Laserfiche WebLink
Reconnaissance_ Groundwater Sampling, Procedures <br /> This procedure is used when reconnaissance groundwater sampling without permanent wells is <br /> desired. Either HydroPunch® or temporarily cased open boreholes may be used. <br /> 1 . Reconnaissance groundwater sample, handling, and storage will follow guidance documents of <br /> the Environmental Protection Agency and Regional Water Quality Control Board and local <br /> agency guidelines for the investigation. <br /> 2 . Reconnaissance groundwater samples will be collected in the field in temporarily cased <br /> exploratory boreholes using clean Teflon or disposal bailers. The samples will be collected <br /> from temporarily cased exploratory boreholes. All sample containers will be properly <br /> prepared, sealed, labeled, and identified. Label information will include the date, sampler <br /> name, sampling time, and identification number, and the project name and number. <br /> 3 . The sample will be delivered to a State Certified Laboratory within two days of collection. <br /> Samples will be kept on ice and/or refrigerated continuously for shipment to the Laboratory. <br /> 4 . The sealed sample will only be opened by Laboratory personnel who will perform the chemical <br /> analysis. <br /> 5 . The samples will be analyzed according to the approved EPA Method and storage for the <br /> requested analysis. <br /> 6 . Groundwater sampling will begin 24 hours following well development, following the <br /> procedures detailed below for monitoring well sampling. Depth to water measurements are <br /> made to the nearest 0.01 foot a surveyed datum (project or known) and wells are checked for <br /> separate phase product. Boreholes are sealed following water sampling. <br /> Monitoring Well Construction <br /> 1 . The proper permits will be obtained from the appropriate agencv or Water District, using a Well <br /> Inspector as required to be present to witness the installation of the annular seal. The soils <br /> borings will be drilled with a continuous-flight hollow-stem auger of at least 3 inches Inside <br /> Diameter (ID) and 6 to 8 inches Outside Diameter(OD). All augers will be thoroughly steam- <br /> cleaned prior to visiting the site. The augers will be steamed cleaned between borings at a <br /> location well away from the proposed borings or adequate clean auger will be available to <br /> complete all of the wells without reusing auger sections. <br /> 2 . A geologic drilling log will be made of the materials encountered and sample depth for each <br /> boring. The soils/sediment lithology will be logged using the Unified Soil Classification <br /> System. The log will include field descriptions of the soil lithologic variations, moisture. <br /> conditions, geologic data, and anv unusual characteristics which may indicate the presence of <br /> chemical contamination. <br /> 3 . The borings will be advanced to a de th�of 45 <br /> g feet if a saturated zone is not encountered countered (in <br /># absence of other depth specifications). <br />� pIf a saturated zone is encountered, the boring will <br /> advance no further than 15 feet below first encountered groundwater or 5 feet into the <br /> underlying clay aquitard. A seal will be placed in the overdrilled portion of the aquitard. <br /> 4 . During the drilling operations, 55-gallon drums will be on site to contain potentially <br /> contaminated soils and rinse water. <br />{ <br /> Wright Environmental Services, Inc. rev. 6/2/94 <br /> Geoscience Protocols Page 2 <br />