Taking Water Pipe HDD To Extremes

By Jeff Griffin, Senior Editor | June 2011 Vol. 66 No. 6

Mesa Verde National Park is located in the relatively isolated southwestern corner of Colorado, near Durango. More than 1,000 years ago, the area was home to Pueblo-dwelling people, and the park contains more than 4,000 archeological sites -- including 600 cliff dwellings -- which are among the most notable and best preserved in the United States.

The terrain in Mesa Verde (“green table” in Spanish) is dominated by rugged ridges and valleys with elevations ranging from about 6,100 to 8,400 feet.

In these difficult conditions, Laney Directional Drilling installed two horizontal directional drilling (HDD) segments of six-inch-diameter stainless steel pipe to take water to a one million gallon storage tank atop Navajo Hill. The water source is Jackson Lake several miles away. Water feeds from the lake into a treatment plant before being pumped to the storage tank.

The two Laney bores were made to replace a 40-year-old pipe attached to the side of the escarpment, a practice that is no longer permitted for environmental reasons. Each bore required extreme elevation changes and one had a sharp side bend, said Grady Bell, Laney vice president of business development.

The project owner was the U.S. Park Service of the Department of the Interior. The primary contractor was Triad Western Construction, Cortez, CO. The main crews welded, tested and assisted Laney with the difficult task of laying out a mile of steel pipe in very restricted right-of-way. Triad Western also shared with Laney personnel its knowledge of local site conditions.

The point where the new pipe was to connect to the pipe bringing water from the treatment plant was just inside the park’s boundary with no right-of-way available to set up the big drill rig to launch a bore. Therefore, it was necessary put the drill unit up on the mesa, drill down hill and exit at the connection point. The drill pad was about 50 feet off the main park road. When that bore was completed, the drill unit would be turned on the pad to bore further up to the storage tank.

Slow go
“Moving the drill rig and support equipment to the set-up site was difficult because the road to the set-up location ran though on-going drainage construction, and the two-lane road was closed to one lane in some areas because of resurfacing,” said Bell.

Travel time for getting equipment and personnel from the park’s entrance to the launch site was about two hours, depending on delays, and a 15 mph speed limit that was enforced.

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