NR 665.1084(2)(i)4.4. Calculate the MRbio using the mass flow rates and fraction of organic biodegraded determined according to subds. 2. and 3., respectively, and the following equation:

NR 665.1084(3)(a)(a) An owner or operator shall determine the maximum organic vapor pressure for each hazardous waste placed in a tank using Tank Level 1 controls according to the standards in s. NR 665.1085 (3).

NR 665.1084(3)(b)(b) An owner or operator shall use either direct measurement as specified in par. (c) or knowledge of the waste as specified in par. (d) to determine the maximum organic vapor pressure which is representative of the hazardous waste composition stored or treated in the tank.

NR 665.1084(3)(c)(c) If the owner or operator uses direct measurement to determine the maximum organic vapor pressure of a hazardous waste, the owner or operator shall do all of the following:

NR 665.1084(3)(c)1.1. ‘Sampling.’ Collect a sufficient number of samples to be representative of the waste contained in the tank. Collect and handle all samples according to written procedures prepared by the owner or operator and documented in a site sampling plan. The plan shall describe the procedure for collecting representative samples of the hazardous waste which minimizes loss of organics throughout the sample collection and handling process and maintains sample integrity. Maintain a copy of the written sampling plan on-site in the facility operating records. An example of acceptable sample collection and handling procedures may be found in Method 25D in Appendix A of 40 CFR part 60, both incorporated by reference in s. NR 660.11.

NR 665.1084(3)(c)2.2. ‘Analysis.’ Any appropriate one of the following methods may be used to analyze the samples and compute the maximum organic vapor pressure of the hazardous waste:

NR 665.1084(3)(c)2.b.b. Methods described in American Petroleum Institute Publication 2517, Third Edition, February 1989, “Evaporative Loss from External Floating-Roof Tanks”, incorporated by reference in s. NR 660.11.

NR 665.1084(3)(d)(d) If the owner or operator uses knowledge to determine the maximum organic vapor pressure of the hazardous waste, the owner or operator shall prepare and record documentation that presents the information used as the basis for the owner’s or operator’s knowledge that the maximum organic vapor pressure of the hazardous waste is less than the maximum vapor pressure limit listed in s. NR 665.1085 (2) (a) 1. for the applicable tank design capacity category. An example of information that may be used is documentation that the hazardous waste is generated by a process for which at other locations it previously has been determined by direct measurement that the waste maximum organic vapor pressure is less than the maximum vapor pressure limit for the appropriate tank design capacity category.

NR 665.1084(4)(a)(a) Conduct the test according to Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11. Check each potential leak interface (i.e., a location where organic vapor leakage could occur) on the cover and associated closure devices. Potential leak interfaces that are associated with covers and closure devices include, but are not limited to, the interface of the cover and its foundation mounting, the periphery of any opening on the cover and its associated closure device and the sealing seat interface on a spring-loaded pressure relief valve.

NR 665.1084(4)(b)(b) Perform the test when the unit contains a hazardous waste having an organic concentration representative of the range of concentrations for the hazardous waste expected to be managed in the unit. During the test, secure the cover and closure devices in the closed position.

NR 665.1084(4)(c)(c) The detection instrument shall meet the performance criteria of Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11, except the instrument response factor criteria in section 3.1.2(a) shall be for the average composition of the organic constituents in the hazardous waste placed in the waste management unit, not for each individual organic constituent.

NR 665.1084(4)(d)(d) Calibrate the detection instrument before use on each day of its use by the procedures in Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11.

NR 665.1084(4)(e)(e) Calibration gases shall be all of the following:

NR 665.1084(4)(f)(f) Determine the background level according to Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11.

NR 665.1084(4)(g)(g) Check each potential leak interface by traversing the instrument probe around the potential leak interface as close to the interface as possible, as described in Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11. In the case when the configuration of the cover or closure device prevents a complete traverse of the interface, sample all accessible portions of the interface. In the case when the configuration of the closure device prevents any sampling at the interface and the device is equipped with an enclosed extension or horn (e.g., some pressure relief devices), place the instrument probe inlet at approximately the center of the exhaust area to the atmosphere.

NR 665.1084(4)(h)(h) Compare the arithmetic difference between the maximum organic concentration indicated by the instrument and the background level with the value of 500 ppmv except when monitoring a seal around a rotating shaft that passes through a cover opening, in which case the comparison shall be as specified in par. (i). If the difference is less than 500 ppmv, then the potential leak interface is determined to operate with no detectable organic emissions.