Privacy Statement

ARTICLE 1 GENERAL PROVISIONS

1-1 Statement of Basis and Purpose

1-2 Technical Rationale

1-3 Statutory Authority

1-4 Effective Date

1-5 Definitions

1-1 Statement of Basis and Purpose.

These regulations are promulgated to establish rules for the design, installation, registration, construction, and operation of storage tanks used to store regulated substances, including petroleum, other than material classified as hazardous wastes under Subtitle C of the U.S. Solid Waste Disposal Act and to describe the financial responsibility of petroleum storage tank owners/operators.

The main purpose of these regulations is to reduce damage to the environment, risk to the public caused by leaking petroleum storage tanks, and to mitigate such damage effectively when it occurs.

The 1999 amendments to these regulations incorporate an adaptation of the American Society of Testing and Materials Standard E 1739-95 into the requirements of Article 5 of these regulations. These amendments are intended to facilitate the incorporation of risk-based contaminant screening levels into the process of investigating and remediating petroleum releases.

1-2 Technical Rationale.

The technical requirements of these regulations are supported by many studies made by petroleum industry associations, the National Fire Protection Association, the American Society of Testing and Materials, and by studies made by or at the behest of the U.S. Environmental Protection Agency. They represent the consensus of opinion of informed persons, as to the best methods for reducing hazards, posed by storage tanks, to acceptable levels.

1-3 Statutory Authority.

The amendments to these regulations have been created pursuant to Title 8 Article 20.5 Sections (202) and (302) of the Colorado Revised Statutes.

1-4 Effective Date.

These amended rules shall be effective on February 1, 1999. The prior edition of the combined UST/AST regulations was published January 1, 1997. Prior editions of the UST rules were published effective September 30, 1995 and December 1, 1989. Prior editions of the AST rules were published effective September 30, 1995 and October 1, 1994. A prior edition of the Emission Inspection rules was published effective January 1, 1990.

1-5 Definitions.

Terms in these regulations shall have the same definitions as those found in Articles 20 and 20.5 of Title 8 of the Colorado Revised Statutes. In addition, unless the context otherwise requires:

(1) "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 aboveground releases associated with overfills and transfer operations as the regulated substance moves to or from an UST system.

(2) "Ancillary equipment" means any devices including, but not limited to, such devices as piping, fittings, flanges, valves, and pumps used to distribute, meter, or control the flow of regulated substances to and from an UST.

(3) "AST" means an aboveground storage tank which is not permanently closed.

(4) "AST system" means all ASTs at a facility, all the connected piping and ancillary equipment, all loading facilities, and all containment systems if applicable.

(5) "Atmospheric Tank" is a storage tank that has been designed to operate at pressures from atmospheric through 0.5 psig (760 mm Hg through 780 mm Hg) measured at the top of the tank.

(6) "Attenuation" is the reduction in concentrations of chemical(s) of concern in the environment with distance or time due to processes such as diffusion, dispersion, adsorption, chemical degradation, biodegradation, and other similar chemical, biological, or physical processes.

(7) "Belowground release" means any release to the subsurface of the land and/or to groundwater. This includes, but is not limited to, releases from the belowground portions of an AST or UST system and belowground releases associated with overfills and transfer operations as the regulated substance moves to or from an AST or UST system.

(8) "Beneath the surface of the ground" means beneath the ground surface or otherwise covered with earthen materials.

(9) "Bulk Plant" is that portion of a property where liquids are received by tank vessel, pipelines, tank car, or tank vehicle and are stored or blended in bulk for the purpose of distributing such liquids by tank vessel, pipeline, tank car, tank vehicle, portable tank or container. [Note: A bulk plant is normally a wholesale fuel facility where petroleum products are stored prior to resale or redistribution.]

(10) "Capillary fringe" is the zone immediately above the water table, where water is drawn upward by capillary attraction.

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

(12) "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 UST and AST 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 UST and AST systems.

(13) "CERCLA" means the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended.

(14) "Certificate of Eligibility" is a document that entitles the bearer to participate in the Fund without further determination of compliance by the State Inspector of Oils, if that bearer is a mortgagee who has acquired, by foreclosure or receipt of a deed in lieu of foreclosure, property on which the petroleum storage tanks covered by the certificate are located.

(15) "Chemicals of concern" (COCs) are chemical compounds that have been identified for evaluation due to specific risks to human health and/or the environment.

(16) "Committee" means the Petroleum Storage Tank Committee created in C.R.S. ' 8-20.5-104.

(17) "Compatible" means the ability of two or more substances to maintain their respective physical and chemical properties upon contact with one another for the design life of the tank system under conditions likely to be encountered.

(18) "Connected piping" means all 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 AST or UST system, the piping that joins two systems should be allocated equally between them.

(19) "Corrective action " is the sequence of actions that include any or all of the following: interim remedial action, remediation, operation and maintenance, monitoring of progress, and termination of remedial action.

(20) "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.

(21) "Crossgradient" is in the direction of equal static head.

(22) "Dielectric material" means a material that does not conduct direct electrical current. Dielectric coatings are used to electrically isolate systems from the surrounding soils. Dielectric bushings are used to electrically isolate portions of the system (e.g., tank from piping).

(23) "Downgradient" is in the direction of maximum decreasing static head.

(24) "Effective porosity" is the volume fraction of the soil (or rock) that is available to transport water. The effective porosity does not include isolated pore spaces.

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

(26) "Electrolyte" means the soil or liquid adjacent to and in contact with the systems, including the moisture and other chemicals contained in it; the electrically conductive material between the tank and its environment;

(27) "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.

(28) "Existing tank" means an UST system used to contain an accumulation of regulated substances or for which installation commenced before December 22, 1988. Installation is considered to have commenced if:

(a) the owner/operator has obtained all federal, state, and local approvals or permits necessary to begin physical construction of the site or installation of the UST system; and if,

(b)(1) either a continuous on-site physical construction or installation program has begun; or,

(2) the owner/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 UST system to be completed within a reasonable time.

(29) "Exposure pathway" is the course that a chemical of concern takes from a source area to a point of exposure. An exposure pathway describes a unique mechanism by which a person or sensitive environment is assumed to be exposed to a chemical of concern. Each exposure pathway includes a source, an exposure route, and a point of exposure. If the exposure point differs from the source, transport or exposure media (e.g., air, water, dust) are also included. All exposure pathways are assumed to be complete unless an exposure pathway elimination criteria is demonstrated. Exposure pathway elimination criteria are listed in the Owner/Operator Guidance Document.

(30) "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.

(31) "Fire resistant tank" is a single or double walled AST with a U.L. 2085 listing (or with an equivalent listing from a nationally recognized independent laboratory) that has been designed and constructed to provide fire resistive protection from exposure to a high intensity liquid pool fire. The construction shall prevent release of liquid, failure of the primary tank, failure of the supporting structure, and impairment of venting for a period of not less than two hours when tested using the fire exposure environment described in U.L. 2085 or an equivalent testing procedure for ASTs. An AST can meet the above requirements by adding a coating, if such exists, which would cause the AST to receive a listing as mentioned above. The owner/operator must provide evidence of such listing and proper application of the coating.

(32) "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.

(33) "Fraction of organic carbon " is the fraction by weight of total naturally occurring organic carbon in a soil sample.

(34) "Free product" refers to a regulated substance that is present as a nonaqueous phase liquid (e.g., liquid not dissolved in water.)

(35) "Fund" means the Petroleum Storage Tank Fund created in C.R.S. ' 8-20.5-103.

(36) "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.

(37) "Good Engineering Practice", "Good Engineering Standards", and "Nationally Recognized Standard" means in accordance with standards developed by nationally recognized laboratories or associations such as: Underwriters Laboratory (U.L.), American National Standards Institute (ANSI), American Petroleum Institute (API), American Society for Testing and Materials (ASTM), American Society of Mechanical Engineers (ASME), Steel Tank Institute (STI), National Association of Corrosion Engineers (NACE), or the National Fire Protection Association (NFPA).

(38) "Gradient" is the slope of the water table in the direction of groundwater flow. This slope is typically expressed as a unit change in water table elevation per unit horizontal distance (e.g. ft/ft).

(39) "Hazardous substance UST system" means an UST 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.

(40) "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.

(41) "Hydraulic conductivity" is the coefficient of proportionality describing the rate at which water can move through a permeable medium.

(42) "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.

(43) "Industrial property" is property currently zoned industrial by the local zoning authority.

(44) "Infiltration rate " is the volume of water traveling through the unsaturated zone and reaching groundwater per unit time.

(45) "Lens", as referred to in the Tier 2 model, is a horizontal unit of soil which can be assigned different soil properties (e.g. hydraulic conductivity and moisture content), and which is located between a petroleum vapor source and the ground surface or a building. The lens is typically used to estimate volatile chemical diffusion rates when there are units with variable moisture content above a vapor source.

(46) "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.

(47) "Marine Service Station" is that portion of a property where liquids used as fuels are stored and dispensed from fixed equipment on shore, piers, wharves, or floating docks into the fuel tanks of self-propelled craft, including all facilities used in connection therewith.

(48) "Media" are intervening substances through which something is transmitted or carried (e.g. soil, water, or air).

(49) "Mortgagee" refers to a mortgagee or the holder of an evidence of debt secured by a mortgage or deed of trust.

(50) "Motor fuel" means petroleum or a petroleum-based substance that is motor gasoline, aviation gasoline, No. 1 or No. 2 diesel fuel, or any grade of gasohol, and is typically used in the operation of a motor engine.

(51) "New UST" means an UST system that will be used to contain an accumulation of regulated substances and for which installation commenced on or after December 22, 1988 (see also "Existing Tank.")

(52) "Noncommercial purposes" with respect to motor fuel at farms and residences means not for resale.

(53) "Operational life" refers to the period beginning when installation of the tank system has commenced until the time the tank system is properly closed.

(54) "Out of Service" means that the tank is not being operated in accordance with its intended purpose.

(55) "Overfill" is a release that occurs when a tank is filled beyond its capacity, resulting in a discharge of the regulated substance to the environment.

(56) "Owner(s)/operator(s)" means that the task to which this phrase is attached may be performed by either the owner or the operator. If neither the owner nor the operator performs the task, both shall be in violation of these regulations. Duplication of the task is not required. This definition applies to all persons who meet the statutory definition of "owner" or "operator" other than orphaned or abandoned tank owners.

(57) "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.

(58) "Petroleum AST system" means an AST system that contains petroleum or a mixture of petroleum with de minimis quantities of other substances. Such systems include those containing motor fuels, jet fuels, distillate fuel oils, residual fuel oils, lubricants, and used oils.

(59) "Petroleum UST system" means an UST system that contains petroleum 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.

(60) "Pipe" or "Piping" means a hollow cylinder or tubular conduit that is constructed of non-earthen materials and in accordance with NFPA or other nationally recognized piping standards for petroleum storage tanks.

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

(62) "Point of compliance" (POC) is a point or location some specified distance hydraulically downgradient of the activity being monitored for compliance.

(63) "Point of exposure "(POE) is the location at which a person or sensitive environment is assumed to be exposed to a chemical of concern. POEs are: property boundaries, surficial soils, subsurface utilities, structures, groundwater wells, surface water, and sensitive environments.

(64) "Process or Processing" is an integrated sequence of operations. The sequence may be inclusive of both physical and chemical operations and may involve, but is not limited to, preparation, separation, purification, or change in state, energy content, or composition.

(65) "Reimbursement" means an assignment of money from the Fund to reimburse a person for approved costs incurred in remediating petroleum contamination.

(66) "Regulated substance" for UST systems has the same meaning as in C.R.S. ' 8-20.5-101(13). ARegulated substance@ for AST systems means regulated petroleum products.

(67) "Release detection" means determining whether a release of a regulated substance has occurred from the UST or AST system into the environment or into the interstitial space between the UST or AST system and its secondary barrier or secondary containment around it.

(68) "Remediation" means actions taken to reduce concentrations of chemicals of concern (including natural attenuation), or prevent migration of chemicals of concern to POEs. Remediation shall be implemented for sites where no further action is not appropriate.

(69) "Repair" means to restore a tank or system component that has caused a release of product from the UST or AST system.

(70) "Residential property" is property currently zoned residential by the local zoning authority.

(71) "Residential tank" is a tank located on property used primarily for dwelling purposes.

(72) "Residual water content" is the fraction of water remaining in soil after gravity drainage.

(73) "Risk-based screening level(s)"(RBSLs) are the risk-based corrective action target levels for chemical(s) of concern developed using the equations in ASTM E 1739 and the Domenico model.

(74) "Saturated zone"is the subsurface zone which occurs below the water table. The soil pores are filled with water, and the moisture content equals the porosity.

(75) "Secondary Containment" is containment which prevents any release from an AST system from reaching land or waters outside of the containment area.

(76) "Secondary Containment Tank" is a shop fabricated AST which includes a steel or reinforced concrete secondary shell that will provide containment of the entire capacity of the inner tank in case of leaks or ruptures of the inner tank and having means for monitoring the interstitial space for a leak.

(77) "Sensitive Environment" is an area of particular environmental value where regulated petroleum contamination could pose a greater threat than in other less sensitive areas. Sensitive environments include: critical habitat for federally endangered or threatened species, national parks, national monuments, national recreation areas, national wildlife refuges; national forests, campgrounds; recreational areas, game management areas, wildlife management areas, designated federal wilderness areas, wetlands, wild and scenic rivers, state parks, state wildlife refuges, habitat designated for state endangered species, fishery resources, state designated natural areas, wellhead protection areas, classified groundwater areas, and county or municipal parks.

(78) "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 where 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.

(79) "Service Station" is a place where motor fuels are sold to the general public for cash or credit and are dispensed into the fuel tanks of motor vehicles or approved containers. This does not include unattended cardlock system facilities at bulk plants which only use proprietary cards specific to the cardlock system in question.

(80) "Site classification" is a qualitative evaluation of a site based on known or readily available information to identify the need for interim remedial actions and further information gathering.

(81) "Site-specific target level(s)" (SSTLs) are the risked-based remedial action target levels for chemical(s) of concern developed for a particular site under the Tier 2 evaluation.

(82) "Soil bulk density" is the dry weight of soil per unit volume.

(83) "Source concentration" is the highest concentration, in soil and/or groundwater and /or vapor, of the chemicals of concern.

(84) "State Inspector of Oils" means the State Inspector of Oils of the Colorado Department of Labor and Employment or any designees thereof which may include certain employees of the Oil Inspection Section of the Colorado Department of Labor and Employment or other persons.

(85) "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.

(86) "Subsurface soils" are all soils located at a depth of greater than one meter below the ground surface.

(87) "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.

(88) "Surficial soils" are all soils located from the ground surface to a depth of one meter below ground surface.

(89) "Temporary closure" means the time between when a tank is out of service and is permanently closed.

(90) "Tier 1 evaluation" is a risked-based analysis which includes a comparison of the highest levels of contamination remaining on the site with the Tier 1 RBSLs. Each completed exposure pathway must be evaluated. The completed exposure pathway with the lowest RBSLs for a given media will determine the cleanup goals for the site.

(91) "Tier 1A evaluation" is a risked-based analysis to develop site-specific risk-based screening levels (SS-RBSLs) for complete exposure pathways utilizing the Tier 1 models and incorporating data collected from the site. The completed exposure pathway with the lowest SS-RBSLs will determine the cleanup goals for a given media at the site.

(92) "Tier 2 evaluation" is a risk-based analysis to develop site-specific target levels (SSTLs) for complete exposure pathways utilizing saturated and unsaturated zone models such as API DSS VADSAT or BP RISC. Acceptable models for the unsaturated zone will be analytical, transient, capable of modeling one-dimensional dispersion and degradation, and calculating effective solubility for individual constituents in a mixture. Acceptable models for the saturated zone will be analytical or semi-analytical, transient, and simulate retardation, degradation, one-dimensional flow and three-dimensional dispersion. The Tier 2 evaluation incorporates data collected from the site. The completed exposure pathway with the lowest SSTLs for a given media will determine the cleanup goals for the site.

(93) "Total porosity" is the volume of pore spaces divided by the total volume of soil.

(94) "Unattended Cardlock System" is a vehicle fueling facility which uses a mechanical or electronic method of tracking fuel deliveries using an identification card.

(95) "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.

(96) "Unsaturated zone" is a subsurface zone which occurs above the water table. The soil pores are only partially filled with water, and the moisture content is less than the porosity.

(97) "Upgrade" means the addition or retrofit of some systems (such as cathodic protection, lining, modification of the system piping, or spill and overfill controls, etc.) to improve the ability of an UST or AST system to prevent the release of product.

(98) "UST" means an underground storage tank which is not permanently closed.

(99) "UST system" means an UST, connected underground piping, underground ancillary equipment, and containment system, if any.

(100) "Van Genuchten=s N" is a parameter, used in the Tier 2 models, to estimate long-term average moisture content in the unsaturated zone.

(101) "Vault" means an enclosure (other than a secondary containment tank), either above or below-grade, that completely encloses an AST.

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