Larvae Fish Survivability Utilizing Interchangeable Fine Mesh Panels on Ristroph Baskets

The Evoqua Water Technologies’ (Evoqua) traveling water screens with non-metallic modified Ristroph fish baskets are the screen type upon which EPA’s impingement mortality reduction standards were developed.  Under the §316(b) Rule, a determination of Best Technology Available for entrainment is required prior to impingement mortality compliance.  It is anticipated that any technological fix for entrainment will also meet the impingement mortality reduction standard.  Therefore, Evoqua has developed interchangeable fine mesh panel overlays onto their non-metallic modified Ristroph fish basket and have conducted a laboratory (Alden) biological evaluation of these panels.  This presentation will present the methods, data, and results on the laboratory evaluation (transfer efficiency and survivability) with five larval species.  In addition, this presentation will outline how utilizing interchangeable fine mesh panels can meet the requirements of the finalized EPA 316(b) rule for entrainment, whether deployed seasonally (during spring spawning periods) or permanently.