California Becomes the First State with Direct Potable Reuse Regulations

By: Victor Chahin

The American Southwest has recently encountered its driest periods in 1,200 years.[1] California, one of the most populous yet driest states in the United States, continuously grapples with exacerbated drought conditions.[2] Over the past decade, the Golden State has witnessed an increase in both the frequency and severity of dry periods in comparison to wet ones, significantly impacting the state’s water supply and reserves.[3]

Recognizing the urgency of addressing the growing frequency of droughts, the state acknowledges the need for new technologies and approaches. Governor Gavin Newsom responded to the escalating crisis by urging Californians to reduce their water consumption by 15% from July 2021 to March 2023.[4] However, during this timeframe, residential water use only decreased by 7%, translating to a daily reduction of 9 gallons per person.[5] In response to this imperative, California has adopted direct potable water reuse, making the state a pioneer of this transformative technology.[6] The state is actively exploring how to practically and tangibly implement this approach to mitigate the impact of recurrent drought conditions.[7]

Background on DPR

Direct Potable Reuse (DPR) is a wastewater recycling method designed to generate a potable water source.[8] Especially valuable in arid, drought-prone regions such as California, DPR stands out as a self-sustaining water source.[9] Utilizing this technology enables rapid wastewater treatment, transforming it into a safe drinking water supply within hours.[10] Notably, DPR distinguishes itself from indirect potable reuse by eliminating the need for an environmental buffer, thereby streamlining the water recycling process.[11] An environmental buffer acts as a barrier between treated wastewater and drinking water allowing effluent to receive additional treatment and storage before being used as drinking water.[12] 

Despite its safety, efficiency, and practical benefits, potable reuse methods, including DPR, have encountered significant public resistance.[13] Remarkably, there are no standardized state or federal regulations governing DPR implementation in the United States.[14] Nevertheless, California is actively trying to establish uniform state regulations specifically tailored to DPR, reflecting the state’s commitment to embracing and regulating this innovative water reuse technology.[15]


California leaders assert that “the nation is looking for California to be a leader in potable reuse.”[16] Consequently, in January 2018, the California State Assembly enacted Bill 574, which mandates the State Water Resources Control Board to establish regulations for DPR by 2023, provided the board deems these regulations sufficient in safeguarding public health.[17] The Bill specifically stipulates that the California Water Board must finalize these regulations by December 31, 2023.[18] 

By adopting these  regulations, California is poised to make history by becoming the first state in the nation to implement uniform regulations for DPR.[19] This proactive legislative step reflects California’s commitment to leading the way in responsibly and regulatorily adopting innovative water reuse technologies.[20]

Compliance with EPA

Establishing uniform regulations for DPR marks a significant initial stride for California. Nevertheless, it is imperative for lawmakers to ensure that these regulations align with the rigorous federal water quality standards, specifically those outlined in the Safe Drinking Water Act (SDWA).[21] Enacted by Congress in 1974, the SDWA empowers the Environmental Protection Agency (EPA) to establish and oversee standards for the quality of drinking water.[22] 

Under the SDWA, the EPA sets and monitors the standards for drinking water quality.[23] The agency oversees compliance with these standards through state and local authorities and water suppliers, emphasizing the importance of adherence to federally mandated guidelines in safeguarding the public’s access to safe and high-quality drinking water.[24] 

Public Perception

The success of DPR implementation hinges on public acceptance of recycled water as a legitimate water source.[25] Overcoming the inherent “yuck factor” associated with drinking recycled water is paramount for the widespread adoption of this innovative approach.[26] According to Dan McCurry, a professor at the University of Southern California, a shift in mindset is essential.[27] He emphasizes, “[P]eople need that change in mindset, forgetting where your water came from and focusing more on how clean it is when it’s in front of you.”[28]

In an effort to alter public perception, Los Angeles has undertaken initiatives such as public demonstrations showcasing recycled water as a “proof of concept.”[29] Jesus Gonzalez, the manager of the recycled water program at the Los Angeles Department of Water and Power, explains that this public demonstration facility, strategically located in the heart of the city, aims to dispel negative perceptions surrounding DPR.[30]

To further enhance positive public perception, Los Angeles should consider exploring more creative strategies. Jeff Prevatt, Director of the Pima County Regional Water Reclamation Department in Arizona, devised an innovative approach.[31] He and his team spent five months developing a mobile craft brewery that traveled across Arizona.[32] This trailer was equipped with a comprehensive treatment system capable of transforming effluent into highly treated, potable water on-site.[33] Local craft brewers then utilized this water to produce beer, showcasing the potential and safety of recycled water in a tangible and enjoyable way.[34] 

California’s groundbreaking move to establish DPR regulations by December 31st signifies a pivotal step in addressing the water crisis. The convergence of state legislation, federal compliance, and public perception will determine the success of this innovative approach, emphasizing the need for a holistic strategy to secure sustainable water resources in the face of escalating challenges.


[1] Tracking California’s Water Supplies, L.A. Times (Dec. 4, 2023),,in%20more%20than%201%2C200%20.

[2] Id. 

[3] Id. 

[4] Id. 

[5] Id.

[6] Id.

[7] Id.

[8] J. Lahnsteiner et al., Direct Potable Reuse – A Feasible Water Management Option, 8 J. of Water Reuse and Desalination 14-29 (2018).

[9] Id. 

[10] Annika Kim Constantino, What’s in your drinking water? If you live in one of these states, it might soon be recycled sewage, CNBC (Aug. 19, 2022),

[11] Id. 

[12] Id. 

[13] Id. 

[14] Id. 

[15] Id.

[16] Tomasa Dueñas, Bill to Expand the Use of Recycled Water in California is Signed into Law, (Oct. 6, 2017),

[17] Id. 

[18] Id. 

[19] Id. 

[20] Id.

[21] 42 U.S.C.A. § 300g-1 (West).

[22] Id. 

[23] Id.

[24] Id. 

[25] Annika Kim Constantino, What’s in your drinking water? If you live in one of these states, it might soon be recycled sewage, CNBC (Aug. 19, 2022),

[26] Id.

[27] Id. 

[28] Id.

[29] Id. 

[30] Id. 

[31] Zeki Oral, Direct Potable Beer: Potable Reuse Project, Wastewater Digest (May 25, 2021),

[32] Id. 

[33] Id. 

[34] Id. 

Photo Courtesy of Amritanshu Sikdar