McAllister had a bad bug problem. It was (most likely) caused by I-5. When built, the creek was choked at the new freeway. More water backed up and the system became habitat for the bug. Couple this with the hatchery intake, at high tide, sucked in the hatchery effluent.

The Nisqually hatcheries do pretty well for Chinook. But, that system has been a long-time poor performer for coho.