Section 811.65. Plant storage.

  The applicable design standards of ss. NR 811.63 and 811.64 shall be followed for plant storage. In addition:

(1)   Filter washwater tanks. Filter washwater tanks shall be sized, in conjunction with available pump units and finished water storage, to provide the backwash water required by s. NR 811.49 . The design shall address the possibility of having to backwash more than one filter at a time, or several filters in succession.

(2)   Clearwell.

(a) Clearwell storage shall be sized, in conjunction with distribution system storage, to relieve the filters from the strain of fluctuations in water use or peak demands.

(b) When water storage is used to provide proper contact time for disinfection, documentation, including tracer testing, shall be provided to assure adequate detention time under all operating conditions. The department may require the installation of baffle walls or additional reservoir capacity if necessary to prevent short circuiting and to obtain adequate contact times.

(3)   Basins and wet-wells. Receiving basins, pump cans, and pump wet-wells for finished water or water to become finished water shall be designed as finished water storage structures.

History: CR 09-073 : cr. Register November 2010 No. 659 , eff. 12-1-10.