ARCHIVED REPORTS_XR0010419 - Laserfiche WebLink

Home Browse Search

FIELD PROCEDURES Soils rings ' Soil borings MW2 through MW4 were drilled with a truck-mounted, Mobile B61 drill rig equipped with ten-inch diameter hollow-stem augers provided by B & F Drilling Soil samples were collected from the borings at five-foot maximum intervals with a modified California sampler equipped with clean, two-inch diameter, six-inch long brass tubes, samples and drill cuttings were described in the field using the Unified Soil Classification System (USCS) Sample tubes were sealed with ' polytetrafluoroethylene (PTFE)-coated sheets, plastic end caps and duct tape to reduce volatile hydrocarbon loss The samples were screened in the field with an organic vapor analyzer (OVA) to evaluate potential hydrocarbon content Selected samples were placed in an ice chest containing ice, ' and sub.n.:ted under chain-of-custody to a California-certified laboratory for analysis of Total Petroleum Hydrocarbons (TPH) as gasoline using Modified EPA method 8015/Purge-and-Trap, and for Benzene, Toluene, Erhylbenzene, and Total Xylenes (BTEX), using EPA method 8020/Purge-and- Trap Soil generated during urilling activities were placed in 55-gallon labeled drums and store on the site Drilling equipment was steam cleaned between borings Monitor ng Construction ' The borings were converted to monitoring wells The wells were constructed using four-inch diameter, flush pointed, Schedule 40 PVC casing, 0 02-inch slotted casing was used for the screened interval Number 3 sand was placed in the well annulus as a filter pack The filter pack extends ' from the bottom of the screened interval to approximately two feet above the top of the screened interval A two-foot thick bentonite seal was placed in the well annulus above the filter pack A ' grout seal consisting a Portland Cement and bentonite slurry was trerned into ;he wells arinzius above the bentonite seal The wells were completed with a locking well cap and a flush-mounted, traffic-rated well cover An as-built well diagram is shown on Plates 4 through 6 The wells were constructed under the supervision of a California Registered Geologist Monitoring Well Development, PurPring and Sampling ' After a minimum of 24 hours after well construction was completed, the water levet in the wells was measured with an electronic well sounder and the wells checked for free product using a clear bailer, no tree product was detected The wells were subsequently developed by a combination of surging witn a tour-inch surge block/bailer and overpumping using a submersible pump Approximately five well volumes of water were removed during development Water samples were then collected using new polyethylene dizposable bailers A water sample was not collected from well MWI cue to thz o ' WALUCS•KUHL it AS5aCifUZS INC