NR 420.02(24m) (24m) “Liquid tight” means having a liquid leak rate not exceeding 0.10 gallons per hour when measured with a ±5% accuracy.

NR 420.02(25) (25) “Lower explosive limit” or “LEL” means the lower limit of flammability of a gas or vapor at ordinary ambient temperatures expressed as percent propane in air by volume.

NR 420.02(27) (27) “Petroleum” means the crude oil removed from the earth and the oils derived from tar sands, shale, coal and coke.

NR 420.02(29) (29) “Petroleum refinery” means any facility engaged in producing gasoline, kerosene, distillate fuel oils, residual fuel oils, lubricants or other products through distillation of petroleum or through redistillation, cracking, extraction or reforming of unfinished petroleum derivatives.

NR 420.02(29m) (29m) “Process gas” means any gas generated by a petroleum refinery process unit except fuel gas and process upset gas as defined in this section.

NR 420.02(29p) (29p) “Process upset gas” means any gas generated by a petroleum refinery process unit as a result of startup, shutdown, upset or malfunction.

NR 420.02(30) (30) “Refinery process unit” means any segment of a petroleum refinery in which a specific processing operation is conducted.

NR 420.02(31) (31) “Reid vapor pressure” means the absolute vapor pressure of volatile crude petroleum and volatile nonviscous petroleum liquids except liquefied petroleum gases as determined by ASTM D323-08, incorporated by reference in s. NR 484.10 (6).

NR 420.02(32m) (32m) “Top off” means to attempt to dispense more gasoline to a motor vehicle fuel tank after the vapor recovery dispensing nozzle has shut off.

NR 420.02(33) (33) “True vapor pressure” means the equilibrium partial pressure exerted by a petroleum liquid as determined in accordance with methods described in American Petroleum Institute Publication 2517, Evaporative Loss from External Floating Roof Tanks, 3rd edition, February 1989, incorporated by reference in s. NR 484.11.

NR 420.02(34) (34) “Turnaround” means the procedure of shutting a refinery unit down after a run to do necessary maintenance and repair work and putting the unit back on stream.

NR 420.02(35) (35) “Vacuum producing system” means any reciprocating, rotary, or centrifugal blower or compressor, or any jet ejector or device that takes suction from a pressure below atmospheric and discharges against atmospheric pressure.

NR 420.02(36) (36) “Vapor balance system” means a combination of pipes or hoses which create a closed system between the vapor spaces of an unloading tank and a receiving tank such that vapors displaced from the receiving tank are transferred to the tank being unloaded.

NR 420.02(37) (37) “Vapor collection system” means, for the purpose of liquid organic compound transfer operations, a vapor transport system which uses direct displacement by the liquid loaded to force vapors from the tank into a vapor control system or vapor holding tank.

NR 420.02(38) (38) “Vapor-mounted seal” means any primary floating roof seal mounted so that there is an annular vapor space underneath the seal. The annular vapor space is bounded by the bottom of the primary seal, the tank wall, the liquid surface, and the floating roof.

NR 420.02(39) (39) “Vapor recovery system” or “vapor control system” mean a system that gathers organic compound vapors released during the operation of any transfer, storage, or process equipment and processes the vapors so as to prevent their emission into the ambient air.

NR 420.02(39m) (39m) “Vapor tight” means having the detection of less than 10,000 ppm hydrocarbon concentration, as determined by Method 21 in Appendix A of 40 CFR part 60, incorporated by reference in s. NR 484.04 (17), at a distance of one inch from the source.

NR 420.02(40) (40) “Wastewater (oil-water) separator” means any device or piece of equipment which utilizes the difference in density between oil and water to remove oil and associated chemicals from water. This includes any device, such as a flocculation tank, clarifier, etc., which removes petroleum derived compounds from wastewater.

NR 420.02(41) (41) “Waxy, heavy pour crude petroleum” means a crude petroleum with a pour point of 10°C (50°F) or higher as determined by ASTM D97-02, incorporated by reference in s. NR 484.10 (2).

NR 420.02 History History: Renum. from NR 154.01, Register, September, 1986, No. 369, eff. 10-1-86; renum. (2), (3), (4), (7) and (12) to be NR 419.02 (1), 400.02 (11m), (16e), (21m) and (26m), r. (19), am. (21), (29m) and (29p) renum. from NR 420.02 (71) and (72), Register, February, 1990, No. 410, eff. 3-1-90; am. (31), (33) and (41), Register, May, 1992, No. 437, eff. 6-1-92; cr. (8m), (24m), (32m), (38m) and (39m), Register, January, 1993, No. 445, eff. 2-1-93; am. (31), (33), (39m), (41), Register, February, 1995, No. 470, eff. 3-1-95; am. (intro.), renum. (28) to be NR 419.02 (13), Register, December, 1995, No. 480, eff. 1-1-96; am. (41), Register, December, 1996, No. 492, eff. 1-1-97; am. (intro.), (31) and (41), Register, October, 1999, No. 526, eff. 11-1-99; CR 02-146: am (31) and (41) Register October 2003 No. 574, eff. 11-1-03 correction in (33) and (39m) made under s. 13.93 (2m) (b) 7., Stats., Register October 2003, No. 574; CR 11-005: am. (31) Register January 2012 No. 673, eff. 2-1-12; CR 15-077: r. (8m), (26), (32), (38m), am. (39) Register July 2016 No. 727, eff. 8-1-16.

NR 420.03 NR 420.03 Storage of petroleum liquids.

NR 420.03(1) (1) Applicability. The storage, recordkeeping and maintenance requirements of subs. (2), (3) and (4) apply to all storage vessels for petroleum liquids of more than 151,412 liter (40,000 gallon) capacity on which construction or modification is commenced after July 1, 1975, with the exception of:

NR 420.03(1)(a) (a) Storage vessels being used for number 2 through number 6 fuel oils as specified in ASTM D396-02, gas turbine fuel oils numbers 2-GT through 4-GT as specified in ASTM D2880-00, or diesel fuel oils numbers 2-D and 4-D as specified in ASTM D975-02. These ASTM standards are incorporated by reference in s. NR 484.10 (8), (13) and (40).

NR 420.03(1)(b) (b) Storage vessels for the crude petroleum or condensate stored, processed or treated at a drilling and production facility outside a metropolitan county prior to custody transfer.

NR 420.03(1)(c) (c) Pressure vessels which are designed to operate at pressures in excess of 104 kPa (15 psig) without emissions except under emergency conditions.

NR 420.03(1)(d) (d) Subsurface caverns or porous rock reservoirs.

NR 420.03(1)(e) (e) Horizontal underground storage tanks used to store JP-4 jet fuel.

NR 420.03(2) (2) Storage requirements. The owner or operator of any storage vessel to which this section applies shall store petroleum liquids as follows:

NR 420.03(2)(a) (a) If the true vapor pressure of the petroleum liquid, as stored, is equal to or greater than 10.5 kPa (1.52 psia) but not greater than 77 kPa (11.1 psia), the storage vessel shall be equipped with a floating roof, a vapor recovery system or an equally effective alternative control method approved by the department.