ARCHIVED REPORTS_XR0009699 - Laserfiche WebLink

Home Browse Search

4.4 Groundwater Monitoring Well and Vadose Zone Well Installation On May 28 through 30, 1996, wells VW-2, VW-4, VW-5, VW-6, MW-10/VW-1 and MW- 11/VW-3 were installed onsite to depths ranging from 16 5 to 58 5 feet bgs Monitoring well permits were obtained from the SJCEHD prior to the installation of the groundwater and vadose zone monitoring wells Well VW-2 was completed as a dual-completion vadose zone monitoring well Wells VW-4, VW-5 and VW-6 were completed as tnple-completion vadose zone monitoring wells Wells MW-10/VW-1 and MW-11/VW-3 were completed as dual-completion groundwater/vadose zone monitoring wells The wells consisted of 2-inch diameter schedule 40 polyvinyl chloride (PVC) casing and 6 to 20 feet of 0 02-inch slotted casing Gravel pack consisting of number 3 sand was placed in each well annulus Aacent to the screened intervals Bentonite seals were placed between each screened interval in the dual and triple-completion wells and above the top of gravel pack in the groundwater monitoring wells The surface completions consisted of the installation of steel, flush-mounted well covers emplaced in 1 to 2 feet of concrete Well completion details are recorded on the boring logs presented in Appendix B and are summarized in Table 3 4.5 Groundwater Monitoring Well Sampling and Analysis On August 14 and November 26, 1996, groundwater samples were collected from each onsite and offsite groundwater monitoring well not containing free hydrocarbon product by Earth Management Company personnel. Groundwater samples were transported under strict chain-of-custody procedures to American Analytics located in Chatsworth, California American Analytics is a Thrifty contracted, California Department of Health Services (CADHS) approved analytical laboratory Groundwater samples were analyzed for TPHg, BTEX and MTBE according to EPA method 8015 modified, EPA method 8020 and GC/PID, respectively. Groundwater analytical results collected during these sampling events are summarized in Table 4 Copies of the groundwater laboratory data sheets and chain-of-custody forms are included in Appendix D Copies of the groundwater field sampling data sheets are included in Appendix E and copies of groundwater field gauging sheets are included in Appendix F. 5