ARCHIVED REPORTS XR0009922 - Laserfiche WebLink

Home Browse Search

h AW j June 21, 1993 working To Restore Nature ARCO Service Station No 2130 similar design as the sparge well The deeper two PVC pipes were installed at depths of approximately 69 5 feet bsg with screen intervals of approximately 64 5 to 69 5 feet bsg (approximately 5 feet in the saturated zone) The shallower PVC pipes were installed at i depths of approximately 61 feet bsg with approximate screen intervals of 60 to 61 feet bsg (approximately 4 feet above the water surface). The air sparge monitoring wells MS-1 and MS-2 are located 9 feet crossgradient and downgradient of well AS-1, respectively Air sparge monitoring well MS-3 is located 19 5 feet downgradient of well AS-1 The locations of the air sparge and sparge monitoring wells are shown on Plate 2 Air Sparee Pilot Test 1 On October 12 and 13, 1992, and December 22, 1992, RESNA conducted air sparge pilot testing at the site Testing performed on October 12 and December 22 consisted of sparging • only while testing on October 13 included combined sparging and vapor extraction Air Sparging On October 12. 1992, a 5-horsepower two-stage positive displacement blower piped to well AS-1 was used for delivering pressurized air to the saturated zone A pressure gauge and a throttle valve were installed in-line to vary the flow rate and pressure of sparge air Each sparge and sparge monitoring wellhead was equipped with fittings to allow for vapor sample collection and connection of pressure monitoring devices (magnahelic gauges) Prior to sparging, depths to ground water in the sparge and sparge monitoring wells were measured and groundwater and soil gas samples were collected to establish baseline conditions 1 On December 22, an air compressor equipped with a coalescing air filter was used to repeat the air sparging only phase The testing performed on this day was the same as that r • 30003-8 7