1. A. Plugging Material

   1. 1. It is recognized that no material is completely impervious; however, experience and tests have shown that cement-bentonite slurry has a low permeability, good sealing properties, and low shrinkage factor, so as to be preferred for use when plugging an abandoned water well or hole. Cement-bentonite slurry is a mixture of cement, bentonite, and water, consisting of not more than 8 percent bentonite by dry weight of the cement and a maximum of 10 gallons of water per sack (94 pounds) of cement. Additives, in the approved and proper ratio, may be added to the slurry, if required. If the slurry is to be prepared in the field it is recommended that the bentonite be added after cement and water are thoroughly mixed.
   2. 2. Neat cement, which is a mixture of cement and water, consisting of not more than 5 gallons of water per sack (94 pounds) of cement, may be used as plugging material in lieu of cement-bentonite slurry.
   3. 3. When permitted by the methods and standards stated in §531, heavy drilling mud or bentonite slurry, weighing not less than 9 pounds per gallon, may be used as plugging material. The plugging material shall be free of foreign and organic additives.
2. B. Filler Material. When permitted by the methods and standards stated in §531, heavy drilling mud or bentonite slurry, weighing not less than 9 pounds per gallon, coarse ground bentonite or clean sand may be used as filler material. The filler material shall be free of foreign and organic additives.
3. C. Calculations to Verify Adequacy of Plugging Materials. To assure an abandoned water well or hole is plugged and sealed properly and that there has been no "jamming" or "bridging" of the material, verification calculations and measurements shall be made by the contractor to determine whether the volume of the material placed in the well or hole at least equals the volume of the casing or hole plugged and/or filled. When bridge plugs are used, sufficient time shall be allowed for the material to set. Any measurements and calculations made in setting and verifying the location of the plug shall be made available to the department upon request. The department shall be solely responsible for determining whether a well or hole is satisfactorily plugged or sealed.

Authority Note

AUTHORITY NOTE: Promulgated in accordance with R.S. 38:2091-R.S. 38:3097.

Historical Note

HISTORICAL NOTE: Promulgated by the Department of Transportation and Development, Office of Public Works, LR 1:249 (May 1975), amended LR 11:962 (October 1985), repromulgated by the Department of Transportation and Development, Office of Public Works, LR 31:942 (April 2005).