Clearway operates Energy Center San Francisco on Jessie Street behind the Old Mint Building. The center provides steam heat to about 180 downtown buildings. Historically, that meant vaporizing vast quantities of potable water and sending pressurized steam through about 10 miles of pipes. It isn’t a cheap endeavor. Last year, the company’s water bill was around $2.2 million, said Gordon Judd, the energy center’s general manager.
Company officials realized that if they could collect and clean the water draining beneath the train station, they could significantly scale back Clearway’s use of drinking water.
“We thought, ‘Isn’t there a way to tap that (groundwater) and use it for something useful?’” Judd said.
With the help of a $500,000 grant from the San Francisco Public Utilities Commission, the company installed a 1,000-foot pipeline and replaced aging sump pumps to transport the groundwater to its Jessie Street plant, instead of into the sewer system. The company also invested around $3 million into a water-treatment system needed to scrub the brackish water of minerals and large debris that would otherwise build up in the company’s pipes.
“When you’re taking a train, whatever you see down on the tracks, that’s what ends up here,” Judd said. Needles, beer bottles and other unsavory debris routinely end up in the energy center’s holding tanks. But, Judd added, the water has to be made cleaner than drinking water before it gets boiled into steam.
The energy center started processing the recycled water this year and is on track to save around 30 million gallons of drinking water annually. That’s enough to supply 2,000 San Franciscans with water for a year. The SFPUC estimates that each person in the city uses about 42 gallons of water per day.
“This is a tremendous opportunity to save water,” said Paula Kehoe, director of SFPUC’s director of water resources. “It was traditionally viewed as waste, but it’s actually a resource.”