IM&E at desalination intakes studied by WateReuse Assoc

The WateReuse Association has just published a report on The Impingement Mortality and Entrainment (IM&E) Reduction Guidance Document for Existing Seawater Intakes, for which the principal investigator was
 Timothy W Hogan of Alden Research Laboratory Inc.

The operation of intake structures designed to supply feed water to desalination treatment processes creates potential environmental impacts. In particular, the withdrawal of water poses a risk of IM&E of aquatic organisms residing in the source water body.

Careful consideration of these potential environmental impacts is also critical, because they can significantly affect facility economics by dictating intake type, size, location and operational requirements as well as the type and magnitude of mitigation required to offset the impacts.

This report provides guidance on the intake technologies and modifications that have potential for mitigating IM&E of marine organisms at existing seawater intake structures. If existing intakes can be modified for desalination use, the seawater desalination industry can realize reduced capital costs associated with constructing new intakes.

The specific objectives of this project were to:

· Synthesize the available literature on intake technologies and their ability to reduce IM&E
· Present case studies of sites where intakes have been modified to reduce IM&E
· Provide guidance on how to evaluate intake technologies for reducing IM&E at existing intakes
· Describe the methods for measuring IM&E reductions
· Determine the costs associated with modifying intakes
· Describe the likely permitting requirements for modifying intakes.