ST. LOUIS, Mo. — Federal investigators Thursday were focusing on why a fail-safe shut-off valve did not prevent a chlorine gas leak at a plant south of St. Louis, the St. Louis Post-Dispatch reports.
Hundreds of homes and businesses in the Festus-Crystal City area were evacuated and at least 55 people were treated at Jefferson Memorial Hospital on Wednesday. Many complained of shortness of breath and eye, nose and throat irritation.
The accident at DPC Enterprises on Highway 61, about 35 miles south of St. Louis, occurred about 9:30 a.m. Wednesday when a hose burst on a railway tanker car.
Traces of the gas lingered at the site Thursday, hampering the efforts of inspectors from the U.S. Chemical Safety and Hazard Investigation Board to find out what went wrong.
Bill Hoyle, the board’s director of investigations, said the persistent gas prevented inspectors from reaching the source of the release. He said they hoped to inspect the site today.
Hoyle said authorities are trying to determine why an automatic shut-off failed to work, allowing the gas to escape for more than two hours before a hazardous materials team could manually turn it off.
“We’ll also be looking at emergency response procedures at the facility,” Hoyle said.
Wayne Penick, manager of safety, health and environmental services for DPC, said workers were unloading the contents of the rail car into smaller tanks when the accident happened.
Penick said workers are trained to handle leaks, but the cloud of gas grew too large too fast for them to respond. Three of the workers went to a hospital but were released.
The greenish-yellow cloud that was released burned the trees and grass around the plant a to late-autumn brown.
Penick said DPC refitted the plant with new safety equipment 18 months ago.
“It’s supposed to stop what happened,” Penick said. “That’s some of the things that are built into the system to prevent this type of release from happening.”
Penick said the plant had been operating in the area for about 30 years. He said DPC, based in Houston, bought the plant from Jones Chemical Co. in 1998.
A previous release happened on Jan. 7, 1999, when a crane operator dropped a 2,000-pound cylinder of chlorine and it ruptured.
DPC has 13 facilities in the United States. The plants repackage chlorine into one-ton containers and 150-pound containers for use in water treatment and other industries. Penick said the city of St. Louis is among the companies’ customers.
Terry and Kym Hoyt live in the Blue Fountain mobile park, next to the plant. Their 5-year-old Siberian Husky “Sonny” was in the back yard when the chlorine gas descended over their home. A veterinarian has told them he wasn’t certain whether the dog would live.
“I don’t understand if it was a hose that busted why somebody didn’t shut the valve off,” Terry Hoyt said. “How hard is it to shut a valve off?”
The Hoyt’s neighbor, Barbara Hoffman, 62, has lived in the park for 18 years. On Thursday, the wilted begonias and butterfly bushes in her yard had her wondering whether it was time to move.
“Some people have their pets. Some people have their car. I have my yard,” Hoffman said. “It’s sad.”