More than two hours elapsed before emergency crews were told that corrosive acid spilled into a sewer Tuesday at the Three Rivers Water Filtration Plant.
About 6,000 gallons of hydrofluorosilicic acid, used to add fluoride to drinking water, drained from the lower level of the filtration plant into the sewer.
Roger Hirt, acting filtration plant supervisor, said the chemical spill was relatively minor, but it showed the plant might not be prepared for an accident involving a more dangerous substance, such as chlorine.
Four plant employees were treated Tuesday at Parkview Hospital and released after complaining of respiratory problems and headaches from the acid’s fumes.
Emergency management officials said the water supply was not threatened.
Pump operator Alan Boyle found the chemical flowing under a door during a 4 p.m. walk-through of the area and said he notified his supervisors. But the Fort Wayne Fire Department was not called until 6:18 p.m.
“If they called right away, it might not have been 6,000 gallons,” said Capt. Brian Duff, fire department spokesman.
“It’s much better to call as soon as you have the emergency and you realize you can no longer handle it.”
Hirt said Wednesday afternoon he had not determined the exact cause of the spill or why the staff waited two hours before calling the fire department.
“Did we follow the procedures fast enough?” Hirt said. “Did we do the right thing at the right time?”
Hirt said he will check the plant’s protocol.
He was speaking at a City Council meeting Tuesday when the spill was reported to the fire department, which had controlled the accident by the time Hirt left the meeting.
The acid is a common water-treatment chemical that can cause severe irritation to the nose, lungs and throat if its fumes are inhaled.
At 3 p.m. Tuesday, Boyle filled the plant’s fluoride tank with the acid, which is kept in a larger drum outside.
He said an orange light alerted him that the valve between the tanks had closed when the tank was full, and he went back to the plant’s upper level.
However, he found the fluoride tank overflowing an hour later, and caustic fumes had filled the area. Boyle, a 20-year plant worker, said the spill left him with chest pains, a headache and sore eyes.
After the fire department responded, Boyle and three workers on the upper level declined to take an ambulance to the hospital. They drove to Parkview and were monitored until about 12:30 a.m.
“These fumes, they lit up the building,” said Roosevelt Johnson III, a chemical feed operator who decided to go to Parkview after having a severe headache and difficulty breathing.
“There was a small cloud in there. You couldn’t breath.”
The city was unable to add fluoride to the water supply Wednesday because only 300 gallons of the acid remained on site. Hirt said he expected a truck to bring 4,500 gallons of the chemical today.
When the new acid comes in, Hirt said his staff will test the valve to see whether it is still functioning. An electrician also will check for any electrical damage.