BOSTON — Major upgrades to the drinking water treatment plants in Groton and Norwich, Connecticut, are underway in response to claims by the U.S. Environmental Protection Agency (EPA) that the cities’ use of chlorine gas violates federal clean air laws, according to a press release from EPA.

EPA found chlorine gas storage and handling violations in Groton Water Treatment Facility, which included a lack of a management system, “off-site hazard consequence analysis” and proper, regular compliance audits, among others, stated the release. EPA also found Groton had not updated its process hazards analysis for the 15-year period between 1997 and 2012.

The Dr. Charles W. Solomon Water Purification Plant in Norwich presented risk management violations, including a lack of “complete written operating … procedures or a preventative maintenance program,” continued the release.

The facilities will replace the use of chlorine gas for disinfection with the safer sodium hypochlorite, reported the release, which is “easier to handle and less hazardous than chlorine gas.”

Penalties of $7,000 and $8,330 will be incurred by Groton and Norwich, respectively, according to the release, and the price to make upgrades to the facilities, converting them for hypochlorite use, will at least cost Groton $449,000 and Norwich $150,000.

The aim of these upgrades is to “reduce public health risks in their communities by eliminating the use of chlorine gas at these facilities,” the release went on to explain, as chlorine gas offers a higher potential for accidental release, and it presents health risks such as being highly corrosive to the skin, eyes and lungs and can even be fatal.

“EPA is pleased that the Groton and Norwich water treatment facilities will update their plants and eliminate the use of chlorine gas,” said Curt Spalding, regional administrator of EPA’s New England office. “Facilities that store and use hazardous materials have a special obligation to understand and carefully follow regulations designed to protect people, our communities and our environment from potentially catastrophic consequences of accidents.”

Read the entire release here.