270 Brannan

It was critical that most of the suspended solids in the stormwater runoff would be removed before they entered the storage system, so to deliver a complete solution, Wahaso brought in two other partners: SunTree Technologies and Oldcastle Precast. SunTree Technologies recommended their Nutrient Separating Baffle Box system to remove sediment, organic material, and hydrocarbons from large storm flows entering the cistern. The system holds trash above the standing water line and uses a series of baffles to remove suspended solids to less than 350 microns.

Oldcastle Precast supported the design and engineering of the Storm Capture system for this project and was designed to hold 37,000 gallons of pre-treated stormwater below-grade in nine pre-cast modules. Oldcastle also helped to resolve the sightlines requirement by providing an additional module to contain all the harvesting equipment below-grade. An 8’ X 10’ pre-cast equipment room was delivered with ventilation, sump pump, ladder, and large access doors to avoid confined space restrictions. Once suspended solids are removed, Wahaso’s filtration and sanitation skid was designed to further sanitize the water as well as to minimize maintenance of the system. Special high-intensity UV units are utilized in the system to eliminate any potentially harmful pathogens, even if the water is cloudy. To minimize maintenance requirements, a special 50-micron filter was installed that is capable of self-cleaning while it is operating, eliminating the need to replace bag filters.