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302 FILTER GRAVEL PACK <br /> A Prior to placement of the gravel envelope, thin the drilling fluid with clean water <br /> Install filter gravel pack specified in the annular space between the bore hole and <br /> the casing and screen through a temporary construction tremae pipe initially <br /> located 20-feet from the well's bottom The tremae pipe shall be removed in <br /> approximately twenty-foot intervals when the gravel in the borehole reaches the <br /> bottom of the tremae pipe A gravel pump may be used for installing the gravel <br /> B During placement of the gravel in the annular space, add sodium hypochlorite in <br /> granular or liquid form to the gravel at a uniform rate of 1 pound of the granular <br /> form per cubic yard of gravel or 1 pint of liquid form per cubic yard of gravel <br /> C During the entire gravel packing operation, circulate clean water through the <br /> annular space between the wall of the borehole and well screen and casing While <br /> the filter gravel pack is being placed, work a swab opposite all screened sections <br /> As the gravel settles, add more Continue this operation until there is no further <br /> measurable settlement of the filter gravel pack <br /> D Upon completion of this operation and after removal of the swab, remove rock, <br /> ' sand, and foreign materials from the casing by bailing Refill the annulus with filter <br /> gravel to the level as directed by the Engineer Add chlorine to this gravel as <br /> described in Part 3 02 B of this Section <br /> rE Place a 5-foot thick sand layer between the gravel pack and the grout seal to <br /> prevent migration of grout into the gravel pack material <br /> F Record the volume of filter gravel used The volume shall not be less than the <br /> calculated volume of the annular space between the wall of the borehole based <br /> upon the caliper survey and the casing and screen <br /> 3 03 INTERMEDIATE SEAL <br /> Install intermediate seal(s) in locations determined by the Engineer through the <br /> temporary construction tremae pipe <br /> 3 04 GROUT SEAL <br /> A When installation and settlement of the filter gravel pack and sand layer are <br /> complete, fill the remaining open annular space between the casing and the <br /> borehole/surface casing with the grout mix specified using a grout tremae pipe Do <br /> not allow grout to free-fall into the well The grout seal shall extend to the ground <br /> surface <br /> B Upon completion of grouting, the level of grout shall be at ground level After <br /> grouting operations are completed, leave the grout undisturbed for a period of not <br /> less than 24 hours <br /> C Record the volume of grout used The volume shall not be less than the calculated <br /> volume of the annular space between the wall of the borehole and the casing <br /> i <br /> i <br /> ' August 2001 Division 111 -27 Ball Park& Park & Ride Wells Ph 1 <br />