A Corporation of Shepherdstown truck is sprayed after Monday's chlorine gas leak at the wastewater treatment plant. Photo by Michael Theis

Shepherdstown’s Public Works Department Director Frank Welch reports that three workers exposed Monday to chlorine gas at the East High Street wastewater treatment plant are back to work.

Welch said nearly half of a 150-pound cylinder of chlorine gas, which is used to treat effluent before it goes into the Potomac River, had leaked in a storage room. The highly corrosive gas destroyed a computer, and may still take its toll on other equipment. Tuesday, the tank’s manufacturer removed the leaking cylinder, which had not yet been used at the plant.

“I look for other problems,” Welch said. “And I hope I’m wrong.” He said it may take many days before the full extent of the damage is known. Welch is considering calling for an electrical inspection of the building where the leaking tank was stored.

Three Public Works Department employees were treated for chlorine exposure Monday afternoon following the chemical spill. Earlier reports that four employees were exposed were not correct.

According to an official at Town Hall, the spill occurred about 1 p.m. Traffic was routed away from a several-block residential area for at least two hours.

Several emergency response teams from Berkeley and Jefferson counties and Washington County, Md., responded along with a West Virginia Regional Response Team from the Department of Military Affairs & Public Safety.

“Everybody did a great job ,” Welch said of the emergency response workers. “They took control of the scene after they got here.”

Water and wastewater treatment plants use chlorine to reduce water levels of microorganisms that can spread disease to humans, according to the EPA.

An EPA Office of Pollution Prevention and Toxics Fact Sheet reports that chlorine is a “highly reactive gas” and a naturally occurring element.

Breathing small amounts of chlorine for short periods of time adversely affects the human respiratory system, the EPA reports. Effects range from coughing and chest pain to water retention in the lungs. Chlorine irritates the skin, the eyes and the respiratory system.

The EPA reports that people who use laundry bleach and swimming pool chemicals containing chlorine products are usually not exposed to chlorine itself. Chlorine is generally found only in industrial settings.

The town is in the planning stages for a new, multi-million dollar plant to replace the aging facility built more than 30 years ago.

“When we get the new wastewater treatment plant, we won’t have chlorine,” Welch said, noting chemical spills are a danger associated with the job. But he has rarely seen a leak as bad as Monday’s.

“We’re trying to get back to normal,” Welch said.