Section NR 661.1081 - DefinitionsAs used in this subchapter, all terms not defined in this section shall have the meaning given them in ch. 291, Stats., and chs. NR 660 to 666.
(1) "Average volatile organic concentration" or "average VO concentration" means the mass-weighted average volatile organic concentration of a hazardous secondary material as determined in accordance with the requirements specified in s. NR 661.1084.(2) "Closure device" means a cap, hatch, lid, plug, seal, valve, or other type of fitting that blocks an opening in a cover such that when the device is secured in the closed position it prevents or reduces air pollutant emissions to the atmosphere. A closure device includes a device that is detachable from the cover, such as a sampling port cap; manually operated, such as hinged access lid or hatch; or automatically operated, such as a spring-loaded pressure relief valve.(3) "Continuous seal" means a seal that forms a continuous closure that completely covers the space between the edge of the floating roof and the wall of a tank. A continuous seal may be a vapor-mounted seal, liquid-mounted seal, or metallic shoe seal. A continuous seal may be constructed of fastened segments so as to form a continuous seal.(4) "Cover" means a device that provides a continuous barrier over the hazardous secondary material managed in a unit to prevent or reduce air pollutant emissions to the atmosphere. A cover may have openings, such as access hatches, sampling ports, gauge wells, that are necessary for operation, inspection, maintenance, and repair of the unit on which the cover is used. A cover may be a separate piece of equipment that can be detached and removed from the unit, or a cover may be formed by structural features permanently integrated into the design of the unit.(5) "Empty hazardous secondary material container" means any of the following:(a) A container from which all hazardous secondary materials have been removed that can be removed using the practices commonly employed to remove materials from that type of container, such as pouring, pumping, and aspirating, and no more than 2.5 centimeters of residue remain on the bottom of the container or inner liner.(b) A container that is less than or equal to 119 gallons in size and no more than 3 percent by weight of the total capacity of the container remains in the container or inner liner.(c) A container that is greater than 119 gallons in size and no more than 0.3 percent by weight of the total capacity of the container remains in the container or inner liner.(6) "Enclosure" means a structure that surrounds a tank or container, captures organic vapors emitted from the tank or container, and vents the captured vapors through a closed-vent system to a control device.(7) "External floating roof" means a pontoon-type or double-deck type cover that rests on the surface of the material managed in a tank with no fixed roof.(8) "Fixed roof" means a cover that is mounted on a unit in a stationary position and does not move with fluctuations in the level of the material managed in the unit.(9) "Floating membrane cover" means a cover consisting of a synthetic flexible membrane material that rests upon and is supported by the hazardous secondary material being managed in a surface impoundment.(10) "Floating roof" means a cover consisting of a double deck, pontoon single deck, or internal floating cover that rests upon and is supported by the material being contained, and is equipped with a continuous seal.(11) "Hard-piping" means pipe or tubing that is manufactured and properly installed in accordance with relevant standards and good engineering practices.(12) "In light material service" means the container is used to manage a material for which all of the following conditions apply:(a) The vapor pressure of one or more of the organic constituents in the material is greater than 0.3 kilopascals or kPa at 20°C.(b) The total concentration of the pure organic constituents having a vapor pressure greater than 0.3 kPa at 20°C is equal to or greater than 20 percent by weight.(13) "Internal floating roof" means a cover that rests or floats on the material surface, but is not necessarily in complete contact with it, inside a tank that has a fixed roof.(14) "Liquid-mounted seal" means a foam or liquid-filled primary seal mounted in contact with the hazardous secondary material between the tank wall and the floating roof continuously around the circumference of the tank.(15) "Malfunction" means any sudden, infrequent, and not reasonably preventable failure of air pollution control equipment, process equipment, or a process to operate in a normal or usual manner. A failure that is caused in part by poor maintenance or careless operation is not a malfunction.(16) "Material determination" means performing all applicable procedures in accordance with the requirements specified in s. NR 661.1084 to determine whether a hazardous secondary material meets standards specified in this subchapter. Examples of a material determination include performing the procedures in accordance with the requirements specified in s. NR 661.1084 to determine the average VO concentration of a hazardous secondary material at the point of material origination; the average VO concentration of a hazardous secondary material at the point of material treatment and comparing the results to the exit concentration limit specified for the process used to treat the hazardous secondary material; the organic reduction efficiency and the organic biodegradation efficiency for a biological process used to treat a hazardous secondary material and comparing the results to the applicable standards; or the maximum volatile organic vapor pressure for a hazardous secondary material in a tank and comparing the results to the applicable standards.(17) "Maximum organic vapor pressure" means the sum of the individual organic constituent partial pressures that are exerted by the material contained in a tank, and reasonably expected to occur in the tank at the maximum vapor pressure-causing conditions, such as temperature, agitation, or pH effects of combining materials. For the purpose of this subchapter, maximum organic vapor pressure is determined using the procedures specified in s. NR 661.1084(3).(18) "Metallic shoe seal" means a continuous seal that is constructed of metal sheets that are held vertically against the wall of the tank by springs, weighted levers, or other mechanisms and is connected to the floating roof by braces or other means. A flexible coated fabric or envelope spans the annular space between the metal sheet and the floating roof.(19) "No detectable organic emissions" means no escape of organics to the atmosphere as determined using the procedure specified in s. NR 661.1084(4).(20) "Point of material origination" means one of the following: (a) When the remanufacturer or other person that stores or treats the hazardous secondary material is the generator of the hazardous secondary material, the point of material origination means the point where a material produced by a system, process, or material management unit is determined to be a hazardous secondary material excluded under s. NR 661.0004(1) (za).(b) When the remanufacturer or other person that stores or treats the hazardous secondary material is not the generator of the hazardous secondary material, point of material origination means the point where the remanufacturer or other person that stores or treats the hazardous secondary material accepts delivery or takes possession of the hazardous secondary material.(21) "Safety device" means a closure device such as a pressure relief valve, frangible disc, fusible plug, or any other type of device that functions exclusively to prevent physical damage or permanent deformation to a unit or its air emission control equipment by venting gases or vapors directly to the atmosphere during unsafe conditions resulting from an unplanned, accidental, or emergency event. For the purpose of this subchapter, a safety device is not used for routine venting of gases or vapors from the vapor headspace underneath a cover such as during filling of the unit or to adjust the pressure in this vapor headspace in response to normal daily diurnal ambient temperature fluctuations. A safety device is designed to remain in a closed position during normal operations and open only when the internal pressure, or another relevant parameter, exceeds the device threshold setting applicable to the air emission control equipment as determined by the remanufacturer or other person that stores or treats the hazardous secondary material based on manufacturer recommendations, applicable regulations, fire protection and prevention codes, standard engineering codes and practices, or other requirements for the safe handling of flammable, ignitable, explosive, reactive, or hazardous materials.(22) "Single-seal system" means a floating roof having one continuous seal. This seal may be vapor-mounted, liquid-mounted, or a metallic shoe seal.(23) "Vapor-mounted seal" means a continuous seal that is mounted such that there is a vapor space between the hazardous secondary material in the unit and the bottom of the seal.(24) "Volatile organic concentration" or "VO concentration" means the fraction by weight of the volatile organic compounds contained in a hazardous secondary material expressed in terms of parts per million or ppmw as determined by direct measurement or by knowledge of the material in accordance with the requirements specified in s. NR 661.1084. For the purpose of determining the VO concentration of a hazardous secondary material, organic compounds with a Henry's law constant value of at least 0.1 mole-fraction-in-the-gas-phase/mole-fraction-in-the-liquid-phase (0.1 Y/X), which can also be expressed as 1.8 x 10-6 atmospheres/gram-mole/m 3, at 25 °C shall be included.Wis. Admin. Code Department of Natural Resources NR 661.1081
Adopted by, CR 19-082: cr. Register August 2020 No. 776, eff. 9-1-20; correction in (5) (a) made under s. 35.17, Stats., Register August 2020 No. 776, eff. 9/1/2020