The now completed Groundwater Replenishment System can provide up to 130 million gallons of water per day, enough to serve 1 million people.

It's pretty cool. Savoring that precious piss

With the $284 million expansion to the 15-year-old Groundwater Replenishment System, the facility can now provide up to 130 million gallons of water per day, enough to serve 1 million people daily in north and central Orange County.

The county’s wastewater is first treated at an OC Sanitation District plant in either Fountain Valley or Huntington Beach. Then, instead of being discharged into the ocean, it is sent to the Groundwater Replenishment System for several more steps in a purification process, including microfiltration and reverse osmosis, and then sent to replenish the groundwater aquifer. The result is a supply of quality drinking water ready to pump into faucets.

They used to rely on rainwater to replenish the groundwater but since the 90s that hasn't been enough. Probably due to rising population + drought. The first stage of this opened in 2008