Monday, June 25, 2007
Headlines - Region 6
Power outage at Fort Peck Hatchery causes death of 110,000 Chinook salmon
Nearly three quarters of the Chinook salmon scheduled to be released this year into Fort Peck Reservoir suffocated last week when power was lost for several hours at the new Fort Peck Fish Hatchery.
The remaining quarter of the salmon stock, about 36,000 3-inch fingerlings, were salvaged and released into the lake after repeated attempts to restore power to the facility failed.
Fort Peck Hatchery Manager Andrew Ollenburg called the loss of both primary and backup power to the facility "a freak occurrence" and said that causes of the failure - mechanical and electrical systems - were being diagnosed and repaired this week.
"The root cause of the power failure was a tree branch across a power line in the town of Fort Peck on Sunday night," said Ollenburg. "When the hatchery lost power, our backup generator kicked on and our automated phone dialer summoned our on-call employee as it was supposed to. He arrived at the hatchery, made sure pumps were running and then went home."
But when hatchery employees reported for work Monday morning, they found that the backup generator had failed. About 75,000 Chinook in tanks inside the hatchery were dead because fresh-water flows stopped during the night. More than half of the 75,000 salmon in the outdoors raceway also died when water stopped flowing.
"We attempted several times to restart the generator but it kept heating up and shutting off, so we decided to stock out the surviving salmon, about 36,400 fish, to get them out of the hatchery," says Ollenburg. "The salmon were scheduled to be stocked out Wednesday anyway, so they got a couple days head start on their lives in the lake."
Ollenburg says the initial power loss to the hatchery wasn’t uncommon. During a powerful storm the previous day the hatchery lost power, but the backup generator kicked on as intended and kept pumps turning until the main power was restored. The loss of the generator in the second outage was entirely unexpected and apparently was caused by a defective breaker to the radiator and a second, apparently unrelated, problem with an oil pressure sensor.
The problem with the generator went undetected because the automated phone dialer that alerts employees to power loss wasn’t activated since the outlet that powers that device isn’t connected to the circuit powered by the generator.
"So we never got called that the backup generator was out because the monitor didn’t register that power had been restored, then lost again," said Ollenburg. "We learned a lot about our system last weekend. For one, we learned that there’s a loophole in the electrical system that doesn’t connect the auto dialer to the backup generator. And we learned that our alarm system doesn’t have a battery backup. If we had known that our backup power was off, we could have been here in the middle of the night salvaging fish. It’s still a new facility and maybe these glitches are to be expected, but it is never easy to lose fish."
Ollenburg said the only bright spots in the incident were that at least some fish were stocked into the lake and that the power outage didn’t come in early May, when several million walleye eggs were incubating.
"We’re working to identify and correct the problems," he says. "We test our generator every week to make sure it’s working correctly, and it’s always powered up and stayed running just fine. The fact that it failed - and failed twice - is one of flukes that you can’t anticipate but we’re going to work to ensure that it doesn’t happen again."