Crews have to keep rainwater from overflowing and causing a health hazard by sending untreated wastewater into San Francisco Bay.
VIDEO: Strong storm hits Bay Area with heavy rain, lightning, flooding
On a normal day the plant could see 50 million gallons, but with something like Wednesday night's storm they could see up to 300 million gallons of wastewater.
Even as this storm passes crews are monitoring the next round of storms and preparing to handle them.