STATE WATER BOARD: Results from the 2019 Volumetric Annual Report of Wastewater and Recycled Water in California

Data shows 686,000 acre-feet of water was recycled in 2019, far short of the state’s 2020 goal

Recognizing the importance of recycled water as a critical water supply for California, the State Water Board in 2009 developed the Recycled Water Policy that streamlined permitting for recycled water projects and identified and funded the highest priority research needs to ensure the state’s recycled water goals are achieved.

The State Board adopted the most recent amendment to the recycled water policy in December of 2018, which took effect in April 2019. This policy contained a numeric goal to increase the recycled water used to at least 2.5 million acre-feet per year by 2030. Additionally, it included two narrative goals to reuse all dry weather direct discharges to oceans, enclosed bays, estuaries, and coastal lagoons to the extent feasible and to maximize the recycle water use in areas where groundwater aquifers have been depleted.  To evaluate the recycled water use and determine whether the state could achieve these ambitious goals, the policy added requirements for the volumetric reporting of wastewater and recycled water.

At the January 5 meeting of the State Water Board, Rebecca Greenwood, an engineering geologist with the recycled water and desalination unit in the State Water Board’s Division of Water Quality, presented the results from the first year of reporting for wastewater and recycled water facilities statewide.

There are 756 facilities subject to the order. The order requires the annual reporting of volumetric data for influent (or what’s coming into the plant), production (the level of treatment of the water), and then effluent (where’s that water going).  If applicable, recycled water use such as groundwater recharge or landscape irrigation was also reported.

The reporting module is housed in the Geo Tracker system and functions as a fillable form that is user friendly and easy to access.  This makes tracking the data consistent, electronic, and available to everyone.  After the 2019 data was submitted, staff went through quality assurance checks to ensure the data was valid and prepared the data for publishing on the California open data portal.

There was a 93% compliance rate with the reporting, which translates to about only 46 facilities that have not yet been reported, Ms. Greenwood said.  All of the data in this presentation is based on data submitted as of December 21, 2020.

Ms. Greenwood noted key differences between the annual reporting requirements and prior voluntary recycled water survey efforts in 2009 and 2015.  Reporting now is required rather than voluntary and includes requirements to capture additional data on influent and effluent volumes.  Previous survey efforts used a broader definition of recycled water than the new annual reporting requirements, which means that by comparing prior survey year data and this year’s annual report data, it’s comparing apples and oranges.

For example, previous surveys considered discharges to a wetland or an actual system to be recycled water use, whereas the current annual report does not,” she said. “The current annual report considers recycled water to be a wastewater that is treated and used in compliance with California Code Regulation Title 22, consistent with the Board’s recycled water policy.”

Summary of the 2019 data

Ms. Greenwood then went through the results, noting three big picture takeaways from the first volumetric and report.

In 2019, 3.7 million acre-feet of total influent volume entered wastewater treatment plants. The influent volume represents raw, untreated wastewater and does not include influent to facilities that do not treat raw wastewater, such as some recycled water producers that further treat a primary or secondary effluent.   Treated wastewater effluent discharges totaled 2.7 million acre-feet, which represents a range of treatment levels and the potential source for future recycled water.  Recycled water use was 686,000 acre-feet of recycled water use consistent with Title 22 regulations.

Ms. Greenwood noted that 2.7 million acre-feet plus 686,000 acre-feet doesn’t equal 3.7 million, so why is there a difference? “The difference of about 300,000 acre-feet may be accounted for within plant use, pond storage, water loss, and biosolids, or potential loss of water in the process of treating it,” she said.

So while previous surveys focused on the amount of reuse in California, we now have a much bigger picture of what’s going on with wastewater treatment plants and being able to have both input and output numbers,” she said. “This will enable us to evaluate progress towards the state’s recycled water goals, but also evaluate the impacts of conservation reduced flows into wastewater treatment plants and the true availability of wastewater in California.”

Wastewater treatment plants and treatment levels

With the new reporting requirements, facilities are required to classify themselves based on whether they are producing recycled water in compliance with Title 22 or not.

Of the 710 facilities that reported, the 428 facilities shown in the green color on the map are classified as wastewater treatment plants that do not treat water to Title 22 standards; these facilities receive raw influent wastewater, treat it to a standard, and then discharge it as effluent.

There are 265 treatment plants, shown in bluish-purple on the map, are the wastewater treatment plants that produce recycled water in compliance with Title 22.  There are 17 facilities, shown in yellow, which are considered recycled water producers only. These facilities do not receive raw influent wastewater; rather, they receive treated wastewater from an upstream wastewater treatment plant or another source and treat it further to produce recycled water in compliance with Title 22 for an approved use.

Ms. Greenwood then presented a graph that shows the distribution of the treatment levels across all of the reporting facilities.  She pointed out that the largest volume of wastewater is treated to a secondary standard; the largest treatment category for recycled water is a disinfected tertiary.

This is important in evaluating future tech capabilities of plants to see if upgrading a plant to begin producing recycled water is really feasible,” said Ms. Greenwood.  “For example, if a facility is already treating to a secondary standard, maybe they can do some upgrades to their plant to produce recycled water. But if they do that, what is the feasibility and who would actually take that water once it’s produced?

Effluent volume discharged

So where did all the effluent go? If effluent is not recycled in compliance with Title 22, then that effluent is discharged; the largest effluent volume was discharged to ocean waters, enclosed bays, estuaries, and coastal lagoons at nearly 1.8 million acre-feet per year.  The second-largest category is discharges to inland surface waters at around half a million acre-feet per year.

We also collected an additional level of granularity on that question, and we’re able to identify that 242,000 acre-feet of that was discharged to an inland surface water with a minimum and streamflow requirement,” Ms. Greenwood said. “Although discharge to natural systems is not a recycled water category, in the annual report, we do still capture this data.  Note that it is a beneficial use of water; it’s about 43,000 acre-feet per year.

She noted that this data will be informative in water supply planning and in understanding the potential for future recycled water opportunities. As California looks to increase reuse in water-scarce regions, more proposed recycled water projects will likely need an approved wastewater change petition from the Division of Water Rights before proceeding. At the same time, there may be an increased proportion of California’s inland surface waters that require a minimum instream flow requirement.

Ocean discharges

So, given that most of California’s effluent is discharged to the ocean, how much of that wastewater could feasibly be recycled? And where would it go? And what are the factors that affect that feasibility?

Ms. Greenwood said that the State Water Board is currently funding a research project through the Water Research Foundation to identify the amount of wastewater available and feasible to recycle in California. The project will consider factors that affect the ability to recycle water, such as seasonal supply and demand treatment levels, proximity to potential reuse areas, and the availability of funding.  The project will determine the volume of wastewater available for reuse and identify potential applications and sites to characterize the relative weight of the different factors affecting reuse potential.

The report will help the Board evaluate the goals from the policy on how to increase the reuse of effluent discharge to ocean waters and increase reuse in areas where groundwater supplies are threatened. The final report for this project is due in July of 2022.

Recycled water use

Ms. Greenwood then broke down the details for the 686,000 acre-feet of water recycled in 2019 in compliance with Title 22.  The largest portion of the recycled water went to potable reuse, including seawater intrusion barriers and groundwater recharge. Other uses included golf course irrigation, landscape irrigation, and agricultural irrigation.

In terms of progress as compared to previous years, there was a 1.8% decrease in recycled water use, but she pointed out that this is not an “apples to apples” comparison.”

Besides the exclusion from natural systems as a recycled water use category, the 2019 annual report also does not consider discharges of wastewater to spray fields to be recycled water use,” she said. “This is because although a crop may have been harvested, the primary purpose of this discharge is the disposal of treated wastewater and there is not reuse taking place in compliance with Title 22.  So as we can see from this graph, there’s a decrease in recycled water use in the Central Valley in the yellow color, which may be due in part to the decrease in recycled water use for agriculture irrigation overall.”

Ms. Greenwood acknowledged that out of the 46 reports that have not been filed, 34 are from the Central Valley; however, staff does not think the additional numbers would likely make a significant impact on the recycled water volume.

Recycled water use varies by region.  The Los Angeles and Santa Ana regions have the highest potable uses, and they also use a large portion of non-potable water. The Central Valley region has the highest agricultural reuse of all of the regions.

Recycled water use trends

This slide compares reuse by categories from the 2009 and 2015 surveys and the 2019 annual report.  While not all category categories can be compared directly, Ms. Greenwood said this grouping provides the closest comparison.

As you can see, many other reuse categories stayed around the same, hovering about a similar number over these timeframes,” she said. “For example, golf course irrigation and landscape irrigation are about the same but showing a slight decrease from 2015. These slight decreases in these categories may result from successful conservation efforts coming out of the last drought, but we’re not sure. The biggest difference that you can see in this graph is in agriculture irrigation. In 2009, it was a little under 250,000 acre-feet. It dropped in 2015.  Now it has fallen even further sitting just below 150,000 acre-feet.”

Chair Joaquin Esquivel pointed out that in previous years, wastewater disposed of through spray fields was categorized as recycled water, so the reclassification is the likely source of that great of a reduction. He noted great examples of projects, such as Turlock and Ceres, who are recycling water and selling it for agricultural use.

Hopefully, this can help better explain the drop for what I know, a priority for many of us in the state,” he said.

Ms. Greenwood agreed, noting that they have drawn a hard line for recycled water to be Title 22 compliance; they still collect the numbers for those discharges to lands, such as spray field irrigation and natural wetlands.

We still do have those numbers. It’s just where we’re drawing a line in the sand for what’s considered recycled water use,” said Ms. Greenwood.

She also noted that they had discussions about the potential reasons for the large decrease.  “There may be an overall trend in more water-efficient crops in irrigation practices since the last drought. For example, there’s been significant investment in programs such as CDFA’s State Water Efficiency Enhancement Program, which provides financial assistance in the form of grants to implement irrigation systems that reduce greenhouse gases and save water.”

She pointed out that groundwater recharge is increasing, as is potable reuse. As projects funded through the Prop 1 water recycling funding program begin to come online, that number will likely increase.

Meeting the state’s recycled water goals

Ms. Greenwood acknowledged that the goal to increase water recycling to 2.5 MAF by 2030 is ambitious, and so far, the state is not on track to meet that goal.  However, they’ve taken a significant step forward with being more informed, and now they will have consistent data.

This data set is going to be used to reevaluate and continue to explore options for water recycling increases,” she said. “We’re going to continue to work with the recycled water community and develop new goals informed by these data and be able to track this great resource for California.”

Ms. Greenwood pointed out that there has been significant recent investment in recycled water projects through the State Water board’s water recycling funding program. “From 2015 through 2019, the State Water Board funded 61 projects, representing an additional 190,000 acre-feet per year. About 75% of these projects are still in the construction phase. But we do anticipate a significant increase in recycled water used for groundwater recharge, landscape, irrigation, and agricultural irrigation as a result of the funding from Prop 1, Prop 13, Prop 68, and the Clean Water State Revolving Fund.”

Next steps

As for the next steps, they will be publishing the 2019 data set on the open data portal and will continue to work with facilities that have not yet reported the 2019 data.  Once that is completed, they will notify the Office of Enforcement of the remaining facilities that still need to report to achieve compliance as required. The reporting module in Geo Tracker will be open this month, so any early bird reporters will be able to log in and get the reports entered as soon as they want.  The 2020 annual report data is due by April 30, 2021.

The Annual report is a big step toward making the data consistent, streamlined and centralized. Staff will continue to evaluate water reuse trends and evaluate the impacts of conservation efforts.

Tracking these trends means we’re going to be able to look at some declines in recycled water use, but additionally, potential increases in others, especially with the more potable reuse projects coming online with the development of the regulations for the direct potable reuse,” said Ms. Greenwood. “We’re going to continue to evaluate what’s coming into these plants and where all of the effluent is going so that we can continue to inform other water board programs, including water rights petitions and the water recycling funding program.”

All of these data are going to inform water supply planning efforts,” she continued. “It’s not just going to affect us locally, but it’s going to affect us on a national scale.  We’re going to be able to look at updates to the California Water Plan, track goals in the water resilience portfolio, and support the implementation of the US EPA national water reuse action plan. And finally, these data will allow us to track progress towards goals in the recycled water policy and determine whether revisions to this goal may be appropriate for the next recycled water policy amendment.  This volumetric reporting demonstrates the state board’s commitment to using high-quality data to inform and support the long term stewardship of California’s water resources.”

Chair Joaquin Esquivel expressed appreciation for the presentation, noting that it will show the impact of the regulations. Hopefully, we’ll see increases with the advancement of indirect potable reuse regulations and the increasing groundwater recharge with recycled water. Hopefully, when the direct potable regulations are done, we’ll see a real change and we’ll be well primed to see it and accommodate for it.


On behalf of the California Coastkeeper Alliance, Sean Bothwell was also appreciative of the report.  “This is a really big moment because we never had this data before. We never knew the potential of what we could recycle … I have three major takeaways I want to share with the Board. The first is that we now have this data to set the goals that we have properly. … The current goals that we have for water recycling, you know, need to be tailored to what the data actually shows; we shouldn’t be asking folks to recycle if there’s not the potential out there to recycle it, and we also shouldn’t be cutting ourselves short if there’s more potential out there.”

The second thing … the 1.7 9 million acre-feet of water wasted annually to the ocean. For me, that was a big number, and we’ve been curious to see what is out there because we do find that to be wasteful,” continued Mr. Bothwell.  “Third, now that we have the data, it would be great for the State Board to consider what type of carrots or sticks policy sticks are there to get us to move to meet our goals. For example, what type of financial incentives can we provide for folks that are going to take achieving these goals seriously … And for a more stick-like policy approach, an example could be the state could be not approving ocean desal facilities when in the same region, they are still wastefully discharging millions of acre-feet of water to the ocean every year.”

Daniel Cooper, with LA Waterkeeper, pointed out that in Southern California, 500 million gallons per day were discharged to Santa Monica Bay directly or via the LA River and is a significant contributor to the 1.7 MAF discharged to the ocean.

Just to remind you, the Superior Court did order the State Board to conduct a waste and unreasonable review of those discharges and to decide whether using the water in that manner was reasonable given the overall context,” said Mr. Cooper. “The State Board has the tools in place to conduct the waste and unreasonable use review.  It’s typically done in a water rights permit issuance context. There are precedential orders from all of you setting out the factors to be considered. So there is a process set out that has been implemented a number of times …

Mr. Cooper suggested implementing binding requirements as part of the NPDES permit, rather than voluntary goals. “It’s clear from the report that we’ve stagnated.  Currently, the voluntary program, in the LA Waterkeepers view, is that it’s not making significant progress … We need to have binding commitments in an enforceable permit issued by the regional and or state boards, rather than just voluntary promises from an administration that changes with every election cycle.

Jennifer West with WateReuse pointed out that major potable reuse projects are coming online in Southern California; they are extremely complex projects that have been planned in San Diego and Los Angeles.  They expect these numbers to go up dramatically within the next ten years. She noted that some of these projects are direct potable reuse projects that depend on the Board completing the Direct Potable Reuse regulations.

Ms. West said she was pleased to see the staff included a specific category for reporting instream flows where recycled water is required to be discharged.  “The total we have from this report is 686,000 acre-feet; the instream flow requirement requiring recycled water is 242,000 acre-feet. So I would hope that while we are messaging out these numbers, while we’d like these numbers to be bigger, that one is not optional. And it is a huge benefit that recycled water plays while not technically Title 22. … I just think it’s unnecessarily discounting its use if we do not co report those numbers.”

Regarding the drop in agricultural reuse, Ms. West said she wanted to look closer at the numbers to determine why the decrease. “I would submit that it would be more if recycled water was being applied on a field used for agricultural purposes in a net using agronomic methods. Yes, they might not have filed an engineering report. But I think again, that should count as ag reuse.  Those crops, whether alfalfa or some other low-level crop, would need to be watered with another source. So we need more specifics. And this decrease is so significant that I think it warrants that we are all supportive of agri-use. Obviously, potable reuse is a huge focus for us. But agri-use is important for the state’s narrative goal for maximizing recycled water in the groundwater. So we want to commit to working on it. We’ve already reached out to the farm community and about this decrease because we got a briefing, and they’re willing to work with us too.”

Shahla Farahnak, Deputy Director at the State Water Board, pointed out that there are many facilities in the inland area that both have a Waste Discharge Permit and Recycled Water Permit. “Part of the year, when they have customers, they recycle water, and other portions of the year they’re not recycling the water because there are no customers, so in those cases, they are discharging.  In the future, we could be looking at, are they discharging in the fields that otherwise would have been irrigated with water? or are they discharging in the fields that normally are not irrigated? So those are certainly some of the complications and issues that staff will look at as we move forward in the future.”

Board member DeDe D’Adamo said what strikes her from the comments is that we need to drill down more on the exact use, as well as any impediments that may create a challenge.  “Overall, I think the goal is to increase the agricultural use of recycled water because you don’t have to go through as much treatment as in other uses. And that can be helpful from a greenhouse gas emissions perspective and for beneficial reuse.”

Board member D’Adamo noted that she was involved in the Turlock-Ceres-Modesto project.  “That project aligned really well because the water use by agriculture is not all year round. That project, in particular, has another use, which is the wildlife refuges during a period of time in which the water is not needed for agricultural use. So the stars aligned really well for that project.  Hopefully, there will be other opportunities … the refuges are always seeking additional supplies, as well as agricultural suppliers. So I think there’s potential for an opportunity here.

Jared Voskuhl from the California Association of Sanitation Agencies disagreed with the comments interpreting the data as saying that recycling has been stagnant.  He wonders if the data were adjusted to make it an ‘apples to apples’ comparison and projects under construction were factored in, the number would significantly change. “Such a revised figure for this year would actually exhibit a much more dynamic and successful story about the many great efforts by our members across the state to get projects online,” he said.


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