An update on the state of the sewers in Iroquois, Morrisburg and Williamsburg was given at the July 17 South Dundas council meeting.
Todd Grant of AECOM was on hand to deliver a presentation outlining the issues found in each of the locations as well as an account of what needs to be done and a timeline and cost approximation for the work to be completed.
The 2011-2012 study of the sewers in Iroquois, which has 14 kilometers of “mainly concrete” pipe and 125 manholes, revealed “clear evidence of infiltration and pipe deterioration.”
The streets needing work in Iroquois were divided into high priority and low priority, with the high priority streets expected to be addressed first.
The study of Morrisburg’s sewers took place from 2009 through 2011, revealing that the 19 kilometers of pipes and 250 manholes also had “clear evidence of infiltration and pipe deterioration.”
All listed streets needing work in Morrisburg were listed as high priority. In addition, a section on Lakeshore Drive is in such a state of disrepair that it cannot be rehabilitated, but requires replacement.
Grant’s report also covered the findings from the 2011 study of Williamsburg’s sewers, which include four kilometers of pipe and 20 manholes. These, he said, were in “generally good condition” and need only minor repairs.
The studies revealed extraneous flow, which is a combination of infiltration and inflow issues.
Infiltration refers to ground water entering the sewers through defective pipes and/or cracks in manholes while inflow refers to water entering the sewers through inappropriate connections.
Inappropriate connections can include such things as roof drains, foundation drains, sump pumps, street catch basins and yard drains.
The impact of the extraneous flow is loss of capacity in the sewer collection system as well as higher water treatment costs.
It was suggested that operating costs could be reduced by as much as 30 percent if all systems were completely repaired.
Grant suggested council look into an education program for residents highlighting and explaining the various inappropriate connections.
He informed council that final reports will be submitted by July 27 with the expectation that tender preparation will be completed by August 31 with a tender closing of September 21. Rehabilitation work would then begin on October 1, 2012 and run through to October 31, 2013.
The section of Lakeshore Drive requiring replacement has a design deadline of October 30, 2012 with the expectation that tender preparation will be completed by November 9, 2012 with a tender closing of March 2013. Work would take place between May and September of 2013.
“That was very interesting,” said deputy-mayor Jim Locke, following Grant’s presentation, “and not frightening.”