SECTION 252:626-17-4. Distribution storage

  The maximum design variation between high and low levels in storage structures providing pressure to distribution system is 30 feet.

(1)   Drainage. Design storage structures that provide pressure directly to the distribution system so they can be isolated from the distribution system and drained for cleaning or maintenance without losing pressure in the distribution system. Pipe the drain to the ground surface with no direct connection to a sewer or storm drain.

(2)   Level controls. Provide adequate controls to maintain levels in distribution system storage structures.

(A)   Control pumps by sensing tank water levels and transmitting the signal by telemetering equipment when any appreciable head loss occurs in the distribution system between the pump and the storage structure.

(B)   Provide altitude valves or equivalent controls for a second and subsequent structures on the system based on the hydraulic profile.

(C)   Provide overflow and low-level warnings or alarms.

(3)   Inlet and outlet lines. Provide separate inlet and outlet lines for positive circulation of water in the tank. Terminate the inlet line at a minimum elevation of 30% or greater tank height to ensure adequate circulation in the tank. Locate the outlet line at least 18 inches above bottom of tank to prevent withdrawal of sediment.

[Source: Added at 18 Ok Reg 1612, eff 6-1-01; Amended at 25 Ok Reg 2304, eff 7-11-08]