Mississippi Administrative Code
Title 11 - Mississippi Department of Environmental Quality
Part 5 - Underground Storage Tank Regulations
Chapter 2 - Mississippi Commission on Environmental Quality Underground Storage Tanks Regulations Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks (UST) (Adopted March 22, 1989; Amended August 25, 2011, Last Amended August 23, 2018)
Rule 11-5-2.1 - Program Scope and Interim Prohibition
Section 11-5-2.1-280.12 - Definitions
Aboveground release means any release to the surface of the land or to surface water. This includes, but is not limited to, releases from the above-ground portion of an UST system and above-ground releases associated with overfills and transfer operations as the regulated substance moves to or from an UST system.
Ancillary equipment means any devices including, but not limited to, such devices as piping, fittings, flanges, valves, dispensers, and pumps used to distribute, meter, or control the flow of regulated substances to and from an UST.
Belowground release means any release to the subsurface of the land and to groundwater. This includes, but is not limited to, releases from the belowground portions of an underground storage tank system and belowground releases associated with overfills and transfer operations as the regulated substance moves to or from an underground storage tank.
Beneath the surface of the ground means beneath the ground surface or otherwise covered with earthen materials.
Cathodic protection is a technique to prevent corrosion of a metal surface by making that surface the cathode of an electrochemical cell. For example, a tank system can be cathodically protected through the application of either galvanic anodes or impressed current.
Cathodic protection tester means a person who can demonstrate an understanding of the principles and measurements of all common types of cathodic protection systems as applied to buried or submerged metal piping and tank systems. At a minimum, such persons must have education and experience in soil resistivity, stray current, structure-to-soil potential, and component electrical isolation measurements of buried metal piping and tank systems.
CERCLA means the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended.
Certificate of Operation (Receipt of UST Payment) means a document identifying an underground storage tank facility as being registered with the MDEQ and having paid all of the known tank regulatory fees for the time period indicated on the certificate. The Certificate of Operation will be issued annually upon payment of tank regulatory fees and is valid only for the fiscal year in which it was issued. The Certificate of Operation must be conspicuously displayed at the facility. The Certificate of Operation does not verify that all components of the UST system have been properly registered with the MDEQ as MDEQ is unable to make that determination until the time of an inspection.
Compatible means the ability of two or more substances to maintain their respective physical and chemical properties upon contact with one another for the operational life of the tank system under conditions likely to be encountered by the UST system.
Connected piping means all underground piping including valves, elbows, joints, flanges, and flexible connectors attached to a tank system through which regulated substances flow. For the purpose of determining how much piping is connected to any individual UST system, the piping that joins two UST systems should be allocated equally between them.
Consumptive use with respect to heating oil means consumed on the premises.
Containment sump means a liquid tight, secondary containment device installed underneath a dispenser, at the tank or along a piping system designed to prevent leaks from the dispenser, submersible pump, piping connectors, fittings or other UST system ancillary components from reaching the environment. Containment sumps may be single walled or secondarily contained.
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. Such a 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.
Delivery prohibition means prohibiting the delivery, deposit, or acceptance of product to an underground storage tank that has been determined to be ineligible for such delivery, deposit or acceptance.
Delivery prohibition tag means a tag, device, or mechanism on the tank's fill pipe that identifies an underground storage tank as ineligible for product delivery. The tag or device is easily visible to the product supplier and clearly states and conveys that it is unlawful to deliver to, deposit into, or accept product into the ineligible underground storage tank.
Dielectric material means a material that does not conduct direct electrical current. Dielectric coatings are used to electrically isolate UST systems from the surrounding soils. Dielectric bushings are used to electrically isolate portions of the UST system (e.g., tank from piping).
Dispenser means a device located above ground that meters the amount of regulated substances transferred to a point of use outside of the UST system, such as a motor vehicle. This definition does not include the "hanging hardware" (breakaways, hoses, nozzles) associated with the dispenser.
Dispenser system means the dispenser and the equipment necessary to connect the dispenser to the underground storage tank system.
Electrical equipment means underground equipment that contains dielectric fluid that is necessary for the operation of equipment such as transformers and buried electrical cable.
Excavation zone means the volume containing the tank 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.
Existing tank system means a tank system used to contain an accumulation of regulated substances or for which installation has commenced on or before December 22, 1988. For purposes of determining whether or not secondary containment is required, an existing tank system means a tank system used to contain an accumulation of regulated substances for which installation has commenced before October 1, 2008. Installation is considered to have commenced if:
(a) The owner or operator has obtained all federal, state, and local approvals or permits necessary to begin physical construction of the site or installation of the tank system; and if,
(1) Either a continuous on-site physical construction or installation program has begun; or
(2) The owner or operator has entered into contractual obligations-which cannot be cancelled or modified without substantial loss-for physical construction at the site or installation of the tank system to be completed within a reasonable time.
Expeditiously emptied means that any accumulation of regulated substances in a UST is removed within 24 hours or another time frame determined by the MDEQ to be reasonable.
Farm tank is a tank located on a tract of land devoted to the production of crops or raising animals, including fish, and associated residences and improvements. A farm tank must be located on the farm property. "Farm" includes fish hatcheries, rangeland and nurseries with growing operations.
Flow-through process tank is 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.
Free product refers to a regulated substance that is present as a non-aqueous phase liquid (e.g., liquid not dissolved in water.)
Gathering lines means any pipeline, equipment, facility, or building used in the transportation of oil or gas during oil or gas production or gathering operations.
Guidelines for the Permanent Closure of Petroleum Underground Storage Tank Systems means the Mississippi Department of Environmental Quality document containing the established procedures for conducting permanent closure of petroleum underground storage tank systems
Hazardous substance UST system means an underground storage tank system that contains a hazardous substance defined in section 101(14) of the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (but not including any substance regulated as a hazardous waste under subtitle C) or any mixture of such substances and petroleum, and which is not a petroleum UST system.
Heating oil means petroleum that is No. 1, No. 2, No. 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.
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.
Interstitial monitoring means a method of monitoring the interstitial space of a secondarily contained UST system for a leak of regulated substances or ingress of external fluids (groundwater or other fluids not intended as monitoring fluids).
Interstitial space means the opening formed between the primary (inner) and secondary (outer) wall of a UST system with double-walled construction or the opening formed between the wall of a containment sump and the UST system component that it contains.
Leak means any spilling, leaking, emitting, discharging, escaping, leaching or disposing from an UST system or resulting from the operation of the UST system. A leak may or may not result in a release to the environment. A leak from a single-walled UST system will normally result in a release to the environment. A leak from the primary containment of a secondarily contained UST system may or may not result in a release to the environment depending upon the integrity of the secondary containment.
Leak detection means determining if a leak of a regulated substance has occurred from the UST system.
Life safety/critical function UST means any one or combination of tanks (including underground pipes connected thereto) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground and is used to maintain operation of critical function equipment for the preservation of human life.
Liquid trap means sumps, well cellars, and other traps used in association with oil and gas production, gathering, and extraction operations (including gas production plants), for the purpose of collecting oil, water, and other liquids. These liquid traps may temporarily collect liquids for subsequent disposition or reinjection into a production or pipeline stream, or may collect and separate liquids from a gas stream.
MDEQ means the Mississippi Department of Environmental Quality.
Maintenance means the normal operational upkeep to prevent an underground storage tank system from leaking or releasing product.
Motor fuel means petroleum, petroleum-based substances, biofuels or any petroleum/biofuel blend that is typically used in the operation of a motor engine. This definition includes all biofuels, including 100% biodiesel or ethanol.
New tank system means a tank system that will be used to contain an accumulation of regulated substances and for which installation has commenced after December 22, 1988. (See also "Existing Tank System.") This term applies to underground tanks, piping, dispensers, and submersible pumps.
(a) Underground tank - A new tank is one that is installed where there previously was no tank. The tank may be one that has never been used before or may be one that has been previously used but recertified by the manufacturer.
(b) Pipe - A new pipe is one that is installed where there previously was no pipe. It may be an entirely new piping run from the tank to the dispensers or it may be a new section of pipe added to an existing pipe. The new piping cannot have been previously used.
(c) Dispensers - A new dispenser is one that is installed where there previously was no dispenser. The dispenser may be one that has never been used before or may be one that has been previously used.
(d) Submersible pump - A new submersible pump is one that is installed where there previously was no submersible pump. The submersible pump may be one that has never been used before or may be one that has been previously used.
Noncommercial purposes with respect to motor fuel means not for resale.
On the premises where stored with respect to heating oil means UST systems located on the same property where the stored heating oil is used.
Operational life refers to the period beginning when installation of the tank system has commenced until the time the tank system is properly closed under Rule 2.7.
Operator means any person in control of, or having responsibility for, the daily operation of the UST system.
Overfill release is a release that occurs when a tank is filled beyond its capacity, resulting in a discharge of the regulated substance to the environment.
Owner means:
(a) In the case of an UST system in use on November 8, 1984, or brought into use after that date, any person who owns an UST system used for storage, use, or dispensing of regulated substances; and
(b) In the case of any UST system in use before November 8, 1984, but no longer in use on that date, any person who owned such UST immediately before the discontinuation of its use.
Person means an individual, trust, firm, joint stock company, federal agency, corporation, state, municipality, commission, political subdivision of a state, or any interstate body. "Person" also includes a consortium, a joint venture, a commercial entity, and the United States Government.
Petroleum UST system means an underground storage tank system that contains petroleum, biofuel, or a mixture of petroleum with de minimis quantities of other regulated substances. Such systems include those containing motor fuels, jet fuels, distillate fuel oils, residual fuel oils, lubricants, petroleum solvents, and used oils.
Pipe or Piping means a hollow cylinder or tubular conduit that is constructed of non-earthen materials that routinely contains and conveys regulated substances from the underground storage tank to the dispenser or other end-use equipment. Such piping includes any elbows, couplings, unions, valves, or other in-line fixtures that routinely contain and convey regulated substances. This definition does not include vent, vapor recovery, fill lines or tank risers.
Pipeline facilities (including gathering lines) are new and existing pipe rights-of-way and any associated equipment, facilities, or buildings.
Register means:
(a) In the case of equipment, to submit written notification to MDEQ on a "State of Mississippi Notification of Underground Storage Tank System" form for any installation, replacement, change in operational status of an underground storage tank, pipe, dispenser or submersible pump; and
(b) In the case of ownership/operation, to submit written notification to MDEQ on a "State of Mississippi Notification of Underground Storage Tank System" form or a "State of Mississippi Underground Storage Tank System Change in Ownership" form when any person becomes the owner/operator of a new or existing underground storage tank system
Regulated substance means:
(a) Any substance defined in section 101(14) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980 (but not including any substance regulated as a hazardous waste under subtitle C);
(b) Petroleum, including crude oil or any fraction thereof that is liquid at standard conditions of temperature and pressure (60 degrees Fahrenheit and 14.7 pounds per square inch absolute); and
(c) Any substance defined as a "motor fuel".
The term "regulated substance" includes but is not limited to petroleum and petroleum-based substances comprised of a complex blend of hydrocarbons derived from crude oil though processes of separation, conversion, upgrading, and finishing, such as motor fuels, jet fuels, distillate fuel oils, residual fuel oils, lubricants, petroleum solvents, and used oils.
Release means a leak from an UST system or resulting from the operation of the UST system that reaches the environment.
Release detection means determining whether a leak of a regulated substance that has occurred from the UST system has reached the environment or a leak has occurred into the interstitial space between the UST system and its secondary barrier or secondary containment around it
Repair means to restore to proper operating condition a tank or UST system component that has caused a leak of product from the UST system or has failed to function properly. As it applies to the integrity of underground storage tanks, piping, and other UST system components, repair means any activity intended to restore a UST system to proper operational condition that does not meet the definition of replace.
Replace - This term applies to underground tanks, piping, dispensers, and submersible pumps. Replaced equipment is considered a new UST system or new UST system components and therefore subject to the same requirements of a new UST system.
(a) Underground tank - Replace means to remove an existing tank and install another tank in its place. The replacement tank may be one that has never been used or one that has been used but recertified by the manufacturer.
(b) Pipe - Replace means to remove an existing pipe and install another pipe in its place. In order to be considered a piping replacement, 50 percent or more of the piping, excluding connectors, needed to transfer the regulated substance from a single tank to the most distant dispenser or end use device must be removed and replaced. Connectors include any flexible connectors, risers or other transitional components such as fittings. The replacement piping must be new from the factory and cannot have been previously used. For tanks with multiple piping runs, this definition applies independently to each piping run.
(c) Dispenser - Replace means to remove an existing dispenser and install another dispenser in its place and the equipment used to connect the dispenser to the piping is also replaced. The equipment necessary to connect the dispensers may include check valves, shear valves, risers, flexible connectors or other transitional components that are beneath the dispenser and connect the dispenser to the piping. The replacement dispensers may be new or may have been used before.
(d) Submersible pump - Replace means to remove an existing submersible pump and install another submersible pump in its place and the equipment used to connect the submersible pump is also replaced. The equipment needed to connect the submersible pump may include ball valves, check valves, flexible connectors unions, tees, ells or other pipe fittings and transitional components that connect the submersible pump to the piping. The replacement submersible pump may be new or may have been used before.
Residential tank is a tank located on property used primarily for dwelling purposes.
SARA means the Superfund Amendments and Reauthorization Act of 1986.
Secondary containment means an impervious layer or barrier (liquid tight) that extends around the primary (inner) tank or pipe that is designed, constructed and installed to contain any leak from any part of the tank or piping that routinely contains regulated substances. Examples of secondarily contained systems include double-walled or jacketed tanks, double-walled or jacketed piping and/or containment sumps that may be installed at the top of the tanks, under dispensers or at piping transitions. Secondary containment must be designed, constructed and installed to:
(a) Prevent the release of regulated substances to the environment for the operational life of the secondary containment system;
(b) Prevent the ingress of water or other external fluids into the interstitial space for the operational life of the secondary containment system;
(c) Allow for monitoring of the interstitial space to detect any leak from the primary tank system and ingress of external fluids;
(d) Be checked for evidence of a leak and ingress of external fluids at least once every 30 days in accordance with § 280.43(g) and § 280.44(c); and
(e) Be compatible with the substances stored and external soil/fluids for the operational life of the secondary containment system.
Septic tank is a water-tight covered receptacle designed to receive or process, through liquid separation or biological digestion, the sewage discharged from a building sewer. The effluent from such 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.
Storm water or wastewater collection system means piping, pumps, conduits, and any other equipment necessary to collect and transport the flow of surface water run-off resulting from precipitation, or domestic, commercial, or industrial wastewater to and from retention areas or any areas where treatment is designated to occur. The collection of storm water and wastewater does not include treatment except where incidental to conveyance.
Submersible pump (also referred to as a "submerged turbine pump") means a device installed within a tank designed to transfer product from the tank to the dispenser in a pressurized piping system. The term submersible pump includes the submersible motor, extractor assembly and the pump head (housing) assembly.
Supplier means any person who delivers or deposits motor fuels into an underground storage tank. This term may include oil companies, jobbers, petroleum transportation companies, or other product delivery entities.
Surface impoundment is a natural topographic depression, man-made excavation, or diked area formed primarily of earthen materials (although it may be lined with man-made materials) that is not an injection well.
Tank is a stationary device designed to contain an accumulation of regulated substances and constructed of non-earthen materials (e.g., concrete, steel, plastic) that provide structural support.
Under-dispenser containment or UDC means containment underneath a dispenser system designed to prevent leaks from the dispenser and piping within or above the UDC from reaching soil or groundwater
Underground area means an underground room, such as a basement, cellar, shaft or vault, providing enough space for physical inspection of the exterior of the tank situated on or above the surface of the floor.
Underground release means any belowground release.
Underground storage tank or UST means any one or combination of tanks (including underground pipes connected thereto) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground. This term does not include any:
(a) Farm or residential tank of 1,100 gallons or less capacity used for storing motor fuel for noncommercial purposes;
(b) Tank used for storing heating oil for consumptive use on the premises where stored;
(c) Septic tank;
(d) Pipeline facility (including gathering lines):
(1) Which is regulated under chapter 61 of Title 49 , or
(2) Which is an intrastate pipeline facility regulated under state laws as provided in chapter 601 of Title 49, and which is determined by the Secretary of Transportation to be connected to a pipeline, or to be operated or intended to be capable of operating at pipeline pressure or as an integral part of a pipeline;
(e) Surface impoundment, pit, pond, or lagoon;
(f) Storm water or wastewater collection system;
(g) Flow-through process tank;
(h) Liquid trap or associated gathering lines directly related to oil or gas production and gathering operations; or
(i) Storage tank situated in an underground area (such as a basement, cellar, mine working, drift, shaft, or tunnel) if the storage tank is situated upon or above the surface of the floor.
The term "underground storage tank" or "UST" does not include any pipes connected to any tank which is described in paragraphs (a) through (i) of this definition.
Upgrade means the addition or retrofit of some systems such as cathodic protection, lining, or spill and overfill controls to improve the ability of an underground storage tank system to prevent the leak of product.
UST compliance manager means any person or persons identified by the owner/operator who has primary responsibility for the proper management, operation and maintenance of the tank system at a UST facility. The UST compliance manager is also responsible for the implementation of all applicable MDEQ requirements necessary to achieve and maintain compliance with the UST system including monitoring, testing, reporting and record keeping. A UST compliance manager can also be known as a Class A/B operator.
UST operations clerk means any person or persons identified by the owner/operator who has primary responsibility for the initial response to any alarms or other indications of emergencies presented by a spill, leak or release from a UST system. The UST operations clerk is typically on-site at the facility and monitors the dispensing of product. A UST operations clerk can also be known as a Class C operator.
UST system or Tank system means an underground storage tank, connected underground piping, underground ancillary equipment, and containment system, if any.
Wastewater treatment tank means a tank that is designed to receive and treat an influent wastewater through physical, chemical, or biological methods.
