President and CEO Robert Watson said things have come up that weren't expected on the $1.3 billion project.
That includes $25 million for steel reinforcement in the building and boiler, $30 million to remove lead paint and asbestos and $35 million for unforeseen engineering changes.
The plan at Boundary Dam is to capture CO2 emissions from the coal-fired power plant.
The CO2 will be sold to oil and gas companies which use it to push more oil out of the ground in what's called enhanced oil recovery.
Watson said construction is 90 per cent complete and the project is on track for next April.
"The facility is going well. I've been down there two times in the last month and it's something still really to be proud of and we're really looking forward to completing the project on time particularly," Watson said in a conference call Friday.
"And as power facilities go, when you rebuild them you find stuff out that you've got to do. There's nothing you can do about it. You have to do (it)."