Crews waved the American flag as one of the nation's largest transmission lines was put into service in mid-January. It was the culmination of four years of work for more than 200 workers involved in the construction of the 220-mile 345-kV Arrowhead-Weston transmission line linking Wausau, Wisconsin, and Duluth, Minnesota. This historic event marked the completion of the first major transmission line installation in the region in 30 years.
The Arrowhead-Weston project increased the reliability of the electric system in northwestern Wisconsin and the upper Midwest. Prior to the new line, demand for electricity had been growing at 2% to 3% per year, but the transmission infrastructure could not reliably accommodate the growth. In addition, Wisconsin only had four interstate high-voltage lines, compared with dozens in neighboring states.
The Arrowhead-Weston line was literally 10 years in the making. Originally proposed by Wisconsin Public Service Corp. and Minnesota Power in 1998, American Transmission Co. (ATC; Waukesha, Wisconsin) took over the project in 2002. But before ATC could begin construction on the line, the utility had to address major opposition from the local communities, landowners and government officials. The 220-mile line would cross the land of some 800 landowners in nine counties. About 75% of the route would be built along existing transmission, gas pipeline and railroad corridors, and 25% would be built on new right-of-way (ROW). Before an application for the construction of the power line was even submitted, Wisconsin regulators received more than 10,000 letters on the topic. Eight county boards and more than 20 town and village boards also passed resolutions against construction of the line.
At the same time, another major issue was developing. Upon adopting the project, ATC conducted a thorough review and determined the cost to build the line had increased from the original estimate of $165 million to $425 million, due to environmental impact mitigation, environmental inspection, farm disease mitigation, increased real estate ROW costs, increased public outreach efforts, and increased labor and benefits. ATC had to resubmit an application to the state regulatory agencies for approval at the higher cost. To address the opposition and cost increases with other groups, the utility launched a grassroots public outreach campaign to raise awareness of the need and local benefits for the new line, and to encourage public officials and business leaders to approve and support moving forward with the project.
Two years later, in February 2004, construction began in Minnesota, and by August 2005, the utility secured the necessary permits and began construction on the line in Wisconsin. Due to permit delays, ATC started the project eight months late, but managed to finish the construction seven months early in November 2007 and energize the line four months ahead of schedule in January 2008. The total project cost came in at $435 million, which was 4% over the estimate but within the 5% contingency set by the Public Service Commission of Wisconsin.
Addressing Environmental Impacts
One major issue the opposition had was the effect of the line on the environment. Northwestern Wisconsin is largely rural with forests, wetlands and natural areas and, understandably, folks were concerned about how construction might impact the land. For that reason, it was imperative for crews to take measures to preserve the land and protect the wildlife. Before ATC arrived in an area, environmental specialists tagged sensitive locations with yellow ribbons, signs and red flags. While it was a painstaking process, it made for a more environmentally friendly project.
The project team came up with innovative ways to cross the terrain without negatively affecting the environment. This was a particular challenge in the 80 miles of wetlands, which, in places, didn't freeze even in the Midwest's frigid winters. To effectively overcome this obstacle, ATC invested $12 million in 36,000 construction mats, which covered 27 miles. The contractor had a special crane to lift the mats, put them in place and then repeat the process for more than 80 miles.
The route also included crossing a wild and scenic river. The National Park Service presented several options for protecting the usage of the river for recreational purposes. The utility decided it would be too risky to go underground, so it designed a way to cross the river using 1800 ft of high-tensiled-strength conductor.
ATC did not experience any major environmental violations during construction, which is a credit to the crews in the field. All of the contractors had a high emphasis on maintaining environmental compliance, and environmental specialists worked directly with ATC crews on a daily basis. The utility had its share of encounters with wildlife, too. In one instance, bears hibernated in a ROW, so rather than disturbing them, ATC decided to come back to that section after the bears awoke in the spring.
Managing the construction timeline was a challenge, as well. When ATC first began the project, it was divided into nine sections in Wisconsin. To meet its deadlines, ATC started construction on four sections simultaneously. It was a huge challenge to keep multiple crews working at the same time.
During the project, ATC also made safety a top priority. Although there were a few loss-time injuries, there were no major accidents. Each time a minor injury occurred, the utility shut down the project temporarily to review the incident and identify ways to prevent it from happening again.
Crews also faced extreme weather conditions such as -20°F temperatures and high winds when building the line. To make sure the transmission line and poles could withstand the wintry and icy conditions around Lake Superior, ATC built that section of the line with heavier conductor, larger foundations and stout construction.
The entire line was also built using steel poles, rather than wood, to minimize the width of the ROW. Taller steel structures allowed the utility to keep the ROW to 120 ft. Using wood poles would have required the ROW to be significantly wider, thus increasing real estate costs and the impact on the environment.
Ten years after Arrowhead-Weston was introduced, ATC energized the line in January 2008. It took a lot of persistence to get this project done, but the line crews and contractors maintained a “can-do” attitude. Those involved learned many lessons from this project, and when the line was energized, it was hard to believe it was finally done.
Pete Holtz is the general manager of overhead projects for American Transmission Co. and served as the project manager for the Arrowhead-Weston transmission line project. He worked for 26 years at Wisconsin Electric and has worked at ATC for the past seven years. firstname.lastname@example.org
BY THE NUMBERS
- 220 miles of transmission line
- 1564 transmission line structures
- 50 million pounds of steel used during construction
- 1700 miles of wire
- Thousands of miles of cable
- 350 million pounds of concrete
- 36,000 wooden mats used to preserve wetlands
- 72 months of permitting
- 27 months of construction
- 345 kV
- 800 MW of carrying capacity
- $439 million to build Source: ATC
Attention readers: To watch a 15-minute video about the project, visit www.atcllc.com