The Southern Environmental Law Center and GreenLaw have filed a challenge to the air permit for a proposed coal-fired power plant in Sandersville.
The state's Environmental Protection Division re-issued the permit for Plant Washington last month after issues identified by a judge were addressed.
Groups challenging the permit in administrative court say it does not meet national standards for harmful emissions.
A year ago, a state court found the initial permit violated Clean Air Act safeguards and directed the EPD to reconsider its permit.
Supporters say the plant is crucial to supplying power to a growing population in need of jobs and energy.
Dean Alford, spokesman for the utility cooperative consortium developing the plant, POWER4Georgians, says the group is committed to building one of the cleanest plants of its kind.