There is a massive recycling project planned in San Francisco, which will transform dirty groundwater into clean steam that will be used to heat hundreds of downtown buildings. Once completed, the project is expected to save tens of millions of gallons of drinking water per year.
Under the Powell Street Bay Area Rapid Transit (BART) Station, water naturally seeps and pools fifty feet below the train stop. Millions of gallons of this water are pumped every month into the city’s sewer system, which has been seen as a potential flooding risk for several years.
Gordon Judd, the general manager for Clearway Energy located across from the station, stated “We thought, ‘Isn’t there a way to tap that (groundwater) and use it for something useful?”
Clearway Energy saw an opportunity to use the dirty water as a way to reduce its large water bill. The company operates Energy Center San Francisco, located on Jessie Street, which provides steam heat to around 180 downtown buildings. The company’s water bill was about $2.2 million last year, because it vaporizes large quantities of potable water. The company has already invested about $3 million into a water-treatment system that scrubs salty water of minerals and large debris that would otherwise build up in the company’s pipes. The company also received a $500,000 grant from the San Francisco Public Utilities Commission to install a 1,000-foot pipeline and to replace aging sump pumps to transport the groundwater to the Jessie Street plant.
This is a great opportunity for the company to significantly reduce its consumption of drinking water. The plant started processing the recycled water earlier this year and it’s estimated to save about 30 million gallons of drinking per year. This is enough water to supply 2,000 San Franciscans with water for a year, based on the estimated 42 gallons of water per day that is consumed in the city by each person. Another added bonus of this recycling project is that the dirty water only needs to travel about 10 miles through underground pipes from the BART station to the plant so that it can be cleaned and steamed. Maybe other cities will look into doing something similar to reduce the amount of potable water being consumed and the amount of dirty water being sent to the sewage system.