Authority: IC 13-14-8; IC 13-14-9; IC 13-15-1-2; IC 13-15-2-1; IC 13-18-3-1; IC 13-18-4-1

Affected: IC 13-11-2; IC 13-13-5-1; IC 13-18-2; IC 22-13-2

Sec. 7. (a) The discharge pipe of an air gap must terminate a minimum of:

1. (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. (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:

   1. (A) a side wall, rib, or similar obstruction is spaced closer than three (3) diameters from the piping affecting the air gap; or
   2. (B) two (2) intersecting walls are located closer than four (4) pipe diameters from the piping affecting the air gap.

(b) Double check valve assemblies, reduced pressure principle backflow preventers, and pressure vacuum breakers to be installed must be:

1. (1) approved by the Foundation for Cross-Connection Control and Hydraulic Research*; or
2. (2) acceptable under the Indiana plumbing code under 675 IAC 16-1.4.

(c) Reduced pressure principle backflow preventers must be installed according to the following:

1. (1) Horizontally or vertically as determined by the Foundation for Cross-Connection Control and Hydraulic Research in accordance with the following:

   1. (A) A plug or additional piping must not be affixed to the pressure differential relief valve port.
   2. (B) The pressure differential relief valve port must be a minimum of twelve (12) inches above floor level.

2. (2) At a location that allows the following:

   1. (A) Leakage from the pressure differential relief valve port to be noticed.

   2. (B) Access to the valve for the following:

      1. (i) Maintenance.
      2. (ii) Testing from floor level without use of a ladder or other similar temporary apparatus.
3. (3) Above ground grade level.

4. (4) In a manner that will not subject the device to the following:

   1. (A) Flooding.
   2. (B) Excessive heat.
   3. (C) Freezing.

(d) All double check valve assemblies must be installed at a location that:

1. (1) allows access to the device for maintenance and testing from floor level without use of a ladder or other similar temporary apparatus; and

2. (2) will not subject the device to:

   1. (A) flooding;
   2. (B) excessive heat; or
   3. (C) freezing.

(e) Pressure vacuum breakers and spill resistant vacuum breakers must be installed according to the following:

1. (1) As near as possible to the irrigation facility.
2. (2) 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.

3. (3) In a manner that will not subject the device to the following:

   1. (A) Flooding.
   2. (B) Excessive heat.
   3. (C) Freezing.

4. (4) Between two (2) tightly closing shutoff valves, with its center line or datum point a minimum of twelve (12) inches above:

   1. (A) floor level;
   2. (B) the highest downstream piping or shutoff valve; and
   3. (C) the highest downstream overflow rim or discharge point.

(f) Atmospheric vacuum breaker backsiphonage prevention assemblies must be installed according to the following:

1. (1) 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.

2. (2) In a manner that will not subject the device to the following:

   1. (A) Flooding.
   2. (B) Excessive heat.
   3. (C) Freezing.
3. (3) With a minimum of six (6) inches clearance above the overflow rim or downstream piping.
4. (4) Without means of shutoff on the discharge side of vacuum breaker.
5. (5) Without being under continuous pressure for more than twelve (12) hours in any twenty-four (24) hour period.

*A list of approved backflow prevention assemblies may be obtained from the Foundation for Cross-Connection Control and Hydraulic Research at http://fccchr.usc.edu/list.html or is available for review at the Indiana Department of Environmental Management, Office of Legal Counsel, Indiana Government Center North, 100 North Senate Avenue, Thirteenth Floor, Indianapolis, Indiana 46204.

(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; errata filed Jul 31, 2017, 11:06 a.m.: 20170809-IR-327170349ACA; errata filed Sep 22, 2017, 11:46 a.m.: 20171004-IR-327170437ACA; filed Oct 24, 2018, 3:24 p.m.: 20181121-IR-327170563FRA; readopted filed Jun 14, 2019, 1:59 p.m.: 20190710-IR-327190246BFA; readopted filed Oct 18, 2024, 1:57 p.m.: 20241113-IR-327230810RFA)