Nearly half of existing coal- and oil-fired powerplants may need pollution-control upgrades under a newly proposed Environmental Protection Agency rule that sets the first national standard for mercury, arsenic, nickel and other pollutants.

The proposed rule was released on March 16 in response to a court-ordered deadline that was set following a case brought by several environmental groups. A final rule is required by November.

EPA estimates that coal-fired plants produce 99% of mercury emissions and that existing technology could prevent 91% of mercury in coal from being released. EPA expects the rule, when final, to encourage the 44% of coal-fired plants that lack sufficient pollution controls to adopt solutions.

EPA estimates the rule could lead to 31,000 short-term construction jobs and 9,000 long-term utility jobs. Plants would have up to four years to meet the standards.

“This will be the primary driver for installation of air quality control equipment at powerplants,” says Andy Byers, associate vice president for global energy at Black & Veatch, Kansas City, Mo. The new proposal is one of a suite of proposed EPA regulations aimed at powerplants, Byers adds. In light of these rules, Black & Veatch estimates that up to 16% of existing powerplants may be retired in the coming years.