California – The Metropolitan Water District of Southern California’s Pure Water program recently got a shot in the arm of $80 million from the state. This project aims to turn wastewater into drinking water.
Pure Water Southern California currently has a demonstration facility in Calabasas and plans to begin construction in earnest in 2025. It hopes to start delivering purified sewage water in 2032. Construction was estimated to cost $3.4 billion in 2021 with annual operating expenses of $129 million. The project also includes a possible 60 miles of additional pipeline.
Once completed, the treatment plant is expected to produce as much as 168,000 acre-feet per year or 150 million gallons daily. That’s enough water for an estimated 500,000 homes in the Southern California region.
Under current water regulations, treated water must be added to existing aquifers or reservoirs before consumption. But new rules in development could mean that, for the first time, recycled water could be delivered directly to the drinking water supply system.
A draft version of the new regulations for wastewater treatment was released in July and has not been finalized. The rules must still undergo review and comments from the public and industry experts. The State Water Resources Control Board could vote on the regulations easly in December.
Experts stress this is not a “toilet-to-tap” project as several layers of treatment and filtration are included in the new rules – above and beyond the current protocols – including reverse osmosis, high-intensity UV light, oxidation, carbon filtration and reintroducing minerals removed in the treatment process, such as calcium.
The next phase in the project is the Environmental Impact Report (EIR) planned for 2024.