NR 440.70(4)(b)(b) Each drain in active service shall be checked by visual or physical inspection initially and monthly thereafter for indications of low water levels or other conditions that would reduce the effectiveness of the water seal controls. NR 440.70(4)(c)(c) Except as provided in par. (d), each drain out of active service shall be checked by visual or physical inspection initially and weekly thereafter for indications of low water levels or other problems that could result in VOC emissions. NR 440.70(4)(d)(d) As an alternative to the requirements in par. (c), if an owner or operator elects to install a tightly sealed cap or plug over a drain that is out of service, inspections shall be conducted initially and semiannually to ensure caps or plugs are in place and properly installed. NR 440.70(4)(e)(e) Whenever low water levels or missing or improperly installed caps or plugs are identified, water shall be added or first efforts at repair shall be made as soon as practicable, but not later than 24 hours after detection, except as provided in sub. (8). NR 440.70(4)(f)(f) Junction boxes shall be equipped with a cover and may have an open vent pipe. The vent pipe shall be at least 90 cm (3 ft.) in length and may not exceed 10.2 cm (4 in.) in diameter. NR 440.70(4)(g)(g) Junction box covers shall have a tight seal around the edge and shall be kept in place at all times, except during inspection and maintenance. NR 440.70(4)(h)(h) Junction boxes shall be visually inspected initially and semiannually thereafter to ensure that the cover is in place and to ensure that the cover has a tight seal around the edge. NR 440.70(4)(i)(i) If a broken seal or gap is identified, the first effort at repair shall be made as soon as practicable, but not later than 15 calendar days after the broken seal or gap is identified, except as provided in sub. (8). NR 440.70(4)(j)(j) Sewer lines may not be open to the atmosphere and shall be covered or enclosed in a manner so as to have no visual gaps or cracks in joints, seals or other emission interfaces. NR 440.70(4)(k)(k) The portion of each unburied sewer line shall be visually inspected initially and semiannually thereafter for indication of cracks, gaps or other problems that could result in VOC emissions. NR 440.70(4)(L)(L) Whenever cracks, gaps or other problems are detected, repairs shall be made as soon as practicable, but not later than 15 calendar days after identification, except as provided in sub. (8). NR 440.70(4)(m)(m) Except as provided in par. (n), each modified or reconstructed individual drain system that has a catch basin in the existing configuration prior to May 4, 1987 shall be exempt from the provisions of this subsection. NR 440.70(4)(n)(n) Refinery wastewater routed through new process drains and a new first common downstream junction box, either as part of a new individual drain system or an existing individual drain system, may not be routed through a downstream catch basin. NR 440.70(5)(a)(a) Each oil-water separator tank, slop oil tank, storage vessel or other auxiliary equipment subject to the requirements of this section shall be equipped and operated with a fixed roof, which meets the following specifications, except as provided in par. (d) or in sub. (11). NR 440.70(5)(a)1.1. The fixed roof shall be installed to completely cover the separator tank, slop oil tank, storage vessel or other auxiliary equipment with no separation between the roof and the wall. NR 440.70(5)(a)2.2. The vapor space under a fixed roof may not be purged unless the vapor is directed to a control device. NR 440.70(5)(a)3.3. If the roof has access doors or openings, such doors or openings shall be gasketed, latched and kept closed at all times during operation of the separator system, except during inspection and maintenance. NR 440.70(5)(a)4.4. Roof seals, access doors and other openings shall be checked by visual inspection initially and semiannually thereafter to ensure that no cracks or gaps occur between the roof and wall and that access doors and other openings are closed and gasketed properly. NR 440.70(5)(a)5.5. When a broken seal or gasket or other problem is identified, first efforts at repair shall be made as soon as practicable, but not later than 15 calendar days after it is identified, except as provided in sub. (8). NR 440.70(5)(b)(b) Each oil-water separator tank or auxiliary equipment with a design capacity to treat more than 16 liters per second (250 gpm) of refinery wastewater shall, in addition to the requirements in par. (a), be equipped and operated with a closed vent system and control device, which meet the requirements of sub. (7), except as provided in par. (c) or in sub. (11). NR 440.70(5)(c)(c) Each modified or reconstructed oil-water separator tank with a maximum design capacity to treat less than 38 liters per second (600 gpm) of refinery wastewater which was equipped and operated with a fixed roof covering the entire separator tank or a portion of the separator tank prior to May 4, 1987 shall be exempt from the requirements of par. (b), but shall meet the requirements of par. (a) or may elect to comply with par. (c) 1. NR 440.70(5)(c)1.1. The owner or operator may elect to comply with the requirements of par. (a) for the existing fixed roof covering a portion of the separator tank and comply with the requirements for floating roofs in sub. (11) for the remainder of the separator tank. NR 440.70(5)(d)(d) Storage vessels, including slop oil tanks and other auxiliary tanks that are subject to the requirements of s. NR 440.27, 440.28 or 440.285, are not subject to the requirements of this subsection. NR 440.70(5)(e)(e) Slop oil from an oil-water separator tank and oil wastewaters from slop oil handling equipment shall be collected, stored, transported, recycled, reused or disposed of in an enclosed system. Once slop oil is returned to the process unit or is disposed of, it is no longer within the scope of this section. Equipment used in handling slop oil shall be equipped with a fixed roof meeting the requirements of par. (a). NR 440.70(5)(f)(f) Each oil-water separator tank, slop oil tank, storage vessel or other auxiliary equipment that is required to comply with par. (a) and not par. (b), may be equipped with a pressure control valve as necessary for proper system operation. The pressure control valve shall be set at the maximum pressure necessary for proper system operation, but such that the valve will not vent continuously. NR 440.70(6)(6) Standards: aggregate facility. Anew, modified or reconstructed aggregate facility shall comply with the requirements of subs. (4) and (5).