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Lack of water spurs ski resorts to explore the use of reclaimed wastewater for snowmaking operations on the mountain.

By Henry Vere


Drought and perhaps climate change have forced an Australian ski resort to find inventive ways to deal with the need for snow on its slopes. Victoria’s Mount Buller has devised a $3.5 million plan to use water recycled from the resort’s wastewater for snowmaking. Backers of the project suggest this may be the first such project in the world.Philip Nunn, the chief executive officer of the Mount Buller Alpine Resort Management Board, says Mount Buller, like many other areas of Australia, is out of water for making snow. The plan is to purify the wastewater to a higher level, salvage 2 million liters of water per day, and derive water that’s clean enough to use in snowmaking. A recent Australian Broadcasting Corporation (ABC) news report mentioned how climate change could very likely make the situation even more dire: 2006 saw the worst snowfall on Mount Buller in 30 years.

All of this information regarding such a snowmaking plan would appear to make great sense and portray the whole issue of reclaimed water use as a so-called slam-dunk. According to his interview with the ABC, however, resort engineer Heath Chidgey admitted, the public perception of skiing on treated sewage (brown snow) takes on a different perspective when water becomes so precious. Right now the issue of water reuse is becoming more interesting as more uses are found for the treated water all around the US.

Photo: Catherine Propper, Northern Arizona University
Treated wastewater effluent flowing in the Rio de Flag wash in Flagstaff, AZ (2004)
Snow melts into the soil and water table.

On Our Slopes
A North American ski area is in a similar situation as the Australian ski resort. The Arizona Snowbowl ski area in Flagstaff occupies roughly 800 acres, about 1% of the San Francisco Peaks, a small volcanic mountain range and local landmark in the region. The Snowbowl maintains a year-round staff of approximately 30 employees. In a snowy year the area has almost 200,000 visitors per year. When there isn’t snow, it’s a disaster. The area’s business cycle can vary by 98% from year to year.

The ski trails cover less than one-third of 1% of the peaks. Because this is a remnant volcano, the geology is such that the mountain is very porous. Snowfall and rain percolate or sublimate before they are able to flow from the peaks. There is no free-flowing water on the San Francisco Peaks, according to J.R. Murray, Arizona Snowbowl ski area’s general manager.

The lack of water has led to a proposal to use reclaimed wastewater for snowmaking operations on the mountain. But this plan for the nearly 70-year-old ski area has been anything but a slam-dunk.

“This is unlike almost any other mountain; this area has very few water sources aside from what falls from the sky,” says Murray. “That’s the reason why there is an issue here. Ninety percent of ski resorts now have snowmaking because it’s required to stay economically viable due to the tremendous variability of yearly winter weather. Snowbowl does not have snowmaking because there is no water source, due to the porous nature of the mountain.”

 For 50 years, the different owners of this ski area have all looked for water. “The ski area opened in 1938; it was recognized early on that snow would have to be made, as it started to be produced at other areas even back then,” says Murray. “No one else has found a water source because even the underground hydrology is such that there’s not a reliable source of water underground there—even with 2,000-foot- to 3,000-foot -deep wells—so it remains speculative.”

The US Geological Survey (USGS) sampled water for the City of Flagstaff from 2004 to 2006. Samples were drawn from the Rio de Flag, below the city’s water treatment facility at the Wildcat Treatment Plant, a Continental groundwater well, and a well in the Woody Mountain Wellfield. These samples were analyzed for hormones, steroids, and household and industrial compounds—all the things referred to today as emerging contaminants, according to Bob Hart, program manager for the Flagstaff office of USGS Water Resources.

“We did have hits of several different compounds at all these sites and even some in the groundwater wells,” says Hart. “But this is not surprising to me as these things are showing up just about everywhere in the environment these days.

“The water we sampled is the same as that which would be used for the snowmaking operations. We put together a proposal after doing all the sampling work to do more of a regional study including sampling on top of the peaks and around the city, but it never went very far.”

Due to the geology and porous nature of the mountain, there is quicker infiltration of precipitation, according to Hart. Water tends to get back into the groundwater easier because of the soil characteristics. Much of the snow sublimates, going straight into the atmosphere.

“On this particular debate though, we try to simply supply the science information and let the land managers and other agencies take care of land-use issues,” says Hart.

Beyond Geology and Hydrology
Catherine Propper, professor of biology at Northern Arizona University (NAU) Department of Biology found some biological effects on reproductive behavior and on the development of the sex organs of certain organisms—fish species and frog species—from the reclaimed water from Flagstaff. “It’s somewhat unclear whether some of the standing water on the San Francisco Peak would be impacted or not as there are some ponds up there,” says Propper. “Because it is a volcanic porous area, the question is how much of that water will work its way back into the groundwater system.

“Full-force wastewater throughout the world in published studies other than my work has also demonstrated impacts on fish and amphibian development. We don’t know what the effects will be when the reclaimed water is sprayed on the peaks and undergoes all the environmental effects it will be exposed to up there; it will be a big experiment.”

The whole issue of reclaimed water reuse is at least now on Arizona’s radar, according to Propper. “The state’s Water Institute is funding a couple of projects to begin to figure out what’s in the water and what types of treatments are best for getting rid of it. Also, the Arizona Department of Water Quality is at least now aware of the issue.”

Northern Arizona University has also conducted chemical and biochemical studies of the water and its impact on the San Francisco Peak with regard to possible snowmaking at the Arizona Snowbowl. Paul Torrence, professor of chemistry and biochemistry at NAU, contends the use of reclaimed water under the conditions of snowmaking at high elevation brings into play factors not considered by anybody in the use of reclaimed water in other situations.

“For me this fact arises from both the nature of the pollutants and the reactions they can undergo, and also from the fact that they’ll be imbedded during the winter in snow as well as how the snow melts,” says Torrence. “One chemical compound of concern to me is triclosan, which is found in a number of different products such as antibacterial soaps, clothes, deodorants, and shampoos. While some of it is changed in the sewage treatment process, it actually does survive the treatment process.”

As described in a number of different scientific papers, triclosan has been shown to be converted by UV light into a dioxin, according to Torrence. It’s not the most deadly dioxin, but it is on the EPA list of carcinogenic agents. Also, anytime there is chlorine in a process, this can affect the Triclosan so that further UV light may convert it into higher chlorinated dioxins with higher toxicities.

“There is a lot more UV light up at the 10,000- to 11,000-foot elevations on the mountain than there is down in Phoenix and what we will be doing is creating dioxins up in the snow pack,” says Torrence. “NAU geologist Abe Springer calculates sublimation of snow pack into vapor results in a 40% to 80% reduction as well, therefore concentrating chemical compounds by a factorof roughly two. Then when the snow melts, pollutants will pulse out, not all at once. There will be a concentration effect 5 to 20 times; combined with the sublimation, this pulsing effect results in at least a 10- or 20-fold increase in concentration of any pollutant.

 “Waters heading to springs containing these chemicals are going to have significantly higher concentrations than would be in the original wastewater itself. I’ve asked the Forest Service to consider this, which they did not.” 

 The original court hearing in Prescott, AZ, didn’t even consider the scientific arguments; essentially, it was all based on the Religious Freedom Restoration Act, asserts Torrence.

“No one has considered the kinds of things that go on in a snow pack and how they melt out and how that affects the nature and concentration of pollutants eventually coming out. People ask me, ‘Why are you worried about reclaimed water for snowmaking when the same thing is used on schoolyards?’” says Torrence.

“I tell them it isn’t the same because those reactions aren’t going on down here in the summertime. No one has really studied what will occur by placing these compounds into the snow pack through snowmaking and letting it sit there all winter. It’s much more of an issue in this type of situation, something no one has ever considered.”

Religious Grounds Come Into Play With Environmental Concerns
Indigenous groups in northern Arizona consider the snowmaking issue part of an ongoing fight for protection of the San Francisco Peaks, sacred ground for a number of Native American tribes in the region. “During the course of a public scoping session we found out about the plans by Arizona Snowbowl to both expand and use reclaimed water for artificial snow,” says Robert Tohe, environmental justice organizer with the Sierra Club. “This led to additional public hearings and a draft of an Environmental Impact Statement by the Forest Service. Three alternatives appeared in the draft, including one suggesting the use of reclaimed water for snowmaking.

“The Arizona Republic quoted the ski area’s owner as stating that, if the ninth Circuit Court ruled against the snowmaking plan, he was prepared to sell the ski area’s operations. This is how the Sierra Club became involved and is also a plaintiff and appellate in that lawsuit.

 “This is the only proposal in the ski operations in this country proposing to use reclaimed water to make artificial snow. The Sierra Club became involved when there was a request from a lot of the tribes and environmental organizations to help them on this campaign to stop the use of this reclaimed water, and specifically we realized at that point that there is an environmental issue involved here.”

Until the ninth Circuit Court makes its decision, emotions will probably continue to run high. A question that perhaps remains for many Flagstaff citizens is: Will reclaimed water that has already been used—with no known ill effects—for many functions in Flagstaff for nearly 25 years make a serious impact on the environment if spread over less than 800 acres of aerated stabilization basin and only in relatively snowless winters? If the snowmaking plan does go forward it will be a big experiment, as Propper reminds us. But when it comes to reclaimed water use, how many other works in progress are also experiments?

Where Do We Go From Here?
For municipal wastewater treatment plant operators as well as for smaller innovative onsite water treatment managers, will problems with religious, ceremonial, social, or simple misperceptions only continue to grow until they dominate the debate? A look at another facet of the issue of reclaimed water use may hold at least part of the answer. Reclaimed water use for agriculture is an area of some debate as well.

“We’ve got to figure out a better way to deal with recycled water than thinking that it is really recycled,” says Frank Pecarich, a soil scientist retired from the US Bureau of Reclamation. 

“One of the things some people say is that all water is recycled. This is true. The problem is, though, that it wasn’t going through a tertiary treatment plant, but Mother Nature’s system. The water we drink is filtered through the soil profile. “When you replace that with tertiary treatment you’re not replacing the water cycle; you’re just short-circuiting or short-cutting it and leaving out a tremendous bacteria-cleansing mechanism of the soil and the profiles of materials it must go through before it reaches the aquifer. There has been great success in getting recycled water to flow through bogs, marshes, and particularly sand to get fairly clean water, in effect letting the whole world of biology go to work for you.”

Pecarich is part of growing group of other retired scientists and some working scientists with great interest in a new area of research on so-called bio-film organisms or those forming colonies that effectively “communicate” with each other, as well as other issues with traditional wastewater treatment systems and uses of such reclaimed water. They also feel E. coli 0157:H7, an adaptable bacterial organism, may be effectively bypassing tertiary wastewater treatment systems causing more and more outbreaks of sickness among people from the consuming of produce such as lettuce and spinach. Though this “super” bug may not get zapped by wastewater systems, this may not be the case if natural bacteria, ready to consume E. coli 0157:H7, are present.

“This all appears to be a very political issue,” says Pecarich. “E. coli 0157:H7 are virtually immune to every known system we can dream up to attack it. It goes into an inactive or ‘stealth’ state and then it activates when it senses an environment more hospitable; some studies suggest it even accelerates its growth at this point, making up for lost time.

“During the latest outbreak of bacterial contamination of fresh produce in California, the FDA kept saying, ‘There will be more outbreaks.’ The reason they say that with such certainty is because you are spraying recycled water on those crops. The political heat is so intense on the people at FDA that they are putting my articles out on the USDA National Library Web site for people to read and then count on the system itself to get the facts out there.”

Another Response on This Key Issue
Takashi Asano, professor emeritus of civil and environmental engineering at the University of California at Davis and winner of the 2001 Stockholm Water Prize for his theoretical and practical contributions to wastewater reclamation, recycling, and reuse, likes to use the expression “Opportunity meets necessity is the key essence” when it comes to the use of reclaimed wastewater for various uses, including agricultural ones. This explanation often arises in the perception of whether there is a shortage of water or not.

“I think in terms of conservation and ethics. When you have something such as a city’s water supply, wastewater generated in that city should be used more efficiently directly at this location, not only once or twice, but even more times than that,” says Asano. “This is the moral argument, also part of the picture of water conservation; if water is right at the doorstep, it is not necessarily simply sewage, but instead a resource if you treat it right.”

Asano considers the Flagstaff ski area and snowmaking from reclaimed water a somewhat complicated issue, especially with involvement of Native American groups and their ancestral lands and subsequent religious factors as well. Water purity issues are also something that has come up in such places as Saudi Arabia, according to Asano.

“The Saudis have severe water shortages and wanted to use sewage water for the pilgrims at Mecca wanting to wash their hands as part of religious ritual in Islamic law. Therefore they’ve decided that treated water is good enough for such a use because the water is purified—a clear case where necessity meets opportunity. Much depends upon where you are and how you can craft things to suit the way people can accept them.”

 Asano points out when it comes to pathogens involved with the irrigation of vegetables, such as leafy green produce and other crops, that surface water is often actually quite dirty. “Typical irrigation water itself is not clean; it may run off the streets, lawns, and the ground, picking up all sorts of pathogens and even pesticides from runoff as well,” says Asano.

“Reclaimed water, by the nature of its treatment and engineering, is actually much cleaner than surface waters because disinfection processes have occurred. Such water is treated to a level of 2.2 coliform count per 100 milliters, approximately the same as that of drinking water; surface irrigation water is 100 to 1,000 times more in its coliform count.

“But these are issues which should be addressed by the Department of Agriculture. Those folks should be much more careful about food safety, a major issue in the news and people’s minds these days.”

Maintaining a Clear Perspective
David Maciolek is vice president of engineering for Worrell Water of Earlysville, VA, which uses Living MachineSystems, an ecological wastewater treatment system that mimics processes found in wetland environments. Regarding the situations with both the ski slope and the problems with reclaimed water for agricultural uses, Maciolek feels that people resist anything they perceive as possibly being of harm to them under any circumstances.

 “The point is, the risk of harm from snow made from reclaimed water is so, so small in comparison to something such as simply driving to the ski area—or skiing itself,” says Maciolek. “Few people understand how much more risk is involved with driving.

“In the end, all water goes back into the environment somewhere; what do people think is going to happen to the pollutants and pathogens? I think if you went out and took bacterial samples from artificial snow made with reclaimed water as well as water from a creek or pond, you would most likely find just as many bacteria in either one of them. There is plenty of bacteria out there already from birds, deer, and other animals … and people.”

Henry Vere writes extensively on engineering and scientific subjects.

OW - May/June 2007


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