Evaluation of Fish Survival from a Hydrolox Traveling Water Screen and Fish Return System at Alabama Power's Barry Generating Station

Modified Ristroph traveling water screens with fish return systems were identified by EPA as best technology available in the 2011 proposed Rule and as “pre-approved screens” in the 2012 EPA Notice of Data Availability. In 2013, Alabama Power Company installed five Hydrolox fish-friendly screens at Plant Barry’s Units 4-5 CWIS making it the first fish-friendly Hydrolox system for an entire CWIS in the United States. Using wild-impinged and hatchery-reared fish, this study evaluated whether Hydrolox screens equipped with fish collection and fish return systems are capable of meeting the 12% annual average mortality limit proposed in the draft Rule. Operational factors, such as, screen reliability and the ability of the system to separate live fish from the debris were also evaluated. From May 2013 to April 2014, impinged fish were collected monthly and evaluated for up to 48 hours to determine latent impingement mortality (LIM). LIM rates for wild fish were highly variable among species and typically exceeded the proposed12% annual limit. However, low mortality was observed for hatchery-reared fish, making them useful to identify mortality sources within the fish return system. Operationally, these screens perform exceptionally well routing fish to the fish return but poorly separate debris from fish.