ARCHIVED REPORTS_XR0010296 - Laserfiche WebLink

Home Browse Search

NOMA July 21, 1993 Working To Restore Nature Fire Engine Company No 2, Stockton, California The screened interval will allow sampling at the air-water interface during seasonal fluctuations of the groundwater level The annular space in the well will be packed with number 3 sand to approximately I to 2 feet above the slotted interval A 2-foot thick bentonite plug will be added above the sand pack The remaining annulus will be backfilled to grade with a bentonite cement slurry The well will be protected with a traffic-rated, cast-aluminum utility box equipped with a PVC skirt The box has a watertight seal to protect against surface-water infiltration and must be opened with a special wrench The design of this box discourages vandalism and reduces the possibility of accidental disturbance of the well Vapor-Extraction Well Construction The vapor-extraction wells will be constructed with thread-pointed, 4-inch-inner-diameter, Schedule 40 PVC casing No chemical cements, glues, or solvents will be used in well construction. The screened portion of the wells will consist of factory-perforated casing with 0 1-inch-wide slots with pea gravel placed in the annular space opposite the screen to a height of two feet above the screen zone The 4-inch well will be completed inside a 10-inch diameter boring drilled to approximately 30 feet below surface grade Approximately 15 feet of 0 1-inch slotted casing will be set through the sand interval and backfilled with pea gravel A 2-foot thick bentonite seal will be added above the gravel pack The remainder of the boring will be backfilled to grade with a bentonite cement slurry. The well will be protected with a traffic-rated, cast- aluminum utility box equipped with a PVC skirt The box has a watertight seal to protect against surface-water infiltration and must be opened with a special wrench The design of this box discourages vandalism and reduces the possibility of accidental disturbance of the well Well Development We will watt a minimum of 24 hours after well installation before developing the groundwater monitoring wells to allow the grout to seal Before developing the monitoring wells, a water sample will be collected for subjective analysts from near the water surface in the well with a Teflon bailer cleaned with a laboratory-grade detergent and deionized water The wells will be developed with a surge block and pump Well development will continue until the discharge water was clear of silt and sand Clay-size sediments derived from the screened portion of the formation cannot be entirely eliminated by well development After the wells stabilize for a minimum of 24 hours, the wells will be purged 38009-9w A-2