American Transmission Co. to conduct soil boring along western portion of Rockdale-West Middleton transmission line route Process will help determine pole placement and design
MADISON, Wis. – American Transmission Co. is continuing preliminary field work for a new 32-mile, 345,000-volt electric transmission line through Dane County between the towns of Middleton and Christiana. ATC will begin conducting soil borings along the western half of the power line route along the Beltline and Highway 14 in the next few days, continuing until the end of January.
The process involves drilling a small 2- or 3-inch diameter hole, at depths up to 40 feet, periodically along the route to sample the soil and assess its makeup. The soil boring information is used to determine the exact placement of the structures, whether they will be placed in soil or rocks, and what provisions will be required to ensure the concrete foundations will adequately secure and stabilize the steel structures.
“Conducting soil boring is a necessary step in designing a transmission line of this type,” says Brian Fischer, ATC project manager. “We like to take advantage of frozen ground conditions when conducting this work in order to minimize environmental impacts.”
Soil boring will be completed by ATC subcontractor Subsurface Exploration Services, LLC at approximately 70 locations along the western half of the route. Most of the work will be completed within Wisconsin Department of Transportation right-of-way. While the 20-ton drilling truck used for the soil borings will be visible from the Beltline, no significant traffic impacts are anticipated.
“Construction mats will be used to protect and level the ground at a handful of locations where the terrain is not level enough for safe operation of the drilling truck,” says Amy Lee, ATC environmental project manager. “ATC will also have environmental monitors on hand to supervise work in environmentally sensitive areas, and some areas will require the removal of minimal vegetation to allow crews to safely maneuver and operate the drill truck.”
Soil boring along the portion of the route that crosses the wetlands adjacent to the Yahara River was completed in January 2010 to take advantage of the opportunity to minimize environmental disturbances during the winter months. No additional borings in the Yahara wetlands are currently planned prior to the start of construction activities, which are planned to begin on the eastern half of the route in fall 2011. Construction of the 32-mile line is expected to be completed in 2013.