The Louisville Water Company has finished the phase-out of two hazardous chemicals that were stored at both of the company’s water treatment plants.

For about a century, Louisville Water has stored pressurized liquid chlorine at its Crescent Hill Treatment Plant, most recently in 90 ton railcars. Since the 1970s, it’s also been storing anhydrous ammonia at the plant in a 12,000 gallon tank. Both chemicals were also stored at the smaller B.E. Payne Plant in Prospect.

Stored at these volumes, both of these chemicals were dangerous enough to require Louisville Water to participate in the Environmental Protection Agency’s Risk Management Program.

Now, Louisville Water has changed its process to eliminate the need to store these chemicals on site.

“As far as the chemicals, nothing’s really changed but we’ve just gone about a safer way of meeting those needs,” said production engineer Scott Smith.

The company now makes a daily supply of chlorine on site from electricity, salt and water. It’s also switched from anhydrous ammonia to aqueous ammonia, which is a less hazardous form.

The chlorine switch was completed last year, while the change to the ammonia process was finished this summer.

Smith said the change was motivated by safety concerns. He said Louisville Water has been working on the switch for about a decade, spurred by events like the Sept. 11, 2001 terrorist attacks and the worry that terrorists could specifically target chemical storage facilities.

“Well, initially after 9/11 occurred we kind of sat back and look at the things that basically kept us up at night,” he said. “And we identified the chlorine system as one of the major treatment processes that did that. So that kind of got the ball rolling.”

The project cost about $23 million, which was included in the Water Company’s capital budget. Smith said the new, safer chemical processes also cost slightly more than storing the hazardous chemicals on site, but those costs will be absorbed by the company.