Ammonia leak kills Issaquah Creek salmon
October 13, 2009
By Warren Kagarise
Ammonia released into the East Fork of Issaquah Creek from the Darigold plant killed dozens of fish last week.
The fish kill occurred after an unknown amount of ammonia entered the creek Oct. 7. Most of the 40-50 dead fish observed by state officials were sculpin, a small freshwater fish.
Department of Ecology spokesman Larry Altose said single-digit numbers of chinook and coho salmon died as a result of the spill. A handful of trout died as a result of the spill as well.
The state Department of Ecology responded to the incident after receiving a report of dead fish from a state Department of Fish and Wildlife biologist surveying spawning salmon in Issaquah Creek. The biologist observed dead or dying fish across a quarter-mile reach of the creek, between Darigold and the confluence of the East Fork and Issaquah Creek.
Chinook and coho, dead at the end of the salmon spawning cycle, were observed in the same area. Altose said fish biologists could determine the difference between salmon that had died after spawning and others affected by the leak.
After ammonia entered the creek near the plant, at 611 Front St. N., workers secured the leak and stopped the ammonia release by midafternoon. Ecology officials do not know how long the leak lasted.
By late afternoon, ammonia in calm pools along the creek appeared to have evaporated, according to a Department of Ecology news release. Darigold is cooperating with the department to investigate the cause of the leak. Altose said the Darigold plant uses ammonia as a refrigerant.
“There are a lot of questions that need to be worked through and tracked back,” Altose said.
Friends of the Issaquah Salmon Hatchery Executive Director Gestin Suttle said the spill did not disrupt spawning activities at the hatchery. Suttle said hatchery workers were notified soon after officials discovered the ammonia leak.
The hatchery is upstream from Darigold, though Suttle noted how migrating salmon could have come into contact with ammonia while swimming upstream.
Altose said Department of Ecology hazardous materials specialists surveyed the site Oct. 8 and observed fish swimming with no problem in the spill area.
Warren Kagarise: 392-6434, ext. 234, or firstname.lastname@example.org. Comment at www.issaquahpress.com.