At a sprawling sewage treatment plant in north San Jose, California, engineers are slowly perfecting the ideal temperature for a smelly mixture of bacteria and human waste as the stew churns inside four massive air-tight cauldrons.
The plant, the largest wastewater treatment facility west of the Mississippi to produce water clean enough to be discharged into a sensitive ecosystem like San Francisco Bay, is experimenting with new heat-loving bacteria that excel at turning poop into compost and energy — harnessing the power of dangerous greenhouse gases.
“It’s like making bread or making yogurt,” said civil engineer Mariana Chavez-Vazquez, who oversaw the renovation of the cauldrons. The bacteria “need to be happy. They need to be a certain temperature. If you put in something that they don’t like, they will go sour.”
