Laserfiche WebLink
Ms.Margaret Lagorio, SJCEHD October 21,2003 <br /> Joe's Truck Plaza Project No. 2033-15600-01 <br /> Work Plan for Additional Site Assessment <br /> Page 9 <br /> stem augers. The borings for wells DW-4 through DW-7 will be advanced using 8-inch <br /> hollow stem augers. <br /> The well screens for wells DW-1 through DW-7 will consist of 7 feet of 2-inch diameter, <br /> 0.02-inch factory slotted PVC, installed from approximately 22 to 28 feet bgs. A filter <br /> pack of LonestarTM #3 sand will be placed in the annular space around the well screen, <br /> from the bottom of the boring to a maximum of 2 feet above the top of the screen. Two <br /> feet of bentonite will be placed on top of the filter pack to provide a transitional seal for <br /> the well. The wells will be surged prior to placement of the bentonite seal to ensure the <br /> filter pack has properly seated. The remaining annular space will be backfilled with neat <br /> cement up to surface grade. A traffic rated vault box will be placed over the wells and a <br /> watertight locking cap will be placed on the top of the well casings. The actual well <br /> construction may be modified in the field based on conditions encountered at the time of <br /> the investigation. <br /> Extraction Well Construction <br /> Stratus proposes to drill out monitoring well MWO-1X to a depth of approximately 30 <br /> feet bgs using 10-inch diameter hollow-stem augers. The boring will then be grouted <br /> from the base of the boring up to the depth of approximately 18 feet bgs, and the grout <br /> will be allowed to cure at least 24 hours to provide a stable platform for the installation of <br /> extraction well EX-1. The boring will then be reamed out to a depth of 18 feet bgs using <br /> 15-inch diameter hollow-stem augers. Well EX-1 will be installed to a depth of <br /> approximately 18 feet bgs, and will be screened between 5 and 18 feet bgs using 6-inch <br /> diameter, 0.02-inch factory slotted PVC. A filter pack consisting of LonestarTM #3 sand <br /> will be placed in the annular space around the well screen from the base of the boring to <br /> approximately 1 foot above static water level. LonestarTM Coarse Aquarium sand will be <br /> placed around the remaining screened interval to a maximum of 1 foot above the top of <br /> the screen. Two feet of bentonite will be placed on top of the filter pack and hydrated <br /> with clean water to provide a transition seal for the well. A surge block will be used to <br /> "seat" the filter pack prior to the installation of a sanitary seal. Neat cement will be used <br /> to backfill the remaining annular space around the well casing. A watertight locking cap <br /> will be placed over the top of the well casing and a traffic rated vault box will be installed <br /> around the top of the well casing. The actual well construction may be modified in the <br /> field based on conditions encountered at the time of the investigation. <br /> Ozone Sparge Well Construction <br /> Wells IW-1 through IW-15 will be installed to the base of the upper sandy zone, <br /> approximately 15 feet bgs. The screened portion (sparge point) of each well will consist <br /> of 2-inch diameter by 30-inch long microporous tubing, installed at the base of each soil <br /> boring. Blank PVC casing (0.75-inch diameter) will be connected to the sparge point and <br /> installed up to surface grade. VitonTM 0-rings, manufactured to resist degradation by <br /> P:\Joe's Truck Plaza\Work Plans\Joes workplan 102103.doc <br />