The Central Heating Plant (CHP) currently utilizes the effluent from the Amherst Waste Water Treatment Plant (reclaimed water) as boiler make-up water to produce steam for the campus. To increase water conservation, the CHP has submitted a Class A Reclaimed Water Application to the Massachusetts Department of Environmental Protection to use reclaimed water at the CHP cooling towers as well.
The Amherst campus currently uses about 340 million gallons of water per year. With the Class A Permit, the CHP would be able to use up to 200,000 gallons per day of reclaimed water, resulting in a potential reduction of potable water consumption of 21%.
Approximately ten years ago, the Town of Amherst Department of Public Utilities requested that UMass investigate ways to reuse the town’s Waste Water Treatment Plant’s effluent (reclaimed water) on campus. UMass commissioned a study to investigate the feasibility of reusing this effluent and confirmed that the reclaimed water was possible for boiler water make-up at the old power plant. The best path forward on this effort was to use proven technology – multi media filters, reverse osmosis membranes, and chlorination.
With approval from the Town of Amherst and the Massachusetts Department of Environmental Protection, the University started utilizing reclaimed water in 2005. The water re-use initiative reduced potable water consumption by about 16%.
The Town of Amherst Wastewater Treatment Plant takes the final treated wastewater from the City of Amherst's wastewater treatment plant, treats the water for use in the boilers, then feeds process water to the UMass steam plant. This alternative to using potable town water has resulted in big savings.
The plant was installed at a cost of $1.8 million and has a rated output of 250 gallons/minute. To commence the disinfected treatment water process, a chlorinated effluent is sent to a sand filter bank then to several final cartridge filters. These cartridge filters remove fine particles. The central feature of the plant, a bank of reverse osmosis (RO) membranes, filters the effluent. Lastly, the treated water is stored in an outside tank until the steam plant can use it. Typically, the steam plant uses the reclaimed water that very same day.
The effluent from the wastewater treatment plant is of better quality then the town water for industrial purposes, which results in the reduction of boiler "blowdowns" by about 10%. This reduction in boiler blow has resulted in roughly a 2% fuel reduction at the steam plant. This water conservation effort is expected to reclaim approximately 9,000,000 cubic feet of water with cost savings of approximately $300,000 for water and $100,000 for fuel.