A pair of highly sustainable comfort stations debuted on Chicago's lakefront over the summer, at 5800 North and 4000 South. Designed by Muller + Muller Architects, the seasonal-use brick structures use natural ventilation, daylighting and low-maintenance materials to minimize their ongoing use of resources. But prime among the pair of buildings' low-impact strategies is the use of captured rainwater for all toilet and urinal flushing.
At both the Osterman Beach and 40th Street Beach comfort stations, 100 percent of rainwater that falls on the roof and permeable paving that surrounds the building is captured, filtered and held in a 2,000-galon below-ground tank. It later gets pumped into a 125-gallon tank that perches above the restrooms—a visible component of the system, and thus part of the Chicago Park District's educational outreach on these buildings—where it waits to pass through a sterilizer before being used as flush water for the toilets and urinals. (The 125-gallon tank is also where the harvested rainwater meets up with supplemental water from the municipal system when necessary.)
'Sometimes public clients really want solar panels or wind turbines for visibility/' says Nick Perry, a project architect at the firm, 'but rainwater harvesting was what made sense on these sites. Their main utility is water.' Harvesting rainwater on the sites would supply 40,000 flushes annually—more than enough, user studies indicated.