Project: Rooftop rainwater to flush toilets - Valley Forge Field House
Challenge: The Chicago Public Building Commission, in coordination with the Chicago Parks Division, wanted its newest Field House on Valley Forge Road to serve as an example of sustainable building practices. So there was interest in retaining and reusing the rainwater and stormwater from the property rather than send it to Chicago's combined sewer and stormwater system.
Solution: Working closely with architects Booth Hansen of Chicago, the Wahaso team designed and built a rainwater harvesting system that will flush toilets in the building more than 90% of the time. The system captures rainwater from the 10,200 square foot roof into a 4,200 gallon underground Atlantis D-Raintank system. Water from the cistern is pumped to a processing room and day tank where it is filtered, chlorinated and pressurized to flush all the toilets in the building. The smart control system automatically reverts to the municipal supply when the cistern is empty, or a problem is detected with the processing system.
Results: The system should save 65-70,000 gallons of municipal water annually, while detaining stormwater from entering the city's combined sewer system during rain events. During his viewing of the system at the building's ribbon-cutting on December 4, 2010, Mayor Daley confirmed his commitment to sustainable water practices - and to his continued support of harvesting systems in all Chicago public buildings.