NR 419.045(2)(b)2.d.d. Equip each opening in the flexible membrane cover with a closure device that is designed to operate so 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 cover opening and the closure device. Notwithstanding the requirements of this subd. 2. d., the flexible membrane cover may be equipped with one or more emergency cover drains for removal of stormwater. Each emergency cover drain shall be equipped with a slotted membrane fabric cover that covers at least 90% of the area of the opening or a flexible fabric sleeve seal.

NR 419.045(2)(b)2.e.e. Whenever an affected VOC wastewater stream or an affected residual is in the surface impoundment, the flexible membrane cover shall float on the liquid and each closure device shall be secured in the closed position. Closure devices may be opened or the flexible membrane cover may be removed to provide access to the surface impoundment for performing routine inspection, maintenance, or other activities needed for normal operations or to remove accumulated sludge or other residues from the bottom of the surface impoundment.

NR 419.045(2)(c)(c) Oil-water separator. For each oil-water separator that receives, manages, or treats an affected VOC wastewater stream or an affected residual, the owner or operator shall comply with either subd. 1. or 2.:

NR 419.045(2)(c)1.1. Equip the oil-water separator with a fixed roof and a closed vent system that route the vapors vented from the oil-water separator to a control device and meet all of the following requirements:

NR 419.045(2)(c)1.a.a. Maintain each opening in the fixed roof in a closed, sealed position at all times that the oil-water separator contains an affected VOC wastewater stream or an affected residual, except when it is necessary to use the opening for sampling or removal, or for equipment inspection, maintenance, or repair.

NR 419.045(2)(c)2.a.a. Except as provided in this subd. 2. a., the floating roof shall have a closure device between the floating roof and the wall of the oil-water separator. For portions of the oil-water separator where it is infeasible to construct and operate a floating roof, such as over the weir mechanism, the owner or operator shall operate and maintain a fixed roof, closed vent system, and control device that meet the requirements specified in subd. 1.

NR 419.045(2)(c)2.b.b. The closure device shall consist of a primary seal and a secondary seal. The primary seal shall be a liquid-mounted seal or a mechanical shoe seal. The secondary seal shall be above the floating roof and cover the annular space between the floating roof and the wall of the separator.

NR 419.045(2)(c)2.c.c. The floating roof shall be floating on the liquid at all times and may not be resting on the roof supports, except during abnormal conditions such as low flow rate.

NR 419.045(2)(c)2.d.d. Each opening in the floating roof shall be equipped with a cover, seal or lid fitted with a gasket, which shall be maintained in the closed position at all times, except during inspection and maintenance. Notwithstanding the requirements of this subd. 2. d., the floating roof may be equipped with one or more emergency cover drains for removal of stormwater. Each emergency cover drain shall be equipped with a slotted membrane fabric cover that covers at least 90% of the area of the opening or a flexible fabric sleeve seal.

NR 419.045(2)(d)(d) Portable containers. For each portable container that receives, manages, or treats an affected VOC wastewater stream or an affected residual, the owner or operator shall operate and maintain a cover on the portable container according to all of the following requirements:

NR 419.045(2)(d)1.1. Maintain the cover in place and maintain all openings in a closed position at all times that an affected VOC wastewater stream or an affected residual is in the portable container, except when it is necessary to use the opening for filling, removal, inspection, sampling, or pressure relief events related to safety considerations to prevent physical damage or permanent deformation of the portable container or cover.

NR 419.045(2)(d)2.2. For portable containers with a capacity greater than or equal to 110 gallons, use a submerged fill pipe when a container is being filled by pumping with an affected VOC wastewater stream or an affected residual. The submerged fill pipe outlet shall extend to no more than six inches or within two fill pipe diameters of the bottom of the container while the container is being filled.

NR 419.045(2)(d)3.3. During treatment of an affected VOC wastewater stream or an affected residual, including aeration, thermal or other treatment, in a portable container, whenever it is necessary for the container to be open, place the container within an enclosure with a closed-vent system that routes the VOC vapors vented from the container to a control device. The control device shall be designed and operated to reduce the VOC vented to it by at least 90% by weight.

NR 419.045(2)(e)(e) Wastewater tanks. For each wastewater tank that receives, manages, or treats an affected VOC wastewater stream or an affected residual, the owner or operator shall operate and maintain a fixed roof for the wastewater tank. However, if the wastewater tank is used for either heating wastewater or for treating by means of an exothermic reaction, or the contents of the tank is sparged, or the wastewater tank has a capacity equal to or greater than 40,000 gallons and the maximum vapor pressure of the stored material is equal to or greater than 1.5 pounds per square inch absolute, the owner or operator shall operate and maintain one of the emission control techniques described in subd. 1., 2., or 3.

NR 419.045(2)(e)1.1. A fixed roof and a closed-vent system that route the VOC vapors vented from the wastewater tank to a control device that complies with both of the following requirements:

NR 419.045(2)(e)1.a.a. Each opening in the fixed roof shall be maintained in a closed position at all times that the wastewater tank contains an affected VOC wastewater stream or an affected residual, except when it is necessary to use the opening for wastewater sampling, removal, or for equipment inspection, maintenance, or repair.

NR 419.045(2)(e)2.a.a. The internal floating roof shall be floating on the liquid surface at all times, except when the floating roof must be supported by the leg supports during initial fill, after the tank has been completely emptied and degassed, and when the tank is completely emptied before being subsequently refilled.

NR 419.045(2)(e)2.b.b. When the floating roof is resting on the leg supports, the process of filling, emptying, or refilling shall be continuous and shall be accomplished as soon as practical.

NR 419.045(2)(e)2.c.c. The internal floating roof shall be equipped with a closure device between the wall of the tank and the roof edge. The closure device shall consist of a liquid-mounted seal, or a metallic shoe seal, or two seals mounted one above the other so that each forms a continuous closure that completely covers the space between the wall of the storage vessel and the edge of the internal floating roof. The lower seal may be vapor-mounted, but both must be continuous seals.

NR 419.045(2)(e)2.d.d. Automatic bleeder vents are to be closed at all times when the roof is floating, except when the roof is being floated off of, or is being landed on, the roof leg supports.

NR 419.045(2)(e)2.e.e. Each opening in a noncontact internal floating roof, except for automatic bleeder vents (vacuum breaker vents) and rim space vents, is to provide a projection below the liquid surface.

NR 419.045(2)(e)2.f.f. Each opening in the internal floating roof, except for leg sleeves, automatic bleeder vents, rim space vents, column wells, ladder wells, sample wells, and stub drains, shall be equipped with a cover or lid. The cover or lid shall be equipped with a gasket.

NR 419.045(2)(e)2.g.g. Each penetration of the internal floating roof for the purposes of sampling shall be a sample well. Each sample well shall have a slit fabric cover that covers at least 90% of the opening.