Laserfiche WebLink
4.7. WELL GROUTING AND CONSTRUCTIONS <br /> The primary purpose is to prevent contamination,pollution and degradation of <br /> water wells and of the ground water by intrusion of poor quality water and cross ' <br /> contamination of aquifers. <br /> 4.7.1. The annular space between the well casing and the wall of the ' <br /> drilled hole, or between the conductor pipe and the wall of the <br /> drilled hole or the well casing shall be filled with approved cement <br /> grout or Bentonite clay, or other sealant material approved by the ' <br /> Director, from the ground surface into an impervious formation <br /> under-laying the uppermost aquifer. If an impervious formation <br /> does not exist, the annular space shall be filled to a sufficient depth <br /> to prevent polluted or contaminated water from entering the well. ' <br /> The minimum depth of the annular seal shall be as follows: <br /> Public Water Supplies....................100 Feet ' <br /> Individual Domestic Well ..............100 Feet <br /> Industrial Wells...........................100 Feet <br /> Agricultural Wells..........................50 Feet ' <br /> 4.7.1.1. Local conditions will determine depth of seal. Any <br /> deviation from Ordinance requirements will require <br /> a Special Water Well Permit. <br /> . 4.7.2. Gravity installation of sealing material,without the aid of tremie or ' <br /> grout pipe is prohibited unless the interval to be sealed is dry and in <br /> no case where the interval is over 30 feet in depth. ' <br /> 4.7.2.1. In placing the annular seal, a tremie pipe shall be <br /> installed within 5 feet of the desired seal depth and <br /> removed as the grout is installed. <br /> 4.7.3. Sealing Material: ' <br /> 4.7.3.1. Neat Cement— 1 bag (94 lbs.)Portland Cement to 5 <br /> to 10 gallons of potable water. <br /> 4.7.3.2. Cement Grout—Not more than two (2)parts by <br /> weight of sand and one(1)part by weight of cement ' <br /> (per bag of cement)to 5 to 7 gallons of potable <br /> water. <br /> 4.7.3.3. Bentonite-sealing materials and their uses shall be in ' <br /> accordance with the manufacturers specifications or <br /> as approved by the Director. <br /> 1 <br /> EHD 43-02-003 Page 13-of 30 <br /> 9/17/2003 ' <br />