NR 420.03(5)(b)4.a.a. The cover, lid or seal is in the closed position at all times except when in actual use. NR 420.03(5)(b)4.b.b. Automatic bleeder vents are closed at all times except when the roof is floated off or landed on the roof leg supports. NR 420.03(5)(b)4.c.c. Rim vents, if provided, are set to open when the roof is being floated off the roof leg supports or at the manufacturer’s recommended setting. NR 420.03(5)(b)5.5. Routine inspections are conducted through roof hatches at monthly intervals during the ozone season. These routine inspections shall include, at a minimum, a visual examination to determine that the roof is resting on the liquid surface, no liquid has accumulated on the roof, no seal is detached and that there are no tears or holes in the seal material. NR 420.03(5)(b)6.6. The vessel is repaired or removed from service as expeditiously as practicable, but no later than 45 days after any routine inspection in which any of the defects described in subd. 5. are found, unless an extension is granted by the department. If a defect identified in subd. 5. cannot be repaired or the vessel removed from service within 45 days, a one time 30 day extension may be requested by the owner or operator. The department may grant such a request if the owner or operator demonstrates that alternative storage capacity is not available or that repair or removal of the tank from service is infeasible for reasons beyond the control of the owner or operator. NR 420.03(5)(b)7.7. A complete inspection of cover and seal is conducted periodically as required by par. (c) NR 420.03(5)(b)8.8. Records are maintained and retained for a minimum of 5 years, unless otherwise noted, that shall include both of the following: NR 420.03(5)(b)8.a.a. The results of inspections conducted under subds. 5. and 7., including LEL readings, if applicable. All LEL readings and inspection report records shall be maintained for a minimum of 10 years if the facility elects to comply with par. (c) through use of par. (c) 2. NR 420.03(5)(c)(c) Complete inspection requirements. All fixed roof storage vessels at a facility to which this subsection applies are required to periodically undergo a complete inspection of cover and seal, and all shall use either subd. 1. or 2. to demonstrate compliance. No facility may use different compliance methods for different fixed roof storage vessels to comply with this paragraph. The complete inspection shall be conducted according to one of the following schedules: NR 420.03(5)(c)1.1. Whenever a fixed roof storage vessel is emptied and degassed or at least every 5 years, whichever is more frequent. NR 420.03(5)(c)2.2. Whenever a fixed roof storage vessel is emptied and degassed or at least every 10 years, whichever is more frequent, if all of the following requirements are met: NR 420.03(5)(c)2.a.a. The routine monthly inspections during the ozone season, in addition to meeting the requirements of par. (b) 5., include the measurement with an explosimeter of the organic vapor space above the internal floating roof to demonstrate that the organic vapor concentration does not exceed 50% of the lower explosive limit (LEL) for the stored petroleum liquid. NR 420.03(5)(c)2.b.b. The fixed roof storage vessel is repaired or removed from service as expeditiously as practicable, but no later than 45 days after the completion of the routine inspection, if any of the defects described in par. (b) 5. are found or if the measurement required under subd. 2. a. exceeds 50% of the LEL. NR 420.03(5)(c)2.c.c. Repair steps meeting the requirements of subd. 2. b. may include tests, maintenance or inspections followed by LEL measurements below 50% within 45 days of the initial LEL reading exceeding 50% that confirm further repair or removal of the tank from service is not warranted. NR 420.03(5)(d)(d) Notification and change of compliance method requirements. All existing facilities which have one or more storage vessels subject to par. (c) shall notify the department in writing, by January 3, 2000, as to whether the facility will comply with this section under the provisions of par. (c) 1. or 2. After January 3, 2000, a facility owner or operator may only change the compliance option from par. (c) 1. to par. (c) 2. after completing a complete inspection of every affected fixed roof storage vessel at the facility. For any newly constructed facility, the owner or operator shall notify the department prior to commencing operation as to which compliance option will be used. A facility owner or operator may at any time elect to change the compliance option from par. (c) 2. to par. (c) 1. provided the following conditions are met: NR 420.03(5)(d)1.1. The facility owner or operator notified the department, in writing, at least 30 days prior to the date on which the facility owner or operator plans to begin meeting the requirements of par. (c) 1. NR 420.03(5)(d)2.2. All tanks at the facility were found to be in compliance with the 50% LEL requirement of par. (c) 2. during their last LEL measurement. NR 420.03(6)(a)(a) Applicability. This subsection applies, subject to the provisions of s. NR 425.03 (4) or (5), to all storage vessels equipped with external floating roofs having capacities greater than 151,412 liters (40,000 gallons) with the exception of: NR 420.03(6)(a)1.1. Storage vessels having capacities less than 1,500,000 liters (396,270 gallons) used to store crude petroleum and condensate prior to custody transfer. NR 420.03(6)(a)3.3. Storage vessels used solely for petroleum liquids with a true vapor pressure of less than 10.5 kPa (1.52 psia). NR 420.03(6)(a)4.4. Storage vessels used solely for petroleum liquids with a true vapor pressure of less than 27.6 kPa (4.0 psia), and which are of welded construction, and presently possess a metallic-type shoe seal, a liquid-mounted foam seal, a liquid-mounted liquid filled type seal, or equally effective alternative control, approved by the department. NR 420.03(6)(a)5.5. Storage vessels of welded construction, equipped with metallic-type shoe primary seal which has a secondary seal from the top of the shoe seal to the tank wall. NR 420.03(6)(b)(b) Storage requirements. No owner or operator of a storage vessel equipped with an external floating roof to which this subsection applies may permit such storage vessel to be used for storing any petroleum liquid unless all of the following requirements are met: NR 420.03(6)(b)1.1. The vessel has been fitted with a continuous secondary seal extending from the floating roof to the tank wall, or the vessel has been fitted with an equally effective alternative control, approved by the department. NR 420.03(6)(b)2.2. The vessel is maintained such that all seal closure devices meet the following requirements: NR 420.03(6)(b)2.a.a. There are no visible holes, tears, or other openings in the seal or any seal fabric or material.