top of page

A “turning point in California’s history”—The Golden State opens the floodgates for recycled water

water basin with mountains overlayed by scientist testing water
Badwater Basin, California. Image Credits: Karsten Winegeart // Unsplash and Orange County Water District. Graphic by Miquéla Thornton

Located in Orange County, California is the world’s largest water purification system for what’s known as indirect potable reuse, aka the most advanced wastewater treatment on Earth, second only to what Mother Nature does herself.

In the case of the Orange County system, which is a groundwater replenishment system or GWRS, previously discharged wastewater from the Pacific Ocean is scrubbed vigorously in a three-step process of microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide until it exceeds all state and federal drinking water standards.

This system provides 130 million gallons of clean water for one million people every day. All of it comes from wastewater that would otherwise be as the name implies… wasted.

However, this is an “indirect” system because as Peter Yolles, founder and managing partner at Echo River Capital, a Bay Area firm investing in water tech for climate adaption, explains in a recent blog post, the water does not go straight into drinking water pipes because some people find it well… “icky.”

The feeling is understandable. Sometimes referred to as “toilet-to-tap,” direct potable reuse has the same rigorous cleaning process as indirect but instead of being pumped into the groundwater basin and blended with 25% dilution water, as the GWRS water is, it’s siphoned directly into drinking water pipes.

The only reason GWRS water is blended is as a precautionary measure. Nevertheless, as the Orange County Water District confirms, “reports have been and continue to validate that the GWRS creates water of the highest quality” that exceeds all standards.

If this water was directly used, however, it could be a game-changer for California’s cache of drinking water amid continuous droughts, which last month, caused the state to allocate $217 million to combat its impacts.

groundwater replenishment system facility, outside
Image Credit: OWDC

The reason direct potable reuse has yet to be a thing is that, as Yolles writes, “The ick factor has prevented California’s water utilities from recycling and reusing even more because it’s hard to find places to recharge groundwater.”

However new legislation from the Golden State allowing for direct water reuse could change that.

The Orange County GWRS system already provides a titanic amount of water for the Kraemer, La Palma, Miller, and Miraloma basins, approximately 35%. The rest comes from the treasured Santa Ana River, rainfall, and imported water from northern California, and the Colorado River.

Yet, as FootPrint Coalition readers know, the Colorado River is relied on by seven states and the basin is slowly diminishing due to climate-fueled prolonged dry spells and excess water demand.

When a third of California’s groundwater comes from rainfall and imported Colorado River water, drought combined with the state’s Colorado River woes are causing the groundwater basins to be depleted.

With the pressures of the climate crisis — from warming temperatures and volatile precipitation to rising sea levels, shrinking snowpack, and wet seasons morphing from long and replenishing to short and intense — California’s groundwater reserves are under pressure.

This depletion could be catastrophic. Together, the state’s 515 groundwater basins and subbasins provide 41% of Californian drinking water, and during dry years, this percentage jumps to upwards of 60%, with 83% of Californians drinking some amount of groundwater and some communities 100% reliant on it.

water basin with mountains
Image Credit: OWDC

That’s why, with the goal of advancing Governor Newsom’s Water Supply Strategy to adapt to a “hotter, drier future,” the State Water Resources Control Board is proposing new 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 proposed regulations, which were announced on July 11, would, as the board puts it, “generate a climate-resilient water source while reducing the amount of wastewater they release to rivers and the ocean.”

It’s a “turning point in California’s history with recycled water,” the board said in the release. In the 20th century, the state began using recycled wastewater for crops. Now, with an evaluation from an expert panel of 12 scientists and engineers, they’ve concluded opening up wastewater for direct reuse is protective of public health amid the climate crisis.

If approved, California would lead the nation in this type of adaptation measure.

“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,” Darrin Polhemus, deputy director for the Division of Drinking Water said in a statement.

“In fact,” he adds, “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.”

Already, Newsom’s strategy includes the goal of recycling and reusing at least 800,000 acre-feet of water per year by 2030. Still, if the direct usage is approved, systems like that of GWRS can create exceptional drinking water from wastewater in a matter of hours, rather than solely undergoing the long process of indirect use which improves treated wastewater through dilution. However, this process takes 2 years.

Image Credit: OWDC

Reports continuously show that GWRS water does not need to be diluted to be safe. That’s why the California Department of Public Health’s permit requiring it for the seawater barrier, a dam that prevents seawater intrusion into groundwater, was lifted in 2010.

If the legislation is approved, Yolles says it will unlock so much value at once. “Water systems will be able to improve their water supply reliability; lower their energy intensity and carbon footprint; and improve the financial stability,” he lists. “This change will also serve to expand the markets for critical technologies that have been piloted and tested and have needed greater commercialization to realize their financial potential.”

Already, water agencies in Santa Clara, San Diego, and the city of Los Angeles have launched pilot projects in recent years, demonstrating this very potential.

“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,” Polhemus said.

“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.”

Image Credit: OWDC

In addition to city agencies, startups have been on the frontlines of wastewater reuse. Earlier this year when the federal government ruled that California would have to use 13% less water amid the Colorado River drought, FootPrint Coalition interviewed Scott Bryan, president of Imagine H2O, a water tech startup accelerator, who said that water reuse projects would be low-hanging fruit the state could easily pluck to meet, and even exceed its goals.

He referenced a deluge of startups including Epic Cleantec, a portfolio company of both Imagine H2O and Echo River Capital which last year, brewed and distributed beer made with recycled water to sway the public’s perception away from thinking water reuse is icky to one that perceives it as normal.

As Epic, which is operating the first approved and operational greywater reuse system in San Francisco, put it in a blog post, “In spite of the fact that there are growing number of brewers embracing the concept of recycled water, there is a public perception that the water is of lesser quality.” Yet, “recycled water is not only safe to drink, but is often even cleaner than many sources of water we commonly consume.”

As Yolles explains, the process of water reuse uses science to mimic what’s accomplished by nature, but instead of soil we use filters, and instead of sunlight, we turn to ultraviolet. In reality, Mother Nature already recycles all of the water we use and drink.

According to Epic co-founder Igor Tartakovsky, who is originally trained in aerospace science, reclaimed water is what astronauts are drinking in space.

It seems that Bryan was right on the money when he said California should turn to water reuse as it attempts to both comply with new federal legislation in the short term and ensure its residents have enough to drink in the long term. If approved the California legislation will be a pivotal change in the water landscape for the state and perhaps the rest of the country — we will all have to drink like the astronauts.


bottom of page