Current through Register Vol. 48, No. 12, March 22, 2024
a)
Cross-Connection (Submergence). Potable water supply piping and water discharge
outlets shall not be submerged in any sewage or toxic substance. Potable water
supply piping or water discharge outlets that are submerged in other substances
shall be provided with backflow protection as listed in subsection (f). (See
Appendix I.Illustrations B and C.)
b) Approval of Devices and Maintenance. All
devices and assemblies for the prevention of backflow shall comply with the
standards listed in Appendix A.Table A. All reduced pressure principle (RPZ),
reduced pressure detector (RPDA), double check (DCA) and double check detector
(DCDA) backflow prevention assemblies shall be tested and approved by a
Cross-Connection Control Device Inspector (CCCDI) before initial operation, and
at least annually after initial inspection. Records to verify testing and
maintenance shall be available at the site of the installation.
c) Backflow. The water distribution system
shall be protected against backflow. Each water outlet shall be protected from
backflow by having the outlet end from which the water flows spaced a
sufficient distance above the flood-level rim of the receptacle into which the
water flows to provide a minimum fixed air gap. When it is not possible to
provide a minimum fixed air gap, the water outlet shall be equipped with an
accessible backflow prevention device or assembly in accordance with subsection
(f) of this Section or Section
890.1140.
d) Fire Safety Systems. The installation of
any fire safety system involving the potable water supply system shall be
protected against backflow as follows:
1)
Backflow protection is not required for fire safety systems constructed as
follows:
A) The system shall be looped, with
no dead ends, to allow circulation, to prevent the stagnation of water in the
line;
B) The system shall not have
any non-potable connections or a fire department hose (Siamese)
connection;
C) The system shall
have 20 sprinkler heads or less; and
D) The system shall be constructed of potable
water supply quality pipe in accordance with Appendix A.Table A.
2) When backflow protection is
required, a double detector check valve or double check valve backflow
preventer assembly shall be installed at the fire safety system's point of
connection to the potable water supply when a fire safety system has no
chemical additives or non-potable connection and:
A) The fire safety system has no fire
department hose connections; or
B)
The fire safety system has one or more fire department hose connections (for
boosting pressure and flow to the fire safety system) that are served only by
fire fighting apparatus connected to a public water supply or a fire department
that does not use chemical additives or rely upon any non-potable water
supply.
3) A fixed air
gap with a break tank or other storage vessel or a reduced pressure principle
backflow preventer assembly (RPZ) shall be installed at the fire safety
system's point of connection to the potable water supply if:
A) The fire safety system contains additives
such as antifreeze, fire retardant or other chemicals. (The RPZ may be located
at the point of connection to that section of the system containing additives
when the system's connection to the water supply is protected by a double
detector check valve backflow preventer assembly.); or
B) Non-potable water flows into the fire
safety system by gravity; or
C)
There is a permanent or emergency connection through which water can be pumped
into the fire safety system from any other non-potable source; or
D) Fire department connections are available
that could permit water to be pumped into the fire safety system from a
non-potable source capable of serving the fire safety system. A non-potable
source of water shall be considered capable of serving the fire safety system
under the following conditions: it must be capable of year-round use,
maintained with at least 50,000 gallons of usable water not subject to
freezing, accessible to fire fighting pumper equipment, and located within
1,700 feet of the facility.
e) Prohibited Connections
1) Sewage Lines. There shall be no direct
connection between potable water lines and sewage lines or equipment and
vessels containing sewage. Connections shall be made only through a minimum
fixed air gap as outlined in subsection (f)(5).
2) Chemical or Petroleum Pressure Vessels. No
direct connection shall occur between any potable water supply and any pressure
vessel, i.e., storage tank, tank car, tank truck or trailer, or other
miscellaneous pressurized tank or cylinder containing or having contained
liquified gaseous petroleum products or other liquified gaseous chemicals. When
it is necessary to discharge from a potable water line to a pressure vessel,
the discharge shall be through a minimum fixed air gap as outlined in
subsection (f)(5). Exception: Chemical pressure vessels containing chemicals
used in the water treatment process, for uses other than private purposes, are
exempt from this subsection (e)(2).
3) If water under pressure is required, as in
subsections (e)(1) and (2), it shall be supplied by means of an auxiliary pump
taking suction from a tank provided for this purpose only with an over-rim
supply having the required minimum fixed air gap.
4) A potable water line to a single wall
refrigerant condenser shall be provided with a backflow preventer complying
with ASSE 1012 or 1013.
5) No pipe
or fitting of the water supply system shall be drilled or tapped nor shall any
band or saddle be used except at the water main in the street. Exception: See
Section
890.320(h)
for potable water use only.
f) Devices for the Protection of the Potable
Water Supply. Approved backflow preventers or vacuum breakers shall be
installed with all plumbing fixtures and equipment that may have a submerged
potable water supply outlet and that are not protected by a minimum fixed air
gap. Connection to the potable water supply system for the following fixtures
or equipment shall be protected against backflow with one of the appropriate
devices as indicated below:
1) Inlet to
receptacles containing low hazard substances (steam, compressed air, food,
beverages, etc.):
A) fixed air gap
fitting;
B) reduced pressure
principle backflow preventer assembly;
C) atmospheric vacuum breaker unit;
D) double check valve backflow preventer
assembly;
E) double check backflow
preventer with atmospheric vent assembly; or
F) dual check valve.
2) Inlet to receptacles containing high
hazard substances (vats, storage containers, plumbing fixtures, etc.):
A) fixed air gap fitting;
B) reduced pressure principle backflow
preventer assembly; or
C)
atmospheric vacuum breaker unit.
3) Coils or jackets used as heat exchangers
in compressors, degreasers and other equipment involving high hazard
substances:
A) fixed air gap fitting;
or
B) reduced pressure principle
backflow preventer assembly.
4) Direct connections that are subject to
back pressure:
A) Receptacles containing low
hazard substances (vats, storage containers, plumbing fixtures, etc.):
i) fixed air gap fitting;
ii) reduced pressure principle backflow
preventer assembly;
iii) double
check valve backflow preventer assembly;
iv) double check backflow preventer with
atmospheric vent assembly; or
v)
dual check valve.
B)
Receptacles containing high hazard substances (vats, storage containers, etc.):
i) fixed air gap fitting; or
ii) a reduced pressure principle backflow
preventer assembly.
5) Inlet to or direct connection with sewage
or lethal substances: fixed air gap fitting.
6) Hose and spray units or stations shall be
protected by one of the appropriate devices as indicated below:
A) Fixed air gap;
B) Reduced pressure principle backflow
preventer assembly;
C) Double check
valve backflow preventer assembly;
D) Double check valve backflow preventer with
atmospheric vent assembly;
E) Dual
check valve backflow preventer assembly;
F) Atmospheric vacuum breaker unit.
g) Installation of
Devices or Assemblies
1) Devices of All
Types. Backflow preventer assemblies and devices shall be installed to be
accessible for observation, maintenance and replacement services. Backflow
preventer devices or assemblies shall not be installed where they would be
subject to freezing conditions, except as allowed in Section
890.1140(d).
2) All in-line backflow/back siphonage
preventer assemblies shall have a full port type valve with a resilient seated
shut-off valve on each side of the preventer. Relocation of the valves is not
permitted.
3) A protective strainer
shall be located upstream of the first check valve on all backflow/back
siphonage preventers unless the device contains a built-in strainer. Fire
safety systems are exempt from the strainer requirement.
4) Atmospheric vacuum breakers shall be
installed with the critical level above the flood level rim of the fixture they
serve, and on the discharge side of the last control valve of the fixture. No
shut-off valve or faucet shall be installed beyond the vacuum
breaker.
5) No in-line double check
valve backflow preventer assembly (DCV) or reduced pressure principle backflow
preventer assembly (RPZ) shall be located more than 5 feet above a floor, or be
installed where it is subject to freezing or flooding conditions. After
installation, each DCV and RPZ shall be field tested in-line in accordance with
the manufacturer's instructions by a cross-connection control device inspector
before initial operation. (See subsection (b).)
6) A dual check backflow preventer with
atmospheric vent assembly shall not be installed where it is subject to
freezing or flooding conditions.
7)
Closed water systems with hot water storage shall have a properly sized thermal
expansion tank located in the cold water supply as near to the water heater as
possible and with no shut-off valve or other device between the heater and the
expansion tank. Exception: In existing buildings with a closed water system, a
properly sized pressure relief valve may be substituted in place of a thermal
expansion tank. For closed water systems created by backflow protection in
manufactured housing, as required in Section
890.1140(i),
a ballcock with a relief valve may be substituted for the thermal expansion
tank.