DPR: State Water Board’s Cindy Forbes Describes What’s Next for Draft Direct Potable Reuse Regulations


Cindy Forbes, Division of Drinking Water, State Water Board

icons_cweanews_water-recycling_finalState Water Board staff has rolled out the draft report on direct potable reuse (DPR) here in California. It’s technically feasible, but challenging to implement they’ve said. It’s a report the Legislature required the staff to complete by January 1, 2017. The State is welcoming public comments on the draft until October 25th.

The draft report was produced by staff from the Division of Drinking Water (DDW) and their Recycled Water office. The report plus two addendums run close to 600 pages and spell out in detail several years of research and analysis by staff members, academics, public health experts and water professionals. It was a monumental undertaking, completed on-time and with the collaboration of hundreds of people across the water sector.

It’s been a busy two years for DDW. In 2014 the Division was moved from the Department of Public Health to the State Water Board. They’re in the process of working with small, disadvantaged water systems to improve drinking water quality during the drought. And they’re finalizing a report and regulations this year on Surface Water Augmentation – a process where high-purity reuse water is added to reservoirs.

We recently had a chance to interview DDW’s leader Cindy Forbes about DPR. Cindy is a drinking water expert with 30 years of experience working for the State on drinking water programs.

1.  First – how does the Division of Drinking Water define DPR – what is it and why are we going through this process?

DDW is undertaking the process of investigating the feasibility of developing uniform water recycling criteria for DPR to address requirements imposed by statute (SB 918 and SB 322), which are incorporated into the Water Code (sections 13560-13569).

DPR is defined by statute as “the planned introduction of recycled water either directly into a public water system, as defined in Section 116275 of the Health and Safety Code, or into a raw water supply immediately upstream of a water treatment plant.”

The Expert Panel, which has been tasked with advising DDW on the public health issues and the scientific and technical aspects of DPR, has further indicated they consider an environmental buffer with a theoretical hydraulic retention time of less than 2 months to be DPR.

2.  What happens next for your Division?

The public comment period ends October 25 at noon, and DDW will review the public comments, consider revisions to the Draft Report, and prepare a final draft report for review by the State Water Board, CalEPA, and the Governor’s Office before submittal of the final report to the Legislature by December 31, 2016.

In the meantime, DDW will begin the process of refining the implementation plan, scope out the work needed to accomplish the milestones in the implementation plan, and in the near future implement the plan to address the identified research needs and fill the knowledge gaps in the development of uniform water recycling criteria for DPR.

DDW staff present the draft DPR report to the State Water Resources Control Board

DDW staff present the draft DPR report to the State Water Resources Control Board

3.  Operators are mentioned 91 times in the three reports, what should wastewater and drinking water operators do now so they’re ready to operate Advanced Water Treatment Facilities (AWTF)?

DDW does not anticipate that DPR facilities will be permitted anytime soon.  That said, there are ongoing efforts to develop curriculum that is specific to DPR, and CA/NV AWWA  (the California-Nevada section of the American Water Works Association) and CWEA are collaborating to undertake a certification program development process.

Operators should be aware of these activities and are encouraged to take part in the development of these certification programs.

Current training and/or continuing education courses that focus on advanced treatment processes such as membrane filtration, advanced oxidation, UV and other emerging technologies may also be beneficial for operators who are interested in potable reuse treatment.

If we’re going to go down this path – the folks in the professional associations need to be in lock-step to make sure we get this right. There is zero tolerance for error.

I’m really concerned with the things people flush down the drain – medications and chemicals. There’s been great public outreach to tell people what to flush. I think Orange County Sanitation District does a great job with their What2Flush public outreach campaign. That’s the kind of stepping-up we’re going to need.

Back in the day people were told to flush old medication down the drain and that’s just wrong. I want to see a lot more public outreach on what to flush because it matters – DPR or not – that water is going to end up in the environment, it’s going to end up as someone’s drinking water.

I want to see communities step up their game about what to flush so they protect their drinking water.

4.  You’ve mentioned some concerns at previous CWEA workshops about wastewater operators making the transition to running drinking water facilities, what are the concerns as operators transition to running AWTFs?

Please keep in mind that there are no uniform water recycling criteria for DPR to date, and transition issues for the operation of potential future DPR facilities are still being deliberated.

That said, the Advisory Group convened per statute (SB 918 and SB 322), as well as CUWA (California Urban Water Association) and other industry groups have advised that a specialized certification and training program for DPR is needed for the public to gain confidence in DPR.

Wastewater operators are skilled and trained on wastewater processes and Clean Water Act regulations, with the water ultimately discharged to the environment.  Because DPR will produce potable water for direct human consumption, operators for DPR facilities would be expected to have the necessary skillset and range of knowledge that are expected of certified drinking water operators as a baseline, but also the skillset and knowledge required for the operation of more advanced treatment plants.

This includes the understanding of drinking water regulations; public health protection principles; the public health implications for drinking water treatment failure; optimization to achieve treatment standards, water quality goals, critical control limits, and water quality standards; rationale for water quality monitoring, monitoring methods and purpose; stringent response protocols, including emergency response to alarms and the necessity of immediate public notification if treatment failure or monitoring indicates an acute hazard to public health; and cross-connection control.

As the success of DPR is directly linked to the optimal operation of the upstream wastewater treatment processes, there is also a need for drinking water operators operating potable reuse treatment plants to be knowledgeable of wastewater treatment processes, especially biological secondary treatment and the challenges in nutrient control.

I think optimization of the wastewater treatment plants is something we want to encourage and we want professionals to focus on. For example, after cryptosporidium was found in Miluwaukee’s water, the drinking water community worked together to optimize every treatment process with a focus on protecting human health not on cost savings. You do whatever you can to optimize your treatment plant.

I don’t see that level of commitment to human health in the wastewater community, the focus is just on meeting the permit requirements. We need you to adopt the drinking water approach and optimize the wastewater treatment plants. We’ve got to step up our game.


Jim Fiedler, a member of the Advisory Group, presents the DPR report during a briefing meeting hosted by WateReuse CA.

5.  Among the water associations we’ve embraced the One Water concept (we can capture and clean any source of water. Whatever the source, it’s all water), but in recent press coverage DDW has called recycled water an imperfect source for drinking water. If it does start to rain heavily in California would you prefer to see DPR connections suspended and return to releasing recycled water into the environment first?

Every Californian has the right to safe, clean, affordable, and accessible water adequate for human consumption, cooking and sanitary purposes.  DDW’s mission is to ensure, through the regulation of public water systems, the delivery of safe drinking water to all consumers.

The vast majority of sources of drinking water for Californians include surface water sources in protected or managed watersheds, groundwater sources generally in pristine or managed aquifers, and mountain spring water sources.  Treatment is not needed or required for most groundwater and spring sources.

Recycled water is primarily domestic wastewater (sewage that enters a wastewater treatment plant) that has been treated to comply with the recycled water regulations. There are different levels of treatment for recycled water, depending on how the recycled water will be reused, in order to protect public health.

Recycled water requires extensive treatment in order for the water to be acceptable for potable reuse.  Treatment processes are complex engineered systems that are susceptible to failure in many different ways, and a tremendous amount of effort is needed to reliably operate a treatment plant so it produces water that is potable and safe to drink at all times.  It should be readily apparent that recycled water is a much poorer (non-ideal) source of drinking water than conventional water sources.

Communities select the best quality source that is available to them.  Decision-making on the subject posed in your question would be a local decision.  DDW is not an agency that regulates discharge flows into the environment.

6.  Did you find anything interesting or exciting in the expert or advisory panel reports?

It was interesting to see the Expert Panel’s research recommendations on the broader issues of public health related to DPR, and their call for a national effort to address difficult scientific and technical issues, such as: development of bioanalytical tools; development of methods to directly measure pathogen concentrations in recycled water; research on antibiotic resistance bacteria and antibiotic resistance genes; and research on unknown chemicals and chemicals of emerging concern present in wastewater.

7.  What should water professionals focus on next – what would convince you DPR is ready for approval?

The Expert Panel has identified some research that is needed to be done concurrently with the development of the draft DPR criteria.  The Expert Panel has also identified research that will help advance the science in a wide array of areas that will be important as we proceed down the path of DPR.

In considering DPR, DDW is drawing upon more than 4 decades of experience regulating indirect potable reuse (IPR) via groundwater recharge with recycled water.  DDW is currently expanding IPR criteria to include surface water augmentation (SWA), where recycled water is introduced into a raw surface water reservoir that is used as a source of drinking water supply.  DDW is drafting uniform water recycling criteria for SWA.

It would be helpful for DDW and the industry to gain experience regulating SWA and operating advanced treatment facilities designed for SWA before DPR is attempted.

A public workshop hosted by the State Water Board.

A public workshop hosted by the State Water Board.

8.  Anything else you want to add about DPR or water reuse?

DDW understands that there is great deal of interest surrounding DPR.  We would like to emphasize that the Draft Report to the Legislature on DPR required by SB 918 and SB 322 is just the first step on the road to implementing DPR in California.

There is still a lot of work ahead in addressing research needs and knowledge gaps and in developing uniform water recycling criteria for DPR such that, when applied, the criteria will ensure that a DPR project will be able to reliably and consistently produce drinking water that is safe, wholesome and potable.

Water and wastewater agencies that are interested in recycling wastewater should consider all forms of non-potable and potable reuse.  When considering potable reuse, keep in mind that the environmental buffer present in IPR provides many important benefits to a project, including storage, attenuation, and response time.

Communities are strongly encouraged to utilize an environmental buffer in potable reuse projects where available, and only consider DPR if an environmental barrier is not available or not feasible.


Thanks Cindy for your team’s patience, thoroughness and expertise in guiding the development of this draft report on DPR regulations!

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Alec Mackie

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