1. (a) Backwash water. Provide adequate backwash water storage tanks, pump units, or finished water storage, to adequately backwash filters.

2. (b) Clearwell. In addition to the requirements of OAC 252:626-17-1 (a) - (c) and (f) - (r), the following requirements shall apply to clearwells:

   1. (1) Construct the top of the clearwell at least 5 feet above the 100-year flood plain.
   2. (2) Size clear wells to provide adequate reserves of treated water for filter washing, pumping to distribution, and for emergencies.
   3. (3) Do not locate the clear well under any part of a building where contamination is probable.
   4. (4) Do not allow a common wall with any basin holding untreated water.
   5. (5) Construct clearwells to prevent external leakage or seepage.
3. (c) Basins and wet-wells. Design receiving basins and pump wet-wells for finished water as finished water storage structures.

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

Amended at 25 Ok Reg 2304, eff 7-11-08