PROJECT NAME:

SFSU Mashouf Wellness Center, San Francisco, CA

CLIENT:

Interface Engineering

SYSTEM TYPE:

Greywater for Toilet Flushing & Irrigation

COMMISSIONING DATE:

September 2017

ABOUT PROJECT:

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-Mashouf

CHALLENGE:

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.

SOLUTION:

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.

RESULTS:

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.