ARCHIVED REPORTS XR0004322 - Laserfiche WebLink

Home Browse Search

Additional Subsurface Investgation And Well Installation Report 4 The Southland Corporation,Store#19978 1399 N Main St Manteca California November 15 1998 L ' 33 Soil Sample Collection ' Sod samples were collected from each sod boring at 5-foot intervals to a maximum depth of 30 feet BGS beginning at 5 feet BGS using a split-spoon sampler lined with 2-inch-diameter by 6-inch-long brass sample tubes The sample tubes were sealed with Teflon pads, plastic caps and tape, labeled, placed on ice in an insulated container,and submitted for analyses under chain-of-custody manifest to state-celled Core Analytical Laboratory, in Anaheim, California Soil samples were field screened for ' hydrocarbon vapors Using a photo-ionization detector Sod was logged using the Unified Sal Classification System by a Fluor Daniel GTI field geologist working under the supervision of a California registered geologist(Appendix A) Twelve soil samples were selected for analysis of BTEX,MTBE, and TPH-G by EPA methods ' 8020/8015 modified, and three of the twelve soil samples were also analyzed for the oxygenates MTBE, TBA, DIPE, ETRE, and TAME using EPA method 8260 3.4 Groundwater Monitoring Well Installation/Surveying On September 2 and September 3, 1998,three groundwater monitoring wells,one of which is dual- nested, were installed in the three bonngs(MW-1,MW-1A,MW-2,and MW-3)at the locations shown on Figure 2 The groundwater monitoring wells were constructed of 2-inch-diameter, Schedule 40 polyvinyl chloride casing with flush threads, and 0 020-inch-slot well screen The well screen was installed in the ' two bonngs, MW-2 and MW-3, from 10 feet to 30 feet BGS Monitoring well MW 1/MW-1A is a dual- nested well with the well screen for MW-1 installed from 10 feet to 30 feet BGS and the well screen for MW-1A installed from 45 feet to 50 feet BGS Sand was placed in each well annulus from the bottom to approximately two feet above the top of the well screen The well annulus was sealed with approximately 2 to 4 feet of bentonite pellets saturated in place on top of the sand pack,and ' neat-cement grout to approximately 10 inches BGS For MW-1A sand was placed from the bottom to approximately two feet above the well screen and then saturated bentonite pellets placed on top of the sand pack to approximately 32 feet BGS From 32 feet BGS to surface MWA A was constructed similarly to the other wells The wellheads are protected at the surface by locking,water-tight well caps and traffic-rated street boxes (with watertight bolted lids)set in concrete Well construction details are shown on the drill logs in Appendix A r ' i9979asr rpt � FLUOR DANIEL GTI