ARCHIVED REPORTS XR0001841 - Laserfiche WebLink

Home Browse Search

' 3.0 GROUNDWATER MONITORING AND SAMPLING 3I-1 Field Groundwater Monitoring and Sampling ' Groundwater monitoring wells for the former Parmar Texaco site( PT-MW 1 to 6) were probed for water depth on December S, 2005 The six wells were probed for depth to groundwater surface, presence of free-floating product, and depth to bottom of well The wells were sampled ' in accordance with the PHSEHD approved site characterization workplan (Muir, 2003) using groundwater monitoring procedures outlined in Appendix 1. ' The wells were initially inspected for integrity and general maintenance conditions with the findings reported on the Well Development/Purging Worksheets provided in Appendix 2 Initially,the static water level was measured with an electronic water level indicator that allowed measurement of depth to approximately 0 01 foot The water level below casing and total depth of each well monitored were recorded on individual Well Development/Purging Worksheets ' (Appendix 2). The groundwater surface elevation was then calculated in feet, mean sea level along with total volumes to be removed prior to well sampling A clear, acrylic bailer was then used to visually inspect an undisturbed sample from the top of the water column to determine if a product layer or sheen was present A slight but pronounced sheen and product layer was visible on the tape and bailers used to sample monitoring wells PT- MW 1, 2 and 3 These wells had a slight, free-product layer on top of the groundwater surface approximately 0 005 foot thick No product layer or sheen was visible in the bailers used for the other monitoring wells A mnumum of three well casing volumes were extracted from each monitoring well using a Teflon bailer and/or submersible 15" diameter pump. This allowed a representative groundwater sample to flow from the reservoir area surrounding each wellbore into the wellbore. This effort is consistent with groundwater monitoring well sampling guidelines established by the RWQCB for petroleum hydrocarbon site investigations. Field parameters (pH,temperature, electrical conductivity(Ec) were measured and recorded on individual well field worksheets during the water purged from each monitoring well. Results are summarized on the attached Tables 1 and 2 Purged water was placed into a 55-gallon drum onsite that had been labeled as non-hazardous Groundwater samples were collected using a disposable Teflon bailer and placed into 40 ml VOA sample containers that had been prepared with a dilute HCl solution for sample preservation and labeled The water samples were handled and transported under accepted chain of custody procedures outlined in the workplan to Kiff Analytical Laboratories, Davis, California After sampling activities were concluded each of the wells were then secured All sampling equipment was decontaminated by Ai uinox and followup distilled water rinse IMainlD\Eewonm=W\Pazmaffcxwo\Rq)mU\QM P-0123105 wo 4