Current through August 31, 2023
01.
Protection from
Contamination. The distribution system shall be protected from
contamination and be designed to prevent contamination by steam condensate or
cooling water from engine jackets or other heat exchange devices.
(3-24-22)
02.
Installation of
Water Mains. Division 400 of "Idaho Standards for Public Works
Construction," referenced in Subsection
002.02, may be used as guidance
for installation of water mains. In addition, the following provisions shall
apply: (3-24-22)
a. Installed pipe shall be
pressure tested and leakage tested in accordance with the applicable AWWA
Standards, incorporated by reference into these rules at Subsection
002.01. (3-24-22)
b. New, cleaned, and repaired water mains
shall be disinfected in accordance with AWWA Standard C651, incorporated by
reference into these rules at Subsection
002.01. The specifications shall
include detailed procedures for the adequate flushing, disinfection, and
microbiological testing of all water mains. (3-24-22)
c. In areas where aggressive soil conditions
are suspected or known to exist, analyses shall be performed to determine the
actual aggressiveness of the soil. If soils are found to be aggressive, action
shall be taken to protect metallic joint restraints and the water main, such as
encasement in polyethylene, provision of cathodic protection, or use of
corrosion resistant materials. (3-24-22)
d. The Department must approve any
interconnection between potable water supplies, taking into account differences
in water quality between the two systems. (3-24-22)
e. A continuous and uniform bedding shall be
provided in the trench for all buried pipe. Backfill material shall be tamped
in layers around the pipe and to a sufficient height above the pipe to
adequately support and protect the pipe. Stones found in the trench shall be
removed for a depth of at least six (6) inches below the bottom of the pipe.
(3-24-22)
f. Water mains shall be
covered with sufficient earth or other insulation to prevent freezing.
(3-24-22)
g. All tees, bends, plugs
and hydrants shall be provided with reaction blocking, tie rods or joints
designed to prevent movement. (3-24-22)
03.
Pressure Relief Valves. All
pumps connected directly to the distribution system shall be designed in
conjunction with a water pressure relief valve of type, size, and material
approved by the Department unless the Department approves another method that
will prevent excessive pressure development. (3-24-22)
04.
Flow Meter Required. Unless
otherwise approved by the Department based on documentation provided by the
design engineer, all source pumps and booster pumps connected directly to the
distribution system shall have an instantaneous and totalizing flow meter,
equipped with nonvolatile memory, installed in accordance with manufacture's
specifications. (3-24-22)
05.
Pipe and Jointing Materials. Pipe and jointing materials comply
with the standards set forth in Subsection
501.01. Pipe shall be
manufactured of materials resistant internally and externally to corrosion and
not imparting tastes, odors, color, or any contaminant into the system. Where
distribution systems are installed in areas of ground water contaminated by
organic compounds: (3-24-22)
a. Pipe and joint
materials which do not allow permeation of the organic compounds shall be used;
and (3-24-22)
b. Non-permeable
materials shall be used for all portions of the system including pipe, joint
materials, hydrant leads, and service connections.
(3-24-22)
06.
Size
of Water Mains. When fire hydrants are provided, they shall not be
connected to water mains smaller than six (6) inches in diameter, and fire
hydrants shall not be installed unless fireflow volumes are available. If fire
flow is not provided, water mains shall be no less than three (3) inches in
diameter. Any departure from this minimum standard shall be supported by
hydraulic analysis and detailed projections of water use. (3-24-22)
07.
Separation of Potable, Non-Potable,
and Raw Water Pipelines. The requirements for the protection of potable
mains from contamination by non-potable pipelines are described in Subsections
542.07.a. through 542.07.c.
For the purposes of Subsection
542.07, the term "pipeline"
applies to both mains and services. The Department will use the Memorandum of
Understanding with the Plumbing Bureau as guidance in determining the relative
responsibilities for reviewing service lines. The conditions of Subsections
542.07.a. and 542.07.b. shall
apply to all potable services constructed or reconstructed after April 15, 2007
and where the Department or the QLPE is the reviewing authority. Raw water
pipelines must be protected from contamination from non-potable pipelines, and
must not contaminate potable pipelines. They shall therefore meet equivalent
separation distances shown below from either potable or non-potable pipelines.
(3-24-22)
a. Parallel installation
requirements. (3-24-22)
i. Potable mains in
relation to non-potable mains. (3-24-22)
(1)
Greater than ten (10) feet separation: no additional requirements.
(3-24-22)
(2) Ten (10) feet to six
(6) feet separation: separate trenches, with the bottom of the potable main
above the top of the non-potable main, and non-potable main constructed with
potable water class pipe. (3-24-22)
(3) Less than six (6) feet separation: design
engineer to submit data to the Department for review and approval showing that
this installation will protect public health and the environment, non-potable
main to be constructed of potable water class pipe, and with the bottom of the
potable main above the top of the non-potable main. (3-24-22)
(4) Non-potable mains are prohibited from
being located in the same trench as potable mains. (3-24-22)
(5) Pressure wastewater mains or other
pressurized mains or lines containing non-potable fluids shall be no closer
horizontally than ten (10) feet from potable mains.
(3-24-22)
ii. New potable
services in relation to non-potable services, new potable services in relation
to non-potable mains, and new non-potable services in relation to potable
mains. (3-24-22)
(1) Greater than six (6) feet
separation: no additional requirements based on separation distance.
(3-24-22)
(2) Less than six (6)
feet separation: design engineer to submit data that this installation will
protect public health and the environment and non-potable service constructed
with potable water class pipe. (3-24-22)
(3) New potable services are prohibited from
being located in the same trench as non-potable mains or non-potable services.
(3-24-22)
b.
Requirements for potable water mains or services crossing non-potable water
mains or services. (3-24-22)
i. If there is
eighteen (18) inches or more vertical separation with the potable water
pipeline above the non-potable pipeline, then the potable pipeline joints must
be as far as possible from the non-potable water pipeline. (3-24-22)
ii. If there is eighteen (18) inches or more
vertical separation with the potable water pipeline below the non-potable
pipeline, then the potable pipeline joints must be as far as possible from the
non-potable pipeline, and the non-potable pipeline must be supported through
the crossing to prevent settling. (3-24-22)
iii. Less than eighteen (18) inches vertical
separation: (3-24-22)
(1) Potable pipeline
joint to be as far as possible from the non-potable pipeline; and either:
(3-24-22)
(a) Non-potable pipeline constructed
with potable water class pipe for a minimum of ten (10) feet either side of
potable pipeline with a single twenty (20) foot section of potable water class
pipe centered on the crossing; or (3-24-22)
(b) Sleeve non-potable or potable pipeline
with potable water class pipe for ten (10) feet either side of crossing. Use of
hydraulic cementitious materials such as concrete, controlled density fill, and
concrete slurry encasement is not allowed as a substitute for sleeving.
(3-24-22)
(2) If potable
pipeline is below non-potable pipeline, the non-potable pipeline must also be
supported through the crossing to prevent settling.
(3-24-22)
iv. Pressure
wastewater mains or other pressurized mains or lines containing non-potable
fluids shall be no closer vertically than eighteen (18) inches from potable
mains. (3-24-22)
c.
Existing potable services in relation to new non-potable mains, existing
non-potable services in relation to new potable mains, and existing potable
services in relation to new non-potable services shall meet the requirements of
Subsection 542.07.b., where practical,
based on cost, construction factors, and public health significance. If the
Department determines that there are significant health concerns with these
services, such as where a large existing service serves an apartment building
or a shopping center, then the design shall conform with Subsection
542.07.b.
(3-24-22)
08.
Separation from Subsurface Wastewater Systems and Other Sources of
Contamination. A minimum horizontal distance of twenty-five (25) feet
shall be maintained between any potable water pipe and a septic tank or
subsurface wastewater disposal system. Guidance on separation from other
potential sources of contamination, such as stormwater facilities, may be found
on the DEQ website http://www.deq.idaho.gov.
(3-24-22)
09.
Dead End
Mains. All dead end water mains shall be equipped with a means of
flushing and shall be flushed at least semiannually at a water velocity of two
and one-half (2.5) feet per second. (3-24-22)
a. Dead ends shall be minimized by making
appropriate tie-ins whenever practical in order to provide increased
reliability of service and reduce head loss. (3-24-22)
b. Flushing shall be performed in such a way
as to minimize any erosion of unprotected areas and, if applicable, shall be
coordinated with the owner of the receiving system. No water main flushing
device shall be directly connected to any sewer. (3-24-22)
c. Stub outs for future main connections
shall meet all requirements for dead end mains listed in Subsection
542.09 as determined by the
Department. Flushing devices may be temporary in nature.
(3-24-22)
10.
Repair of Leaks. Leaking water mains shall be repaired or replaced
upon discovery and disinfected in accordance with American Water Works
Association (AWWA) Standards, incorporated by reference into these rules at
Subsection 002.01. (3-24-22)
11.
Separation from Structures.
Water mains shall be separated by at least five (5) feet from buildings,
industrial facilities, and other permanent structures. (3-24-22)
12.
Meter Vault Required. All
new public water systems shall include a meter vault at each service
connection. A lockable shut-off valve shall be installed in the meter vault.
This requirement shall also apply to extensions of the distribution system of
existing public water systems. (3-24-22)
13.
Minimum Pressure at Building
Sites. Any public water system constructed or undergoing material
modification where topographical relief may affect water pressure at the
customers' premises shall provide the Department with an analysis which
demonstrates that the pressure at each designated building site will be at
least forty (40) psi, based on dynamic pressure in the main, as set forth in
Subsections 552.01.b.i. and 552.01.b.v.,
plus a static compensation from the elevation of the main to the elevation of
each building site. (3-24-22)
a. If forty
(40) psi cannot be provided at each designated building site, the Department
may require that reasonable effort be made to provide notification to existing
and potential customers of the expected pressure. (3-24-22)
b. The Department will not authorize a
service connection at any designated building site where analysis indicates
that pressure will be less than twenty (20) psi static pressure (or twenty-six
point five (26.5) psi for two (2) story buildings).
(3-24-22)
14.
Isolation Valves. A sufficient number of valves shall be provided
on water mains to minimize inconvenience and sanitary hazards during repairs.
(3-24-22)
15.
Air
Valves. At high points in water mains where air can accumulate,
provisions shall be made to remove the air by means of air release and vacuum
relief valves or combination air release/vacuum relief valves. Air release
valves, vacuum relief valves, or combination air release/vacuum relief valves
may not be required if vacuum relief and air release functions in the pipeline
can be adequately handled by approved appurtenances such as fire hydrants.
(3-24-22)
a. The open end of an air valve
shall be extended to at least one (1) foot above grade and provided with a
twenty-four (24) mesh or similar non-corrodible screened, downward-facing
elbow. When the air vent on an air relief valve cannot be practically installed
above ground, the vent may be below grade provided that the valve is manually
operated and the air vent is extended to the top of the valve vault and
provided with a twenty-four (24) mesh or similar non-corrodible screened,
downward-facing elbow. In addition, for below ground vents, the valve vault
must be rated for appropriate traffic loading in traffic areas and the vault
drained to daylight or provided with adequate drainage to prevent flooding of
the vault. (3-24-22)
b. Discharge
piping from air valves or combination air release/vacuum relief valves shall
not connect directly to any storm drain, storm sewer, or sanitary sewer.
(3-24-22)
16.
Backflow Protection. Automatic air relief valves shall be equipped
with a means of backflow protection. (3-24-22)
17.
Surface Water Crossings. For
the purposes of Subsection
542.17, surface water is defined
as all surface accumulations of water, natural or artificial, public or
private, or parts thereof which are wholly or partially within, which flow
through or border upon the state. This includes, but is not limited to, rivers,
streams, canals, ditches, lakes, and ponds. Surface water crossings, whether
over or under water, shall be constructed as follows: (3-24-22)
a. Above water crossings: the pipe shall be
adequately supported and anchored, protected from damage and freezing, and
shall be accessible for repair or replacement. (3-24-22)
b. Under water crossings: A minimum cover of
two (2) feet shall be provided over the pipe. When crossing a water course that
is greater than fifteen (15) feet in width, the following shall be provided:
(3-24-22)
i. The pipe shall be of special
construction, having flexible, restrained, or welded water-tight joints; and
(3-24-22)
ii. Valves shall be
provided at both ends of water crossings so that the section can be isolated
for testing or repair; the valves shall be easily accessible and not subject to
flooding; and (3-24-22)
iii.
Permanent taps or other provisions to allow insertion of a small meter to
determine leakage and obtain water samples shall be made on each side of the
valve closest to the supply source. (3-24-22)
