TITLE 30 - ENVIRONMENTAL QUALITY
PART 1
TEXAS COMMISSION ON ENVIRONMENTAL QUALITY
CHAPTER 344
LANDSCAPE IRRIGATION
SUBCHAPTER E
BACKFLOW PREVENTION AND CROSS-CONNECTIONS
RULE §344.50
Backflow Prevention Methods
(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.