A sewage pipe at Departure Bay is suffering from corrosion and repairs are going to cost more than $5 million.
The 47-year-old steel pipe is situated mainly along Hammond Bay Road, and “the largest forcemain in the RDN wastewater collection system in terms of total flow and diameter,” according to a Regional District of Nanaimo staff report. During examination after a sewage gas leak in late 2019, it was determined an 800-metre section of pipe, in the Hammond Bay-Meadow Lane-Planta roads area, needed “immediate” repairs.
“Corrosive sewer gases” were building up at the top half of the pipe, said the report, leading to deterioration. The project will see about 400m of high-density polyethylene pipe installed, while 400m of pipe will be rehabilitated with an internal structural lining material that won’t require digging. The aim is to limit effects on traffic and residents, the report said.
Windley Contracting Ltd. was awarded the $5.5-million contract, with the RDN board giving the green light at its June 8 meeting.
Vanessa Craig, RDN Gabriola Island area director, wondered at the meeting if the work would change the profile of the pipe so corrosion wouldn’t occur again and Sean De Pol, RDN director of water and wastewater services, said the composition of the pipe is expected to prevent that.
“The profile of the pipe has to remain,” said De Pol. “It follows the contours of the lay of the land in that area. However, the material … is able to withstand hydrogen sulphide, unlike the epoxy-coated steel pipe that was originally installed in 1973.”
The board also approved a recommendation that will see the overall project budget increased by $1.4 million, for a total of $6.9 million. That work will include City of Nanaimo storm water infrastructure, so the municipality will chip in $550,000. The additional spending will also ensure all facets of the design are completed on time, as work needs to be done “during dry season,” said the report.