Metro WWTP Solids Equipment Systems Improvements

Harris was the general contractor responsible for the systems improvements at the Metro Wastewater Treatment Plant in St. Paul, Minnesota. The sewage and waste disposal project required the replacement of several large pieces of equipment which included the primary heat exchangers, boiler economizers and evaporators and ID fan motors. Harris also installed new overfire air systems and a hot media extraction system.

The original design for the HMES system did not account for the specific height restrictions in that area of the plant which required thoughtful solutions to fit the new equipment into the limited space. This project also required the silo to be moved due to underground interferences – which meant the catwalk to the top of the silo obsolete. Harris was able to design and propose a solution for a new catwalk for the silo. The overfire air system required the installation of a large quantity of piping surrounding the 30-foot wide vessels. Due to limited space and extensive obstructions, the piping was custom designed through the efforts of laser scanning, BIM modelling and prefabrication.