Laserfiche WebLink
casing and the annular space between the conductor casing and <br /> the drilled hole filled with sealing material to the depth <br /> specified in Part A of this section. <br /> 4. Wells situated in "hard" consolidated ANNULAR SPACE-_. <br /> formations (crystaline or metamorphic rock). An oversized <br /> hole shall be drilled to the depth specified in Part A of $aI L-- <br /> this section and the annular space filled with sealing <br /> material. If there- is significant overburden, a conductor ISEAL <br /> casing may be installed to retain it. If the material is <br /> heavily fractured, the seal should extend into solidGR *+ cuslNU <br /> material. If the well is to be open-bottomed (lower section <br /> uncased), the casing shall be seated in the sealing material `= <br /> (see Figure 5A). <br /> 5. Gravel packed wells. ` <br /> a. With conductor casing. An oversized DRI ED MOLE <br /> hole, at least 4 inches (100 millimetres) greater than the iOfrertbattom) <br /> diameter of the conductor casing, shall be drilled to the <br /> depth specified in Part A of this section and the annular <br /> space between the conductor casing and drilled hole filled <br /> with sealing material. (In this case the gravel pack may A. WELL DRILLED IN ROCK FORMATION <br /> extend to the top of the well but to prevent contamination by <br /> surface drainage, a welded cover shall be installed over the <br /> top in the space between the conductor casing and the <br /> production casing, see Figure 0). <br /> b. Without conductor casing. An oversized WATERTIGHT CAP GRAVEL FILL PIPE <br /> ANNULAR <br /> hole at least 4 inches (100 millimetres) greater in diameter GRAVEL FILL PIP E ANNULAR <br /> than the production casing, shall be drilled to the depth ;r: SPACE SPACE <br /> specified in Part A of this section and the annular space SOIL <br /> between the casing and drilled hole filled with sealing SOIL; <br /> material. If gravel fill pipes are installed through the <br /> seal, the annular seal shall be of sufficient thickness to GROUT SEAL I:. GROUT SEAL <br /> assure that there is a minimum of 2 inches (50 millimetres) ='7 <br /> between the gravel fill pipe and the wall of the drilled hole. } <br /> The gravel pack shall terminate at the base of the seal (see }` <br /> Figure 5C). If a temporary conductor casing is used, it shall <br /> be removed as the sealing material. is placed. CONDUCTOR <br /> GRAVEL PACK CASING VARIOUS <br /> X.6. For wells situated in circumstances differ- FORMATIONS ti• GRAVEL PACK <br /> ing from those described above, the sealing conditions shall END OF CASING <br /> be as prescribed by the enforcing agency. CLAY IShoel <br /> 7. Converted wells. Wells converted from one CASING <br /> use to another, particularly those constructed in prior years <br /> without annular seals, shall have annular seals installed to INNER CASING X. <br /> II the depth required in Part A of this section and at the <br /> thickness described in Part E. Where it is anticipated that <br /> a well will be converted to another use, the enforcing agency <br /> may require the installation of a seal to the depth specified B.WITH CONDUCTOR CASING C.WITHOUT CONDUCTOR CASING <br /> for community water supply wells.i/ GRAVEL PACKED WELLS <br /> This statement presumes that land use planning has taken <br /> place and that. zoning requirements are in effect. Figure a. SEALING CONDITIONS FOR UPPER ANNULAR SPACE- <br /> HARD ROCK FORMATIONS AND GRAVEL PACKED WELLS <br />