SFSU Mashouf Wellness Center, San Francisco, CA
Greywater for Toilet Flushing & Irrigation
The Mashouf Wellness Center is an exciting, state-of-the-art, 118,700 square-foot facility, supporting general well-being by providing recreation and wellness programs and activities for the SF State campus. The design intentionally reflects a multi-functionality of space to support “a little something for everyone”, providing recreation, wellness, and event space to support activities and programs appealing to our diverse student body.
SFSU wanted to practice sustainability for their flagship wellness center on campus and was projected to use 180,000-gallons per month for non-potable uses of toilet flushing and irrigation. Wahaso was asked to evaluate potential sources of on-site water to replace non-potable uses and design a system that would meet strict new San Francisco Public Utilities Commission guidelines and San Francisco Department of Health safety requirements. In addition to a significant supply of greywater from the showers and sinks in the locker rooms and restrooms, weekly pool back-washing was projected to add 7,500-gallons to total greywater supply. That required a greywater system that could handle and treat irregular supplies of raw greywater and store sufficient treated water to bridge back-washing cycles.
Wahaso designed a system that stores 10,000-gallons of raw greywater and processed greywater below the slab of the mechanical room to save space. The system treats raw greywater in batches of 1,000-gallons, producing over 6,000-gallons of treated water per day. Wahaso’s multi-stage filtration process achieves California’s Title-22 water quality requirement with disk filtration, multi-media filtration and activated carbon filtration. Treated water is then stored in a second 10,000-gallon tank where it is then pressurized to toilets and irrigation with duplex 50 GPM well pumps.
Wahaso’s greywater system was commissioned late in 2016, in time for the building’s opening in 2017. It is projected to save over two million gallons of drinking water per year.