Optimization of Traveling Water Screens for Fish Protection

One approach for reducing impingement mortality (IM) at cooling water intake structures (CWIS) that is expected to be included in the final 316(b) Rule is the installation of modified traveling water screens (TWS).  In the draft 316(b) Rule, EPA required the use of biological monitoring to demonstrate sufficient survival of impinged organisms.  In the Notice of Data Availability (NODA) for impingement mortality, EPA provided a streamlined approach to using TWS that would require a TWS optimization study in lieu of biological monitoring.

This presentation outlines those components of the TWS that could be optimized to improve fish survival and/or transfer efficiency.  A distinction will be made between those components that are best suited for optimization prior to installation versus those that can be optimized in situ.  The relative effort and cost will be identified for those components best suited for field optimization and the potential effect to fish survival and transfer efficiency.  Such information could be used to design a TWS screen optimization study to meet compliance if the streamlined approach is included in the final 316(b) Rule.