NR 661.1084(6)(c)1. 1. The remanufacturer or other person that stores or treats the hazardous secondary material shall measure the external floating roof seal gaps in accordance with all of the following requirements:

NR 661.1084(6)(c)1.a. a. The remanufacturer or other person that stores or treats the hazardous secondary material shall perform measurements of gaps between the tank wall and the primary seal within 60 calendar days after initial operation of the tank following installation of the floating roof and, thereafter, at least once every 5 years.

NR 661.1084(6)(c)1.b. b. The remanufacturer or other person that stores or treats the hazardous secondary material shall perform measurements of gaps between the tank wall and the secondary seal within 60 calendar days after initial operation of the tank following installation of the floating roof and, thereafter, at least once every year.

NR 661.1084(6)(c)1.c. c. If a tank ceases to hold hazardous secondary material for a period of one year or more, subsequent introduction of hazardous secondary material into the tank shall be considered an initial operation for the purposes of subd. 1. a. and b.

NR 661.1084(6)(c)1.d. d. The remanufacturer or other person that stores or treats the hazardous secondary material shall determine the total surface area of gaps in the primary seal and in the secondary seal individually using the following procedure:

1) The seal gap measurements shall be performed at one or more floating roof levels when the roof is floating off the roof supports.

2) Seal gaps, if any, shall be measured around the entire perimeter of the floating roof in each place where a 0.32-centimeter diameter uniform probe passes freely, without forcing or binding against the seal, between the seal and the wall of the tank and the circumferential distance of each such location shall be measured.

3) For a seal gap measured under par. (c), the gap surface area shall be determined by using probes of various widths to measure accurately the actual distance from the tank wall to the seal and multiplying each width by its respective circumferential distance.

4) The total gap area shall be calculated by adding the gap surface areas determined for each identified gap location for the primary seal and the secondary seal individually, and then dividing the sum for each seal type by the nominal diameter of the tank. The total gap areas for the primary seal and secondary seal shall be compared to the respective standards for the seal type as specified in par. (a) 2.

NR 661.1084(6)(c)1.e. e. In the event that the seal gap measurements do not conform to the specifications in par. (a) 2., the remanufacturer or other person that stores or treats the hazardous secondary material shall repair the defect in accordance with the requirements under sub. (11).

NR 661.1084(6)(c)1.f. f. The remanufacturer or other person that stores or treats the hazardous secondary material shall maintain a record of the inspection in accordance with the requirements specified in s. NR 661.1089 (2).

NR 661.1084(6)(c)2. 2. The remanufacturer or other person that stores or treats the hazardous secondary material shall visually inspect the external floating roof in accordance with all of the following requirements:

NR 661.1084(6)(c)2.a. a. The remanufacturer or other person that stores or treats the hazardous secondary material shall visually inspect the floating roof and its closure devices shall to check for defects that could result in air pollutant emissions. Defects include holes, tears, or other openings in the rim seal or seal fabric of the floating roof; a rim seal detached from the floating roof; all or a portion of the floating roof deck being submerged below the surface of the liquid in the tank; broken, cracked, or otherwise damaged seals or gaskets on closure devices; and broken or missing hatches, access covers, caps, or other closure devices.

NR 661.1084(6)(c)2.b. b. The remanufacturer or other person that stores or treats the hazardous secondary material shall perform an initial inspection of the external floating roof and its closure devices on or before the date the tank becomes subject to this section. Thereafter, the remanufacturer or other person that stores or treats the hazardous secondary material shall perform the inspections at least once every year except for the special conditions provided for in sub. (12).

NR 661.1084(6)(c)2.c. c. In the event that a defect is detected, the remanufacturer or other person that stores or treats the hazardous secondary material shall repair the defect in accordance with the requirements under sub. (11).

NR 661.1084(6)(c)2.d. d. The remanufacturer or other person that stores or treats the hazardous secondary material shall maintain a record of the inspection in accordance with the requirements specified in s. NR 661.1089 (2).

NR 661.1084(6)(c)3. 3. Prior to each inspection required under subd. 1. or 2., the remanufacturer or other person that stores or treats the hazardous secondary material shall notify the department in advance of each inspection to provide the department with the opportunity to have an observer present during the inspection. The remanufacturer or other person that stores or treats the hazardous secondary material shall notify the department of the date and location of the inspection as follows:

NR 661.1084(6)(c)3.a. a. Prior to each inspection to measure external floating roof seal gaps as required under subd. 1., the remanufacturer or other person that stores or treats the hazardous secondary material shall prepare and send written notification so that it is received by the department at least 30 calendar days before the date the measurements are scheduled to be performed.

NR 661.1084(6)(c)3.b. b. Prior to each visual inspection of an external floating roof in a tank that has been emptied and degassed, the remanufacturer or other person that stores or treats the hazardous secondary material shall prepare and send written notification so that it is received by the department at least 30 calendar days before refilling the tank except when an inspection is not planned as provided for in subd. 3. c.

NR 661.1084(6)(c)3.c. c. When a visual inspection is not planned and the remanufacturer or other person that stores or treats the hazardous secondary material could not have known about the inspection 30 calendar days before refilling the tank, the owner or operator shall notify the department as soon as possible, but no later than 7 calendar days before refilling the tank. This notification may be made by telephone and immediately followed by a written explanation for why the inspection is unplanned. Alternatively, written notification, including the explanation for the unplanned inspection, may be sent so that it is received by the department at least 7 calendar days before refilling the tank.

NR 661.1084(6)(d) (d) Safety devices, as defined in s. NR 661.1081, may be installed and operated as necessary on any tank complying with the requirements specified in this subsection.

NR 661.1084(7) (7) The remanufacturer or other person that stores or treats the hazardous secondary material who controls air pollutant emissions from a tank by venting the tank to a control device shall meet all of the following requirements:

NR 661.1084(7)(a) (a) The tank shall be covered by a fixed roof and vented directly through a closed-vent system to a control device in accordance with all of the following requirements:

NR 661.1084(7)(a)1. 1. The fixed roof and its closure devices shall be designed to form a continuous barrier over the entire surface area of the liquid in the tank.

NR 661.1084(7)(a)2. 2. Each opening in the fixed roof not vented to the control device shall be equipped with a closure device. If the pressure in the vapor headspace underneath the fixed roof is less than atmospheric pressure when the control device is operating, the closure devices shall be 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 cover opening and the closure device. If the pressure in the vapor headspace underneath the fixed roof is equal to or greater than atmospheric pressure when the control device is operating, the closure device shall be designed to operate with no detectable organic emissions.

NR 661.1084(7)(a)3. 3. 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 liquid and its vapor 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(7)(a)4. 4. The closed-vent system and control device shall be designed and operated in accordance with the requirements specified in s. NR 661.1087.

NR 661.1084(7)(b) (b) Whenever a hazardous secondary material is in the tank, the fixed roof shall be installed with each closure device secured in the closed position and the vapor headspace underneath the fixed roof vented to the control device except as follows:

NR 661.1084(7)(b)1. 1. Venting to the control device is not required, and opening of closure devices or removal of the fixed roof is allowed at the following times: