Faced with aging infrastructure, the potential expansion of a significant industrial user, and the desire to consolidate treatment facilities from two different sites to a single existing site, the Grand Rapids Public Utilities Commission (GRPUC) retained AE2S to plan, design, and administer construction of a WWTP upgrade and expansion project. The overall master plan divided the project into four phases. The first phase of the project is currently under construction at a total project cost of approximately $30 million.
Phase I of the project included replacement of existing facilities that have reached the end of their useful life, including moving the existing primary facilities from the existing primary site to the existing secondary site. This provided for a consolidation of wastewater facilities at a single site closer to the landfill used for disposal of solids from the facility. The facilities included in the Phase I project were a rehabilitated domestic lift station, new domestic force main, new aerated influent channel, two new primary clarifiers, a new primary clarifier sludge pump station, a new solids processing building, new waste activated sludge storage and transfer facilities, odor control facilities, and a new administration and maintenance building.
Pilot testing of dewatering technologies determined that switching to screw presses from their current belt press operation would result in a greater solids concentration, increasing from 30 to 40 percent solids. A one million gallon per day (MGD) effluent water reuse system was designed as part of a green initiative for the facility. This initiative resulted in acquiring a $1.7 million grant for the project. The effluent water system provides seal water for pumps, polymer make down water, wash up water for the dewatering equipment, chemical dilution water, yard hydrants and irrigation, and an effluent heat recovery system. The effluent heat recovery system is designed to heat and cool the buildings, providing a clean and economical source of energy. The second phase of the project will continue with the theme of efficiency and energy reduction by upgrading the existing activated sludge system to reduce energy consumption by approximately 30 percent at an estimated annual savings of over $350,000 per year.