ARCHIVED REPORTS_XR0009220 - Laserfiche WebLink

Home Browse Search

Additional Site Assessment Report 3 • The Southland Corporation,Store#17334,4501_North_ Pershing Avenue,Stockton,CA . .- January 15, 1998 3 3 Soil Sample Collection Soil samples were collected from each borehole at 5-foot depth intervals from 5 feet BGS to total depth In addition, soil bonngs MW-1A and MW-2 were sampled continuously from 15 feet BGS to total depth Due to the close proximity of boring MW-1A,soil samples were not collected from boring MW-1 Samples were collected using a 2-inch O D split-spoon sampler, lined with three 1 5-inch-diameter by 6-inch-long brass tubes The sampler was driven 18 inches ahead of the augers at each sample point Sotl samples were field screened for hydrocarbon vapors using a photo-ionization detector(PID) Soil was logged using the Unified Soil Classification System by a Fluor Daniel GTI field geologist working under the supervision of a California registered geologist(Appendix B) One sample tube from each 5-foot sample interval in soil bonngs MW-3 and MW-4 and at selected sample depths from bonngs MW-1A and MW-2 was sealed, labeled and placed on ice in an insulated container for transport under chain of custody manifest to West Analytical Labs(WEST)in Davis, California for analysis Soil samples were collected from monitoring well MW-1A at a location approximately 2 feet north of boring GP-4, however, upon attempting to install the well casing in the boring,the bentonite seal swelled inside the augers requiring removal of the entire well casing The resultant borehole was grouted with Portland cement from approximately 36 feet BGS (the depth of the top of the bentonite seal)to surface grade MW- 1A was later installed at the location shown on Figure 2 A total of twenty-three sod samples collected from the soil bonngs were submitted for laboratory analysis of benzene,toluene, ethylbenzene and total xylenes(BTEX), MTBE and TPH-G using U S Environmental Protection/Agency(EPA) methods 8020/modified 8015 Selected samples were additionally analyzed for tert butanol (TBA),MTBE,di-isopropyl ether(DIPE), ethyl tert butyl ether(ETRE), and tert-amylmethyl ether(TAME) by EPA method 8260 In addition to the samples collected from the bonngs,ten soil samples were collected from the drummed sod and combined into two composite sample in the laboratory,for sod disposal charactenzation purpose The two composite sample from the drummed soil (D-1,2,3,4,5 and D- 6,7,8,9,10)were analyzed for BTEX and TPH-G by EPA methods 8020/modified 8015, and total lead by EPA method 6010 3.4 Groundwater Monitoring Well Installation/DevelopmenVSurveying On September 23 and 24, and November 25 and 26, 1997,five groundwater monitoring wells were installed in the four on-site bonngs(MW-1,MWAA, MW-2, MW-3) and one off-site boring (MW-4) at the locations shown on Figure 2 The groundwater monitoring wells were constructed of 2-inch-diameter, schedule 40 polyvinyichlonde(PVC)casing with flush threads, and 0 020-inch-slot well screen The well screen was installed in bonngs MW-1,MW-2, MW-3 and MW-4 from 13 feet to 33 feet BGS,and in boring MW-1A from 38 feet to 40 feet Sand was placed in each well annulus from the bottom to approximately one foot above the top of the well screen. The well annulus was sealed with approximately two feet of bentonite pellets (saturated In place) on top of the sand pack and neat-cement grout to approximately 10 inches BGS The wellheads are protected at the surface by locking,expandable well caps and traffic-rated . truserrpt FLUOR DANIEL STI