About 200,000 young rainbow trout were killed on Dec. 11 at the Idaho Fish and Game hatchery in Grace when a chlorine pipe began to leak.

Hatchery manager Phil Coonts was disinfecting vats during routine cleanup when a standpipe began leaking chlorine. The chlorine flowed into the large raceways at the hatchery where it came into contact with fingerlings and small trout.

Officials still are investigating the cause of the leak.

No dead fish were seen in the settling ponds or in Whiskey Creek near the southeast Idaho hatchery.

Fish and Game notified nearby landowners, the state Department of Environmental Quality, and the federal Environmental Protection Agency of the incident.

Hatchery personnel are cleaning up, and Fish and Game is looking at fish production at other hatcheries to determine whether other fish can be brought to Grace Hatchery.

“We will make every effort to ensure there are minimal impacts to the local fisheries which rely on the support of Grace Hatchery,” said Tom Frew, resident hatcheries supervisor.