1. (a) Cross connections. Avoid cross connections in the system.

   1. (1) Do not allow a physical connection between a line carrying a public drinking water supply and a line carrying water of unknown or questionable quality.
   2. (2) Do not allow connections from any PWS system to any device or system that poses a health threat unless it is equipped with an air gap of at least 6 inches or two pipe diameters, whichever is larger, above the overflow or drain pipe. The installation of a reduced pressure zone backflow prevention device will be considered in lieu of an air gap. To allow maintenance on the backflow prevention device, the design shall include a diversion line with equal backflow prevention. Do not locate backflow prevention devices in a pit or vault where they can become submerged. A fire suppression system is not considered a hazardous water supply.
   3. (3) Do not allow a cross-connection between a public water system and any private water system.
   4. (4) Provide an air gap at all points where finished water is discharged to a drain.
2. (b) Cooling water. Designs proposing the return of steam condensate, cooling water from engine jackets or other heat exchange devices are not allowed by the DEQ.
3. (c) Interconnections. Obtain approval from the DEQ for interconnections between potable water supplies.

4. (d) Water loading stations. To prevent contamination of the PWS, provide the following:

   1. (1) a device on the fill line to provide an air break and prevent submerging the line,
   2. (2) construct the fill line and cross connection control device so that when hanging freely it will terminate at least 2 feet above the ground surface, and
   3. (3) the discharge end of the fill line must be unthreaded or constructed to prevent the attachment of additional line, piping or other appurtenances.

5. (e) Chemical feed equipment. Provide cross-connection control to assure that:

   1. (1) service water lines discharging to solution tanks or pots are protected from backflow. Provide a minimum 6-inch air gap between the end of the service water line and the spill line of the solution tank. An air gap of less than 6 inches in conjunction with an approved backflow preventer is acceptable,
   2. (2) no direct connection will occur between any sewer and a drain or overflow from the feeder, solution chamber or tank by terminating all drains at least 6 inches or 2 pipe diameters, whichever is greater, above the overflow rim of a receiving sump, conduit or waste receptacle, and
   3. (3) discharge all drain and overflows from feeder(s), solution chamber(s), and tank(s) that discharge to sanitary sewers through a sump. Terminate drain and overflow lines a minimum of 6 inches or 2 pipe diameters whichever is greater above the overflow rim of the sump.
6. (f) Piping. Design and install all piping to eliminate possible back-siphonage in conformity with the latest American Standards Association, Recommended Practice for Backflow Prevention and Cross-Connection Control, Manual of Water Supply Practices, C14, 3^rd Edition, 2004. Provide an air gap for all filter-to-waste connections. Filter pipe gallery floors and pump rooms must be protected from flooding by backflow from filter waste lines, sewers or drains.

Added at 18 Ok Reg 1612, eff 6-1-01