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September 2011

No Footprint Behind

Copper Mountain expanded its snowmaking system with very little environmental impact. Here's how.

Written by Scott Towsley, Towsley Welding & Construction | 0 comment

How do you install snowmaking or other facilities in sensitive environmental areas? The imperatives for environmental protection, in both legal and public relations terms, make that question a key one. And in 2010, Copper Mountain, Colo., showed how it could be done.

Not that it was a fast solution. Copper Mountain Resort began working with the Forest Service and SE Group in 1997 to determine which on-mountain projects to take through the National Environmental Policy Act (NEPA) process for review and approval. The NEPA process for Copper analyzed capital projects across the entire resort in an Environmental Impact Statement (EIS). This analysis required environmental surveys for all resources over multiple years.


THE GROUND RULES
Three of the key issues in the EIS were stream health, wetlands and sensitive plants. Wetland delineations were completed for all project areas, and determined the presence of fen wetlands. Fens are typically saturated during the growing season, and include Histosol soils with groundwater as the primary source of hydrology. In plain language, fens are considered peatlands with a thick organic layer that receive water from below and can take thousands of years to develop. For this reason, fens receive special protection from the EPA, Army Corps of Engineers and the Forest Service.

Copper’s proposal included the installation of snowmaking lines through areas determined to be fens. To avoid and minimize impacts, SE Group and the Forest Service developed a plan to install the pipelines above ground, using helical screws as supports. Helical screws were chosen because they leave a very small footprint, less than one square foot of disturbance, for each support location. Nor would they disturb the overall function and value of the fen. And on the White River National Forest, projects must maintain or improve long-term stream health.

In addition, Copper had to mitigate the potential impact of grading and increased snowmaking coverage, both of which were analyzed in Copper’s EIS. Certain watersheds were rigorously studied to determine if projects would be consistent with the maintain-or-improve benchmark. SE Group and the Forest Service determined that the snowmaking project (as well as others) could use site-specific drainage design to “disconnect” the increased snowmaking runoff from impacting nearby streams.

Botanical surveys were completed within project areas, with a close eye on moonworts, some of which are rare, and most of which are difficult to protect from damage. All sensitive moonworts were flagged and GPSed to ensure projects would avoid these plants.

In 2006, the Forest Service approved projects in the EIS and allowed Copper to implement them as capital became available.


TIME TO MOVE AHEAD
In early 2010, shortly after purchasing Copper, Powdr Corp. decided to install snowmaking infrastructure on two trails in the Timberline (T-Rex) pod. SE Group hit the ground to conduct the additional survey and design work needed to meet the wetland, watershed and sensitive plant requirements for approval by the Forest Service.

At the same time, Copper, Towsley Welding & Construction and Torrent Engineering fast-tracked a design and moved ahead quickly to prepare for construction while the slopes were still covered with snow. Over-the-snow installation was essential to avoid impacts to the fen; the terrain would only be able to support heavy equipment while the snow was deep.

It is essential to plan early in the winter when preparing for construction on the snow. Access to the construction area should be available as soon as it does not interfere with skiing, to ensure that there’s plenty of time to complete the process. Once the snowpack can no longer support the necessary machinery, all work must come to an end.

SE Group completed its in-depth survey of the two snowmaking trails, as well as other areas within the watershed, to prepare a drainage management plan for the project. The drainage plan included water routing, culvert installation, and other measures to “disconnect” the additional grading and snowmaking, ensuring stream health would be maintained into the future.

Lastly, an SE Group botanist conducted the follow-up sensitive plant surveys required by the Forest Service to ensure pipeline disturbance would avoid sensitive species. All sensitive plants were re-identified, flagged, and GPSed to protect them from disturbance.


TREADING LIGHTLY
The survey results and plans became a component of the implementation package the Forest Service reviewed and approved prior to construction activities.

Copper snowmaking manager Mike Looney, along with Towsley and Torrent, prepared and submitted a design and construction methods plan to the Forest Service to receive authorization to install the helical screws, pier supports and pipeline over the snow. This decision allowed the construction team to work in the fen with heavy equipment, but not impact the fen.

With the snow still several feet deep, SE Group located and staked the boundaries of the fens using GPS. Then Copper and Towsley began the process of installing the helical screws, pipeline piers and pipeline over the snow.

The construction process included a specially-designed machine that set the helical piers five to six feet into the ground. A crew of 10 men from the Copper snowmaking department, Towsley Welding and a snowcat fitted with lifting forks did the work.

The pipe supports were prefabricated and designed to bolt directly to the helical pier supports. The pipe was installed on the piers using precise centerlines to insure it followed the layout of the piers and stayed a constant distance from the trail’s edge. Load calculations of the water-filled pipeline were used to determine how many supports, how far apart and what size piers and saddles were needed.

The team also developed a best management practice (BMP) plan for the installation of 5,000 feet of pipe through the large on-trail wetlands areas later that summer. That plan included rerouting and filtering ground water out of the pipeline right of way during construction. The excavators doing the trenching and pipe install walked on specially-built “swamp pads.” Spoils were placed on geo fabric and contained with silt fence that allowed water to drain out, but kept the material from mixing with the existing ground cover.

The steel pipe was joined using the Zap-Lok method, which minimizes the space and equipment needed for installation, and therefore lessens the impact to the area. Zap-Lok also minimizes the construction timeframe significantly, and consequently, the cost for construction. The result was an impact to the wetlands that was only as large as the width of the trench.

The construction resulted in virtually no impact to the fen and the on-trail wetlands and was deemed a complete success by the project team, including the Forest Service.

“We are thrilled with the result of the construction in the fen area, where 2,500 feet of pipeline is suspended on piers, and also the minimal impact of the buried pipeline install that included over 5,000 lineal feet of wetlands. The BMPs and construction methods resulted in a footprint that was as minimal as possible,” says Shelly Grail Braudis of the USFS. “The overall implementation of this project from start to finish is a good example for other ski areas on how to be successful in building resort infrastructure while protecting environmentally sensitive areas.”


EFFICIENCIES ALL AROUND
Copper Mountain project manager Mike Looney adds, “This project was a long time in the planning and approval process. We had a substantial investment of time, money and sweat even prior to starting construction. But the project itself was completed ahead of schedule, on budget and consistent with our approved plan and design.”

The process worked so well that Copper and Towsley completed another over-the-snow pipe install of 5,000 feet of pipe this spring, right after the resort closed for the season, to minimize impact to the areas where construction was to take place. Towsley Zap-Lok’ed the pipe and pulled it over the snow and in place on the pipeline right of way. Once the snow melted, the company trenched and installed the pipe.

Such a method is particularly effective for coated pipe. All the pipe can be connected and put in place with no nicks or scrapes to the corrosion-protective coatings. Plus, the time savings when excavation begins are enormous.

In the end, the Copper projects show that snowmaking installations can not only cross environmentally sensitive areas, but can do so economically. All it takes is snow cover, a bit of ingenuity, and a good plan.