lowered into the well slowly as to not disturb the water within the casing. The bailer is lowered on a stainless steel cord that is wound onto a poly reel. Then the poly reel is spooled back up and the sample is decanted slowly as to not oxygenate or volatilize any possible constituents within the sample media Only containers with the appropriate preservatives are used to collect these samples. All sample containers are provided by a state certified laboratory pre-preserved. C' Immediately after sampling all of the samples collected are labeled and logged into a Chain-of- Custody. The samples are then placed into a ice chest with a mixture of blue ice and ice(frozen water.) The well head is now sealed up,decontamination of all downhole sampling equipment is completed with a field portable decontamination trailer. Each piece is thoroughly cleaned and returned to a clean container for storage. We then move on to the next sampling point or monitoring well and repeat the procedure. CExample of preprinted labels used by Del-Tech on a routine basis: CLIBIrr: YOUR CGTPANY NME / CONTACT (503) 555-1212 t'7 SITE: YOUR SITE NAM / ADDRESS � PRSSSRVATIVES: HCL U TION: MN-- COLLECTED BY: DEL-TECH 847-e757 Any additional site specific quality control or quality assurance measures required during the monitoring event will be adhered to as requested and required ( Del-Tech Geotechnical Support Standard Operating Procedures.t Groundwater Monitoring 2006 1 y s C )