Mechanical contracting firm Haberberger Inc. of Affton has started work on a project at the Metropolitan St. Louis Sewer District’s Wastewater Treatment Plant in Lemay.

Haberberger is working alongside Good-win Brothers, the general contractor, to complete the above-grade piping tie-ins and valve vaults on both ends of a rock tunnel that is roughly 3,200 feet long.

Harbererger is supporting prime contractor SAK Construction’s work to in-stall a 96-inch redundant force main in the tunnel. The project is set for completion in April 2015.