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). NR 440.70(7)(7) Standards: closed vent system and control devices. NR 440.70(7)(a)(a) Enclosed combustion devices shall be designed and operated to reduce the VOC emissions vented to them with an efficiency of 95% or greater or to provide a minimum residence time of 0.75 seconds at a minimum temperature of 816°C (1,500°F). NR 440.70(7)(b)(b) Vapor recovery systems, for example, condensers and absorbers, shall be designed and operated to recover the VOC emissions vented to them with an efficiency of 95% or greater. NR 440.70(7)(d)(d) Closed vent systems and control devices used to comply with provisions of this section shall be operated at all times when emissions may be vented to them. NR 440.70(7)(e)(e) Closed vent system shall be designed and operated with no detectable emissions, as indicated by an instrument reading of less than 500 ppm above background, as determined during the initial and semiannual inspections by the methods specified in sub. (14). NR 440.70(7)(f)(f) Closed vent systems shall be purged to direct vapor to the control device. NR 440.70(7)(g)(g) A flow indicator shall be installed on a vent stream to control a control device to ensure that the vapors are being routed to the device. NR 440.70(7)(h)(h) All gauging and sampling devices shall be gas-tight except when gauging or sampling is taking place. NR 440.70(7)(i)(i) When emissions from a closed system are detected, first efforts at repair to eliminate the emissions shall be made as soon as practicable, but not later than 30 calendar days from the date the emissions are detected, except as provided in sub. (8). NR 440.70(8)(a)(a) Delay of repair of facilities that are subject to the provisions of this section will be allowed if the repair is technically impossible without a complete or partial refinery or process unit shutdown. NR 440.70(8)(b)(b) Repair of such equipment shall occur before the end of the next refinery or process unit shutdown. NR 440.70(9)(a)(a) Delay of compliance of modified individual drain systems with ancillary downstream treatment components will be allowed if compliance with the provisions of this section cannot be achieved without a refinery or process unit shutdown. NR 440.70(9)(b)(b) Installation of equipment necessary to comply with the provisions of this section shall occur no later than the next scheduled refinery or process unit shutdown. NR 440.70(10)(10) Alternative standards for individual drain systems. NR 440.70(10)(a)(a) An owner or operator may elect to construct and operate a completely closed drain system. NR 440.70(10)(b)(b) Each completely closed drain system shall be equipped and operated with a closed vent system and control device complying with the requirements of sub. (7). NR 440.70(10)(c)(c) An owner or operator shall notify the department in the report required in s. NR 440.07 that the owner or operator has elected to construct and operate a completely closed drain system. NR 440.70(10)(d)(d) If the owner or operator elects to comply with the provisions of this subsection, then the owner or operator does not need to comply with the provisions of sub. (4) or (11) (j) note.