Town slides showing slippery “black slop” that added “significant costs” to final phase of the Lorne St. flood control project

Tantramar Town Council has approved spending an extra $173,242 to complete Phase III of the $5.2 million Lorne Street flood control project.

During a council meeting on Wednesday, Town Engineer Jon Eppell explained that the extra money is needed because construction crews had to deal with unexpected problems caused by soft soils.

“It’s really black slop that we encountered,” he said, adding that the soft stuff kept sliding down into the excavation and had to be replaced by rocks to stabilize the slopes.

Eppell blamed it partly on an unusually rainy summer.

“It’s been very wet and not surprisingly, working in a wetland is not a great place to be when we’re having a wet summer and this has caused us a lot of challenges and issues.”

Eppell showed this slide with 3 excavators (upper left & right) working to remove the black sloppy soils

Eppell explained that excavators had trouble removing the black slop as he showed a slide with three of them at work.

“There were more than that at certain times working away to excavate the material,” he said.

“A lot of times they had to reach out, excavate it, move it once and then excavate it and move it twice because they had set up positions with timber mats where they could keep position, but they couldn’t really move around a great deal.”

Diagram showing locations of soft soils marked in red (click to enlarge)

One of Eppell’s slides showed areas marked in red to indicate where the “black slop” had to be removed and replaced.

“You can see how extensive they were,” he said.

The marked areas include parts of the site around the large retention pond that has been dug behind the community gardens on Charles Street as well as the new ditches between Sloan Drive and Crescent Street and the ones between Crescent and the dyke beside the Tantramar River.

“My only concern is first, were samples not taken when you guys were doing the project to see what kind of land was there?” Councillor Josh Goguen asked.

“And the second concern is, do you anticipate any more overages with the work that still needs to be completed?”

“As far as sampling, it is a large site,” Eppell answered.

“You’re only taking statistically a small percentage of samples to try and determine what you’re dealing with and it’s quite easy not to capture everything,” he said, adding that the geotechnical work was done before he took over as town engineer.

He said he didn’t anticipate any further problems with soft soils.

Town Engineer Jon Eppell answering council’s questions

Eppell suggested various ways of cutting costs that included skimping on the crushed gravel needed to make the service roads around the new retention pond more walkable for hikers.

But in the end, council decided to accept his recommendation that the extra $173,242 be added to the contract awarded to Beale & Inch.

Treasurer Michael Beal said the money would come out of the capital reserve fund without the need for any borrowing.

He added that the town will try to recover at least some of the money from New Brunswick’s Regional Development Corporation.

Eppell said Phase III of the flood control project should be finished by mid-December and if all goes well, a new provincially-funded aboiteau to drain flood waters into the Tantramar River will be installed by the end of next March.

To read Eppell’s report to council on the flood project, click here.

Warktimes first reported on the black, sloppy soils in July. To read that report, click here.