When Salesforce Tower in San Francisco fully reopens this year after 16 months of pandemic-induced closure, one of its more unusual features will be found in the basement. A series of pipes and cast-in-concrete holding tanks, arrayed on two levels in the parking garage like some hidden microbrewery, will take the dirty water generated by the structure’s daily operations through a six-step filtration process and return it as clean, nonpotable water for use in toilets and drip irrigation. Taking up the space of 16 cars, the black-water system, so called because it treats all wastewater, including from toilets and showers, will filter an estimated 30,000 gallons per workday, or 7.8 million a year. The system, the most comprehensive of its kind in a high-rise tower in the nation, is designed for people to visit — each step of the process is labeled, said Amanda von Almen, head of sustainable built environment at Salesforce.

Source: New York Times August 03, 2021 12:56 UTC