ARCHIVED REPORTS_XR0009781 - Laserfiche WebLink

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Langston's Market, 15615 Seventh Street,Lathrop, California Work Plan Phase II Lateral& Vertical Extent of January 10, 1996 Second GroundrvaterAquifer, Revised Page. 4 ' Upon termination, the boring into the saturated zone will be completed as a monitoring well and backfilled with concrete grout, after a Bentonite seal has been placed The boring for the monitoring well will be of a diameter at least 4 inches greater than the 2 inch diameter of the ' well casing to be used The cuttings from the drilling operation will be containerized on-site during drilling for proper ' disposition The proper method of disposal will be dependent upon results of laboratory analysis ' 3.2 Well Construction All materials used in well construction will be thoroughly cleaned prior to introduction into the ' boinng A Bentonite or cement and Bentonite grout will be placed at the bottorr, of the borng as necessary Aftei the seal has been allowed to set Iong enough to support the weight of the casing, a 2- inch diameter well casing (stainless steel or PVC) with end cap and facto,-,, ' perforations for placement to the saturated zone (taking into account seasonal vanat.on; will Le p'.aced in the bunng The screen and filter pack sizes will be as noted in the well con�tnzc:cc.,n drav,.ng (Egure 3) The casing and end caps will be threaded or joined by staailh s�, sty cl screws, no PVC cement will be used The filter pack will extend two feet above the perflorated zone A Bentonite seal two to three feet thick will be placed in the annular space aLK)ve UA" ' f1te. pact,- followed try a cement grout to the surface Seal and filter pack elevatio,,s may change based on the underlying geology The wells v.111 be surveyed by a state .nursed ,,1n'edor ' 3.3 Well Dcvelopenerd crud Sumphng ice well will be developed until the well water appears clear of sediment, or u,I't am appropriate number of well volumes (based apon tine judgment of the responsible proft!ssion.ai) have been evacuated The v4ater produced during well development wilt be containerized and left on-site in 55-gallon drums, or other suitable containers for disposal as hazardous waste if deemed necessary upon receipt of laboratory results Disposal will be the responsibility of the client unless other arrangements have been made The wells will be allowed to stabilize for twenty-four(24) hours prior to sampling All soil and ground water samples will be properly labeled with date collected, project number, sample coordinator, and sample identification Field records will document the above information and other significant data, such as names of on-site personnel, sampling methods, date and time of sampling, the number of well volumes removed before sampling, preservatives added(if any), and any filtration performed on samples The samples will be refrigerated immediately for delivery to the laboratory and will under no circumstances be opened by anyone other than laboratory personnel Chain of Custody records will be maintained at all times(Figure 4)