Found Water: Reuse and the Deconstruction of “Wastewater”

By G. Tracy Mehan, III


In the classic 1942 film “Casablanca,” Rick, played by Humphrey Bogart, is asked by the world-weary Vichy French Captain Renault, played by Claude Rains, “What in heaven’s name brought you to Casablanca?”

“I came to Casablanca for the waters,” replies Rick. Captain Renault responds, “The waters? What waters? We’re in a desert.”

“I was misinformed,” deadpans Rick.

So what, in heaven’s name, has brought so many Americans to live in the desert or arid regions—say, drought-plagued California or the Colorado River basin? Arizona increased its population by 40 percent between 1990 and 2018, Colorado by 30 percent. Clark County, Nevada, home to Las Vegas, doubled its water consumption between 1985 and 2000. Water levels in nearby Lakes Mead and Powell are dropping precipitously. California will grow to 44.1 million people by 2030 from 38.7 million in 2015. Add the risk of drought, climate variability, loss of snowpack, and groundwater depletion to this growth as aggravating water supply challenges. Were all the Americans moving west misinformed?

The Paris-based Organization for Economic Co-operation and Development (OECD) notes that global water demand is projected to increase 55 percent due to growing demand from manufacturing, thermal electricity generation, and domestic use—largely from emerging economies and developing countries (OECD, 2012).

Western states have made solid progress in reducing water consumption over the past few years. But the question remains: can water utilities keep up with growing populations, expanding economies, drought, and climate variability?

A set of new practices and technologies, collectively referred to as water reuse, provide new opportunities to discover “found water” in a community’s own wastewater stream and convert it into a valuable resource (American Water Works Association, 2016). These new approaches deconstruct the very idea of “wastewater.” No longer is there such a thing. There is only water that is wasted.

The Future of Water

Like Rick in “Casablanca,” many are misinformed as to what water reuse entails. A primer published by the American Water Works Association in 2016 provides some useful definitions. Water reuse involves using water more than once to expand a community’s available supply. Nonpotable reuse refers to water that is not used for drinking but is safe to use for its intended purpose, such as irrigation (including golf courses and lawns) or industrial processes. Potable reuse “refers to recycled or reclaimed water that is safe for drinking.” Indirect potable reuse “introduces purified water into an environmental buffer” (like a groundwater aquifer, reservoir, or lake) “before the blended water is introduced into a water supply system.” Finally, direct potable reuse “introduces purified water directly into an existing water supply system.” Direct potable reuse is the final frontier of water reuse and is just beginning to come into its own in the United States (Alex Gerling, Opflow, 2018).

Water reuse is local, sustainable, and cost-effective because wastewater is available even during drought conditions and causes less damage to the environment than other water-supply solutions like dams, reservoirs, and canals. It is an interesting question whether, because of cost advantages, reuse may in the long run outdistance desalination of ocean water. The competition, though, is healthy; and both are needed (Jennifer Duffy, HDR, 2018).

In 2012 the board of the Water Environment Federation, the primary organization for wastewater utilities in the United States, formally replaced the traditional term “water treatment plant” with “water resource recovery facility,” to reflect the facilities’ expanded functions—recovering and reusing water, nutrients, and energy (Water Environment Federation, 2014). This shift represents what Berkeley professor David Sedlak has described as Water 4.0 in his 2014 book of the same name. In the beginning Water 4.0 will look like upgraded versions of current centralized systems in which “imported water will be supplemented or replaced by desalination and potable water recycling,” according to Sedlak, along with a vast array of incentives for conservation. Sewage treatment plants “will evolve from a means of protecting surface waters from pollution to systems that recover water, energy, and nutrients from the sewage” (David Sedlak, 2014).

Ancient Romans perfected our current linear model of moving water from a source, often distant, through a treatment train, and then distributing it to water users. That model will now be complemented, not necessarily replaced, by an integrated portfolio that includes a circular model of reuse.


These new approaches deconstruct the very idea of “wastewater.” No longer is there such a thing. There is only water that is wasted.


The Rise of Water Reuse

Wastewater is treated for release to nearby rivers or other surface waters by a combination of biological treatment and clarification that allows solids to settle. But for potable reuse, plants must also take additional treatment steps, including membrane filtration to remove particles and microorganisms, reverse osmosis to remove salts and contaminants, advanced oxidation with UV disinfection, and disinfection with chlorine and potentially granular activated carbon as well.

One of the early pioneers of indirect potable reuse in the United States was not in the arid west but in northern Virginia. Beginning in the mid-twentieth century, suburban development led to the profusion of wastewater pollution into a drinking water source, the Occoquan Reservoir, one of the area’s two primary sources of water that today serve nearly two million residents just outside Washington, DC. By the early 1970s, eleven wastewater plants were all discharging into tributaries of the reservoir, thereby polluting an important source of drinking water.

As a solution, all wastewater was rerouted to a single wastewater treatment plant equipped with technologies that, according to Dr. Sedlak, were “a water engineer’s dream.” Observes Sedlak, “The plant’s designers threw everything they could come up with at the wastewater: activated sludge, filtration, activated carbon treatment, ion exchange, chlorination, and lime clarification.”

After this expanded treatment, “the water in the Occoquan Reservoir was probably better than water flowing in rivers and reservoirs downstream of many cities,” writes Sedlak.

There was resistance in the water sector to reuse based on the standards of source water protection or the “multiple-barrier approach” to drinking water protection. According to the American Water Works Association’s G300 standard, this approach requires selecting the highest-quality source water possible and protecting that source, among other steps (American Water Works Association, 2014). Observers asked: is reused water the highest quality? Time, experience, and necessity have substantially reduced concerns, but care must be taken in the design and operation of any system given that public health is at stake, most especially for direct potable reuse. Pathogens, say, require careful attention.

Out of concern for public health impacts, the WateReuse Association, American Water Works Association, and the Water Environment Federation contracted with the National Water Research Institute to convene an expert panel and develop a risk management strategy for direct potable reuse based on the available research. In 2015, the panel released its Framework for Direct Potable Reuse: A Path Forward, the first of its kind in the United States (Journal AWWA, 2015). It provides a systems approach to developing direct potable reuse through modern technology, control systems, governance structures, and personnel training for the protection of public health.

Presently, there is no direct federal regulation of potable reuse other than the baseline water quality statutes of the Safe Drinking Water and Clean Water Acts, the fundamental regulations with which all projects must comply. Nevertheless, the Environmental Protection Agency published nonbinding guidelines for reuse in 2012 and followed with a 2017 Potable Reuse Compendium, both very useful resources.

Many states are moving forward with their own regulatory regimes for direct potable reuse (U.S. Environmental Protection Agency, 2017). According to HDR, an international engineering firm, no states have yet promulgated regulations for direct drinking water reuse (although they do regulate other kinds of reuse). North Carolina is moving in that direction, though, and approved legislation in 2014 allowing limited direct potable reuse with engineered storage buffering and blending with other sources. In 2016 the California State Water Resource Control Board concluded it is feasible to develop uniform water quality criteria for direct potable reuse, a big first step toward regulation. Thus, the 2015 Framework will help utilities and communities navigate such regulatory requirements.

Las Vegas may be associated in the popular mind with wretched excess but suffers from no excess supplies of water. The Las Vegas strip is home to many of the world’s largest hotels, with fountains, a lake, and even pirate ship battles in the middle of a scorching desert. Water reuse and recycling make this all possible. When the political pundit George Will visited the city in 2009, he was impressed that the average hotel room used 300 gallons per day, almost all of it recycled. The strip uses between one and three percent of Nevada’s water but accounts for close to 60 percent of its economic output. Statewide, agriculture accounts for 75 percent of water use.

Water reuse is a new source of supply for California’s Orange County Water District, which provides drinking water to 2.5 million people in a region with less than 15 inches of precipitation annually. The district wholesales groundwater to retail water agencies serving the county. In 2018 the utility celebrated the 10th anniversary of its Groundwater Replenishment System, the world’s largest potable reuse project. Orange County now has diverse sources of water including the Santa Anna River, rainfall, imported water from the State Water Project and the Colorado River as well as potable reuse. According Mike Markus, general manager of Orange County Water District, the Groundwater Replenishment System takes treated wastewater which would otherwise flow to the sea and puts it through advanced purification utilizing microfiltration, reverse osmosis, and ultraviolet light with hydrogen peroxide (Municipal Water Leader, 2018). Approximately one-third of this water is injected into a seawater barrier along the coast, and pumps the remainder is pumped to recharge basins 17 miles away. This is a new source of supply for the groundwater basin and produces 100 million gallons per day. Potable reuse provides 30 percent of the basin’s supply. The district operates under very strict California standards.

In California, the Orange County Water District’s Groundwater Replenishment System takes treated wastewater which would otherwise flow to the sea and puts it through advanced purification process to produce potable water.

Orange County’s project is cutting edge. It starts with treated wastewater and serves up purified water. It pumps this water into a groundwater basin taking a year to move through sand, gravel, and clay before consumption as drinking water. The advanced treated water is cleaner than the groundwater into which it is injected (Sedlak, 2014).

More reuse is coming in California. The City of San Diego is pursuing its Pure Water project, a $1.4 billion investment in a new advance facility to produce 30 million gallons per day of high-quality drinking water (Water Finance & Management, 2018). And the Metropolitan Water District of Southern California, in partnership with the Sanitation Districts of Los Angeles County, is commencing a $13.9 million pilot, a first step toward what will be the Regional Recycled Water Program, one of the world’s largest water recycling projects. The pilot’s advanced water treatment demonstration facility will take treated wastewater and purify it with a view to replenishing the region’s groundwater basin. The complete project will cost $2.7 billion (Water World, 2017).

In Texas, El Paso is pursuing potable reuse given concerns with decreasing flows in the Rio Grande. According to a 2018 story from CNN Health’s Nadia Kounang, “Now, El Paso is on track to become the first large city in the United States to treat its sewage and send it directly back into its taps” (CNN Health, 2018). Technology, necessity, and familiarity may be swinging public perceptions in favor of reused water. In 2017 the global water technology company Xylem commissioned a survey of California residents regarding attitudes on recycled water (Water Finance & Management, 2018). Three-quarters “supported using recycled water as an additional local water supply, regardless of water shortages.” Eighty-seven percent “were willing to use recycled water in their daily lives.” Seventy-five percent indicated that they “felt more willing to use recycled water for personal household purposes after learning more about the treatment process used to purify recycled water.” And 90 percent said they would be supportive if it reduced monthly bills.

Back in Virginia the Hampton Roads Sanitation District, serving 1.7 million people over 3,087 square miles, has established its Sustainable Water Initiative for Tomorrow (SWIFT) with the opening of the SWIFT Research Center (Hampton Roads Sanitation District, 2018). Hampton Roads is home to the world’s largest naval base. As we will see, the initiative delivers multiple benefits. The center replenishes the Potomac Aquifer with one million gallons per day of effluent from the nearby treatment plant, adding advanced treatment (ozone biofiltration with granular activated carbon adsorption) meeting safe drinking water standards for public health as opposed to just ambient water quality standards under the Clean Water Act. The research center will provide data to inform permitting and design of full-scale implementation at five facilities throughout the region. These new reuse-ready facilities will have a combined capacity in excess of 100 million gallons per day by 2030.

Of no small consequence for the Chesapeake Bay and its tributaries, at full-scale the initiative will reduce nutrient discharge by approximately 90 percent below current requirements of the applicable total maximum daily limit, the relevant pollution budget. That is nearly three million pounds of nitrogen and 300,000 pounds of phosphorus for the James River alone. These reductions have made the Hampton Roads Sanitation District a nutrient credit supplier in the trading market for 11 localities holding “MS4” stormwater permits, supplying 95 percent of the reductions the municipalities together required.

The Hampton Roads project also has the potential to reduce the rate of land subsidence, the harmful sinking of land due to aquifer withdrawal. In this region it accounts for roughly 25 percent of net sea level rise, and early modeling data indicate that aquifer recharge may actually slow, stop, or reverse subsidence (Hampton Roads Sanitation District, 2018).

The Way Forward

Policy recommendations for water reuse and recycling usually involve a mix of subsidies; mandates; educational and recognition programs; and the elimination of regulatory barriers (General Electric Ecomagination, 2015). For instance, California’s Water Code Section 13551 states, “A person or public agency, including a state agency, city, county, city and county district, or any other political subdivision of the state, shall not use water from any source of quality suitable for potable domestic use for nonpotable uses” (California Water Code Sec. 13551). Florida’s “Ocean Outfall” bill of 2008 requires all facilities discharging domestic wastewater through outfall pipes into the ocean to meet higher treatment requirements and achieve at least 60 percent reuse of the wastewater by 2025.

Presently, reuse is eligible for funding under the new federal Water Infrastructure and Finance Innovation Act as well as state revolving loan programs under the Clean Water and Safe Drinking Water Acts. The Bureau of Reclamation also funds projects under its Title XVI program. The WateReuse Association recommends the establishment of a federal tax credit for retrofitting industrial facilities to use municipal recycled water or to recycle water onsite. The group also believes that federal procurement mandates, such as Buy America requirements that limit purchase of imported goods, impair the development of critical infrastructure including water reuse and recycling.

The question of federal regulation of this evolving practice is often raised. Yet, this may be an instance where the concept of state laboratories or “laboratories of democracy,” as articulated by Justice Louis D. Brandeis’s famous 1932 dissent in New State Ice Co. v. Liebmann, makes sense for testing new laws and regulations (New State Ice Co. v. Liebmann, 1932). Brandeis suggested state jurisdictions should be allowed “to try novel social and economic experiments without risk to the rest of the country.” There is constant research and technological innovation underway in the water reuse space, and there may be a real danger of locking in, by way of national regulation, what may become obsolete technology given the ponderous pace of federal regulating and the near impossibility of changing existing environmental laws post-factum. Also, private voluntary associations and international bodies have been effectively working to develop practices, standards, frameworks, and manuals for all aspects of reuse projects.

According to Bluefield Research, current reuse capacity of reclaimed flows in the United States is expected to increase 37 percent by 2027 (Bluefield Research, 2017). Industrial applications will grow 31 percent by the same year. The United States is already the largest reuse market by volume with further future growth projected. The development of water reuse is a sustained, organic process of measured growth and evolution and should be allowed to proceed at its own pace and continue to prove its effectiveness over time.


Tracy Mehan, III, is the executive director of government affairs for the American Water Works Association (AWWA) in Washington, D.C. He served as Assistant Administrator for Water at the U.S. Environmental Protection Agency from 2001-2003.

This piece was authored by Mehan for the recent book, “A Better Planet: Forty Big Ideas for a Sustainable Future,” published by Yale University Press. Reprinted with permission. Copyright ©2019 Yale University.

One Comment

  1. A few years ago, the State of California, in part on my instance, created a panel of experts to look at the development and use of recycled water and potential public health impacts. Unfortunately, the State’s initial panel did not have expertise in the generation and through-put of antibiotic resistant microbes, as results from the conversion of wastewater into recycled. Nonetheless, because it lacked the necessary understandings on the development and augmentation of resistant organisms and their genes, this initial panel deemed the process to be safe and stated so in their report. I flagged this deficiency and that panel later, in a subsequent report, admitted that it did not have the requisite background to make such statements.

    Wishing to still promote the expansion of recycled water, the State convened a subsequent panel that did look at the unavoidable generation, inclusion and dispersal of antibiotic resistant microbes and their recalcitrant genes in Title 22 wastewater from which most recycled water is generated.

    This later panel came out with a report (Expert Panel Final Report, August 2016) produced the following: (Evaluation of the Feasibility of Developing Uniform Water Recycling Criteria for Direct Potable Reuse, CSWRCB).

    In its recommendations, that expert panel noted the need for those contemplating the direct potable use, to have a well organized association with a local public health agency to track potential blow-outs and rise in epidemiology indicators that might be associated with the direct potable reuse (DPR) of recycled water. In checking with the state Department of Public Health, that agency thinks that there may be three counties in the state that would have the capacity to undertake this function. In checking within my local area (Santa Barbara County) of the agencies that one might presume to be associated with this public health function, none feel this is within their jurisdiction; also these agencies are ill equipped or staffed for such a function and there is no funding. Notwithstanding this apparent lack of interest and capacity, water agencies seem to be pushing ahead on developing programs for reuse.

    There is a serious policy disconnect in this that warrants review.

    Dr Edo McGowan

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