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Wyoming solves water scarcity and treatment issues with its Cheyenne reuse system.
By Carol Brzozowski
Back in the 1950s, one of Cheyenne, WY’s leaders—W.J. Dinneen—made what was to become a forward-thinking observation about the area’s water supply. He said: “The story of the long struggle for water in Cheyenne is typical of the general situation of the arid West and leads to the conclusion that in order to meet the demands of the future, the existing sources of water must be conserved.
“Residents of this area must learn to use water so that a 1-gallon supply provided by nature will perform the duty of 2 gallons as it is now used. Probably the most promising source of additional water at Cheyenne is the reclamation of sewage effluent for industrial use.”
That statement made a half-century ago by the then-president of the City of Cheyenne Board of Public Utilities (BOPU) has been adopted as a mission statement of sorts by the modern-day BOPU as it proceeds with a new water recycling program, which is being instituted among other water efficiency measures.
“Here we are 50 years later and we are now realizing that,” says Clint Bassett, water conservation and public relations specialist for the BOPU. “Even back in the 1950s, Cheyenne saw how important it is to use our water resources wisely.”
The impact of recent climate changes—particularly drought conditions that occurred in 2002—precipitated the move toward water recycling, notes Tim Wilson, director for the BOPU. “Cheyenne has a very good water supply system, but it is heavily dependent upon snowpack,” he says.
In 2002, the region received a record low runoff from the snowpack as well as a record high water usage. There had been little rain during the hot, dry summer months.
“The record low runoff and the high water usage resulted in our reservoir levels going down, dropping below 50% of their fill capacity,” notes Wilson. “We started looking at additional water supply sources.”
The first strategy: looking in-house, adopting WaterWise conservation measures.
“An extensive program was developed to assist us with the over-usage of water when supply was low, such as watering only for a certain number of hours on assigned watering days,” says Wilson.
Cheyenne’s second course of action was to purchase a nearby 17,000-acre ranch in summer 2003 with the intent to explore groundwater development, says Wilson, adding that this process is ongoing.
Treating the city’s wastewater to a higher standard for reuse in irrigation constitutes the city’s third course of action. Recycled water is a drought-resistant water source that will enable its hosts, such as parks and athletic fields, to stay green and be safe to play on during droughts. Additionally, the water recycling will provide additional water storage for population growth and extend the life expectancy of the city’s water treatment plant.
The reduced demand on Cheyenne’s drinking-water resources as a result of the water reuse program is a prime factor in the program being instituted. The city’s oldest water source is Crow Creek, which provides about 3,500 acre-feet of water. The city consumed 18,000 acre-feet in 2002 and averaged 14.700 acre-feet since implementing water conservation measures in 2003. The remaining needs are met by wells or an extensive collection system that draws water from streams two mountain ranges away.
Using Nature as a Template
The technologies being implemented to reclaim water will mimic nature’s water cycle but in a more rapid fashion. The process begins with wastewater carried from homes and businesses throughout Cheyenne to the Crow Creek Water Reclamation Facility. There, the wastewater is screened to filter out large debris. Next, the water is placed in clarifying tanks that allow heavy particles to settle and be removed.
Moving Bed Biofilm Reactor treatment (MBBR) follows. Compressors pump air into large tanks to encourage beneficial bacteria to decompose the pollutants in the water. The water then goes through a secondary clarifying process to allow material—mostly beneficial bacteria—to settle out of the water.
That process is followed by UV disinfection. Polymers are injected into the water to bond suspended materials together and make them larger, enabling easier removal through filtration. Residual disinfection is provided through chlorine, and the water moves through the new pipes to designated areas for irrigation.
The recycled water will be class A, the most stringent classification in Wyoming. Using fecal coliform levels as a determining factor in safety, the class A standard requires the water to contain less than 2.2 colony-forming units of fecal oviform per 100 milliliters of water (anything less than 200 colony-forming units per 100 milliliters is considered safe for swimming).
Half of the effluent or outflow water from the city’s sewage treatment plant will be purified and then stored in a golf course retention pond. From there it will be pumped upstream for irrigation throughout the city. Through this process, Cheyenne obtains its goal of “1 gallon of water will perform the work of 2.” Since water that was flushed down the drain and treated at the Crow Creek Water Reclamation Facility was lost to Cheyenne, officials estimate the project would produce and save up to 4 million gallons of water each day.
The pipe constructed to convey the recycled water was painted a distinct purple color. “It’s a different-colored pipe so a contractor or developer who is digging and needed to extend the water main or tap into an existing water main would be able to recognize it from the drinking-water distribution main,” says Wilson.
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Photo: Clint Bassett |
| Recycled water cascades from sand filters into a trench at the Crow Creek Water
Reclamation Facility. The water will be used to irrigate city landscaping. |
Photo: Clint Bassett |
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| Purple pipes for recycled water will be laid in the ground to keep this water
supply distingushable from the non-recycled water supply in Cheyenne, WY. |
With respect to treatment costs, Jim Hughes, water reclamation manager for the BOPU, points out that typical wastewater effluent is treated to remove solids and other matter before being released back into Crow Creek.
But because it is being recycled rather than put back into the creek, it must be treated more extensively; therefore, technology such as sand filtration adds to the cost.
“We are also using continuous backwash filters supplied by US Filter,” says Hughes. “It’s actually water-quality-type technology we are using for our reuse. We also have the ability to add alum and polymer to remove the solids and disinfect using sodium hyperchloride. All of the system is instrumented so we can monitor the sodium hyperchloride dosage and the turbidity units as the water leaves the plant. It’s state-of-the-art technology.”
Meeting Project Goals Through Funding and Design
In what is one of the first efforts at water recycling in the state of Wyoming, Cheyenne has invested $11.5 million in a new recycled water system. The system consists of 12 miles of newly constructed PVC pipes, three new pump stations, and additional treatment capabilities for the Crow Creek Water Reclamation Facility. The system is expected to be online in spring 2007.
Cheyenne’s water recycling project was funded in part with $5 million from the State of Wyoming in the form of a $2.5 million grant and a $2.5 million loan, with the balance of the funding coming from low-interest state loans from the Clean Water State Revolving Fund. Of the $11.5 million spent on the project, $5.7 million were spent to construct the 12 miles of pipe and the pumping stations. Jack Meena, a project consultant and engineer with the States West Water Resources, designed and managed the recycled water transmission and distribution system.
The upgraded treatment system at the Crow Creek Water Reclamation Facility plant costs $5.8 million. The treatment facilities at the Crow Creek Water Reclamation Facility were designed by the engineering firm of Black & Veatch, with Mike Gossett serving as the project manager. One pumping station will be a “high service” pump, located at the Crow Creek Water Reclamation Facility. The second large pumping area is at the Prairie View Golf Course reservoir. A third and smaller pump will be located near a community park to maintain pressures there.
Initially, the water will be used to irrigate golf courses, parks, athletic fields, cemeteries, and the Veterans’ Affairs Medical Center grounds, although in the future it may be used in non-potable applications such as cooling water or processing water.
The recycled water use on the local golf course is even expected to increase playability, Bassett notes. “I love the name of the golf course—it’s called Prairie View,” notes Bassett. “They’re very much looking forward to the additional water resource out there, because out on the prairie we’re not accustomed to a lot of water obstacles, but we’re going to create a water obstacle right off the first fairway there. It will change the playability.
“The BOPU is proud to be using the recycled water,” says Bassett. “Signs that will be posted in areas to receive recycled water read, ‘We are using water resources wisely by irrigating with recycled water.’”
Bassett believes one of the reasons why the water-recycling program is going to be good for Cheyenne is the water savings. “We’ll be replacing the drinking water that is currently used to irrigate at those locations,” he says. “By replacing it with recycled water, we are able to keep that drinking water in our reservoirs, and that helps us prepare for growth and it also helps us to be more drought-resistant.”
From the point of view of water reclamation, Hughes finds it gratifying that the water will be used for beneficial purposes rather than going into the creek and on down the stream. “It’s nice for our division in particular to be involved with helping to supply a viable water resource,” he notes.
While there are other places throughout Wyoming that use recycled water or have a reuse project, Bassett believes those projects are for just a few locations rather than Cheyenne’s more widespread citywide effort. “I’ve heard other cities are watching us to see how our program goes and are making plans based on how well we perform,” he adds.
In total, 1,062 parks and playgrounds and 597 schoolyards throughout the nation are irrigated with reclaimed water, according to the WateReuse Foundation.
Throughout the country, issues such as increasing development and occasional fires create a greater demand on water resources, and it’s no different in Cheyenne.
“Our growth has not been as heavy as what other front-range communities experience, but Cheyenne has grown and we do have some additional demand,” says Wilson.
The water recycling effort is “the development of an additional water resource for the community of Cheyenne to help meet its current needs and also help meet its future needs,” says Wilson.
Citizen Support
The public has acted favorably to the system, Bassett says. “When we introduced it, we went to our end users first—the soccer association, Junior League, owners of the fields, city parks and recreation staff, and golf organizations. We answered their questions and described how the process is going to work, what the water quality was going to be like, and how safe the water was going to be,” he says.
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Photo: Clint Bassett |
| Three pumps and purple pipes stand ready to deliver recycled water
to athletic fields, parks, and green spaces in Cheyenne, WY. |
Bassett anticipated questions such as if a child skins his knee playing soccer, would he be safe on a field irrigated with recycled wastewater? And while people were concerned about that, “The first question we would always get was, ‘When can I get this water at my house?’” says Bassett.
Hughes notes that having the support of the governing bodies of Cheyenne and its citizens will result in a project “that’s going to be really successful.”
The engineering firm of CH2M Hill was contracted to put together the public education program for the water recycling effort. Cheyenne serves as a model for how the issue of water reuse can be effectively rolled out to the public, says Linda Macpherson, a vice president with CH2M Hill.
“Out of fondness for that client, I’ve got to say CH2M Hill was especially proud to be associated with them because of their commitment and dedication to furthering the word about reuse and the importance of combining technology with understanding,” she says. “They really tried to let other people know what they did and why they did it. They exemplified a ‘best in class’ approach to public education about water and water reuse and the important role it can play in addressing critical water challenges,” she says.
“I can’t say enough about the leadership of the Board of Public Utilities in Cheyenne, including Jim, Tim, and Clint,” she adds. “Clint did the heavy lifting and is very dedicated to the topic. He did a lot of public meetings, providing people with factual information. I believe everybody had a lot of trust—and justifiably so—in the Board of Public Utilities and in the staff that was bringing the information forward.”
Macpherson was especially impressed by Cheyenne’s BOPU follow-through on what she calls the “outstanding foresight” Dinneen exemplified a half a century ago.
“Cheyenne was able to celebrate its history to say that this is the commitment they made a long time ago to look to making sure that 1 gallon of water used in Cheyenne will perform the duty of 2 gallons,” says Macpherson.
One of the biggest public concerns is the quality of water being used for reuse, Macpherson notes. “Something that’s really important is to understand is that generically, not all reuse programs are the same because they don’t have the same objective, so there is higher-level treatment for a reuse project where people are going to consume the water than a reuse project where there’s going to be irrigation of the water onto parks and play lots,” she says. “The program Cheyenne did was very sensitive to public concerns and public health issues and I think it will serve them well.”
Future Potential
As BOPU officials look to the future, they envision a combined approach of WaterWise practices, the use of recycled water, and obtaining more water supplies. Ultimately, the question remains as to why more communities throughout the United States aren’t engaging in water recycling efforts.
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Photo: Clint Bassett |
| Flags at Prairie View Golf Course wave in the wind behind a pond of recycled water. The City of Cheyenne Board of Public Utilities
filled the pond for the first time during April 2007. The recycled water will irrigate a total of 230 acres. |
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Photo: Clint Bassett |
“We are focused on using the right water for the right use,” says Bassett. “I believe that as there are more and more demands on our water resources throughout the country, we’re going to have to start exercising that practice of using the right water for the right use.”
Macpherson says the only way water issues throughout the world can be effectively addressed is if reuse can be “celebrated for its safety, security, and sustainability” through public understanding of the issue.
“Reuse projects around the world have been turned down—sometimes at extraordinary costs—because the jurisdictions have already made engineering investments, and when the public doesn’t understand the issue of use and reuse, they can turn those projects down,” she says.
“One of the things we have focused on is ways to inform the public about water in general so they can make informed decisions around the issues of water reuse. The whole notion is that you can’t make informed decisions about whether or not you want to reuse water until you understand the water cycle,” says Macpherson.
“We have made a firm commitment in combining technology and public understanding; that means we want to work with our clients to spread the word about the importance of understanding the water cycle—water quality in particular—and how reuse can be very safe for the public.
“We felt that’s a very effective, genuine, and factually accurate way to start projects.”
Macpherson believes there is an increasing recognition of global climate throughout society.
“There’s more understanding about water supply, and it will be necessary for many places to think about reuse for lots of different reasons, not all of which deal with drought but some of which deal with issues related to just making sure that there’s enough water in receiving streams for the right uses,” Macpherson says. “There are all kinds of reasons for reuse. In the case of Cheyenne, the issue was to maximize their potable water sources.”
Cheyenne officials chose water recycling over other options such as dam construction or drilling for wells because it is a less expensive option. However, the city’s BOPU continues to seek additional resources. In addition to purchasing the nearby ranch for groundwater resources, the city is looking to establish an additional reservoir for increased water storage capabilities. But officials point out that surface and groundwater supplies—although they can be used to buffer droughts—are not drought-resistant and are impacted by low precipitation and runoff.
Cheyenne joins other cities throughout the United States using recycled water for parks, playgrounds, and schoolyards. Those states include Washington, Oregon, Colorado, Nevada, Arizona, New Mexico, Texas, Hawaii, North Carolina, Florida, and California, with the latter two leading the nation in the most widespread usage. Irvine Ranch Water District in California has one of the most oldest and successful recycled water programs, dating back nearly 40 years.
And as these and other communities approach that juncture of using water for “the right use,” Macpherson has some advice: “Get people thinking about the water cycle and their place in it, use appropriate images and words, start at the beginning, and your public will follow. Not only will they follow, but you’ll be able to celebrate success.”
Carol Brzozowski is a journalist in Coral Springs, FL.
OW - July/August 2007 |
