Screening
Asdiscussed above, most large facilities use
mechanically cleaned screening systems to remove
larger materials because they reduce labor costs and
they improve flow conditions and screening capture.
Typically, only older or smaller treatment facilities
use a manually cleaned screen as the primary or
only screening device. A screening compactor is
usually situated close to the mechanically cleaned
screen and compacted screenings are conveyed to a
dumpster or disposal area. However, plants
utilizing mechanically cleaned screens should have
a standby screen to put in operation when the
primary screening device is out of service. This is
standard design practice for most newly designed
plants.