By Neco Cockburn, Ottawa Citizen
OTTAWA — City staff aim to prevent another big problem like the Hwy. 174 sinkhole through measures such as additional training and making sure information about infrastructure is accurate, councillors heard Tuesday.
At a meeting of council’s environment committee, politicians got their first chance to ask detailed questions about an independent review into the Sept. 4 sinkhole that swallowed a car and caused east-side traffic headaches for almost two weeks.
Most wanted to know what staff are doing to ensure that the city’s records and documentation accurately reflect what’s underground, and whether the right people are in place to make decisions about inspections.
The review, conducted by Goderich firm B.M. Ross & Associates, found that shoddy records and the city’s failure to physically inspect a corroded storm sewer under the eastbound lanes at the Jeanne d’Arc Boulevard off-ramp contributed to its collapse and the resulting sinkhole.
Staff who saw a video of the pipe shot by a robot in August 2011 believed it wasn’t at risk of imminent failure and planned a $1.7-million relining project that started just before the pipe collapsed.
However, severe corrosion seen in the video warranted further inspection, said Steve Burns, a senior engineer with the firm. Since a physical investigation didn’t happen, “my interpretation was that the right people hadn’t seen that,” Burns told councillors.
City manager Kent Kirkpatrick’s take was that “maybe it’s not different people that needed to look at it, but the people that we have that have that role need better training, better tools, better information, and that’s the responsibility of management to provide that to those people.”
No disciplinary action was taken against those who watched the video and didn’t arrange further inspection, Kirkpatrick told reporters after the meeting.
“It’s the responsibility of management to make sure staff have the right training, the right tools and the right information to make better decisions, and that’s where I think the responsibility lies,” he said.
Deputy city manager Nancy Schepers told the committee that “several eyes” saw the video and reached the same conclusion. Physical inspections are now to be used to along with video inspections, Schepers said, and “we are supplementing the training and we are supplementing the practices.”
The city has also started a risk-based assessment of its storm and sewer assets, Schepers said, and that “will assist us in making sure that we are doing adequate inspection frequencies and prioritizing investments appropriately.”
Juan Pedro Unger suffered minor injuries when his car fell into the sinkhole, and his lawyer has given notice of a possible claim against the city. The legal department is working to resolve the issue outside court.
Emergency replacement of the collapsed pipe cost the city about $4.5 million. Legal staff have also determined there’d be little chance of success if the city filed a claim related to the pipe’s installation by a developer decades ago.
Similarly, there’s likely no case against a contractor that the review found likely triggered the collapse when it started to clear the pipe before the planned relining, says a staff report.
The contractor’s work wasn’t the main reason for the pipe’s failure, the review determined. The root cause, it found, “was that the structure’s inherently greater risks were not identified and acted on before the pipe’s structural integrity was lost.”
The 3.6-metre diameter steel pipe’s greater risks included its age of about 37 years, along with its size, material and location in a corrosive environment under a busy highway, Burns said.
The pipe was installed in the mid-’70s for the Township of Gloucester by a contractor working for Costain Estates Ltd., a developer. Records indicated that the full 127-metre length was galvanized when it was not, the review found, meaning that part of it was more susceptible to rust.
The corrugated steel ends were galvanized, but the middle section was installed by tunnelling under the highway and was composed of 48 meters of “tunnel liner plate” that was not galvanized, the probe determined.
Records also indicated there was concrete grouting on the outside of the tunnel liner plate section and asphalt coating inside, and that wasn’t the case, it found.
Orléans Councillor Bob Monette asked how confident staff are in the accuracy of information in the city’s inventory, and Schepers said data compiled on new items since amalgamation “is very good.” Information is being verified for older high-risk items that might have questionable records, she said.
City staff agree with all five recommendations from the review, and most are implemented through a “comprehensive asset management” program that’s already been adopted by council, Schepers said.
Councillor Maria McRae, the committee’s chair, said she’s satisfied that it’s “really not possible to point a finger at an individual” over the sinkhole.
“The city would never have allowed workers in that sewer had we believed that there was any danger of imminent collapse, and I think it’s a function of many different processes that had to be tightened up in terms of how we’re either inspecting some of this property or even recording data about it,” McRae told reporters.
The city also didn’t have accurate information about the pipe “through no fault of the city’s,” she said.