We have posted about “toilet-to-tap” initiatives in several cities in Texas in the past. Now, California, is expanding their embrace of the technology. From CNBC:
As the California drought worsens, some communities such as Orange County, San Diego and the Silicon Valley are expanding water recycling programs, and support for “toilet to tap” programs appears to be growing from a once-squeamish public.
The Silicon Valley Advanced Water Purification Center, located in San Jose, began operations last year and produces up to 8 million gallons per day of purified water from wastewater. The facility was built at a cost of $72 million in a partnership between the Santa Clara Valley Water District (SCVWD) and the city of San Jose. The facility treats wastewater that would otherwise go into the San Francisco Bay for use as reclaimed water in irrigation, construction and industrial uses. They eventually hope to use some of the purified water to refill groundwater sources.
The Santa Clara County facility gets wastewater from the cities of San Jose and Santa Clara, and the goal had been to expand the recycled water to make up at least 10 percent of total county water demand by 2025. But due to the 4-year-old drought, the water agency is pushing its goals further: It’s pursuing plans to expedite that goal by three years—to reach the 10 percent number by 2022—and partnering with other cities in the county to purity their water.
Meanwhile, the Orange County Water District (OCWD) is undergoing an expansion of its own at the water agency’s high-tech Groundwater Replenishment System in Fountain Valley, California. The $481 million plant has been operational since 2008 and currently processes about 70 million gallons of treated sewage wastewater each day into drinking-quality water that goes into groundwater basins for later reuse as potable water. OCWD, which serves more than 2.4 million people, is spending $142 million to increase capacity at the facility to approximately 100 million gallons per day, or enough water for 850,000 residents.
“Recycled water is a huge benefit,” said OCWD General Manager Michael Markus. “We can produce the water for about half the energy it takes to import water from Northern California and about a third of the energy it takes to desalinate sea water.”
Orange County’s plant, for example, can produce recycled water for about $480 an acre-foot—well below the estimated $2,000 per acre-foot a new desalination plant in nearby San Diego County will be paying for new water. Similarly, the recycled water runs about half the roughly $1,000 per acre-foot price of water from the Metropolitan Water District, the giant water wholesaler for Southern California, which on Tuesday announced a 15 percent reduction in the amount of water it will supply to its 26 member agencies.
Purified wastewater could provide enough potable water to supply all municipal needs for more than 8 million people, or roughly one-fifth of California’s projected population for 2020, according to a report released last year and sponsored by the WateReuse Association, an organization supported by water utilities and companies that promote water reuse. The report also pointed out that NASA and the International Space Station already use a technology that produces potable water for six crew members from a combination of condensation and collected urine.
In 2014, two Texas towns launched the nation’s first direct-to-potable reuse water programs. Wichita Falls and Big Spring, about 230 miles apart, treat wastewater with a multistep cleaning process and then send the purified water directly to homes. The last U.S. Drought Monitor data shows 49 percent of Texas suffering from some level of drought.
San Diego is targeting an initial 15 million gallon per day water purification facility to be in operation by 2023—and there’s a longer-term goal of producing up to 83 million gallons of purified water by 2035, or enough to supply one-third of the city’s future drinking water supply. San Diego conducted a four-year demonstration project starting in 2009 and found it could produce water that met all federal and state drinking water standards.
With most of the state suffering through an exceptional level of drought, dismal snowpack data and tugs-of-war among all the needy constituencies, there is some pragmatism floating around. From a recent story in Mother Jones:
The chart below, part of a report by the Natural Resources Defense Council and the Pacific Institute, sums up some of the options for saving water. California could reduce its water use by 17 to 22 percent with more efficient agricultural water use, including fixes like scheduling irrigation when plants need it and expanding drip and sprinkler irrigation. Urban water use could be reduced by 40 to 60 percent if residents replaced lawns with drought-tolerant plants, fixed water leaks, and replaced old toilets and showerheads with more water-efficient technology. And instead of channeling used water into the ocean, the state could treat it and reuse it—a practice that tends to gross some people out (because of the “drinking pee” factor) but has long been used in Orange County and is becoming more popular as the drought continues.
Beyond the need to invest significant capital in municipal water infrastructure improvement projects, towns both big and small can contribute to their water well-being by embracing the concept of local water outlined by Brian Young, Sustainable Infrastructure product manager at Autodesk, in this recent article featured in the Economist Intelligence Unit.
In a world increasingly dry or flooded – depending on the circumstances –, city leaders and infrastructure experts are quick to advocate mega-projects to tap, convey or treat our most precious of natural resources: water.
California spends 5% of its electricity just conveying and treating water, and is in the midst of building a US$1bn desalination plant. China’s South-North Water Diversion Project plans to reroute enough water each year to submerge the United Kingdom 18 cm deep, over a distance between London and Barcelona.
Yet these Herculean efforts – both in terms of cost and engineering – fail to acknowledge a basic efficiency principle: use water where it falls. “Local water”, which exists even in arid regions, provides more benefit than adding new mega-projects, in three major ways:
Financially: Desalinating water can cost twice as much as recycling and four times as much as conservation. Furthermore, desalination plants become stranded assets once the rains return.
In contrast, local sources of water – the under-tapped streams of stormwater, wastewater, leaks, and conservation – can shrink the supply and demand gap at a fraction of the cost of desalination. In fact, a study last year found that simple conservation, reuse, and stormwater capture could save as much water every year as all of California’s cities require annually.
The city of Philadelphia is using code to convert stormwater into a resource, requiring developers to install green infrastructure like rain gardens and cisterns to capture rainfall that once drained away. Melbourne uses leak detection and metering technologies to reduce their water losses, which in some cities reach 40%. Parts of Virginia and California opted to recycle wastewater for use in irrigation and cooling, rather than create more water demand. These local alternatives enable cities to find more water without placing all their chips on one big bet that may become a very expensive matter.
Environmentally: Capturing rainfall, reusing wastewater and plugging leaks reintroduces lost water back into the system, offsetting the need to draw water from fragile ecosystems or convey it from other regions. And recycling it requires less than half the energy of desalinating saltwater.
Capturing and reusing water also keeps runoff and sewage overflows from contaminating nearby rivers and oceans, one of the leading causes of surface water pollution, while also acting as air and heat “filters”. Even in a place as arid as Arizona, a government study recently found that “green infrastructure” to capture and retain stormwater would generate a significant return on investment by reducing heat stress mortality and air pollution.
Socially: The “buy local” food movement (food production and distribution that is geographically localised, rather than national or international) educates shoppers as to where their food comes from, leading them to value it more. Governments and water utilities have done a good job of making water infrastructure invisible (i.e. below ground or behind walls), so much so that consumers don’t use water wisely, nor do they see the need to pay for infrastructure upgrades.
This wasteful type of behaviour is starkly different from communities that rely upon wells or stormwater, where water is considered precious. Local and visible solutions around rainwater capture, water recycling and conservation will help consumers appreciate the value of water more, and create a virtuous circle in their willingness to pay to protect it.
Cities aiming to solve their water scarcity problems should begin their search within their own municipal boundaries. With today’s technologies, water that was once lost to leaks, discharges, and wasteful use can now be found. And unlike the freshwater sources from afar, this rediscovered “local” water carries lasting financial, environmental, and social benefit.
Here’s how you can do your part to help manage the global water crisis.