Jul 08, 2015

Tight Squeeze

Louisville, Ky., development chooses hydrodynamic separator to treat storm water

Louisville, Ky., development chooses hydrodynamic separator to treat storm water

Germantown Mill Lofts is an extensive renovation of an entire city block in the middle of Louisville, Ky. The original building on the site was built in 1888 as the Louisville Cotton Mill. The property consists of over 250,000 sq ft of numerous buildings spreading over almost eight acres.

The site was challenging, as it had a very tight footprint that was locked on all four sides. Two sides were locked by a street and set outlet elevation; the other two sides were locked by utilities and a grading plan that would need to provide enough cover to help prevent floatation of the system.

Ultimately, engineers chose a detention system made from 955 ft of 78-in.-diameter Aluminized Steel Type 2 corrugated metal pipe (CMP) that provides 237,130 gal of storage. The ability to use a large-diameter, cost-effective CMP system and stay within a tight footprint helped the engineer and owner select Contech over alternatives.

A Vortechs storm water treatment system was used to pre-treat the storm water. Vortechs is a hydrodynamic separator that combines swirl concentration and flow controls into a shallow treatment unit that removes trash, debris, sediment, and hydrocarbons from storm water runoff. The variety of water quality units that Contech provides allowed the design team to revisit the design during budgetary revisions and come up with alternative configurations to be even more cost-efficient.

Installation took place over a two-week period using excavators with straps to sit the pipe, gaskets and steel bands for the joints, and a rock thrower to backfill around and between the pipe barrels. Flynn Construction Services was extremely happy with the timely manufacturing and delivery of the system, as well as how easy all the components were to install. The engineer, Land Design & Development, was pleased with the design support it had throughout the process, along with the green practice options that were discussed during the design process.