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EPA Tightens the Limit on Coke Oven Emissions

04/05/2005 - The Environmental Protection Agency (EPA) has issued final amendments to reduce emissions of toxic air pollutants from coke oven batteries. The new rule will reduce allowable emissions to 9.8 tons per year, 13% lower than the 11.3 tons per year originally specified under the 1993 MACT (maximum achievable control technology).

The Environmental Protection Agency (EPA) has issued final amendments to reduce emissions of toxic air pollutants from coke oven batteries. The new rule will reduce allowable emissions to 9.8 tons per year, 13% lower than the 11.3 tons per year originally specified under the 1993 MACT (maximum achievable control technology).

EPA’s final amendments apply to coke oven emissions from nine batteries at five coke plants for which the 1993 MACT standard applied.

Approximately 14 other coke oven plants have installed controls more stringent than MACT — referred to as Lowest Achievable Emissions Reductions (LAER) — and will not be affected by the rule at this time.

Because the LAER batteries opted to reduce their emissions by more than the 1993 MACT required, they do not have to comply with this newest rule until 2020.

EPA’s final amendments apply to charging, leaks, and bypass stacks at coke oven batteries. Emissions from these processes occur at the start of the process, primarily as the coke ovens are heating up. The amendments do not apply to the pushing and quenching processes, which are regulated under a 2003 MACT. EPA will make a risk-based determination whether additional emissions reductions are necessary from this process by 2011.

The amendments limit visible emissions from charging, topside leaks, and door leaks. Allowable visible emissions from coke oven doors will be reduced to 4.0% (previously 5.5%) for foundry coke batteries, and to 3.3% (previously 5.0%) for other batteries. Allowable visible emissions from topside port lids (covers placed over openings through which coal is charged to the oven) will be reduced to 0.4% (previously 0.6%). Allowable visible emissions from offtake systems (piping systems that provide passage for raw coke oven gas) will be reduced to 2.5% (previously 3.0%). The final amendments require these batteries to meet more stringent emission limits using a combination of pollution prevention and work practices.

The EPA says that most existing facilities are have already reduced emissions beyond the limits required by the 1993 regulation.

Within 8 years of setting the MACT standards, EPA is required to assess the remaining health risks from each source category to determine whether the MACT standards appropriately protect public health. Applying this “risk-based” approach called residual risk, EPA must determine whether more health-protective standards are necessary.

The final amendments related to the 8-year MACT review apply to charging emissions from new or reconstructed coke oven batteries and reflect changes that have occurred in emission control practices during the past 8 years. Final amendments establish emissions limits that apply to the control equipment for charging operations and an opacity limit for fugitive emission from the charging operation. These amendments do not apply to existing sources.

Other final amendments add work practice requirements to supplement the current visible emissions limit for door leaks. These requirements are simply a revision of the 1993 MACT and apply to all nine batteries.

Affected plants must comply with the new requirements within 90 days after publication of the final amendments in the Federal Register.