Toilet to Tap (DPR) Changes 100 Years of Public Health Policy

by Sheryl Hamlin

California Water Boards held a webinar to announce the beginning of Public Comments for the proposed plan for Direct Potable Reuse (DPR) of wastewater. The comment period ends on 6/25/2021. Comments should be sent to [email protected].

The source of the documents is located at

The webinar may be viewed here: video


The four panelists are shown below.

History and Theory

Randy Barnard said that in theory the introduction of recycled water into drinking water is achieved by controlled regulation of the two. He then went on to discuss California legislation starting in 2016 which authorizes research for DPR (Direct Potable Reuse). Protecting public health is essential. The systems must have the ability to take corrective action within minutes if problems are detected. He said that the DPR Framework changes 100 years of Public Health Policy.

DPR Framework Sections

Speaker Jing Chao said there are 27 sections in the DPR framework. There is a new Article 10 under Title 22 which is Chapter 17 having to do with Surface Water. This is important and will be shown in the scenarios slide. A level 5 AWT (Advanced Water Treatment) operator is required and additional coursework in advance treatment.

Four Scenarios are under consideration: 1) send AWTF (Advanced Water Treatment Facility) water to raw water augmentation facility such as a small pond or reservoir, 2) Send AWTF water to pipeline or aquifer, 3) Send AWTF water to tank to feed the SWTF (Surface Water Treatment Facility) and 4) Send AWTF directly to the end user drinking water distribution plant. The following chart shows all four entities with one path from option 1.

DPR Scenarios Option 1

Variations on these scenarios include potable and non-potable scenarios.

Pathogen Control

Effective pathogen control includes: real-time monitoring, redundant treatment, validate treatment train to monitoring for each treatment, and real time control for each treatment that responds accordingly.

He said the goal is 1 in 10,000 infections per year. He said nothing about death rates.

The three measurements are virus, giardia and crypto, all shown as log reductions. Here is information on illness from crypto and giardia: report.

They must identify all pathogens, he said, and understand how they work. He did not elaborate on virus. And there will be new SCADA systems for pathogens..

There must be a risk assessment, he said, for contaminants in the sewer shed such as chemicals that pass through Reverse Osmosis. He gave an example from Orange County where Acetone which was being measured shot up for some period of time and was sent to the drinking water. He did not indicate the length or the seriousness of this breach of operations.

Next Steps

After the comments period, all material will be sent to an EXPERT PANEL for review consisting of these types of skills.

DPR in the United States

Although not discussed in the webinar, several states, notably Texas and Arizona, both drought states, have legalized DPR and have pilot projects. Note that the Arizona Framework was approved in 2018 pre-covid. And the California legislation as mentioned above, was also approved pre-COVID. Scottsdale was the first to receive a DPR permit in 2019. Texas started DPR in 2014, again this was pre-COVID. Read here about Texas and DPR.

To watch the video click here.

Note that California gave a multi-million dollar grant to help with this project. Read about that here.

To read about the author, click sherylhamlin dot com

Get Headlines free  SUBSCRIPTION. Keep us publishing – DONATE


5 2 votes
Article Rating
Notify of
Oldest Most Voted
Inline Feedbacks
View all comments
Sheryl Hamlin

Submitted comments to DPR team:

I listened to the recent DPR webinar and came away with several questions:

1. If the system must take action in real time to suspend delivery of water once a problem is detected, how will such systems be tested to ensure this type of rapid response? Where are the testing labs for the SCADA systems?
2. How will new conditions be tested and added to the test patterns of the SCADA systems? Will there be a redundant test system at each facility producing DPR water?

3. The speaker under Pathogen control said the goal is 1 in 10,000 infections per year. He said nothing about death rates. How many people or animals will die because of pathogens?  

4. Wouldn’t it be more efficient to require removal of solids prior to treatment by the wastewater system? Some plants probably do this now, but might it eventually be a DPR requirement?

5. In terms of costs to produce this water, a proper scientific study should include alternatives. One obvious alternative is the cost of one desalination plant versus upgrading a large municipal wastewater plant. One speaker said that all wastewater plants must add BAC to the RO and, of course, there is the new SCADA system and testing requirements. The desalination option should be evaluated.  

Compare the cost of a desal plant to the Orange County System…

6. The systems for DPR in operation today are all pre-COVID. How is such a system as Orange County retrofitted for COVID capture? Is the CA DPR Framework sensitive to virus and virus variants? How often must the SCADA system be updated for new virus variants?

7. India has been using toilet-to-tap and its COVID death rate has been enormous. Has anyone dared correlate this extreme COVID response to the toilet-to-tap? Singapore also has a high COVID death count and has started using DPR. Who is studying these implementations?

We have already seen problems with recycled wastewater for irrigation. Just today this story came out of Peoria in Arizona where animals playing in a park using recycled water have become sick. So the problem could be either sludge as fertilizer or recycled water or both, but all are related.

8. And another alternative to DPR could be water storage and evaporation loss control. 

California’s costs are exorbitant as it is without adding new layers of potentially dangerous water costs. As one speaker said, DPR changes 100 years of Public Health Policy. That was a very profound statement.

Gayle Washburn

If those scenarios were viable, they would have been used for chlorides. Pathogens are even more difficult to treat than chlorides! And, they left out(at least) one important consideration; $$$…billions of dollars to build and operate these scenarios. The PE’s and their engineering firms are salivating over this.

Sheryl Hamlin

And all RO plants will have to add organic BAC (biologic activated carbon) filters at huge costs.

George Pattone

Thank you for bringing this insidious topic to light as most people would miss this development.

Sheryl Hamlin

Thanks. And the idea that service must be DISCONTINUTED in REAL TIME is absurd. All of this water delivery depends on real time monitoring of hundreds of parameters with new SCADA systems. The chance of error is enormous.