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idowngradient of the site The proposed locations of these monitoring <br /> wells is shown on Figure 4 <br /> The drilling will be directed by a qualified ASE geologist Undisturbed soil <br /> samples will be collected every 25-feet for subsurface hydrogeologic <br /> description and possible chemical analysis The samples will be described <br /> by the ASE geologist according to the Unified Soil Classification System <br /> The samples will be collected in brass tubes using a split-barrel drive <br /> sampler advanced ahead of the auger tip by successive blows from a 140- <br /> lb hammer dropped 30-inches Each sample will be immediately removed <br /> from the sampler, trimmed, sealed with Teflon tape and plastic caps, <br /> secured with duct tape, labeled with the site location, sample designation, <br /> date and time the sample was collected, and the initials of the person <br /> collecting the sample The samples will be placed into an ice chest <br /> containing wet ice for delivery under chain of custody to a CALrEPA <br /> certified analytical laboratory <br /> Soil from the remaining tubes not sealed for analysis will be removed for <br /> hydrogeologic description and will be screened for volatile compounds <br /> with an organic vapor meter (OVM) The soil will be screened b y <br /> emptying soil from one of the tubes into a plastic bag The bag will b e <br /> sealed and placed in the sun for approximately 10 minutes After the <br /> hydrocarbons have been allowed to volatilize, the OVM will measure the <br /> vapor through a small hole, punched in the bag These OVM readings will <br /> be used as a screening tool only since these procedures are not a s <br /> rigorous as those used by an analytical laboratory <br /> All sampling equipment will be cleaned in buckets with brushes and a <br /> trisodium phosphate (TSP) or Alconox solution, then rinsed twice with t a p <br /> water Rinsates will be contained on-site in 55-gallon steel drums until <br /> off-site disposal can be arranged <br /> Monitoring wells will be constructed within the hollow stem augers using <br /> 2-inch diameter flush-threaded, schedule 40, 0 020-inch slotted PVC well <br /> screen and blank casing The wells will be screened between <br /> approximately 9 and 19-feet bgs to monitor the first water bearing zone <br /> encountered The well casing will be lowered through the augers and <br /> #2112 filter pack sand will be placed in the annular space between the <br /> well casing and the borehole from the bottom of the boring to <br /> approximately 2-feet above the screened interval Approximately 1 to 2- <br /> feet of bentonite pellets will be placed on top of the sand pack prior t o <br /> Placing the cement sanitary seal The bentonite will be hydrated with <br /> water prior to placing the cement sanitary seal Cement mixed with 3 to 5 <br /> Frank's One Stop Workplan — June 2000 <br /> -14- <br /> I <br />