1. (a) Subject to (b), below, for wells that are required to have grouted well casings, as specified in We 602.14, We 602.16, We 602.22, and We 602.25, the following construction methods shall be used:

   1. (1) The void area outside the well casing shall be filled with:

      1. a. Neat cement;
      2. b. Cement-sand grout;
      3. c. Cement bentonite grout containing no more than 5 percent bentonite; or
      4. d. High solids bentonite grout;

   2. (2) For bedrock wells:

      1. a. One of the following techniques shall be used to set grout material in place:

      2. i. Grout shall be pumped through a tremie pipe inserted on the outside of the casing to the bottom of the pilot hole while the pipe is raised in a continuous operation, as the void area is filled, to the ground surface; or

         ii. The casing shall be secured approximately 12 inches above the bottom of a pilot hole, drilled into bedrock, and grout shall be pumped into the casing with sufficient pressure to force the grout out of the bottom of the casing into the void area outside of the casing and to fill the annulus from the bottom up to the ground surface; and

      3. b. After grout has been set as specified in a.ii, above, the casing shall be firmly driven to the bottom of the hole; and
   3. (3) For wells constructed in gravel, grout shall extend from 5 feet below the pitless adapter to a depth, based on well design, sufficient to prevent surface water from channeling along the casing to groundwater.

2. (b) This section shall not apply to:

   1. (1) Excavated wells constructed as specified in We 602.31; and
   2. (2) Driven and drive-and-wash wells constructed as specified in We 602.28.

Source. (See Revision Note at chapter heading for We 600) #12083 eff 3-1-17