On Wednesday, California’s State Water Resources Control Board formally adopted criteria for recycling wastewater.

The Water Board’s rules are a big deal, a very big deal, and they provide California’s cities a clear and definite alternative for assuring a reliable water supply. But the action has been expected for some time – after all, communities in southern California have already committed billions of dollars and have begun constructing recycling projects.

San Diego’s “PureWater” recycling program will provide additional supplies AND help clean up its beloved beaches.

Recycling wastewater is not entirely new. Singapore has been recycling wastewater for more than 20 years, a technology its Prime Minister promoted by drinking “NEWater” on television. And Orange County has been recycling wastewater for decades as well, although those supplies have been injected in aquifers before being extracted and treated for use.

The Water Board’s new rules allow wastewater to be treated and stored in local surface reservoirs or delivered directly to customers. Any skeptics might want to visit a recycling plant to see the extensive process, which includes that same nanofilters used for desalination. (Pushing recycled water through the nanofilters requires a fraction of the energy that desalinating seawater requires.)

Recycling is expensive indeed. In some cases (e.g. San Diego), however, the cost of recycling is a large part of the cost of reducing pollution of its beaches from wastewater plants. Obviously recycling wastewater would reduce pollution in San Francisco Bay as well as enable restoration of Hetch Hetchy Valley in Yosemite National Park – something we argued in an editorial opinion in the San Francisco Chronicle last year after a toxic algae bloom killed tens of thousands of fish.

Restore Hetch Hetchy believes San Francisco needs to modernize its water system so that Yosemite National Park can again be made whole. We’ve emphasized groundwater banking as a lower cost alternative than recycling (or expanding Calaveras Reservoir) – but recycling wastewater would indeed provide a huge water quality benefit to the Bay.

Hetch Hetchy Valley – no place for a reservoir!

As we explain in Yosemite’s Opportunity: Options For Replacing Hetch Hetchy Reservoir (2022): “The recent investments that California’s cities have made in groundwater, recycling and local surface storage would replace Hetch Hetchy Reservoir more than 15 times over. The San Francisco Public Utilities Commission has the opportunity to pursue any or all of these technologies.” Not a drop of supply need be lost!