Testing underway near Oxford
Investigation to include drilling of several boreholes
OXFORD, N.S. – The Nova Scotia government has begun investigating the potential for sinkhole development under the Trans-Canada Highway near Oxford.
Several weeks after saying it did not see the need to do additional testing of the highway, despite the presence of a depression, the Department of Transportation and Infrastructure Renewal has hired a company to conduct geotechnical testing in the area.
“Logan Drilling, overseen by Harbourside Engineering, has begun a geotechnical investigation at Highway 104, Exit 6, that will give us a clear understanding of the conditions at this site and how best to monitor and/or respond to the findings going forward,” department spokeswoman Marla MacInnis said in an email to the Amherst News.
Minister Lloyd Hines was not available for comment.
MacInnis said site work began this week and will include the drilling of several boreholes.
“The depth of the drilling is expected to be between 100 and 125 feet below the roadway but could vary at each borehole location depending on subsurface conditions encountered,” she said.
The investigation is in addition to regular monitoring and annual road surface testing done at that location.
The testing comes a month after the Oxford Lions Club decided to abandon its parkland property in the community following the release of finding of a geotechnical study of the popular playground that was closed in August 2018 when a massive sinkhole suddenly developed.
At the time, Cumberland-Colchester MP Bill Casey, Cumberland South MLA Tory Rushton and Cumberland EMO coordinator Mike Johnson joined Oxford chief administrative officer Rachel Jones in calling on the province to do additional testing focusing on the Trans-Canada Highway and Highway 321 that comes into Oxford.
Jones said the province was invited to participate in the study by GHD Engineering but declined and the engineering firm’s final report recommended additional study of the Trans-Canada Highway and the road into town. At the time, the province refused, saying it regularly does its own testing.
Casey said he’s pleased with the province’s decision.
“All along we’ve had these indications there could be a problem. Hopefully, this will clarify whether there is a problem or not,” Casey said. “I’m very much appreciative of the province taking the steps to confirm what’s going on there. It’s important we know.”
The MP said his biggest concern is not the potential lost commerce should a sinkhole open up, it’s the danger it would present should a tanker, a bus or a car fall into it.
“We all know how quickly the sinkhole developed in the park and we don’t want that to happen on the highway,” he said. “This analysis will hopefully provide peace of mind that won’t happen.”
Casey is hoping the testing is deep enough because that’s what the geologists said needed to be done. He’s also optimistic that if a problem is identified the provincial and federal governments will work quickly to mitigate it.
“There are sinkholes all over the world and there are construction methods to fix that before the hole opens up,” he said. “We don’t know if there is a sinkhole under there, but there are indications that there is.”
Rushton, who raised the issue in the legislature as recently as two weeks ago, said he was told by the minister the testing would be conducted within two weeks.
The sinkhole that closed the Lions Park in Oxford is located in an area of karst topography that is prone to sinkholes. There are sinkholes directly across the Trans-Canada from Oxford and there is aerial photography from before the highway’s construction indicating there may have been a sinkhole where the highway is today. LiDAR images, which hadn’t been completely analyzed in September, also indicated depressions around the highway.