Brookings residents may have quizzically noticed an odd-looking apparatus that at times appears to spew steam from a pipe extending from a manhole at various locations around town.
It’s all a part of a $536,151 project to install a plastic liner in some 10,000 lineal feet of sewer main and rehabilitate 17 manholes to reduce the amount of storm water infiltrating into the City’s wastewater treatment plant.
"Storm water infiltration into the sewer collection system results in higher operating costs at the wastewater treatment plant,” City Manager Gary Milliman noted. “Storm water moving through the plant requires the use of more chemicals and more electricity than is needed to process sewage."
"Infiltration can also result in overwhelming the capacity of the sewer mains, which were designed to handle a certain sewage flow,” Milliman said. “This can cause sewage discharges during heavy rain events.”
The City retained Michels Corporation of Salem to undertake the sewer lining project. Work is expected to continue for another three weeks.
“This is a major project…one that people can’t see,” Milliman noted. The underground work is being done with minimal disturbance to the road surface. “We are using the lining method to avoid the high cost of digging up and replacing the sewer main pipe. We expect to get about 50 years of service from the lining.”
Steam is used in the process to help fuse the plastic lining to the pipe.
Locations of the work were determined after the City public works crew completed a television inspection of the sewage collection system. About five per cent of the entire system is being lined. The current project is about $90,000 under budget and the City may contract for some additional lining and manhole rehabilitation work in June.
The City maintains approximately 200,000 lineal feet of sewer main.