Problem: The source water for Collins Park Water Treatment Plant in Toledo, Ohio, comes from the western basin of Lake Erie. In 2014 the lake experienced seasonal toxic algal blooms.

Solution: The city chose a multi-barrier approach with powdered activated carbon, ozone, and chlorine. The 40 mgd plant expansion included two identical ozone contactor buildings each with two dissolution basins. To introduce and mix ozone, venturi sidestream injection and pipeline flash reactors from Mazzei Injector were chosen. Together they deliver at least 95% mass transfer efficiency. The reactors require just a few feet of pipeline for mixing and were sited in a three-story stack that minimized the footprint.

Result: The multi-barrier system removes 99.7% of the toxins while controlling taste and odor; removing endocrine-disrupting compounds, pharmaceuticals and personal-care products; reducing disinfection byproducts; minimizing polyaluminium chloride usage. Lower PAC usage for taste and odor control reduced operating costs. 661-363-6500; www.mazzei.net