Current through Register No. 13, March 27, 2025
(a) Where
operational pressure is anticipated to be less than 30 pounds per square inch
(psi), the service line shall be oversized so as to reduce frictional
losses.
(b) Maximum system pressure
shall be 100 psi. Any portion of the water distribution piping system where
pressure is expected to exceed 100 psi shall have pressure reducing valves
installed on each individual water service line or on the water main to
maintain pressure at less than 100 psi. Any bypass line around a water main
pressure reducer shall also have a pressure reducer. The water system shall
maintain all pressure reducing devices.
(c) For non-community water systems serving
campgrounds, the following shall apply:
(1)
The water distribution piping system shall be capable of passing peak flow
without excessive frictional loss, such that at peak flow, pressure at each lot
or site shall be at least 20 psi;
(2) Consideration shall be given to possible
future expansion in the sizing and layout of the proposed water distribution
piping system;
(3) The water
distribution piping system shall be so valved as to allow isolation of major
sections of the water distribution piping system for repairs while still
providing service to most of the water system;
(4) The spacing for on-line gate valves
installed on water mains shall not exceed every 1,500 feet, and gate valves
shall be provided at all intersecting pipes;
(5) Blow-offs shall be installed to allow
flushing of the water distribution piping system near the ends of the water
mains, and shall be sized so as to permit high velocities, at least 2.5 feet
per second, to be developed in the water distribution piping;
(6) Where possible, dead-end piping shall not
be used. Near the temporary end of a water main, a gate valve shall be
installed to allow future piping extension without shutting down the system or
jeopardizing the health of existing consumers;
(7) Water distribution piping shall be bedded
in sand or other appropriate material with a minimum cover of not less than 5
feet for year-round systems;
(8)
Piping and valving material and installation techniques shall conform with the
appropriate American Water Works Association (AWWA) specification, in
accordance with Env-Dw 407, for that type of piping material where such
specification exists. Where such specification does not exist for the size pipe
specified in the system design, the minimum pressure rating for piping shall be
200 psi and the piping shall meet the manufacturing requirements of the
American Society of Testing and Materials (ASTM) specification 2241, available
as noted in Appendix B; and
(9) All
buried non-metallic piping shall be backfilled with an effective metal tracing
element located above the pipe approximately 6 inches below the finished
grade.
(d) Subject to
(e), below, if a water main and sewer pipe are to be installed adjacent to one
another, a minimum horizontal separation of 10 feet shall be
maintained.
(e) When conditions
prevent 10 feet of separation, the following shall be considered by the water
system:
(1) Where other utilities or
obstacles, not including bedrock, prevent such separation, a waiver may be
requested to allow location of the sewer pipe not less than 3 feet from a water
main horizontally, provided that the water main is in a separate trench or on
an undisturbed earth shelf located on one side of the sewer and at an elevation
so the bottom of the water main is at least 18 inches above the top of the
sewer pipe;
(2) If a water main
shall cross a sewer pipe, the water main shall cross above the sewer pipe, with
not less than 18 inches of clear separation;
(3) Water piping may cross under sewer piping
only when this is demonstrated to be unavoidable and only when granted by
specific waiver. Special construction, including use of ductile iron water and
sewer pipe, no pipe joints within 9 feet of the crossing points, and minimum 18
inches clearance shall be required; and
(4) Technical criteria supporting a waiver of
sewer pipe and water main separation criteria shall include:
a. The topography of the area; and
b. The number of utility
interferences.
(f) Other utilities, including, but not
limited to natural gas, storm drainage, electric, telephone, steam, and cable
television, shall not be installed within 3 feet of water mains.
(g) On-line gate valves and service shut-offs
shall be equipped with cast iron gate box extensions. Gate valve boxes shall
have cast iron covers clearly marked by the word "water" or other appropriate
water supply marking and shall be installed flush with the finished
grade.
(h) Rigid connections shall
not be used to construct or repair water distribution piping systems.
(See Revision Note at part heading for Env-Dw 406)
#10613, eff 6-1-14