SECTION 252:656-13-1. Screening devices

(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.

[Source: Added at 17 Ok Reg 1140, eff 6-1-00; Amended at 23 Ok Reg 937, eff 6-15-06]