NR 661.1083(4)(f) (f) The background level shall be determined according to the procedures in Method 21 in appendix A of 40 CFR part 60, incorporated by reference in s. NR 660.11.

NR 661.1083(4)(g) (g) Each potential leak interface shall be checked 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, all accessible portions of the interface shall be sampled. 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, such as some pressure relief devices, the instrument probe inlet shall be placed at approximately the center of the exhaust area to the atmosphere.

NR 661.1083(4)(h) (h) The arithmetic difference between the maximum organic concentration indicated by the instrument and the background level shall be compared 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.

NR 661.1083(4)(i) (i) For the seals around a rotating shaft that passes through a cover opening, the arithmetic difference between the maximum organic concentration indicated by the instrument and the background level shall be compared with the value of 10,000 ppmw. If the difference is less than 10,000 ppmw, then the potential leak interface is determined to operate with no detectable organic emissions.

NR 661.1083 History History: CR 19-082: cr. Register August 2020 No. 776, eff. 9-1-20; correction in (1) (a) 1. (intro.), 1., (3) (d) made under s. 13.92 (4) (b) 7., Stats., Register April 2021 No. 784.

NR 661.1084 NR 661.1084 Standards: tanks.

NR 661.1084(1) (1) The provisions of this section apply to the control of air pollutant emissions from tanks for which s. NR 661.1082 (2) references the use of this section for such air emission control.

NR 661.1084(2) (2) The remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from each tank subject to this section in accordance with one of the following requirements as applicable:

NR 661.1084(2)(a) (a) For a tank that manages hazardous secondary material that meets all of the conditions specified in subds. 1. to 2., the remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from the tank in accordance with the Tank Level 1 controls specified in sub. (3) or the Tank Level 2 controls specified in sub. (4).

NR 661.1084(2)(a)1. 1. The hazardous secondary material in the tank has a maximum organic vapor pressure less than the maximum organic vapor pressure limit for the tank’s design capacity category as follows:

NR 661.1084(2)(a)1.a. a. For a tank design capacity equal to or greater than 151 m3, the maximum organic vapor pressure limit for the tank is 5.2 kPa.

NR 661.1084(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 661.1084(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 661.1084(2)(a)2. 2. The hazardous secondary material in the tank is not heated by the remanufacturer or other person that stores or treats the hazardous secondary material to a temperature that is greater than the temperature at which the maximum organic vapor pressure of the hazardous secondary material is determined for the purpose of complying with subd. 1.

NR 661.1084(2)(b) (b) For a tank that manages hazardous secondary material that does not meet all of the conditions specified in par. (a) 1. and 2., the remanufacturer or other person that stores or treats the hazardous secondary material shall control air pollutant emissions from the tank by using Tank Level 2 controls in accordance with the requirements under sub. (4). An example of a tank required to use Tank Level 2 controls is a tank for which the hazardous secondary material 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 661.1084(3) (3) A remanufacturer or other person that stores or treats the hazardous secondary material controlling air pollutant emissions from a tank using Tank Level 1 controls shall meet all of the following requirements:

NR 661.1084(3)(a) (a) The remanufacturer or other person that stores or treats that hazardous secondary material shall determine the maximum organic vapor pressure for a hazardous secondary material to be managed in the tank using Tank Level 1 controls before the first time the hazardous secondary material is placed in the tank. The maximum organic vapor pressure shall be determined using the procedures specified in s. NR 661.1083 (3). Thereafter, the remanufacturer or other person that stores or treats the hazardous secondary material shall perform a new determination whenever changes to the hazardous secondary material 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 661.1084(3)(b) (b) The remanufacturer or other person that stores or treats that hazardous secondary material shall equip the tank with a fixed roof designed to meet all of the following specifications:

NR 661.1084(3)(b)1. 1. The fixed roof and its closure devices shall be designed to form a continuous barrier over the entire surface area of the hazardous secondary material in the tank. The fixed roof may be a separate cover installed on the tank, such as a removable cover mounted on an open-top tank, or may be an integral part of the tank structural design, such as a horizontal cylindrical tank equipped with a hatch.

NR 661.1084(3)(b)2. 2. The fixed roof shall be installed 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 661.1084(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 661.1084(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 661.1084(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 secondary material is managed in the tank, except during any of the following periods:

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. Following completion of the activity, the remanufacturer or other person that stores or treats the hazardous secondary material shall 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 661.1084(3)(b)4. 4. The fixed roof and its closure devices shall be made of suitable materials that will minimize exposure of the hazardous secondary material 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 be considered 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 secondary material 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 661.1084(3)(c) (c) Whenever a hazardous secondary material is in the tank, the fixed roof shall be installed with each closure device secured in the closed position except as follows:

NR 661.1084(3)(c)1. 1. Opening of closure devices or removal of the fixed roof is allowed at the following times:

NR 661.1084(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 such 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. Following completion of the activity, the remanufacturer or other person that stores or treats the hazardous secondary material shall promptly secure the closure device in the closed position or reinstall the cover, as applicable, to the tank.