| (a) All backflow prevention assemblies installed per
this chapter shall be installed according to manufacturer's recommendations
and provided with sufficient clearance to facilitate testing.
(b) If conditions that present a health hazard exist,
one of the following types of backflow prevention shall be used.
(1) An air gap may be used if installed per the definition
of air gap in §344.1(1) of this title (relating to Definitions).
(2) Reduced pressure principle backflow prevention
assemblies may be used if installed per subsection (a) of this section
and:
(A) the assembly is installed at a minimum of 12 inches
above ground in a location that will ensure that the assembly will
not be submerged; and
(B) drainage is provided for any water that may be
discharged through the relief valve.
(3) Pressure vacuum breakers may be used if installed
per subsection (a) of this section and:
(A) there is no actual or potential for a back-pressure
condition; and
(B) the assembly is installed at a minimum of 12 inches
above any downstream piping and the highest downstream opening. Pop-up
sprinklers are measured from the retracted position from the top of
the sprinkler.
(4) Spill-resistant pressure vacuum breakers may be
used if installed per subsection (a) of this section and:
(A) there is no actual or potential for a back-pressure
condition; and
(B) the assembly is installed at a minimum of 12 inches
above any downstream piping and the highest downstream opening. Pop-up
sprinklers are measured from the retracted position from the top of
the sprinkler.
(c) If there are no conditions that present a health
hazard, double check valve backflow prevention assemblies may be used
to prevent backflow if the assembly is tested upon installation and:
(1) a local regulatory authority does not prohibit
the use of a double check valve; and
(2) test cocks are used for testing only.
(d) Double check valve assemblies installed below ground
shall meet the following installation requirements:
(1) test cocks shall be plugged, except when the double
check valve is being tested;
(2) test cock plugs shall be threaded, water-tight,
and made of non-ferrous material; and
(3) there shall be a clearance all the way around the
assembly to allow space for testing and repair.
(e) At a minimum, all backflow prevention assemblies
shall be tested by a licensed backflow prevention assembly tester
upon installation, repair, replacement, or relocation. Those backflow
prevention assemblies used in irrigation systems designated as health
hazards shall be tested annually.
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