Backfilling in any street opened or excavated pursuant to an excavation permit issued under this chapter shall be compacted to a degree equivalent to that of the undisturbed ground in which the trench was dug. Compacting shall be done by mechanical tappers or vibrators, by rolling in layers, or by water settling, as required by the soil in question and sound engineering practices generally recognized in the construction industry. The decision as to whether a trench shall be backfilled by water settling shall be based upon sound engineering practices. When water is taken from a fire hydrant, the permittee shall assign one man to operate the hydrant and shall make certain that such man had been instructed by the town in the operation of the hydrant. The town shall likewise be notified at both the beginning and the end of the job so that the condition of the fire hydrant can be checked on both occasions. Any damage done to the hydrant during the excavation shall be the responsibility of the permittee. Water shall be paid for by the permittee on the terms agreed upon with the town.
(1981 Code, sec. 18-87; Ordinance 97-51, sec. 1, adopted 1997)
When backfilling is done by water settling, excavated materials above utility installations shall be deposited uniformly in layers of not more than five feet (5') in thickness and shall be thoroughly flooded. During the flooding, the water shall be allowed to flow slowly to the trench from high points and shall be worked down to the full depth of the layer of backfill with bars. All bars used shall be long enough to extend entirely through the layer being filled and shall be forced down through the loose backfill material. As the bars are withdrawn, the water shall be allowed to flow downward around the bar. The channel or hole formed by the bar shall be kept open and the water kept running into it until the fill has settled. All work shall be done in such manner as to obtain a relative compaction through the entire depth of the backfill of not less than that existing adjacent to the excavation.
(1981 Code, sec. 18-88; Ordinance 97-51, sec. 1, adopted 1997)
Backfilling up to the first eighteen inches (18") above the top of the utility pipes or similar installations shall be done with thin layers in dry backfilling. Each layer is to be tamped by manual or mechanical means. Layers that are hand tamped shall not exceed four inches (4") in thickness. Layers that are power tamped shall not exceed six inches (6") in thickness. The same requirements shall apply to the remainder of the backfilling, if tamping is the method used for backfilling. Backfilling of all pipes of over twenty-four inches (24") in diameter shall be carried up to the spring line of the pipe in three inch (3") layers, with each layer moistened and thoroughly tamped with suitable mechanical equipment. The backfill around all pipes twenty-four inches (24") or less in diameter shall be flooded or tamped as specified above to a depth of eighteen inches (18") above the top of the pipe before any additional backfill is placed thereon.
(1981 Code, sec. 18-89; Ordinance 97-51, sec. 1, adopted 1997)
Whenever any excavation for the laying of pipe is made through rock, the pipe shall be laid six inches (6") above the rock bottom of the trench, and the space under, around and six inches (6") above the pipe shall be backfilled with clean river sand, noncorrosive soil or one-quarter inch (1/4") minus gravel. Broken pavement, large stones and debris shall not be used in the backfill.
(1981 Code, sec. 18-90; Ordinance 97-51, sec. 1, adopted 1997)
Backfilling shall be completed by placing the backfill material well up over the top of the bench. For dry backfilling, the material shall be compacted with a roller of an approved type, or with the rear of a truck carrying at least five (5) tons, until the surface is unyielding. The surface shall then be graded as required.
(1981 Code, sec. 18-91; Ordinance 97-51, sec. 1, adopted 1997)