The rapid growth of residential construction in northwest Colorado caused demand for natural gas to surge in the region, requiring construction of a new natural gas transmission line to service the area. With winter looming, Blackeagle was called upon to help plan and execute the project in a dramatically compressed timeline so new homes would have heat in time for cold weather. What normally would have required a couple of years of upfront engineering had to be accomplished in just a few months. That’s enough of a challenge, but this project had more surprises in store – and the timeline couldn’t change.

• Given only months to accomplish years-long project
• Environmental considerations: river and protected fen wetland
• 600-foot elevation difference
• Horizontal directional drilling (HDD) into bedrock
• Multiple stakeholders: customer, residential developer, forestry service

The Challenge

In addition to the accelerated timeline that compressed years of work into just a few months, the project also required a 600-foot difference in elevation across its 1.5 miles – from underground to the side of a mountain. We already knew we’d be crossing a river, but then we discovered a previously unknown fen wetland in the pathway as well. Fens are federally protected because they take thousands of years to develop and are hotspots of biodiversity. They often are home to rare plants, insects, and small mammals. The planned open trench construction was no longer viable because it would destroy the fen’s surface. The only option was to go deep, deep under, right through the bedrock. There were already a host of stakeholders, but the introduction of the environmental element added even more. There were suddenly a lot more cooks in the kitchen, and all had to agree on the way forward.

The Solution

Blackeagle has worked with this customer on numerous previous jobs, and is often chosen to execute their toughest assignments because of our reputation for getting things done the right way. That level of familiarity and trust certainly helped. In complex cases like this, it’s important to bring everyone together early in the process and maintain open lines of communications throughout. Blackeagle already approaches every project this way, so we were off to a good start.

Our team began with site analysis conducted side-by-side with the customer’s engineering team. Based on the information gleaned, we developed a constructability survey to find the best route for the natural gas line. (Getting all stakeholders to agree required a total of nine constructability iterations.)

To address the highly sensitive nature of boring under the river and wetlands, we contracted with an environment expert that specializes in horizontal directional drilling (HDD). They use special drills encircled by steel casing that can drill horizontally without disturbing the surrounding ground. When drilling is complete, we remove the drill and run our gas line, in this case 2400 feet long, through the casing.

For running line on the mountainside, our Blackeagle team had to be highly aware of their own personal safety. Daily safety meetings are part of our standard operating procedure for any project, including this one. Equipment operators each had spotters directing excavator traffic to help ensure a smooth, safe project.

The Result

Service to the new residential development was operational in just three months, with temporary service completed to heat new homes. Work paused during winter and was completed the following spring, for a total project length of five months. The HDD was successful, allowing 2400 feet of gas line to run under the river and fen wetland with no disturbance to the topside ecosystem. All Blackeagle team members performed their work expertly and safely. Against tough odds, another successful project.