Ammonia leak forces evacuation

An ammonia leak at the Teton Valley Ranch food processing plant resulted in the temporary evacuation of about 75 homes in the south part of town Wednesday night.

One person was reported to have been treated, and later released, by Elmore Medical Center, for a minor case of ammonia fume inhalation, although the hospital did receive several calls from people who wanted information about possible symptoms.

The incident occurred after the plant had been shut down for the evening.

There were no workers in the plant at the time. Officials believe a pressure release valve on a refrigerant unit in the plant failed, releasing an unknown amount of ammonia.

The Mountain Home Volunteer Fire department was called out at 7:09 p.m. when dispatch began getting calls from residents of the Freedom Circle area adjacent to the plant, reporting the smell of ammonia.

Upon arrival, the fire crews verified the smell of the potentially deadly gas and set up an incident command post on the west side of the area, upwind from the plant. They then entered the building in full protective gear, including oxygen masks, and verified the leak. Fireman Brian Reed said crews found a 3-foot wide puddle of ammonia on the floor near one of the refrigerators.

At that point they began shutting traffic down in the area and called for Boise Hazardous Materials (Hazmat) teams to assist, as well as contacting the refrigeration company.

Reed said both smell, and later more detailed information provided by portable detection devices used by the department, caused firemen to believe that it was worth declaring an "imminent danger" to area homes.

By 7:44 police had been called in to take over traffic control, and at the recommendation of the Boise Hazmat team, an evacuation of the surrounding homes was begun. Police went door-to-door clearing residents from an area from E. 6th South St. to E. 12th South St., and from S. Main to S. 14th East

St. Those residents were directed to go to the junior high school gymnasium, where medical teams were positioned to help anyone who might have experienced any side effects of breathing the fumes.

The wind was blowing from the west at 10-15 miles an hour, and according to Sgt. Rick Viola of the Mountain Home Police Department the evacuation area was actually slightly larger than recommended, "but we wanted to err on the side of caution."

Hazmat teams from the airbase fire department were requested to show up later that evening, at about 11:45 p.m., to beef up the on-scene trained hazmat personnel.

Repairmen from the refrigeration company arrived, identified the problem and effected repairs.

At 1:13 a.m. police released the families at the junior high to return home.