NR 666.106(7)(a)(a) General. Emission testing for metals shall be conducted using Method 0060, Determinations of Metals in Stack Emissions, EPA SW-846, as incorporated by reference in s. NR 660.11. NR 666.106(7)(b)(b) Hexavalent chromium. Emissions of chromium are assumed to be hexavalent chromium unless the owner or operator conducts emissions testing to determine hexavalent chromium emissions using procedures prescribed in Method 0061, Determination of Hexavalent Chromium Emissions from Stationary Sources, EPA SW-846, as incorporated by reference in s. NR 660.11. NR 666.106(8)(8) Dispersion Modeling. Dispersion modeling required under this section shall be conducted according to methods recommended in Appendix W of 40 CFR part 51 (”Guideline on Air Quality Models (Revised)” (1986) and its supplements, incorporated by reference in s. NR 660.11), the “Hazardous Waste Combustion Air Quality Screening Procedure”, provided in ch. NR 666 Appendix IX , or in Screening Procedures for Estimating the Air Quality Impact of Stationary Sources, Revised, EPA-450/R-92-019, incorporated by reference in s. NR 660.11, to predict the maximum annual average off-site ground level concentration. However, on-site concentrations shall be considered when a person resides on-site. NR 666.106(9)(9) Enforcement. For the purposes of license enforcement, compliance with the operating requirements specified in the license (under s. NR 666.102) shall be regarded as compliance with this section. However, evidence that compliance with those license conditions is insufficient to ensure compliance with this section may be information justifying modification or revocation and re-issuance of a license under s. NR 670.041. NR 666.106 HistoryHistory: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06; corrections in (2) (intro.), (a), (b) 1., (c), (e), (3) (intro.), (a), (b), (4) (b), (5), (6) (b) 1., 2. a., (8) made under s. 13.92 (4) (b) 7., Stats., Register March 2013 No. 687; CR 16-007: am. (1) Register July 2017 No. 739, eff. 8-1-17. NR 666.107NR 666.107 Standards to control hydrogen chloride (HCl) and chlorine gas (Cl2) emissions. NR 666.107(1)(1) General. The owner or operator shall comply with the hydrogen chloride (HCl) and chlorine (Cl2) controls provided by sub. (2), (3) or (5). NR 666.107(2)(a)(a) Tier I feed rate screening limits. Feed rate screening limits are specified for total chlorine in ch. NR 666 Appendix II as a function of terrain-adjusted effective stack height and terrain and land use in the vicinity of the facility. The feed rate of total chlorine and chloride, both organic and inorganic, in all feed streams, including hazardous waste, fuels and industrial furnace feed stocks may not exceed the levels specified. NR 666.107(2)(b)(b) Tier II emission rate screening limits. Emission rate screening limits for HCl and Cl2 are specified in ch. NR 666 Appendix III as a function of terrain-adjusted effective stack height and terrain and land use in the vicinity of the facility. The stack emission rates of HCl and Cl2 may not exceed the levels specified. NR 666.107(2)(c)(c) Definitions and limitations. The definitions and limitations provided by s. NR 666.106 (2) for the following terms also apply to the screening limits provided by this subsection: terrain-adjusted effective stack height, good engineering practice stack height, terrain type, land use and criteria for facilities not eligible to use the screening limits. NR 666.107(2)(d)(d) Multiple stacks. Owners and operators of facilities with more than one on-site stack from a boiler, industrial furnace, incinerator or other thermal treatment unit subject to controls on HCl or Cl2 emissions under an operating license or interim license shall comply with the Tier I and Tier II screening limits for those stacks assuming all hazardous waste is fed into the device with the worst-case stack based on dispersion characteristics. NR 666.107(2)(d)2.2. Under Tier I, the total feed rate of chlorine and chloride to all subject devices may not exceed the screening limit for the worst-case stack. NR 666.107(2)(d)3.3. Under Tier II, the total emissions of HCl and Cl2 from all subject stacks may not exceed the screening limit for the worst-case stack. NR 666.107(3)(a)(a) General. Conformance with the Tier III controls shall be demonstrated by emissions testing to determine the emission rate for HCl and Cl2, air dispersion modeling to predict the maximum annual average off-site ground level concentration for each compound, and a demonstration that acceptable ambient levels are not exceeded. NR 666.107(3)(b)(b) Acceptable ambient levels. Chapter. NR 666 Appendix IV lists the reference air concentrations (RACs) for HCl (7 micrograms per cubic meter) and Cl2 (0.4 micrograms per cubic meter). NR 666.107(3)(c)(c) Multiple stacks. Owners and operators of facilities with more than one on-site stack from a boiler, industrial furnace, incinerator or other thermal treatment unit subject to controls on HCl or Cl2 emissions under an operating license or interim license shall conduct emissions testing and dispersion modeling to demonstrate that the aggregate emissions from all such on-site stacks do not result in an exceedance of the acceptable ambient levels for HCl and Cl2. NR 666.107(4)(4) Averaging periods. The HCl and Cl2 controls are implemented by limiting the feed rate of total chlorine and chloride in all feedstreams, including hazardous waste, fuels and industrial furnace feed stocks. Under Tier I, the feed rate of total chloride and chlorine is limited to the Tier I screening limits. Under Tier II and Tier III, the feed rate of total chloride and chlorine is limited to the feed rates during the trial burn (for new facilities or an interim license facility applying for a license) or the compliance test (for interim license facilities). The feed rate limits are based on either of the following: NR 666.107(5)(5) Adjusted Tier I feed rate screening limits. The owner or operator may adjust the feed rate screening limit provided by ch. NR 666 Appendix II to account for site-specific dispersion modeling. Under this approach, the adjusted feed rate screening limit is determined by back-calculating from the acceptable ambient level for Cl2 provided by ch. NR 666 Appendix IV using dispersion modeling to determine the maximum allowable emission rate. This emission rate becomes the adjusted Tier I feed rate screening limit. NR 666.107(6)(6) Emissions testing. Emissions testing for HCl and Cl2 shall be conducted using the procedures described in Methods 0050 or 0051, EPA SW-846, as incorporated by reference in s. NR 660.11. NR 666.107(8)(8) Enforcement. For the purposes of license enforcement, compliance with the operating requirements specified in the license (under s. NR 666.102) shall be regarded as compliance with this section. However, evidence that compliance with those license conditions is insufficient to ensure compliance with this section may be information justifying modification or revocation and re-issuance of a license under s. NR 670.041. NR 666.107 HistoryHistory: CR 05-032: cr. Register July 2006 No. 607, eff. 8-1-06; corrections in (2) (a), (b), (3) (b), (5) made under s. 13.92 (4) (b) 7., Stats., Register March 2013 No. 687. NR 666.108NR 666.108 Small quantity on-site burner exemption.