| 
|
Winter sports are as popular as ever, and hundreds of thousands of people come from around the world, year after year, to take advantage of the Canadian Rocky Mountains’ fresh snow, clean air, and relaxed atmosphere. The slopes of Sun Peaks Resort, near Kamloops, BC, have been open to skiers and year-round outdoor enthusiasts for more than 40 years. Snowboarding’s introduction in the 1980s sparked an explosion in the mountain resort industry, and Sun Peaks has been expanding its capacity since it was acquired by the Nippon Cable Company in 1992. Extensive development of the resort—including new runs, new lifts, and new facilities—has required corresponding expansion of Sun Peaks’ infrastructure, and water treatment technology needed to be adjusted to accommodate the resort’s vastly increased tourist volume.
Treating wastewater at ski resorts presents a number of challenges. In a mountainous environment there isn’t a great deal of available land for disposal facilities, and any available real estate is extraordinarily valuable. Extreme variations in temperature add another challenge to designing effective solutions, as does the sudden, exponential rise and fall of a resort’s visitation and use. Sun Peaks’ tourist volume varies between its busiest months and its off-season; furthermore, during snow season, visitation is higher on weekdays than during busy weekends in the summer, and peak volume over a holiday weekend can increase more than tenfold beyond that. To add to this dynamic mix of challenges, as “tourism” has given way to “ecotourism,” the sustainable use of ecology and the preservation of biodiversity have become increasingly important to mountain resorts.
| |
 |
|
|
When Sun Peaks needed to upgrade its septic system in 1999, its utility department knew that the solution it chose would need to address all of these issues, plus provide accommodation for the three hotels, three housing developments, and 14 restaurants constructed over the past two years, as well as additional projects slated for the beginning of the 21st century. Previously the resort had used a septic field, which was subsequently upgraded to an aerated lagoon. However, operating an aeration system in temperatures as low as -40 degrees Fahrenheit had proved to be challenging: Wastewater is less treatable when frozen than it is in liquid form! Sun Peaks required a system that could work in sub-zero temperatures above 4,000 feet and that utilized an all-natural treatment process. Further, the solution needed to be modular and expandable, capable of exceeding 40-BOD, 40-TSS criteria with the option to go to tertiary treatment, as well as being capable of handling the fluctuating on-season–off-season flow experienced at mountain resorts.
 |
 |
| Snow ghosts punctuate the landscape at Sunpeaks. |
 |
| Six seasons later, the bioreactor's capacity has increased. |
Sun Peaks’ utilities management used the assistance of an independent engineering company to help refine the decision-making process. After sending a list of requirements to several manufacturers of rotating biological contactors and sequencing batch reactors, the resort’s board of directors and senior utilities management ultimately elected to install an Upflow Sludge Blanket Filtration Clarifier, manufactured by ECOfluid Systems Inc. ECOfluid’s patented USBF system was selected for its highly efficient design, which operates at high sludge concentration, and which offers a high clarifier separation rate, along with nitrification, denitrification, and sludge stabilization all in a single bioreactor.
In comparison to sequencing batch reactors, “the USBF system is more hydraulically flexible,” reports Karel Galland, President of ECOfluid, “which allows it to be better able to absorb the flow fluctuations experienced at a site like Sun Peaks.” The key to the USBF’s highly efficient aeration and clarification capabilities lies in its uniquely shaped clarifier, which can be conical or prismatic. Sludge enters at the bottom of the clarifier, and surface area of the sludge blanket becomes larger as flow increases. “The higher the flow, the higher the liquid rises in the clarifier, and the larger the filtration area becomes,” according to Galland. This makes for a self-adjusting, self-regulating system that can operate continuously. “The key with this plant is that it deals with changing flows that don’t require an operator’s intervention,” says Sun Peaks Utilities Manager Pat Miller. “The only decisions we need to make are when to switch between winter and summer modes, and how much sludge to waste.”
As is the case at most ski resorts, the choice to go with ECOfluid was made after the end of the ski season, and there was a pressing need to have the new reactor up and running by the start of the following season. This left a narrow window, but once Sun Peaks had made its decision, construction was rapidly under way. When the lifts stopped operating on April 30, the resort was in a race against the clock. “The contractor and ECOfluid were great,” says Miller. “The operators were involved with the design-and-construction process, and the new plant was powered up on Nov. 18—less than six months from the end of the ski season and the start of the decision process—on time and on budget!” Flows at the resort reached well below the designated discharge criteria within two weeks, and well before Christmas flows hit. Six seasons later, the plant continues to operate as promised and better than expected.
And six seasons later, Sun Peaks’ USBF reactor has 300% the capacity it had in 1999. “They needed expandability, and they got it,” says Galland. The original system was installed with two 300-cubic-meter tanks and three USBF clarifiers. A fourth clarifier was subsequently added, along with two additional cells to allow for winter operation, one anoxic and one aeration zone. The bioreactors can switch from “summer” mode, operating the two original cells, to “winter” mode, which operates the full four-cell system. This allows utilities operators at Sun Peaks to operate appropriately sized plants for the expected flows, which range from 400 cubic meters in the summer up to 1,400 cubic meters in the winter. Miller is very pleased with the system’s trouble-free constitution. “The plant always produces great results. Even when an operator gets pulled away to perform emergency duties elsewhere on the mountain, the plant continues to operate as promised and better than expected. This is a real comfort to the operators, and I don’t know if any other system would be able to do that.”
Residents and planners at Sun Peaks have a strong commitment to preserving the environment and have focused on cleaner energy and maximizing environmental efficiency. Wasted sludge from the water treatment plant is combined with naturally downed trees to make compost, which is used to feed the gardens and landscaping at the resort. Additionally, Sun Peaks uses hydroelectric power and propane heating. In 2003 it became the first resort in North America to receive ISO 14001 certification, and in 2004 the National Ski Areas Association granted Sun Peaks the prestigious Silver Eagle Award. “With this track record, it’s very important for us that our wastewater system doesn’t negatively impact the Sun Peaks community and those downstream of us,” Miller says. “The community recently voted for a rate increase in order to pay for expanded composting facilities, because they like having an all-natural treatment plant.”
As Sun Peaks continues to gain popularity, further expansion of its wastewater utilities is planned. In 2008, Miller plans to clone the existing plant, which will increase flow capacity to 600% of its original size in less than 10 years’ time. She says that one of the biggest challenges faced with expanding the plant has to do with how Sun Peaks’ ongoing water conservation efforts would affect operation of the wastewater treatment plant. “Normal communities use about 400 liters per person per day. At Sun Peaks, the average person uses about 220 liters per day, but adds the same biological loading to the system,” she reports. “Thus, when we expanded the plant in 2002, we increased the biological capacity significantly. This kept the price down, didn’t use as much land as we expected, and made the plant easier to operate.” The planned expansion would double the biological capacity and will keep Sun Peaks running smoothly into the next decade. The modularity of the USBF system makes expansions like this easier and more economical and allows the plant to continue operating during construction. This ensures trouble-free operation for the residents and guests at the resort.
SAM MASSON is editor of Onsite Water Treatment and an avid winter sports enthusiast. He can be reached at sam@forester.net.
OW - March/April 2006 |
