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withdrawn, the water shall be allowed to flow downward around the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)
