Snare Falls shutdowns cost NWT Power Corporation at least $510K
Two oil leak-related shutdowns of the Snares Fall hydro plant last year cost the NWT Power Corporation more than half a million dollars.
Noel Voykin, president and chief executive of the corporation – also known as NTPC – confirmed the figure to Cabin Radio on Thursday. He said costs were higher than expected because of safety protocols related to the pandemic, but the bill won’t be passed on to customers.
The extra cost primarily came in the form of diesel backup power generation with the hydro plant offline. Voykin said that would have no impact on customers’ rates as the cost of diesel backup is already included.
The power corporation first shut down the Snare Falls unit on April 25 last year after staff noticed an oil sheen on the water. While an initial inspection found no evidence of a leak, a second inspection on May 4 discovered oil was missing. Following repairs, the plant was returned to service on May 29.
During both shutdowns, Yellowknife’s Jackfish diesel plant supplied backup power. In May, the corporation asked customers in the city to conserve power in order to reduce costs.
Voykin said the full cost of the December shutdown is still unknown, but the cost of diesel replacement totalled around $260,000. The cost of the earlier shutdown had been put at $250,000.
The shutdown in May was the result of a leaking pipe. Voykin said the oil collected in a sump in an area that couldn’t be seen and eventually overflowed. Staff cleaned out the sump and tightened loose pipes.
The shutdown in December was due to a leak in another area of the unit, he said. In that case, a seal failed that holds oil used to change the pitch of blades in contact with the water. The corporation changed to a thicker lubricant.
Pandemic made repairs tricky
In both cases, the power corporation brought divers and contractors into the territory to help bring the unit back online. Internal documents show public health restrictions made that tricky.
“It was quite a significant issue,” Voykin said. “Because hydro units are very specialized pieces of infrastructure, we had to bring in out-of-territory contractors both from a diving perspective – that had the skill sets we needed – and then specialist engineer and maintenance staff from a hydro contractor to help us troubleshoot.”
A report to NTPC’s board of directors shows that by May 17, following approval from Protect NWT, two contractors and four divers had arrived in the NWT to conduct an underwater inspection and find the source of the leak.
“It took a little longer than we would have preferred to work our way through the approval process, but it has given us valuable experience in knowing what information we need from out-of-territory contractors and how to complete the necessary forms so that their entry can be expedited,” Voykin wrote.
In notes for a Skype call to staff on May 21, Voykin indicated the divers had completed much of their work.
Three days later, however – after the divers had left the territory – another issue arose at Snare Falls. Staff were concerned that water flowing into sumps was building up too quickly and the hydro plant could flood.
“We need divers back from outside of NWT immediately to seal it off. At this point we are keeping up with sump pumps but the flow is increasing,” Voykin texted power corporation chair Joe Dragon. “If we can’t keep up, the plant will flood and create significant damage.”
While NTPC urgently tried to get health officials to allow the divers back into the territory, an on-site team was able to stop the flow of water. Later that day, Voykin reported the divers were no longer needed.
Speaking to Cabin Radio this month, Voykin said he doesn’t expect more leaks or shutdowns at Snare Falls. Later this year, when the weather is warmer and electricity demand is lower, the corporation plans a detailed inspection followed by any repair work required.
“We believe the issue that caused this problem has been addressed,” he said.
Voykin said oil spilled into the river had been captured by a boom.
The corporation faced a number of challenges in 2020. During the first shutdown, power corporation staff were also dealing with a ransomware attack, an unrelated power outage in Yellowknife, and preparations for flooding in Hay River.
Voykin believes staff handled the issues well.
“We have a very robust emergency management culture within our organization and I believe we adjusted to the various emergencies and emerged stronger,” he said.
Both Voykin and Shane Thompson, the minister formerly responsible for the power corporation, have highlighted challenges with the territory’s ageing power infrastructure.
According to a 2007 abandonment and restoration plan, Snare Falls is the second-oldest plant in the Snare hydro system. It has been in service since 1960.
“NTPC has maintained the assets as they’ve aged to prolong their use and defer capital expenditures as much as possible,” Voykin recently told Cabin Radio.
“We recognize the long-term economic and environmental sustainability of the corporation is heavily dependent on reliable assets. We’re moving forward on a significant capital plan over the next several years to address the ongoing challenge of ageing infrastructure.”
The power corporation’s latest annual report states a 20-year strategic plan has been in development since late 2017 and was approved by its board in early 2020. An “ambitious capital program” includes refurbishing hydro units, building new plants in remote communities, and new transmission lines.
While the pandemic affected many projects, the corporation made some progress in the past year. That included refurbishing units at the Snare Forks hydro facility, installing new generators in Délı̨nę and Nahanni Butte, and upgrading the ventilation system at the Inuvik plant.
Voykin said the corporation next plans to refurbish the Taltson hydro plant along with replacements in Sachs Harbour and Łútsël K’é.