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7150.0030 DEFINITIONS.

Subpart 1.


For the purposes of this chapter, the terms in this part have the meanings given them. Terms that are not specifically defined have the meanings given in Minnesota Statutes, sections 115.01, 115C.02, and 116.46.

Subp. 2.


"Agency" means the Minnesota Pollution Control Agency or, if a regulated substance is released or spilled, the Minnesota duty officer pursuant to Minnesota Statutes, section 115E.09.

Subp. 2a.

Agency-approved tester.

"Agency-approved tester" means a person approved by the commissioner to inspect and test components of a UST system according to part 7150.0216, subpart 6, item A.

Subp. 2b.

Airport hydrant fuel distribution system.

"Airport hydrant fuel distribution system," also called an airport hydrant system, means a UST system that fuels aircraft and operates under high pressure with large diameter piping that typically terminates into one or more hydrants or fill stands with fueling points.

Subp. 3.


"Appurtenances" means components of a UST system such as piping, fittings, flanges, valves, dispensers, and pumps used to distribute, meter, or control the flow of regulated substances to or from an underground storage tank.

Subp. 4.

Beneath the surface of the ground.

"Beneath the surface of the ground" means below the surface of the ground, concrete, or asphalt or otherwise covered with earthen materials.

Subp. 4a.

Business hours.

"Business hours" means a minimum of six hours each day, Monday through Friday, excluding holidays, during which business is conducted.

Subp. 5.

Cathodic protection.

"Cathodic protection" means using a technique to prevent corrosion of a metal surface by making that surface the cathode of an electrochemical cell. For example, a UST system can be cathodically protected through the application of either sacrificial anodes or impressed current.

Subp. 6.

Cathodic-protection tester.

"Cathodic-protection tester" means a person who has demonstrated an understanding of the principles and measurements of all common types of cathodic-protection systems as applied to buried or submerged metal piping and UST systems by passing a test on cathodic protection given by NACE International or the Steel Tank Institute. The person must also have education and experience in soil resistivity, stray current, structure-to-soil potential, and component electrical isolation measurements of buried metal piping and UST systems.

Subp. 7.

Change in status.

"Change in status" means a permanent removal from service or a change in the reported uses, contents, or ownership of an underground storage tank under Minnesota Statutes, section 116.48, subdivision 3, including temporary closure of 90 days or more and change to storage of a nonregulated substance.

Subp. 8.

[Repealed, 43 SR 1253]

Subp. 8a.

Class A operator.

"Class A operator" means an individual who has primary responsibility to operate and maintain the UST system.

Subp. 8b.

Class B operator.

"Class B operator" means an individual who has daily responsibility to operate and maintain the UST system.

Subp. 8c.

Class C operator.

"Class C operator" means an individual who has daily on-site presence and responsibility to handle emergencies and alarms pertaining to a spill or release from the UST system.

Subp. 9.


"Commissioner" means the commissioner of the Minnesota Pollution Control Agency.

Subp. 10.


"Compatible" means the ability of two or more substances to maintain their respective physical and chemical properties upon contact with one another under conditions likely to be encountered in the UST system.

Subp. 11.

Connected piping.

"Connected piping" means underground piping including valves, elbows, joints, flanges, and flexible connectors attached to a UST system through which regulated substances flow. For the purpose of determining how much piping is connected to an individual UST system, the piping that joins two UST systems is allocated equally between them.

Subp. 12.

Consumptive use.

"Consumptive use," with respect to heating oil, means consumed on the premises.

Subp. 12a.

Containment sump.

"Containment sump" means a single- or double-walled liquid-tight container that:


protects the environment by containing leaks and spills of regulated substances from piping, dispensers, pumps, and related components in the containment area; and


is located at the top of the tank, such as tank top or submersible turbine pump sumps; underneath the dispenser, such as underdispenser containment sumps; or at other points in the piping run, such as transition or intermediate sumps.

Subp. 13.

Corrosion expert.

"Corrosion expert" means a person who, by reason of thorough knowledge of the physical sciences and the principles of engineering and mathematics acquired by a professional education and related practical experience, is qualified to engage in the practice of corrosion control on buried or submerged metal piping systems and metal tanks. The person must be accredited or certified as being qualified by the National Association of Corrosion Engineers or be a registered professional engineer who has certification or licensing that includes education and experience in corrosion control of buried or submerged metal piping systems and metal tanks.

Subp. 14.

Dielectric material.

"Dielectric material" means a material that does not conduct direct electrical current. Dielectric coatings are used to electrically isolate underground storage-tank systems from the surrounding soils. Dielectric bushings are used to electrically isolate parts of the UST system, for example, tank from piping.

Subp. 14a.


"Dispenser" means equipment that is used to transfer a regulated substance from underground piping, through a rigid or flexible hose or piping located above ground, to a point of use outside of the UST system, such as a motor vehicle. A dispenser does not include a loading rack used to transfer a regulated substance into the storage compartment of a bulk transport vehicle.

Subp. 15.

Electrical equipment.

"Electrical equipment" means underground equipment that contains dielectric fluid that is necessary for the operation of equipment such as transformers and buried electrical cable.

Subp. 16.

Excavation zone.

"Excavation zone" means the volume containing the UST system and backfill material bounded by the ground surface, walls, and floor of the pit and trenches into which the UST system is placed at the time of installation.

Subp. 17.

[Repealed, 32 SR 1751]

Subp. 18.

Farm tank.

"Farm tank" means a tank located on a tract of land devoted to the production of crops, raising animals, including fish, range land, nurseries with growing operations, and associated residences and improvements. A farm tank must be located on the farm property.

Subp. 18a.

Field-constructed tank.

"Field-constructed tank" means a tank that is built or assembled at the tank site, but does not include a tank with a lining.

Subp. 19.

Flow-through process tank.

"Flow-through process tank" means a tank that forms an integral part of a production process through which there is a steady, variable, recurring, or intermittent flow of materials during the operation of the process. Flow-through process tanks do not include tanks used for the storage of materials prior to their introduction into the production process or for the storage of finished products or by-products from the production process.

Subp. 20.

Free product.

"Free product" means a regulated substance that is present as a nonaqueous phase liquid, for example, liquid not dissolved in water.

Subp. 21.

Gathering lines.

"Gathering lines" means a pipeline, equipment, facility, or building used in the transportation of oil or gas during oil or gas production or gathering operations.

Subp. 22.

Hazardous substance.


"Hazardous substance" means:


a substance listed in Code of Federal Regulations, title 40, part 302, including petroleum constituents under subpart 36, item C, but not including:


a hazardous waste listed or identified under chapter 7045 or Code of Federal Regulations, title 40, part 261, and subtitle C of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA); or


petroleum under subpart 36, item A, B, or D; or


any mixture of substances identified in subitem (1) and petroleum, unless the amount of the substance identified in subitem (1) is de minimis.


Substances identified in item A that also meet the definition of petroleum are considered hazardous substances.

Subp. 23.

[Repealed, 43 SR 1253]

Subp. 24.

Heating oil.

"Heating oil" means petroleum that is Nos. 1, 2, and 4 light, No. 4 heavy, No. 5 light, No. 5 heavy, and No. 6 technical grades of fuel oil; other residual fuel oils, including Navy Special Fuel Oil and Bunker C; and other fuels when used as substitutes for one of these fuel oils. Heating oil is typically used in the operation of heating equipment, boilers, or furnaces.

Subp. 25.

Hydraulic lift tank.

"Hydraulic lift tank" means a tank holding hydraulic fluid for a closed-loop mechanical system that uses compressed air or hydraulic fluid to operate lifts, elevators, and other similar devices.

Subp. 25a.

[Repealed, 43 SR 1253]

Subp. 25b.

Impressed current or impressed-current system.

"Impressed current" or "impressed-current system" means a method of corrosion protection that generates a cathodic current from a power source, such as a rectifier that converts alternating current to direct current, where the cathodic current flows from the anodes through the soil to the UST system and returns to the power source through an insulated wire attached to the UST system.

Subp. 25c.


"Leak" means discharge of a regulated substance or any other potentially harmful substance from a point in a UST system that is not intended to be a discharge or dispensing point. A leak that reaches the environment is a release.

Subp. 25d.

Leak detection.

"Leak detection" has the meaning given under subpart 42.

Subp. 25e.


"Lessee" means a person that leases a UST system. A lessee is also an operator if the lessee is in control of the daily operation of the UST system.

Subp. 25f.

Lining or internal lining.

"Lining" or "internal lining" means a coating of noncorrosive material bonded to the interior surface of a tank.

Subp. 25g.

Liquid tight.

"Liquid tight" means that liquid is not able to leak from a component of a UST system and that subsurface water is not able to infiltrate a tank, pipe, or secondary-containment area.

Subp. 26.


"Maintenance" means the normal operational upkeep to prevent a UST system from releasing a regulated substance.

Subp. 27.

Motor fuel.

"Motor fuel" means a complex blend of hydrocarbons used to operate a motor engine, such as motor gasoline, aviation gasoline, No. 1 or No. 2 diesel fuel, or a blend containing one or more of these substances.

Subp. 28.

[Repealed, 32 SR 1751]

Subp. 29.

Noncommercial purposes.

"Noncommercial purposes," with respect to motor fuel, means not for resale.

Subp. 29a.

Noncorrodible material.

"Noncorrodible material" means a synthetic or processed material that is certified for use in UST systems and compatible with the substance being stored in a UST system and the surrounding environment.

Subp. 30.

On the premises where stored.

"On the premises where stored," with respect to heating oil, means underground storage-tank systems located on the same property where the stored heating oil is used.

Subp. 31.

Operational life.

"Operational life" means the period beginning when installation of the UST system has begun until the time the UST system is permanently closed under part 7150.0410.

Subp. 32.



"Operator" means a person who:


has control of or responsibility for the daily operation of the UST system;


had control of or responsibility for the daily operation of the tank immediately before discontinuation of the tank's use;


is responsible under Minnesota Statutes, section 115C.021, for a release from an underground storage tank containing petroleum; or


is responsible under Minnesota Statutes, section 115B.03, for a release from an underground storage tank containing a hazardous substance.


Operator does not include a person who operates a tank if the tank is not regulated by this chapter.

Subp. 32a.

Other potentially harmful substances.

"Other potentially harmful substances" means substances that are not regulated substances when used as intended by the manufacturer but that may cause harm to human health and the environment if released from a leaking UST system because of the volume and nature of the release. Other potentially harmful substances does not include:


petroleum substances under standard temperature and pressure; or


hazardous substances.

Subp. 32b.

Out of service.

"Out of service" means the status of a UST system from which a regulated substance is not or has not been introduced or dispensed, pending a decision or action to close the UST system or begin reusing the UST system.

Subp. 33.

Overfill release.

"Overfill release" means a release occurring when a tank is filled beyond its capacity, resulting in a discharge of the regulated substance to the environment.

Subp. 34.



"Owner" means a person who:


holds title to, controls, or possesses an interest in an underground storage tank;


held title to, controlled, or possessed an interest in the tank immediately before discontinuation of the tank's use;


is responsible under Minnesota Statutes, section 115C.021, for a release from an underground storage tank containing petroleum; or


is responsible under Minnesota Statutes, section 115B.03, for a release from an underground storage tank containing a hazardous substance.


Owner does not include a person who:


owns a tank if the tank is not regulated by this chapter; or


holds an interest in a tank solely for financial security, unless through foreclosure or other related actions the holder of a security interest has taken possession of the tank.

Subp. 34a.

Permanent closure.

"Permanent closure" means permanently taking a UST system out of service by either closing it in place or removing it from the ground.

Subp. 35.


"Person" means an individual, partnership, association, public or private corporation, or other legal entity, including the United States government, an interstate commission or other body, the state, or any agency, board, bureau, office, department, or political subdivision of the state, but does not include the Minnesota Pollution Control Agency.

Subp. 36.


"Petroleum" means one of the following substances:


diesel fuel oil, gasoline, and heating fuel oil as defined in Minnesota Statutes, section 296A.01, subdivisions 14, 23, and 26;


crude oil or a fraction of crude oil that is liquid at a temperature of 60 degrees Fahrenheit and pressure of 14.7 pounds per square inch absolute;


constituents of gasoline and fuel oil under item A and constituents of crude oil under item B; or


petroleum-based substances that are comprised of a complex blend of hydrocarbons, such as motor fuels, jet fuels, distillate fuel oils, residual fuel oils, lubricants, and used oils.

Subp. 37.

Petroleum UST system.

"Petroleum UST system" means a UST system that is used to contain petroleum or a mixture of petroleum with de minimis quantities of hazardous substances.

Subp. 38.

Pipe or piping.

"Pipe" or "piping" means a hollow cylinder or tubular conduit for conveying a regulated substance from one point to another within a UST system that is made of nonearthen materials.

Subp. 38a.

[Renumbered subp 38c]

Subp. 38b.

Pipeline facilities.

"Pipeline facilities," including gathering lines, means new and existing pipe rights-of-way and any associated equipment, facilities, or buildings.

Subp. 38c.

Piping system.

"Piping system" means piping, secondary containment, leak-detection devices, tubing, flanges, gaskets, valves, fittings, flexible connectors, and other pipe appurtenances that mix, separate, distribute, meter, or control flow and any core components that allow the piping system to function as intended and in accordance with installation requirements. Piping system includes:


a pipe run, which is the portion of the pipe from the submersible pump to the furthest dispenser, or in the case of suction piping, from the top of the tank to the furthest dispenser, or in cases where piping enters a building, the first pipe joint inside the building. UST systems may have multiple pipe runs;


a pipe segment, which is the portion of pipe between components in a pipe run, such as from the pump to a dispenser or between two dispensers; and


a pipe section, which is the portion of a pipe segment that is limited to ten feet in length.

Subp. 39.

[Renumbered subp 38b]

Subp. 39a.


"Product" means a regulated substance.

Subp. 40.

Regulated substance.

"Regulated substance" means a hazardous substance or petroleum.

Subp. 41.


"Release" means a spilling, leaking, emitting, discharging, escaping, leaching, or disposing from a UST system into the environment including spills associated with overfills and transfer operations as the regulated substance moves to or from a UST system. Release does not include discharges or designed venting allowed under agency rules.

Subp. 42.

Release detection or leak detection.

"Release detection" or "leak detection" means determining whether a release of a regulated substance has occurred from the UST system:


into the environment; or


into the interstitial space between the UST system and its secondary barrier or between the UST system and its secondary containment.

Subp. 43.


"Repair" means to correct or restore a component of a UST system to the component's original design function or operating condition.


"Piping repair" includes installing a single section of up to ten feet of new piping to replace existing piping.


"Dispenser repair" includes installing a new dispenser to replace an existing dispenser if work is performed entirely on or above any shear valves and check valves.


"Tank repair" includes repairing a tank lining, patching or coating damaged areas, and repairing or replacing corrosion protection.

Subp. 43a.

Replace or replacement.

"Replace" or "replacement" means to install a new component for a UST system in substantially the same location as another component of a UST system in lieu of that component. Replacement includes:


piping repair to install a single piping segment or an accumulation of piping segments of more than ten feet of new piping to replace existing piping;


installing a new dispenser if work is performed beneath any shear valve or check valve or on any flexible connector or unburied riser; and


installing a replacement submersible pump that involves removing the pump head from the riser.

Subp. 43b.

[Renumbered subp 43d]

Subp. 43c.

Residential tank.

"Residential tank" means a tank located on property used primarily for dwelling purposes.

Subp. 43d.

Retrofit tank.

"Retrofit tank" means a new tank installed in an existing host tank as an internal lining according to part 7150.0205, subpart 1.

Subp. 44.

[Renumbered subp 43c]

Subp. 44a.

[Repealed, 43 SR 1253]

Subp. 44b.

Sacrificial-anode system.

"Sacrificial-anode system" means a cathodic-protection system that uses zinc, magnesium, or other anodic metals buried near and connected to the metal surface that is being protected.

Subp. 44c.

Secondary containment or secondarily contained.

"Secondary containment" or "secondarily contained" means a release-prevention and release-detection system that is used for a UST system and that has an inner and outer barrier with an interstitial space that is monitored for leaks.

Subp. 45.

Septic tank.

"Septic tank" means a watertight, covered receptacle designed to receive or process through liquid separation or biological digestion, the sewage discharged from a building sewer. The effluent from the receptacle is distributed for disposal through the soil and settled solids and scum from the tank are pumped out periodically and hauled to a treatment facility.

Subp. 45a.

Spill bucket.

"Spill bucket" means a containment structure designed to capture releases that may occur in the UST fill port when a regulated substance is transferred. "Spill containment," "spill container," and "spill catchment basin" have the same meaning as spill bucket.

Subp. 46.

Storm water or wastewater collection system.

"Storm water or wastewater collection system" means piping, pumps, conduits, and any other equipment necessary to collect and transport the flow of surface water runoff resulting from precipitation, or domestic, commercial, or industrial wastewater to and from retention areas or areas where treatment is designated to occur. The collection of storm water and wastewater does not include treatment, except where incidental to conveyance.

Subp. 46a.


"Sump" means an area belowground that is designed to provide access to components of a UST system such as pumps, valves, piping, and fittings. Sump includes a dirt sump, an uncontained sump, and a containment sump.

Subp. 47.

Surface impoundment.

"Surface impoundment" means a natural topographic depression, artificial excavation, or diked area formed primarily of earthen materials, although it may be lined with synthetic materials, that is not an injection well.

Subp. 48.


"Tank" is a stationary device designed to contain an accumulation of regulated substances and constructed of nonearthen materials, such as concrete, steel, and plastic, that provide structural support.

Subp. 49.

[Repealed, 43 SR 1253]

Subp. 49a.

Unattended card-lock facility.

"Unattended card-lock facility" means a facility where dispensing a regulated substance during business hours is mechanically or electronically controlled without the constant on-site presence of a class A, B, or C operator.

Subp. 50.

Underground area.

"Underground area" means an underground room such as a basement, cellar, shaft, or vault providing enough space for physical inspection of the entire exterior of the tank or the tank's secondary containment, situated on or above the surface of the floor.

Subp. 50a.

Underground storage tank or UST.

"Underground storage tank" or "UST" means any one or combination of tanks, vessels, enclosures, structures, or internal linings that is used to contain an accumulation of regulated substances or other potentially harmful substances when the combined volume, including the volume of connected pipes, is ten percent or more beneath the surface of the ground. An underground storage tank does not include any tank described in part 7150.0010, subpart 2.

Subp. 51.

Underground storage-tank system or UST system.


"Underground storage-tank system" or "UST system" means an underground storage tank and any underground piping or equipment connected to an underground storage tank that is used to:


dispense a regulated substance or other potentially harmful substance;


provide for safe operation of the tank, piping, or appurtenances; or


detect and prevent a release to the environment.


UST system does not include any tanks, pipes, or appurtenances connected to a tank described in part 7150.0010, subpart 2.

Subp. 51a.

Unusual operating condition.

"Unusual operating condition" means:


a condition, equipment deficiency, or occurrence that results in a release of a regulated substance;


an unexplained presence of water in the tank;


liquid in the interstitial space of secondary-containment systems;


erratic behavior of product dispensing equipment;


a sudden loss of product from the UST system; or


monitoring results that indicate the possibility of a leak from a UST system.

Subp. 52.

[Repealed, 32 SR 1751]

Subp. 53.

Wastewater treatment tank.

"Wastewater treatment tank" means a tank that is designed to receive and treat an influent wastewater through physical, chemical, or biological methods.

Statutory Authority:

MS s 115.03; 116.49


16 SR 59; 17 SR 1279; L 1992 c 575 s 53; 25 SR 556; 32 SR 1751; 43 SR 1253

Published Electronically:

June 6, 2019

Official Publication of the State of Minnesota
Revisor of Statutes