Chapter NR 446

Register November 2008 No. 635

Chapter NR 446

CONTROL OF MERCURY EMISSIONS

Subchapter I — General Provisions

NR 446.01   Applicability; purpose.

NR 446.02   Definitions.

NR 446.03   Mercury emission limits.

NR 446.04   Procedures for determining annual mercury emissions.

Subchapter II — Control of Mercury Emissions from Major Utilities

NR 446.05   Mercury emission limits for major utilities.

NR 446.06   Baseline mercury emissions for major utilities.

NR 446.07   Procedures for determining baseline mercury emissions for major utilities.

NR 446.08   Annual mercury emissions determination and reporting for major utilities.

Subchapter III — Control of Mercury Emissions from Coal-Fired Electric Generating Units

NR 446.09   Applicability.

NR 446.10   Definitions.

NR 446.11   Mercury emission limits for new or modified coal-fired electric generating units.

NR 446.12   Mercury emission limits for small coal-fired electric generating units.

NR 446.13   Mercury emission limits for large coal-fired electric generating units.

NR 446.14   Multipollutant reduction alternative for coal-fired electrical generating units.

NR 446.15   Early mercury emission reduction credits.

NR 446.16   Electric reliability compliance extension.

NR 446.165   Large coal-fired electric generating unit variance.

NR 446.17   Annual compliance report, emission limitation election and BACT determination.

NR 446.18   Emission determination and compliance demonstration.

NR 446.185   Compliance alternatives.

NR 446.19   Evaluation reports.

Subchapter IV — Mercury Emission Standards for Other Sources

NR 446.20   Mercury emission limits.

NR 446.21   Stack sampling.

NR 446.22   Monitoring of emissions and operations.

Ch. NR 446 Note Note: Corrections made under s. 13.93 (2m) (b) 7., Stats., Register, January, 1997, No. 493.

subch. I of ch. NR 446 Subchapter I — General Provisions

NR 446.01 NR 446.01 Applicability; purpose.

NR 446.01(1) (1) Applicability. This chapter applies to all air contaminant sources which may emit mercury and to their owners and operators.

NR 446.01(2) (2) Purpose. This chapter is adopted under ss. 285.11, 285.13, 285.17 and 285.27, Stats., to establish emission limitations, stack sampling procedures and emission monitoring requirements for mercury emissions from air contaminant sources in order to protect air quality and reduce atmospheric mercury deposition.

NR 446.01 Note Note: Subchapter IV of this chapter is based on the federal regulations contained in 40 CFR part 61, Subpart E, created October 14, 1975, as last revised October 17, 2000.

NR 446.01 History History: Cr. Register, September, 1986, No. 369, eff. 10-1-86; am. (1), Register, May, 1992, No. 437, eff. 6-1-92; CR 01-081: am. (2) Register September 2004 No. 585, eff. 10-1-04.

NR 446.02 NR 446.02 Definitions. The definitions contained in ch. NR 400 apply to the terms used in this chapter. In addition, the following definitions apply to the terms used in this chapter:

NR 446.02(1) (1) “Allowable emissions” means the annual mercury emissions of a stationary source, calculated using the maximum rated capacity of the source, and by accounting for enforceable limits which restrict the operating rate or hours of operation or both.

NR 446.02(1c) (1c) “Baseline mercury emissions” means the calculated level of annual mercury emissions from a major utility as determined under s. NR 446.07.

NR 446.02(1e) (1e) “Best available control technology” or “BACT” means an emission limit for mercury based on the maximum degree of reduction practically achievable as specified by the department on an individual case-by-case basis taking into account energy, economic and environmental impacts and other costs related to the source.

NR 446.02(1g) (1g) “Cell room” means a structure housing one or more mercury chlor-alkali cells.

NR 446.02(1n) (1n) “Certified emission reduction” means a reduction of mercury emissions that has been certified by the department and made enforceable through a construction permit, operation permit or other appropriate means.

NR 446.02(1r) (1r) “Commission” means the public service commission.

NR 446.02(2) (2) “Condenser stack gases” mean the gaseous effluent evolved from the stack of processes utilizing heat to extract mercury metal from mercury ore.

NR 446.02(3) (3) “Denuder” means a horizontal or vertical container which is part of a mercury chlor-alkali cell and in which water and alkali metal amalgam are converted to alkali metal hydroxide, mercury, and hydrogen gas in a short-circuited, electrolytic reaction.

NR 446.02(4) (4) “End box” means one or more containers located on one or both ends of a mercury chlor-alkali electrolyzer which serves as a connection between the electrolyzer and denuder for rich and stripped amalgam.

NR 446.02(5) (5) “End box ventilation system” means a ventilation system which collects mercury emissions from the end boxes, the mercury pump sumps, and their water collection systems.

NR 446.02(6) (6) “Hydrogen gas stream” means a hydrogen stream formed in the chlor-alkali cell denuder.

NR 446.02(6e) (6e) “Major stationary source” means a stationary source whose mercury emissions are 10 pounds per year or greater.

NR 446.02(6m) (6m) “Major utility” means a Class A utility, as defined under s. 199.03 (4), Stats., that generates electricity or an electrical cooperative association organized under ch. 185, Stats., whose mercury emissions from all stationary sources under the common ownership and control of the utility or the association are 100 pounds per year or greater.

NR 446.02(6s) (6s) “Mercury” has the meaning given in s. NR 445.02 (9).

NR 446.02(7) (7) “Mercury chlor-alkali cell” means a device which is basically composed of an electrolyzer section and a denuder or decomposer section and utilizes mercury to produce chlorine gas, hydrogen gas, and alkali metal hydroxide.

NR 446.02(8) (8) “Mercury chlor-alkali electrolyzer” means an electrolytic device which is part of a mercury chlor-alkali cell and utilizes a flowing mercury cathode to produce chlorine gas and alkali metal amalgam.

NR 446.02(9) (9) “Mercury ore” means a mineral mined specifically for its mercury content.

NR 446.02(10) (10) “Mercury ore processing facility” means a facility processing mercury ore to obtain mercury.

NR 446.02(10m) (10m) “Method X”, where “X” is a number or a number followed by a letter, means the specified method contained in Appendix B of 40 CFR part 61, incorporated by reference in s. NR 484.04 (23).

NR 446.02(11) (11) “Sludge” means sludge produced by a treatment plant that processes municipal or industrial wastewater.

NR 446.02(12) (12) “Sludge dryer” means a device used to reduce the moisture content of sludge by heating to temperatures above 65ºC (ca. 150ºF) directly with combustion gases.

NR 446.02 History History: Renum. from NR 154.01, Register, September, 1986, No. 369, eff. 10-1-86; am. (intro.) and (2), cr. (10m), Register, May, 1994, No. 461, eff. 6-1-94; am. (10m), Register, December, 1995, No. 480, eff. 1-1-96; CR 02-097: am. (intro.) Register June 2004 No. 582, eff. 7-1-04; CR 01-081: renum. (1) to be (1g), cr. (1), (1c, (1n), (1r), (1w), (6e), (6m), (6s), (8m) and (10s) Register September 2004 No. 585, eff. 10-1-04; CR 07-036: cr. (1e), r. (1w), am. (1c) Register November 2008 No. 635, eff. 12-1-08.

NR 446.03 NR 446.03 Mercury emission limits.

NR 446.03(1) (1) No person may cause, allow or permit emissions of mercury in such quantity and duration as to cause the ambient air concentration to exceed 1 mg/m3, averaged over a 30-day period.

NR 446.03(2) (2) 

NR 446.03(2)(a) (a) No person may commence construction or modification of a stationary source that results in an increase in annual allowable emissions of mercury of 10 pounds or more from the new or modified source unless the person has obtained a permit under ch. NR 406. The department may not issue a permit under ch. NR 406 for the source unless the department finds that emissions of mercury will be controlled to a level which is best available control technology.