Tim Ryan, tryan@wolfrivermedia.com
City officials on Wednesday approved a bid to replace stainless steel saddles at eight Main Street locations at risk for water main breaks due to potential corrosion.
The Shawano Common Council approved a $19,200 bid from Grunewald Inc. The bid was about $800 under what was budgeted.
Work was expected to begin this month and be wrapped up by Oct. 31.
The saddles hold in place the service connection to the water main.
Three of the saddle replacements will take place in the 100 block of North Main Street, two in the 100 block of South Main Street, one in the 200 block of North Main, one in the 200 block of South Main and one in the 100 block of West Fourth Street.
High levels of chloride in the soil were responsible for three water main breaks along Main Street since December 2010, and random soil tests conducted last year found eight other spots where chloride levels are high.
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. Another saddle failed in the 200 block of South Main Street in September 2013.
Random soil tests were done last summer by Mach IV Engineering, of Green Bay. Out of 20 locations sampled, chloride levels above 500 parts per million were found at three locations. Five others had chloride levels above 300 ppm.
Public Works Coordinator Eddie Sheppard said the stainless steel used in the saddles could start to deteriorate at chloride levels over 300 ppm. At levels above 500 ppm, the deterioration is much faster.
Chloride levels in the area of the three water main breaks were in the range of 900 ppm, as a result of years of street salt seeping into the soil.
The saddles were installed during the Main Street reconstruction project in 2002 and 2003, which stretched from the channel to the Mountain Bay Trail at Oshkosh Street.