EPHRATA — The primary construction contract for upgrades and refurbishment to the generators and turbines at Priest Rapids Dam may exceed $100 million by the end of the 10-year project. That’s up from the current estimate for the contract of about $95 million.

Grant County PUD engineer Jeff Niehenke updated commissioners at the last commission meeting.

In answer to a question from commissioner Dale Walker, Niehenke explained the repairs and refurbishment identified to date would push the price over $100 million for the entire project contract. Alstom Hydro is the main construction contractor.

Refurbishment of the turbines and generators begins in August. There are 10 generator-turbine units, with one scheduled for refurbishment and upgrading each year.

The turbine-generator units date back to the dam construction 50 years ago. Some parts have worn out, some have been superseded by new technology. Others are at the point where they no longer work as intended. Some parts are showing signs of stress, but “the solution (to fix them) isn’t clear” yet, due to the difficulty of getting to those parts, Niehenke said.

“With any piece of equipment that’s 50 years old, we’re going to go in there and do a lot of inspection on it, and we’re likely to find some problems.” But so far the repairs and refurbishment shouldn’t affect the timeline. Refurbishment will cost about $5 million for the parts identified so far, compared with a replacement cost of $14 million, he said.

Commissioner Larry Schaapman asked if the repairs and refurbishment found so far were included in the original budget. Niehenke said engineers budgeted for repairs they knew would be needed, and added in some contingency funds. So far all expenses are within contingency, he said.

Over the course of refurbishing an entire generator, “we have ups and downs on every component. In some areas we’re doing better than we anticipated, other areas we’re doing worse,” he commented.

Engineers are still working on solutions for problems identified so far, he said, so they won’t know the impact on the total project budget until those designs are finished.

Some of the repairs and refurbishment are proving to be challenging and not all the solutions are clear yet. Figuring out the solutions will be “a very big job, and it’s going to be a lot of design work to figure out how to do this reliably.”

Some problems were anticipated, others have been discovered during the inspections, he said, and could add to the price but should be within the budget. “We have a clear idea of what the remaining engineering needs to be.” He estimated the extra engineering cost would be about $260,000.

“In total we’re looking at over $6 million across 10 units in additional work.” But that’s within the contingency, he added.

It’s an expensive process, he said, but less expensive than buying new parts. Niehenke estimated the PUD will save about $76 million by refurbishing components rather than replacing them.