Bloomberg BNA — Virtually all of the water flushed down toilets and sent down drains in U.S. homes and businesses goes to wastewater treatment plants where it is cleaned up and then discharged into rivers, lakes, streams and oceans.
Only a small percentage is directly reused.
A conservation push spurred in part by drought, and expectations of greater shortages in the future, could change that. Soon, consumers could be irrigating their lawns or washing their cars with water that has come directly from a wastewater treatment plant.
Some might even be drinking it, experts tell Bloomberg BNA.
“We need to view stormwater as tomorrow's drinking water—or wastewater as tomorrow's drinking water,” said Benjamin Grumbles, president of U.S. Water Alliance, which promotes the concept of “one water” rather than the traditional approach of treating and regulating wastewater and drinking water separately.
In many areas, especially in the arid Southwest, reclaimed water is already being used to water golf courses or to fill fountains. But with predictions of increasingly dry periods, a result of climate change, and a growing demand for water, the use of reclaimed wastewater in more applications is expected to grow.
Cost of Recycling Water Poses Challenge
Communities looking to recycle wastewater face numerous challenges, cost being the primary concern. While many consumers would prefer that all recycled wastewater be fit for human consumption—an expensive proposition—some experts who spoke to BBNA said localities should have the flexibility to vary wastewater treatment for end use and thereby cut down on the treatment costs.
“My opinion is that reused water should be ‘fit for purpose,' but as a minimum be treated to allow for unrestricted reuse, but not necessarily potable standards,” Graham Symmonds, senior vice president of regulatory affairs and compliance and chief technology officer at Global Water Resources, told BBNA in an e-mail. His Arizona-based company owns and operates water, wastewater and recycled water utilities.
Wastewater treatment generally involves the physical separation of solids, followed by a secondary biological treatment to kill bacteria. Many facilities employ a third process to remove more contaminants and to address nutrients.
Using these treatment processes, the West Basin Municipal Water District in Carson, Calif., near Los Angeles, produces five distinct types of recycled wastewater for different end uses. The cleanest—treated beyond drinking water standards—is sent into underground wells that line the coast and act as barriers against the sea. On the other end of the scale, water used for irrigation undergoes a less intensive level of treatment and may not be suitable for drinking.
Treating wastewater to a higher level of cleanliness requires more energy and thereby more expense, and the level of treatment required depends on the effluent limits contained in each utility's National Pollutant Discharge Elimination System permit.
Treating for Specific Applications
Wade Miller, former executive director of the nonprofit WaterReuse Association and the WaterReuse Research Association, told BBNA that water should be treated only to the purity level needed for the application. Water treated at drinking water standards is not needed to irrigate highway medians or for toilet flushing in high-rise buildings in Irvine, Calif., he said.
“We don't use jet fuel to heat our homes. Nor can we use the 3-in-1 oil that we use to lubricate a squeaky door to power our automobiles,” Miller said in an e-mail. “Oil yields many different qualities of products for various applications. So does water.”
Under the Clean Water Act, EPA regulates direct wastewater discharges to surface waters through the National Pollutant Discharge Elimination System permit program. Discharges of industrial wastewater to the sewer system are regulated through the pretreatment program in which the treatment plant operator serves as the regulator to ensure no harmful pollutants pass through or interfere with the treatment works.
No Explicit Regulations for Reuse
No explicit federal regulations govern the treatment of wastewater for reuse.
“From a legal perspective, the Safe Drinking Water Act and the Clean Water Act don't really address water reuse. Water reuse falls between the cracks,” said Grumbles, who formerly was the EPA assistant administrator for water in the administration of George W. Bush and former secretary of the Arizona Department of Environmental Quality.
In an e-mail to BBNA, EPA noted: “there are no federal regulations directly governing water reuse practices in the United States; reclaimed water is regulated by individual states.”
The agency said it supports efficient water use practices, including well-planned recycling, and since 1980 has issued guidelines for water recycling for nonpotable uses and indirect potable uses, most recently in 2012.
One barrier to moving forward on expanding the types of uses for reclaimed water is public acceptance or what many in the treatment industry refer to as overcoming the “yuck factor.” In 2000, the Los Angeles Department of Water and Development completed a sewage reclamation plant in Van Nuys capable of providing water to 120,000 homes. The plan was shelved when several media outlets referred to it as “toilet to tap,” sparking public opposition.
The department is preparing a study on the feasibility of direct potable reuse in California by 2016, according to information on its website. By 2035, the city projects a demand for more than 168,000 acre feet per year of imported water even after implementing nonpotable reuse and groundwater replenishment projects.
By 2035, the city's recycled water master plan calls for expanding nonpotable reuse systems, via a purple pipe network, to provide 29,000 acre feet per year of recycled water for irrigation, industrial cooling, and other non drinking uses. The plan also seeks to replenish groundwater in the San Fernando Basin with up to 30,000 acre feet per year of purified cycled water.
“You have to look at water and see how it will be reused,” said Bill Bonkoski, executive sales manager for GE water and process technologies whose focus is on water reuse.
According to Bonkoski, wastewater can be treated for indirect use, such as injecting very high quality wastewater effluent into a lake that has a drinking water intake pipe at the bottom as GE has done with Lake Lanier outside of Atlanta, and with the Potomac River in Northern Virginia, or for direct use by residents through purple pipes, as is the case in Florida.
In Singapore, Bonkoski, said the state had to run a massive public relations campaign to persuade the people to directly consume treated wastewater.
And in San Diego, initially there was nonacceptance, but then the community saw the benefits of water reuse, according to Eileen O'Neil, executive director of the Water Environment Federation (WEF), a nonprofit organization for water quality professionals.
The National Research Council in a 2012 study found the risk of contamination from potable reused water to be much lower than that from existing water supplies.
EPA Should Set Minimum Standards, Officials Say
Still, the NRC and most analysts interviewed by BBNA agreed that the EPA ought to at least establish minimum federal risk-based standards under the Clean Water Act to regulate nonpotable uses of treated municipal wastewater, municipal wastewater effluent or reclaimed water.
These minimum standards would set a baseline for states and offer some uniformity, the NRC report said.
Ron Wildermuth, the public affairs manager at the West Basin Municipal Water District, said that the utility would like both state and federal standards.
“Federal have general, minimum requirements and states have more specific standards applicable to their goals,” Wildermuth said.
Unlike other water officials, Barry Liner, WEF director of water science and engineering, said that basing the treatment level on how the water is to be used could eliminate the need for a specific numeric federal standard. But he agreed that federal involvement would give the issue national visibility that it needs.
Jason Dadakis, regulatory affairs liasion for the Orange County Water District in California, said the need for a federal minimum health risk standard is obviated in states such as California and Florida, which have “mature” programs. A federal standard would be helpful in states that have no regulations on the books, but are just starting to recycle wastewater.
EPA reported in its 2012 Guidelines for Water Reuse that 30 states and one U.S. territory have adopted regulations, and 15 states have guidelines or design standards, that govern water reuse.
The 2012 revised EPA guidelines include recommendations states should consider as they build water reuse programs, but the agency has preferred to let states take the lead on tailoring water reuse to fit their end uses.
Regulated by Individual States
Communities in arid regions have been the first to adopt water reuse, such as those in Arizona, California, Florida and Texas.
Georgia, not typically thought of as an arid state, but one that has experienced severe drought in recent years, has had to rely on treated wastewater to recharge the underlying water table.
In January, California Gov. Jerry Brown (D) declared a drought emergency for that state after the National Weather Service issued an outlook projecting the dry conditions along the West Coast would “persist and worsen” through the spring.
In the days following the drought emergency, California released a five-year action plan to manage the state's scarce water supplies. In that plan, California said that “most new water will come from a combination of improved conservation and water use efficiency, conjunctive water management (i.e., coordinated management of surface and groundwater), recycled water, drinking water treatment, groundwater remediation, and brackish and seawater desalination.”
Water always has been scarce in California. In Southern California, water districts began exploring the use of recycled water during the severe drought of the late ‘80s and the early ‘90s, Wildermuth, of the West Basin Municipal Water District, said.
In particular, the utilities considered the use of both water imported from Northern California and recycled water to replenish groundwater aquifers and protect them from seawater intrusion. Groundwater aquifers are the main sources of drinking water in Southern California.
Treating Wastewater for End Use
Symmonds, of Global Water Resources, told BBNA that most recycled wastewater provided to customers is not for human consumption. He wrote in a May 2011 presentation to the International Desalination Association that 39 percent is used outside the home for things like washing cars and watering yards, while toilet use represents about 25 percent of the total water demand for a residence.
“These are ideal applications for recycled water and represent an opportunity to replace at least 59 percent of the water demand with a nonpotable supply,” said Symmonds.
Some, such as WEF's O'Neil are encouraging wastewater utilities to view treated wastewater as an option a community can use to meet its water needs, for industrial, commercial, or residential purposes.
And WEF's Liner would like the public to view reclaimed water as a product, not as waste. “Like any product, you want to make the product for the intended use,” he said.
Replenishing Groundwater With Treated Wastewater
The Orange County Water District and the Orange County Sanitation District in Southern California have jointly operated a Groundwater Replenishment System since January 2008. Highly treated wastewater that would have normally been discharged into the Pacific Ocean is purified using a three-step advanced wastewater treatment process consisting of micro filtration, reverse osmosis and ultraviolet light with hydrogen peroxide.
According to the districts, the process produces high-quality water that exceeds all state and federal drinking water standards. This water is then injected into a seawater barrier and pumped to recharge basins, where it naturally percolates into the groundwater basin.
The districts have been producing 70 million gallons of water daily since this replenishment system became operational. About half of this water serves as a seawater intrusion barrier, while the remainder is pumped in a 13-mile-long pipe to recharge basins in Anaheim, where it filters through sand and gravel to replenish the deep aquifers of Orange County's groundwater basin and becomes part of the region's drinking water supplies.
In South Florida, the Miami-Dade Water and Sewer Department provides 90 million gallons of wastewater treated with high level disinfectants daily for Florida Power and Light's cooling processes, under a 2012 agreement. Douglas Yoder, deputy director of the department, said the county was required by its 20-year water use permit to reuse 170 million gallons a day of treated wastewater, and the agreement helped it to both meet its mandate and to save money.
But Yoder criticized as too expensive a Florida mandate that requires it to extensively treat and use reverse osmosis techniques on reclaimed water to recharge the Biscayne Aquifer.
Likewise, Virginia regulations require wastewater slated for use in recycling to be treated beyond the standards the state sets for drinking water.
Tom Bonacquisti, director of water treatment at the Broad Run Treatment facility in Loudoun County, Va., told BBNA that all the water it sells is used to cool data centers, and yet Virginia law requires that wastewater be treated beyond drinking water standards. The facility is located upstream of a drinking water treatment plant on the Potomac River.
Potential for Overtreatment
In an October 2013 webcast for the WateReuse Association, Larry Schimmoller, global technology leader of water reuse at CH2M Hill, and Mary Jo Kealy, senior principal economist at CH2M Hill, presented findings from a study they conducted to ensure that the right wastewater treatment process was being applied for the intended use without expending unnecessary funds, energy, and greenhouse gas emissions.
The analysis—which required a simultaneous assessment of full lifetime costs, environmental costs of complying, and social costs owing to public perception—found a potential for overtreatment for both potable and nonpotable uses.
The WateReuse Association and the WateReuse Research Association are currently working with the West Basin Municipal Water District and several other California water utilities to explore the barriers to use of recycled water for direct potable use, according to Wildermuth.
Traditional System ‘Flawed'
Symmonds finds the traditional design of water distribution systems to be flawed from a water efficiency and conservation perspective because it only provides one piped source of water for use.
Under this system, he said, “communities are locked into a model in which all water must be treated to potable standards; all water must be maintained at a suitable pressure for instantaneous use; and new water must be found and accessed for each new unit.”
Using reclaimed water as a direct potable source is costly, but scarcity of water is driving people to rethink the current model of wastewater treatment plants.
“We have these massive wastewater treatment plants that are located at the lowest points by the river,” Symmonds said. “We have to pump recycled water all the way back to the customer. That adds cost and requires infrastructure, such as pipes.”
Instead, Symmonds recommends decentralized small plants located near where the water is treated and used.
Future Conflicts Over Water, Not Oil
Climate change and population increases are placing a growing demand on water resources that many think will lead to conflict.
In his book “Water: Asia's new battleground,” Brahma Chellaney, an Indian scholar on strategic studies, said future global conflicts will pivot around water supplies, not fuel.
Such conflicts have existed for centuries, but Chellaney say they will come to a head in this century.
Others agree that water conflicts are inevitable.
“The list of civilizations that have fallen due to drought is a long one, and with more people, essentially no additional water supplies and different precipitation patterns from what occurred when most water laws were created, water users face significant challenges,” Eric Garner, an attorney in the Los Angeles office of Best Best and Krieger LLP, said in a Feb. 24 BNA Insights piece, adding that there will be “no end to conflict over water.”
Right now, wastewater recycling is occurring most often in those parts of the world, including the U.S., where water supplies are stressed.
A January 2013 Bloomberg New Energy Finance study on water reuse said, however, that the U.S. and Europe discharge 90 percent of their wastewater annually, but directly reuse only 6 percent and 2 percent, respectively.
China treats around 80 percent of its wastewater, but directly reuses only 8 percent.
In the Middle East and North Africa, only 40 percent of municipal wastewater is treated for use in agriculture, and 8 percent for disposal, while the remainder is discharged into the ocean or other water bodies.
In the coming decades, more U.S. and international communities could join those parts of the world where water supplies are stressed. Seven in 10 U.S. counties could risk freshwater shortages by 2050, with one in three counties classified as having a high or extreme risk of water shortages in the same time period, owing to a increasing water demand and climate change impacts, a 2005 American Chemical Society report states.
Thirty-seven countries out of 181 nations that were evaluated show “extremely high” levels of water stress, meaning that more than 80 percent of the water available to agricultural, domestic and industrial users is withdrawn annually, the World Resources Institute reported in December 2013.
The Future of Water
In order to consider wastewater as a cost-effective, reusable resource, analysts say, the public has to move past the traditional thinking of pumping, treating and disposing wastewater at one central location.
In February 2013, WEF, in partnership with the National Association of Clean Water Agencies, released a blueprint for a utility of the future, which embraces water reuse as a potential recyclable resource, and a revenue source. The blueprint spells out the role of wastewater utilities in the near future as water supplies grow scarce, funds shrink, and needs for cleaner water increase.
With demand growing for water globally, analysts say, treated wastewater cannot be viewed through a traditional lens anymore.
The NRC report said 32 billion gallons of wastewater effluent are discharged daily in the U.S., but the agency claims only 1 percent is actually reused. The NRC does not account for de facto use of wastewater, or treated wastewater that is discharged upstream of drinking water pipes.
“Expanding water reuse—the use of treated wastewater for beneficial purposes including irrigation, industrial uses, and drinking water augmentation—could significantly increase the nation's total available water resources,” the NRC concluded.
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