Section 327IAC8-10-7. Construction and installation requirements for air gaps or other devices

   (a) The discharge pipe of an air gap shall terminate a minimum of:

(1) two (2) pipe diameters of the discharge pipe or six (6) inches, whichever is less, above the maximum recorded flood level or above the flood level rim of the receiving vessel, whichever is higher; or

(2) three (3) pipe diameters of the discharge pipe or six (6) inches, whichever is less, above the maximum recorded flood level or above the flood level rim of the receiving vessel, whichever is higher, where:

(A) a side wall, rib, or similar obstruction is spaced closer than three (3) diameters from the piping affecting the air gap; or

(B) two (2) intersecting walls are located closer than four (4) pipe diameters from the piping affecting the air gap.

  (b) Only those models of double check valve assemblies, reduced pressure principle backflow preventers, and pressure vacuum breakers that have been listed by the "List of Approved Backflow Prevention Assemblies", by the Foundation for Cross Connection Control and Hydraulic Research of the University of Southern California, February 7, 2012, or those acceptable under the Indiana plumbing code under the fire prevention and building safety commission rules at 675 IAC 16-1.2 [675 IAC 16-1.2 was repealed filed Jun 30, 1999, 2:53 p.m.: 22 IR 3414] and 675 IAC 16-1.3, shall be installed.

  (c) Reduced pressure principle backflow preventers shall be installed horizontally or vertically as listed by the Foundation for Cross Connection Control and Hydraulic Research of the University of Southern California, February 7, 2012, with:

(1) no plug or additional piping affixed to the pressure differential relief valve port; and

(2) the pressure differential relief valve port a minimum of twelve (12) inches above floor level.

Additionally, the device must be installed at a location where any leakage from the pressure differential relief valve port will be noticed, and that allows access to the valve for maintenance and testing from floor level, without use of a ladder or other similar temporary apparatus. The device must not be installed below ground grade level and must not be subject to flooding, excessive heat, or freezing.

  (d) All double check valve assemblies shall be installed at a location that allows access to the device for maintenance and testing from floor level, without use of a ladder or other similar temporary apparatus, and that will not subject the device to flooding, excessive heat, or freezing.

  (e) Pressure vacuum breakers and spill resistant vacuum breakers shall be installed as near as possible to the irrigation facility, at a location that allows access to the device for maintenance and testing from floor or ground level, without use of a ladder or other similar temporary apparatus, and that will not subject the device to flooding, excessive heat, or freezing. Additionally, the device must be installed between two (2) tightly closing shutoff valves, with its center line or datum point a minimum of twelve (12) inches above:

(1) floor level;

(2) the highest downstream piping or shutoff valve; and

(3) the highest downstream overflow rim or discharge point.

  (f) Atmospheric vacuum breaker backsiphonage prevention assemblies must be installed at a location that allows access to the device for maintenance and testing from floor or ground level, without use of a ladder or other similar apparatus, and that will not subject the device to flooding, excessive heat, or freezing. Additionally, the device must be installed as follows:

(1) A minimum of six (6) inches clearance above the overflow rim or downstream piping.

(2) Absolutely no means of shutoff on the discharge side of vacuum breaker.

(3) Must not be under continuous pressure for more than twelve (12) hours in any twenty-four (24) hour period.

(Water Pollution Control Division; 327 IAC 8-10-7; filed Sep 24, 1987, 3:00 p.m.: 11 IR 717; filed Mar 31, 1999, 1:50 p.m.: 22 IR 2518; readopted filed Jan 10, 2001, 3:23 p.m.: 24 IR 1518; readopted filed Nov 21, 2007, 1:16 p.m.: 20071219-IR-327070553BFA; filed Nov 13, 2012, 11:39 a.m.: 20121212-IR-327100414FRA; readopted filed Jul 29, 2013, 9:21 a.m.: 20130828-IR-327130176BFA)