A key element in preventing accidental damage to the nation’s underground utility infrastructure is the nation’s One-Call system.
Calling 811 from anywhere in the country connects the caller to the nearest One-Call center which requests member companies to locate and mark their buried infrastructures prior to construction that involves excavation (in damage prevention parlance, excavation is any activity that disturbs the soil).
The Wisconsin Public Service Corp. (WPS) serves more than 437,000 electric customers and 317,000 natural gas customers in central and northeast Wisconsin and an adjacent portion of upper Michigan. Most communities in the WPS service areas contain multiple buried utilities such as gas, electric, telephone, cable TV, and water and sewer lines.
In the summer months, WPS receives approximately 3,500 locate requests per week, said Pete Wurl, WPS manager of customer service. The company uses its own personnel to respond to all One-Call requests.
During the summer’s peak construction periods, when locating demands are high, Wurl manages 29 seasonal locators who are employed from April through November. Winter season locating is handled by other WPS employees.
The basic locating tool is the electromagnetic locator consisting of a handheld receiver and compact transmission unit, such as the Ditch Witch 830R/T locating equipment used at WPS.
The receiver locates underground lines by detecting either magnetic fields created by electrical current passing through the buried lines or by picking up the signal produced by the transmitter, which uses different frequencies and modes to help identify locations of buried utilities.
A receiver alone can detect live power cables. However, in most cases receiver and transmitter are used together. For example, to find steel gas pipe, the transmitter is connected directly to the pipe and puts a signal directly on the pipe, which is detected by the receiver. For locating plastic gas pipe, a tracer wire is buried along with the pipe, and the transmitter puts a signal on the wire, which is detected by the receiver.
The receiver processes the information and displays it on an easy-to-read display so the locations of buried facilities can be marked.
Accurate locates depend upon locating personnel utilizing their experience, quality locating equipment, and using available information, including accurate mapping of the facilities, said Wurl.
“Experience and training are essential to performing accurate locates,” he continued. “A big part of locating is understanding the theory of locating, using quality locating equipment, knowing what facilities are to be located and the routes they take, and being able to interpret data provided by the locating tools in order to make intelligent decisions.”
All WPS locators are screened through the interview process for key attributes needed for locating, then complete initial classroom training followed by on-the-job training with a qualified and experienced locator. Annual refresher training provides updates and the opportunity to receive new information.
Wurl said his continuing challenge is organizing and managing work in an efficient and safe manner while providing 100 percent accuracy.
Based in Green Bay, Wisconsin, Wisconsin Public Service is a subsidiary of Integrys Energy Group.