- (a) Required. Screening devices are required at all mechanical treatment plants.
(b) Bar screens. Bar screens shall comply with the following:
- (1) Flow measurement. Locate screening devices so that changes in backwater elevations due to intermittent cleaning of screens will not interfere with flow measuring equipment.
- (2) Size. Clear openings between bars shall not be greater than 1 3/4 inches. Screens shall be designed to be easily raked.
- (3) Slope. Hand-cleaned screens, except those for emergency use, shall slope 30 to 45 degrees from horizontal.
- (4) Channels. Shape the channels before and after screens to prevent sedimentation of solids. The channel entrance to the screens must evenly distribute the flow to minimize turbulence.
- (5) Controls. All mechanical units operated by timing devices shall have auxiliary controls to start operation at predetermined high water elevations. Automatic controls shall have a manual override.
- (6) Screenings. Hand-cleaned screens must have a platform with suitable drainage and ample facilities for removal, handling, storage and disposal of screenings.
Added at 17 Ok Reg 1140, eff 6-1-00
Amended at 23 Ok Reg 937, eff 6-15-06