This section was developed using information and original text from the Zebra Mussel (Dreissena polymorpha) Control Handbook for Facility Operators.
Options other than completely draining all pipes in a raw water system include:
1) Installation of a swivel joint on a smaller diameter intake permits the intake to be lifted out of the water (dewatered) when the pump is not in use. This design modification exposes the intake pipe to ambient aerial conditions; subsequently, leaving residual water in the system stagnant.
2) Isolating and dewatering the intake only or providing an undesirable intake water environment when the system is not in use.
3) The placement of a larger pipe over the intake and angled 90° downward to produce a still well effect, or the lowering of a larger pipe sealed at the upper end to trap air over an intake facing upward, exposing the intake to the atmosphere.
In any of these three cases, the intake pipes would have to be uncovered or returned to operating position before use.
Management and Control Contents