PRESS RELEASE: Next phase of recycled water begins for California *UPDATED with advance copy of the regulations

State advances nation-leading proposed regulations to convert wastewater to high-quality drinking water

From the State Water Resources Control Board

Achieving a major milestone in the state’s efforts to maximize the potential of recycled water, the State Water Resources Control Board announced today proposed regulations that would allow for water systems to add wastewater that has been treated to levels meeting or exceeding all drinking water standards to their potable supplies. The process, known as direct potable reuse, will enable systems to generate a climate-resilient water source while reducing the amount of wastewater they release to rivers and the ocean.

This development advances Gov. Newsom’s all-of-the-above Water Supply Strategy, which includes the goal of recycling and reusing at least 800,000 acre-feet of water per year by 2030.

This turning point in California’s history with recycled water, which began in the mid-20^th century with the use of recycled water for crops, comes after an expert panel of 12 scientists and engineers evaluated work by the State Water Board’s Division of Drinking Water and determined that the proposed regulations are protective of public health. The regulations are the most advanced in the nation and reinforce California’s position as a leader of innovative solutions to climate challenges. They are now open for public comment and subject to revision based on that input.

“This moment has been some time in the making because we have been careful and thorough to produce regulations that ensure, down to a chemical level, that water treated to these standards will be pure and wholesome,” said Darrin Polhemus, deputy director for the Division of Drinking Water. “In fact, the extensive treatment requirements we’ve proposed mean that direct potable reuse processes in California will produce water of higher quality and lower risk than many traditional drinking water sources.”

Direct potable reuse relies entirely on immediate, multi-barrier treatment that can recycle wastewater to drinking water standards in a matter of hours. This contrasts to the method currently being deployed in major projects launched throughout the state, called indirect potable reuse, which further improves treated wastewater over time through groundwater recharge or dilution with surface water. While no formal direct potable reuse projects can be initiated in California until the regulations are adopted, water agencies in Santa Clara, San Diego and the city of Los Angeles have launched pilot projects in recent years.

“We’ve seen real enthusiasm and interest from major urban water agencies, who are the ones that will take direct potable reuse forward, adding it to their water supply portfolios to increase resiliency,” added Polhemus. “California has been a leader for years in water recycling, and this last step–going directly from treatment to usage as drinking water–builds on that experience and the expertise of scientists and engineers who have worked with recycled water for many years.”

The board will consider adoption of the regulations before the end of the year.

Advance copy of the regulations

The State Water Board is pleased to provide an advance copy of the proposed draft Direct Potable Reuse regulations. Please note that formal rulemaking will not begin until the Notice of Proposed Rulemaking is published in the California Notice Register, which starts the formal 45-day public comment period under the Administrative Procedure Act.

PLEASE NOTE:

• Do not submit comments to the State Water Board on the advance copy. Comments submitted before the start of the formal 45-day public comment period will not be considered by the State Water Board.
• Revisions could be made to the advance copy, and therefore, the proposed DPR regulations that will be posted for the 45-day public comment period under the Administrative Procedure Act may be different than the advance copy provided today. Stakeholders are cautioned to obtain the official version of the proposed regulations once the Notice of Proposed Rulemaking is published.

The State Water Board expects that the Notice of Proposed Rulemaking will be published in the California Notice Register on July 21, 2023.

The State Water Board’s mission is to preserve, enhance and restore the quality of California’s water resources and drinking water for the protection of the environment, public health, and all beneficial uses, and to ensure proper resource allocation and efficient use for present and future generations.