NR 665.1085(6)(c)1.1. Measure the external floating roof seal gaps according to all of the following requirements:
NR 665.1085(6)(c)1.a.a. 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 665.1085(6)(c)1.b.b. 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 665.1085(6)(c)1.c.c. If a tank ceases to hold hazardous waste for a period of one year or more, subsequent introduction of hazardous waste into the tank is an initial operation for the purposes of subd. 1. a. and b.
NR 665.1085(6)(c)1.d.d. Determine the total surface area of gaps in the primary seal and in the secondary seal individually using the following procedure:
1) Perform the seal gap measurements at one or more floating roof levels when the roof is floating off the roof supports.
2) Measure seal gaps, if any, around the entire perimeter of the floating roof in each place where a 0.32-centimeter (cm) diameter uniform probe passes freely (without forcing or binding against the seal) between the seal and the wall of the tank and measure the circumferential distance of each location.
3) For a seal gap measured under this paragraph, determine the gap surface area 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) Calculate the total gap area 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. Then compare these total gap areas per unit of tank diameter for the primary seal and secondary seal to the respective standards for the seal type in par. (a) 2.
NR 665.1085(6)(c)1.e.e. In the event that the seal gap measurements do not conform to the specifications in par. (a) 2., repair the defect according to sub. (11).
NR 665.1085(6)(c)1.f.f. Maintain a record of the inspection according to s. NR 665.1090 (2).
NR 665.1085(6)(c)2.2. Visually inspect the external floating roof according to all of the following requirements:
NR 665.1085(6)(c)2.a.a. Visually inspect the floating roof and its closure devices to check for defects that could result in air pollutant emissions. Defects include, but are not limited to, 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 665.1085(6)(c)2.b.b. Perform an initial inspection of the external floating roof and its closure devices on or before the date that the tank becomes subject to this section. Thereafter, perform the inspections at least once every year except for the special conditions provided for in sub. (12).
NR 665.1085(6)(c)2.c.c. In the event that a defect is detected, repair the defect according to sub. (11).
NR 665.1085(6)(c)2.d.d. Maintain a record of the inspection according to s. NR 665.1090 (2).
NR 665.1085(6)(c)3.3. Prior to each inspection required by subd. 1. or 2., notify the department in advance of each inspection to provide the department with the opportunity to have an observer present during the inspection. Notify the department of the date and location of the inspection as follows:
NR 665.1085(6)(c)3.a.a. Prior to each inspection to measure external floating roof seal gaps as required under subd. 1., prepare and send written notification so that the department receives it at least 30 calendar days before the date the measurements are scheduled to be performed.
NR 665.1085(6)(c)3.b.b. Prior to each visual inspection of an external floating roof in a tank that has been emptied and degassed, prepare and send written notification so that the department receives it at least 30 calendar days before refilling the tank except when an inspection is not planned as provided for in subd. 3. c.
NR 665.1085(6)(c)3.c.c. When a visual inspection is not planned and the owner or operator could not have known about the inspection 30 calendar days before refilling the tank, 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 the department receives it at least 7 calendar days before refilling the tank.
NR 665.1085(6)(d)(d) Safety devices, as defined in s. NR 665.1081, may be installed and operated as necessary on any tank complying with this subsection.
NR 665.1085(7)(7)The owner or operator who controls air pollutant emissions from a tank by venting the tank to a control device shall meet all of the following requirements:
NR 665.1085(7)(a)(a) Cover the tank with a fixed roof and vent the tank directly through a closed-vent system to a control device according to all of the following requirements:
NR 665.1085(7)(a)1.1. Design the fixed roof and its closure devices to form a continuous barrier over the entire surface area of the liquid in the tank.
NR 665.1085(7)(a)2.2. Equip each opening in the fixed roof not vented to the control device 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, design the closure devices 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, design the closure device to operate with no detectable organic emissions.
NR 665.1085(7)(a)3.3. Make the fixed roof and its closure devices of suitable materials that will minimize exposure of the hazardous waste 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 consider 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 665.1085(7)(a)4.4. Design and operate the closed-vent system and control device according to s. NR 665.1088.
NR 665.1085(7)(b)(b) Whenever a hazardous waste is in the tank, install the fixed roof 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 665.1085(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: