NR 664.1084(2)(a)1.b.b. For a tank design capacity equal to or greater than 75 m3 but less than 151 m3, the maximum organic vapor pressure limit for the tank is 27.6 kPa. NR 664.1084(2)(a)1.c.c. For a tank design capacity less than 75 m3, the maximum organic vapor pressure limit for the tank is 76.6 kPa. NR 664.1084(2)(a)2.2. The hazardous waste in the tank is not heated to a temperature that is greater than the temperature at which the maximum organic vapor pressure of the hazardous waste is determined for the purpose of complying with subd. 1. NR 664.1084(2)(b)(b) For a tank that manages hazardous waste that does not meet all of the conditions in par. (a) 1. to 3., control air pollutant emissions from the tank using Tank Level 2 controls according to sub. (4). Examples of tanks required to use Tank Level 2 controls include a tank used for a waste stabilization process, and a tank for which the hazardous waste in the tank has a maximum organic vapor pressure that is equal to or greater than the maximum organic vapor pressure limit for the tank’s design capacity category as specified in par. (a) 1. NR 664.1084(3)(3) Owners and operators controlling air pollutant emissions from a tank using Tank Level 1 controls shall meet all of the following requirements: NR 664.1084(3)(a)(a) Determine the maximum organic vapor pressure for a hazardous waste to be managed in the tank using Tank Level 1 controls before the first time the hazardous waste is placed in the tank. Determine the maximum organic vapor pressure using the procedures in s. NR 664.1083 (3). Thereafter, perform a new determination whenever changes to the hazardous waste managed in the tank could potentially cause the maximum organic vapor pressure to increase to a level that is equal to or greater than the maximum organic vapor pressure limit for the tank design capacity category specified in sub. (2) (a) 1., as applicable to the tank. NR 664.1084(3)(b)(b) Equip the tank with a fixed roof designed to meet all of the following specifications: NR 664.1084(3)(b)1.1. Design the fixed roof and its closure devices to form a continuous barrier over the entire surface area of the hazardous waste in the tank. The fixed roof may be a separate cover installed on the tank (e.g., a removable cover mounted on an open-top tank) or may be an integral part of the tank structural design (e.g., a horizontal cylindrical tank equipped with a hatch). NR 664.1084(3)(b)2.2. Install the fixed roof in a manner such that there are no visible cracks, holes, gaps or other open spaces between roof section joints or between the interface of the roof edge and the tank wall. NR 664.1084(3)(b)3.3. Each opening in the fixed roof, and any manifold system associated with the fixed roof, shall be any of the following: NR 664.1084(3)(b)3.a.a. Equipped with a closure device designed to operate such that when the closure device is secured in the closed position there are no visible cracks, holes, gaps or other open spaces in the closure device or between the perimeter of the opening and the closure device. NR 664.1084(3)(b)3.b.b. Connected by a closed-vent system that is vented to a control device. The control device shall remove or destroy organics in the vent stream, and shall be operating whenever hazardous waste is managed in the tank, except as follows: 1) During periods when it is necessary to provide access to the tank for performing the activities of subd. 3. b.2), venting of the vapor headspace underneath the fixed roof to the control device is not required, opening of closure devices is allowed and removal of the fixed roof is allowed. After completing the activity, promptly secure the closure device in the closed position or reinstall the cover, as applicable, and resume operation of the control device.
2) During periods of routine inspection, maintenance or other activities needed for normal operations, and for removal of accumulated sludge or other residues from the bottom of the tank.
NR 664.1084(3)(b)4.4. Make the fixed roof and its closure devices of suitable materials that will minimize exposure of the hazardous waste to the atmosphere, to the extent practical, and will maintain the integrity of the fixed roof and closure devices throughout their intended service life. Factors to consider when selecting the materials for and designing the fixed roof and closure devices shall include organic vapor permeability, the effects of any contact with the hazardous waste or its vapors managed in the tank, the effects of outdoor exposure to wind, moisture and sunlight and the operating practices used for the tank on which the fixed roof is installed. NR 664.1084(3)(c)(c) Whenever a hazardous waste is in the tank, install the fixed roof with each closure device secured in the closed position except as follows: NR 664.1084(3)(c)1.1. Opening of closure devices or removal of the fixed roof is allowed at the following times: NR 664.1084(3)(c)1.a.a. To provide access to the tank for performing routine inspection, maintenance or other activities needed for normal operations. Examples of those activities include those times when a worker needs to open a port to sample the liquid in the tank, or when a worker needs to open a hatch to maintain or repair equipment. After completing the activity, promptly secure the closure device in the closed position or reinstall the cover, as applicable, to the tank. NR 664.1084(3)(c)2.2. Opening of a spring-loaded pressure-vacuum relief valve, conservation vent or similar type of pressure relief device which vents to the atmosphere is allowed during normal operations for the purpose of maintaining the tank internal pressure according to the tank design specifications. Design the device to operate with no detectable organic emissions when the device is secured in the closed position. Establish the settings at which the device opens such that the device remains in the closed position whenever the tank internal pressure is within the internal pressure operating range determined by the owner or operator based on the tank manufacturer recommendations, applicable rules, 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. Examples of normal operating conditions that may require these devices to open are during those times when the tank internal pressure exceeds the internal pressure operating range for the tank as a result of loading operations or diurnal ambient temperature fluctuations. NR 664.1084(3)(c)3.3. Opening of a safety device, as defined in s. NR 665.1081, is allowed at any time conditions require doing so to avoid an unsafe condition. NR 664.1084(3)(d)(d) Inspect the air emission control equipment according to all of the following requirements: NR 664.1084(3)(d)1.1. Visually inspect the fixed roof and its closure devices to check for defects that could result in air pollutant emissions. Defects include, but are not limited to, visible cracks, holes or gaps in the roof sections or between the roof and the tank wall, broken, cracked or otherwise damaged seals or gaskets on closure devices and broken or missing hatches, access covers, caps or other closure devices. NR 664.1084(3)(d)2.2. Perform an initial inspection of the fixed roof and its closure devices on or before the date that the tank becomes subject to this section. Thereafter, perform the inspections at least once every year except under the special conditions provided for in sub. (12). NR 664.1084(4)(4) Owners and operators controlling air pollutant emissions from a tank using Tank Level 2 controls shall use one of the following tanks: NR 664.1084(4)(a)(a) A fixed-roof tank equipped with an internal floating roof according to sub. (5).