(1) Except as provided in 220 CMR 109.09(2), any buried pipeline shall be installed with a minimum cover of three feet from the top of the pipe to the finished grade.
(2) Where an underground man-made structure prevents the installation of a pipeline with a minimum cover, the pipeline may be installed with less cover provided that it is installed with additional protection to withstand anticipated external loads.
(3) Bed, side, and top fill material shall extend at least six inches around the circumference of the pipe after compaction. The fill material shall be a natural granular soil or sand with 100% of the particles finer than a 3/4-inch sieve and less than 10% of the particles finer than a No. 200 sieve.
(4) Material used for backfilling over the top fill to a point approximately two feet over a pipeline shall contain no rock larger than eight inches in its greatest dimension. There shall be no concentrated organic matter in the backfill.
(5) All fill material shall be placed in lifts of no more than 12 inches, loose measurement. Each lift shall be thoroughly compacted by mechanical or pneumatic means before the next lift is placed.
(6) There shall be no puddling or jetting of the backfill material.
(7) Reinforced yellow-colored warning tape, at least eight inches wide and composed of a material resistant to deterioration in soil, shall be buried flat, over the pipeline along the entire buried portion of its route. The warning tape shall be buried approximately one foot below grade. The following caption or its equivalent, shall be repeatedly printed on the warning tape: "CAUTION - GAS PIPELINE BURIED BELOW."
Amended by Mass Register Issue 1432, eff. 12/11/2020.