ARCHIVED REPORTS_XR0011443 - Laserfiche WebLink

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------------ --------------- S E C O R - documenting sample number, well identification, collection date and time, type of sample and type of preservative (if applicable) are affixed to each sample. The samples are then placed into an ice-filled cooler for delivery under chain-of-custody to a laboratory certified to perform the specified tests by the State of California Department of Health Services Environmental Laboratory Accreditation Program. Trip Blanks To assure the quality of the collected samples and to evaluate the potential for cross contamination during transport to the laboratory, a distilled-water trip blank accompanies the samples in the cooler. The trip blank is analyzed for the presence of volatile organic compounds of concern. For petroleum hydrocarbons, the trip blank is typically analyzed for TPHg, BTEX, and MtBE by EPA Method 8260. Containment and Disposal of Generated Water/LPH All wastewater, purge water and LPH (if present) generated during the field activities are retained on-site in appropriate containers (i.e. DOT-approved drums or bulk tanks) for future disposal. All wastewater is delivered under appropriate manifest to a facility certified and licensed to receive such waste streams. Related Procedures: =`_= • Standard Procedure for Equipment Decontamination STANDARD PROCEDURE FOR GROUNDWATER MONITORING WELL CONSTRUCTION FOR WELLS SCREENED ACROSS THE PHREATIC SURFACE UNCONFINED AQUIFERS — HOLLOW STEM AUGER METHOD Groundwater monitoring wells are constructed by inserting or tremming well materials through the annulus of the hollow stem auger. In general, the groundwater monitoring wells are constructed with 10 feet of screen below groundwater and 10 feet above groundwater, for a total screen length of 20 feet. Where shallow groundwater is encountered or perched water dictates otherwise, the screen is adjusted, as appropriate, to maintain a proper seal at the surface (minimum three feet) and to avoid penetrating low permeable horizons or aquicludes. All groundwater wells are installed in accordance with the conditions of the well construction permit issued by the regulatory agency exercising jurisdiction over the project site. The well screen will consist of schedule 40 polyvinyl chloride (PVC) casing with 0.02 machine slots. The screen is then filter packed with Lonestar 2112 or No. 3 sand. Once the borehole has been drilled to the desired depth, approximately six inches of filter sand are tremmied to the bottom of the boring. The well screen and blank well casing are then inserted through the annulus of the hollow stem augers. The well screen is sandpacked by tremming the appropriate filter sand through the annulus between the casing and augers while slowly retracting the augers. During this operation, the depth of :<-»: the sand pack in the auger is continuously sounded to make sure that the sand remains in