SPCC Glossary of Terms

The following is a glossary of terms commonly used in SPCC Plans and FRPs. For general information and requirements on SPCC Plans go to our SPCC HOME PAGE.

Aboveground storage tank: any tank or other container that is aboveground, partially buried, bunkered, or in a subterranean vault. This includes floating fuel systems.

Barrel: 42 U.S. gallons at 60 degrees Fahrenheit.

Belowground storage unit: a tank or other container located completely below the natural grade of the earth.

Berms: either dirt, concrete or other constructed embankments that are commonly employed for secondary containment or drainage diversion purposes at oil storage or related operations.

Boom: a temporary floating barrier used to contain an oil spill.

Bulk storage tank: any container used to store oil. These tanks are used for purposes including, but not limited to, the storage of oil prior to use, while being used, or prior to further distribution in commerce.

Bunkered tank: a storage tank constructed or placed in the ground by cutting the earth and re-covering it such that the tank breaks the natural grade of the land, or an abovegrade tank covered with earth. A bunkered tank is considered to be an AST and must have secondary containment.

Catch basin: a depression, trench, or pit, which is a collection point for drainage, either water or spilled oil, that provides a means of containment for and prevents the uncontrolled discharge of the collected liquid from a facility or oil storage area.

Cathodic protection: any one of several methods for protecting underground tanks and pipelines from corrosion. Corrosion results from an electric current which is caused by contact between metal surfaces, water, and the chemicals present in soils and water; cathodic protection counteracts this current.

Dike: an embankment or wall that contains drainage water or spilled oil inside the walled area.

Discharge: any emission (other than natural seepage), intentional or unintentional, and includes, but is not limited to, spilling, leaking, pumping, pouring, emitting, emptying or dumping. For purposes of this part, the term “discharge” shall not include any discharge of oil which is authorized by a permit issued pursuant to Section 13 of the River and Harbor Act of 1899 (30 Stat. 1121, 33 U.S.C. 407), or Sections 402 or 405 of the FWPCA Amendments of 1972 (86 Stat. 816 et seq., 33 U.S.C. 1251 et seq.).

Emulsification: the formation of a mixture of two liquids, such as oil and water, in which one of the liquids is in the form of fine droplets and is dispersed in the other.

Evaporation: the physical change by which any substance is converted from a liquid to a vapor or gas.

Facility: any mobile or fixed onshore or offshore building, structure, installation, equipment, pipe, or pipeline used in oil well drilling operations, oil production, oil refining, oil storage, and waste treatment. The boundaries of a facility may depend on several site-specific factors, including, but not limited to, the ownership or operation of buildings, structures, and equipment on the same site and the types of activities at the site.

Facility Response Plan: a detailed plan which must be prepared in accordance with 40 CFR 112.20 by facilities which may cause “substantial harm” to the environment or exclusive economic zone. The plan must contain an emergency response action plan (ERAP) and demonstrate that a facility has the resources to respond to a worst case scenario discharge.

Hydrocarbons: a large class of organic compounds containing only carbon and hydrogen, common in petroleum products.

Impervious: incapable of being penetrated. Secondary containment structures must be sufficiently impervious to the types of products stored within the area of containment.

Incineration: the destruction of wastes by burning at high temperatures.

Inland waters of the United States: those waters of the United States lying inside the baseline from which the territorial sea is measured and those waters outside such baseline which are a part of the Gulf Intracoastal Waterway.

Level gauging systems and alarms: any engineering control that indicates the level of liquid inside the tank and that is installed on tanks to prevent overfilling and spilling of liquid and damage to the tank(s).

Mobile or portable storage tank: any container used to store oil and that is capable of being easily moved. For example, a 55-gallon drum or a 3000-gallon tank on wheels would both be considered mobile storage. These storage containers require secondary containment, which must be addressed in the facility’s SPCC Plan.

Mousse: a thick, foamy oil and water mixture formed when petroleum products are subjected to mixing with water by the action of waves and wind.

Natural resources: land, fish, wildlife, biota, air, water, groundwater, drinking water supplies, and other such resources (including the resources of the exclusive economic zone) belonging to, managed by, held in trust by, appertaining to, or otherwise controlled by, the United States, any state or local government or Indian tribe, or any foreign government.

Navigable waters: the waters of the United States including the territorial seas. This covers:

All waters that are currently used, were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters subject to the ebb and flow of the tide.

All interstate waters, including interstate wetlands.

All other waters such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds, the use, degradation, or destruction of which could affect interstate or foreign commerce including any waters that could be used for recreational purposes, or from which fish or shellfish could be taken and sold in interstate or foreign commerce; or that are used or could be used for industrial purposes by industries in interstate commerce.

All impoundments of waters otherwise defined as waters of the United States under this section.

Tributaries of waters identified above and wetlands adjacent to waters identified above (other than waters that are themselves wetlands).

Waste treatment systems, including treatment ponds or lagoons designed to meet the requirements of the CWA (other than cooling ponds as defined in 40 CFR 123.11(m), which also meet the criteria of this definition) are not waters of the United States.

Offshore facility: any facility located in, on, or under any of the navigable waters of the United States, which is not a transportation-related facility.

Offshore oil drilling, production, or workover facilities: may include all drilling or workover equipment, wells, flowlines, gathering lines, platforms, and auxiliary non-transportation-related equipment and facilities in a single geographical oil or gas field operated by a single operator.

Oil: defined under several statutes including the Clean Water Act (CWA) and the Oil Pollution Act of 1990 (OPA). As a result, overlapping regulatory interpretations exist. For this reason, the U.S. EPA and the U.S. Coast Guard are currently developing a nationally consistent program policy and methodology for facilities to determine whether a given substance is considered an oil under the existing CWA.Under the CWA, the definition of oil includes oil of any kind and any form, such as petroleum and nonpetroleum oils. Generally, oils fall into the following categories: crude oil and refined petroleum products, edible animal and vegetable oil, other oils of animal or vegetable origin, and other nonpetroleum oils.

Many substances are easily recognizable as oils (e.g., gasoline, diesel, jet fuel, kerosene, and crude oil). Under the CWA definition, many other substances are considered oils that may not be easily recognizable by industry, including mineral oil, the oils of vegetable and animal origin and other nonpetroleum oils. Therefore, facilities should work closely with the EPA and USCG (if applicable) to make determinations for the substances they store, transfer, and refine.

Oil Removal Contingency Plan: when it is determined that the installation of diversionary structures and equipment listed in 40 CFR Part 112.7.

Specific gravity: the ratio of the density of a substance to the density of water.

Spill event: a discharge of oil into or upon the navigable waters of the United States or adjoining shorelines in harmful quantities, such that applicable water quality standards are violated or that causes a film or sheen upon the water.

Spill history: if a facility has experienced one or more spill events, the SPCC Plan must include a written description of each such spill, corrective actions taken, and plans for preventing its recurrence.

Storage capacity: the volume of a tank or container, for purposes of determining the applicability of 40 CFR Part 112, means the total capacity of the tank or container, whether the tank or container is filled with oil, or a mixture of oil and other substances, or is empty and not permanently closed.

Sump: a depression or trench constructed to collect drainage of water or spilled oil from storage, transfer or unloading areas.

Tank appurtenances: in addition to the tank itself, the additional pieces of equipment necessary to bring the tank into service. Examples of tank appurtenances include, but are not limited to:

  • Ladder and gaugers platform.
  • Shell manholes.
  • Inlet – outlet connections.
  • Drawoffs (condensate, water and product).
  • Gauge hatch.
  • Vent connections.
  • Liquid gauges and alarms.

Tar balls: dense, black, sticky spheres of hydrocarbons formed from weathered oil.

Transportation-related: interstate and intrastate onshore and offshore pipeline systems, including pumps and related appurtenances, and in-line or breakout storage tanks needed for the continuous operation of a pipeline system.

Underground storage tank: a tank that is completely covered with soil, situated below the natural grade of the land.

United States: the States, the District of Columbia, the Commonwealth of Puerto Rico, the Canal Zone, Guam, American Samoa, the Virgin Islands, and the Trust Territory of the Pacific Islands.

Valve: a movable mechanism that opens and closes to control the flow of liquid through a pipe or other passageway. Examples of valves include check, ball, and gate.

Vessel: every description of watercraft or other artificial contrivance used, or capable of being used, as a means of transportation on water, other than a public vessel.

Viscosity: the internal properties of a liquid that offer resistance to flow. Substances that are extremely viscous do not flow readily.

Weathering: action of the elements on a substance, such as oil, that leads to disintegration or deterioration of the substance.

Wetlands: those areas that are inundated or saturated by surface or ground water at a frequency or duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include playa lakes, swamps, marshes, bogs, prairie potholes, wet meadows, prairie river overflows, mudflats, and natural ponds.

Workover: any of several remedial operations performed on a producing well in an attempt to restore or increase production. Sand or liner removal, casing repair, acidizing, fracture stimulation, cementing, deeper drilling, recompletion to a different producing zone or stratum, and sidetracking are some examples of workover operations.