Only four chemical plants in the country still use mercury to make chlorine.
Olin’s Augusta plant is one of them.
More than a hundred plants have converted to mercury-free processes.
The Mercury Pollution Reduction Act would have given companies like Olin until 2015 to make the switch.
Jackie Savitz is with the environmental lobbying group Oceana.
She says people in communities like Augusta, still want the switch:
"The residents are actually dealing with the down side of using mercury which is mercury in their environment, mercury in fish, lost productivity and all the health risks that go along with that."
Olin officials opposed the legislation saying they need more time to convert.
Savitz says she hopes the bill will generate renewed interest when the new congress meets next year.