ST9401WA-CS 960917WATER AND SANITARY SEWER INSTALLATIONS
1- GENERAL - Longitudinal water and sanitary sewer pipelines shall
be placed on uniform alignment three (3) to ten (10) feet from the
right of way line. The minimum depth of cover shall be twenty-four
(24) inches for non-plastic lines and thirty (30) inches for plastic
lines- If a nonmetallic line is installed, a durable metal wire or
other device shall be concurrently installed for detection purposes.
Each line may be installed with enough vertical flexibility to prevent
excessive stresses, however, horizontal "snaking" of the line is
prohibited.
The utility agency shall place identification markers at the right of
way line in sufficient number for longitudinal installations and at
each highway crossing.
All paved side streets crossed by a longitudinal line within TxDOT
right of way must be installed as outlined in item #2 below.
2. CROSSINGS - Highway crossings are to be installed at or near right
angles to highway and must be installed with an encasement pipe.
Encasement pipe is also to be installed under normal center medians
and is to extend from the top of backslope for cut sections and five
(5) feet beyond the toe of slope for fill sections, unless an
additional length is required as outlined in the "TRENCH EXCAVATION
AND PIT LOCATION" specification.
All crossings under existing pavement must be installed as outlined
in the "CONSTRUCTION OF HIGHWAY CROSSINGS BY BORE" Specification.
The depth of cover for crossings shall be twenty-four (24) inches for
non-plastic pipe and thirty (30) inches for plastic pipe under
ditches. The encasement pipe must be a minimum of eighteen (18)
inches or 1/2 the diameter of the pipe, whichever is greater, below
the bottom of the pavement structure.
The encasement shall consist of a steel pipe around and outside the
carrier pipe and support the load of the ground above the pipe, the
highway, and the superimposed loads thereon, including construction
equipment. The strength of the encasement pipe shall equal or exceed
the structural requirements for highway drainage culverts covered
under ASTM specifications.
3. ABOVE GROUND APPURTENANCES - Fire hydrants, air release valves,
and other similar appurtenances shall be located at or near the right
of way line. All fire hydrants will be equipped with breakaway bases
and should not be located in the sidewalk-