NR 664.1084(6)(b)1.1. When the floating roof is resting on the leg supports, the process of filling, emptying or refilling shall be continuous and shall be completed as soon as practical. NR 664.1084(6)(b)2.2. Except for automatic bleeder vents, rim space vents, roof drains and leg sleeves, secure and maintain each opening in the roof in a closed position at all times except when the closure device must be open for access. NR 664.1084(6)(b)3.3. Bolt or fasten covers on each access hatch and each gauge float well when secured in the closed position. NR 664.1084(6)(b)4.4. Set closed automatic bleeder vents at all times when the roof is floating, except when the roof is being floated off or is being landed on the leg supports. NR 664.1084(6)(b)5.5. Set to open rim space vents only at those times that the roof is being floated off the roof leg supports or when the pressure beneath the rim seal exceeds the manufacturer’s recommended setting. NR 664.1084(6)(b)6.6. Secure the cap on the end of each unslotted guide pole in the closed position at all times except when measuring the level of the liquid in the tank or collecting samples of the liquid. NR 664.1084(6)(b)7.7. Secure the cover on each gauge hatch or sample well in the closed position at all times except when the hatch or well must be opened for access. NR 664.1084(6)(b)8.8. Both the primary seal and the secondary seal shall completely cover the annular space between the external floating roof and the wall of the tank in a continuous fashion except during inspections. NR 664.1084(6)(c)(c) Inspect the external floating roof according to all of the following procedures: NR 664.1084(6)(c)1.1. Measure the external floating roof seal gaps according to all of the following requirements: NR 664.1084(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 664.1084(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 664.1084(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 664.1084(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 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) 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 664.1084(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 664.1084(6)(c)2.2. Visually inspect the external floating roof according to all of the following requirements: NR 664.1084(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 664.1084(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 664.1084(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 664.1084(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 664.1084(6)(c)3.b.b. Prior to each visual inspection of an external floating roof in a tank that has been emptied and degassed, 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 664.1084(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.