Clarification on RPZ requirements from TCEQ
March 12, 2020
Members, in the interest of offering more clarity on TCEQ's requirements for backflow protection, we wanted to post an excerpt from RG-478 p.15.
Many irrigation systems are installed on sites that have an on-site sewage facility (OSSF), such as a septic tank. The existence of the OSSF elevates the classification of the irrigation system to a health hazard requiring the installation of an RP. Before 2009, a Double-Check Valve Assembly was allowed on irrigation systems installed on sites that also had an OSSF. As a result, there are currently installed irrigation systems that do not have the correct backflow prevention assembly. To address this, the current version of the landscape irrigation rules states:
30 Texas Administrative Code (TAC) 344.52(a): if an irrigation system is connected to a potable water supply and requires major maintenance, alteration, repair, or service, the system must be connected to the potable water supply through an approved, properly installed backflow prevention method as defined in this title before any major maintenance, alteration, repair, or service is performed.
Historically, this regulation was taken to mean that systems that were installed before 2009 were essentially grandfathered until they required "major maintenance, alteration, repair, or service." When the backflow preventer can no longer be repaired in line and must be replaced, it must be upgraded to the required RP.
The rule requirement itself:
30 TAC 344.51(d) If an irrigation system is designed or installed on a property that is served by an on-site sewage facility, as defined in Chapter 285 of this title (relating to On-Site Sewage Facilities), then:
30 TAC 344.51(d)(1) all irrigation piping and valves must meet the separation distances from the On-Site Sewage Facilities system as required for a private water line in 285.91(10) of this title (relating to Minimum Required Separation Distances for On-Site Sewage Facilities);
30 TAC 344.51(d)(2) any connections using a private or public potable water source must be connected to the water source through a reduced pressure principle backflow prevention assembly as defined in 344.50 of this title (relating to Backflow Prevention Methods); and
30 TAC 344.51(d)(3) any water from the irrigation system that is applied to the surface of the area utilized by the On-Site Sewage Facility system must be controlled on a separate irrigation zone or zones so as to allow complete control of any irrigation to that area so that there will not be excess water that would prevent the On-Site Sewage Facilities system from operating effectively.
Hopefully this notice helps clear up any confusion. If you have any questions please feel free to contact the office at (512)932-3701 or (254)547-9430.