The city of Shawano is hoping to start boring into the soil on Main Street within the next few weeks to determine just how serious the problem is that led to several water main breaks over the last four years.
High levels of chloride in the soil were responsible for three water main breaks along Main Street since December 2010, according to an engineering study that ruled out any problem with the materials used in Shawano’s downtown reconstruction project.
Eddie Sheppard, assistant city administrator and public works coordinator, said the Department of Public Works sought quotes from two companies on the cost of doing soil borings at 20 locations up and down Main Street.
Sheppard said the DPW sought quotes rather than put the project out for bid given the specialized nature of the work.
One of the companies has given a price of $4,600, Sheppard said, and he is waiting to hear from the other one.
The company would bore about 6 to 8 feet into the soil to gather samples from around the water main.
Sheppard said the work should not cause any traffic disruption and would involve a 1- to 2-inch bore located off the side of the road.
Corrosion of stainless steel saddles that hold in place the service connection to the water main were the common denominator in the three breaks, and it was uncertain for a while whether there was a soil problem or the saddles were defective.
But tests done by TPS Consulting Engineers, of Green Bay, found the saddles met metallurgical standards and had been properly welded in place.
Meanwhile, soil tests at the locations of the three water main breaks showed high levels of chloride, mostly likely caused by road salt leaking down through cracks in the pavement over the years.
City officials said there are no health concerns because there is no contact between the chloride and the city’s water.
The Main Street reconstruction project in 2002 and 2003 stretched from the channel to the Mountain Bay Trail at Oshkosh Street.
The contractor on the project was Degroot Construction of Green Bay, which purchased the saddles from Davies Water Equipment of Appleton. The saddles were manufactured by Smith Blair Inc. of Texarkana, Texas.
The first two water main breaks occurred in the 100 block of North Main Street in February 2009 and December 2010, only about 50 to 75 feet away from one another. The most recent was in the 200 block of South Main Street on Sept. 25.