Terms and Definitions

Background sample - A sample collected from outside the impacted area nearby, that is representative of the previously unimpacted soil or water conditions.

Benzene, toluene, ethylbenzene, and xylene (BTEX) - A group of volatile organic compounds that are of particular concern in many oilfield releases. Also known as BTEX.

BKG - Background

BLM - Bureau of Land Management

Brine - Another term for saltwater and produced water.

Bromide (Br^-) - The anion of the element bromine. Bromide is present in seawater and is used as a marker of deep well water (produced water) spills.

BTEX - Benzene, Toluene, Ethylbenzene, and Xylenes

Central tank battery - A central tank battery, also known as a CTB, is a centralized location between multiple oil wells that serves as a gathering point of pre-treated oil, gas, and produced water.

C.F.R. (or CFR)- Code of Federal Regulations

Chloride (Cl^-) - The anion of chlorine and a component of the sodium chloride (salt, halite, table salt) found in produced water.

Close/closure - Closure is the North Dakota Department of Environmental Quality's (NDDEQ) determination that no further action is necessary for a remediation of a spill at this time. Closure does not release the responsible party from liability and the site can be reopened at any time if the NDDEQ determines additional remediation is necessary.

Compatible soils - Soils that are similar in composition. The United States Department of Agriculture (USDA) Soil Survey can provide locations for compatible soils. The USDA soil survey information is available on the USDA's Web Soil Survey.

Condensate - Condensate is also known by the terms natural gas condensate, natural gas liquids, or natural gasoline. Condensate is a low-density mixture of hydrocarbon liquids that condense from natural gas.

Competent person - A person who has a thorough understanding of the conditions and regulatory requirements associated with a remediation project.

Constructed well pad - Also known as a well pad, this is an area used by an oil or gas company for the equipment or facilities necessary for the drilling, production, or plugging of an oil or gas related well. A constructed well pad will have an associated North Dakota oil and gas permit. The boundaries of a well pad are determined by a tertiary berm or vegetation growth.

Crude oil - Unrefined liquid petroleum found accumulated in some porous rock formations. Crude oil is extracted and refined for burning as fuel or processing into various chemical products.

Delineation - Delineation is the practice of defining the area impacted by a spill. Defining impacts requires determining both the horizontal and vertical boundaries of the contaminant. Delineation must also document the contaminant concentrations of the impacted media.

Diesel range organics (DRO) - Also known as DRO, diesel range organics include hydrocarbons in the 10 to 28 carbon range. Diesel range organics are flammable and produce a lot of energy when burned. They are used in a variety of household oils and fuels. Bakken crude oil is most closely associated with this range.

DMR - Department of Mineral Resources

Downgradient - The direction down a gradient from a starting position. In most cases, this means downhill, downstream, or the direction that groundwater flows towards.

DRO - Diesel Range Organics

EA - Enforcement Action

EC - Electrical Conductivity

Ecosystem - A community of living organisms in conjunction with the nonliving components of their environment. This includes all terrestrial and non-terrestrial life.

EK - Electrical Conductivity

Electrical conductivity (EC) - Also known as conductivity or EC, electrical conductivity is the measure of a solution's ability to conduct electricity. Elevated salts can increase the electrical conductivity of soil or water.

Electrokinetic system - Also known as an EK system. Electrokinetic systems are an advanced recovery method that uses electricity to remediate oils and groundwater by removing organic, inorganic, and heavy metal particles.

Elecromagnetic survey - Also known as an EM survey, an electromagnetic survey is a diagnostic tool used for the delineation of produced water or other saline solution releases.

EM - Electromagnetic

Emulsion - A mixture of gas, oil, and produced water existing before the separation process.

Enforcement action - A formal proceeding initiated by the NDDEQ to correct a violation of law or regulation. An enforcement action is typically initiated with the issuing of a letter of apparent noncompliance or notice of violation.

EPA - Environmental Protection Agency

E&P - Exploration and Production

Facility - Refers to any location or structure that can be the source or recipient of a release. This includes all permanent and mobile sources.

Flow-back water - Water recovered during the hydraulic fracturing process.

Flowline - A pipeline that caries emulsion produced from an oil well to a central tank battery to be separated into crude oil, produced water, and gas.

Formation water - Naturally occurring subterranean water. Formation water can have elevated total dissolved solids (TDS) which lead to elevated salt concentrations and may be considered saltwater.

Freshwater - Naturally occurring water that is not salty and is suitable for consumption if clean or processed. Freshwater has a TDS of less than 3000 mg/L.

Gasoline range organics (GRO) - Hydrocarbons in the 6 to 12 carbon range. Gasoline range organics evaporate easily and are very flammable. They are typically found in solvents or gasoline fuel. GROs can also contain benzene, toluene, ethylbenzene, and xylene.

GPS - Global Positioning System

Grab sampling - Also known as spot sampling. A soil sampling technique in which soil is collected from a single location on a site for laboratory testing. This sampling technique provides data only for the exact location of the sample collected.

GRO - Gasoline Range Organics

Groundwater - The water present beneath the Earth's surface in soil pore spaces and in the fractures of rock formations. Groundwater is considered waters of the state.

H - The H at the end of a well name stands for horizontal. Most newer wells drilled in North Dakota are horizontal wells that have undergone the hydraulic fracturing process.

Hydric soils - Soils that are permanently or seasonally saturated with water. Due to the limited oxygen levels, hydric soils have different biological and chemical properties than other soils.

In situ - Remediation in place.

Landform - A natural feature of the Earth's surface.

Landscape position - The landforms in and around an impact area that are likely to have similar soil series, i.e. drainage bottoms, slopes, hilltops.

Leachate - Water that has percolated through a solid and leached out some of the constituents.

Letter of apparent noncompliance (LOAN) - A formal letter notifying a responsible party of an apparent violation of law or regulatory requirements.

LNG - Liquefied Natural Gas

LOAN - Letter of Apparent Noncompliance

LPG - Liquefied Petroleum Gas

MCL - Maximum Contaminant Level

MDL - Method Detection Limit

mg/kg - Pronounced "milligram per kilogram", mg/kg is unit of measure used to express the concentration of a substance in a mass of material (typically soil).

mg/L - Pronounced "milligram per liter", mg/L is a measure used to express the concentration of a substance in water.

Must - Failure to complete this task may result in enforcement action.

N.D.A.C. - North Dakota Administrative Code

N.D.C.C. - North Dakota Century Code

NDDEQ - North Dakota Department of Environmental Quality

NDDEQ certified laboratory - Analytical laboratories that have been certified by the NDDEQ Division of Chemistry to perform environmental chemical analyses. Information about the North Dakota Environmental Laboratory Certification Program (NDELCP) can be found by contacting the Division of Chemistry.

NDDMR - North Dakota Department of Mineral Resources

NDDTL - North Dakota Department of Trust Lands

NDDWR - North Dakota Department of Water Resources

NDELCP - North Dakota Environmental Laboratory Certification Program

NDIC - North Dakota Industrial Commission

NDRBCA - North Dakota Risk Based Corrective Action

NDWQS - North Dakota Water Quality Standards

NFA - No Further Action

NGL - Natural gasses, liquefied

No further action (NFA) - A notation or letter sent to the responsible party indicating no additional or further remedial actions need to take place for the incident at the time the letter can be received. A no further action letter can become invalid at any time if the NDDEQ determines additional remediation work is needed on the site.

Notice of violation (NOV) - A formal civil action taken by the NDDEQ against a responsible party for a breach of law or regulation. An NOV requires a response and/or corrective action.

NOV - Notice of Violation

NRCS - Natural Resource Conservation Service

Oil range organics (ORO) - Hydrocarbons in the 20 to 35 carbon atom range. Oil range organics are harder to ignite and typically used in lubricants, greases, and motor oils.

Open records request (ORR) - An open records request is a request to officially receive documents, communication and/or photos that the NDDEQ has taken or received. More information on open records requests can be found at the DEQ Open Records Request Page.

ORO - Oil Range Organics

ORR - Open Records Request

PID - Photoionization Detector

Primary containment - The tank, tanker truck, or other primary container that is holding a liquid.

Produced water - A type of saltwater recovered as a byproduct of oil and gas extraction operations. Produced water is considered a waste byproduct and also known by the terms brine, wastewater, formation water, or PW.

Promulgated - Put into effect by law.

RCRA - Resource Conservation and Recovery Act

Receptor - Any area where a contaminant may collect. Receptors may include, but are not limited to, groundwater, surface water, wells, utility corridors, and basements.

Reclamation - The act of reclaiming or restoring land that has been altered in some manner.

Remediation - Reversing or stopping environmental damage. This can be accomplished by altering a contaminant or moving it to a non-sensitive area.

Responsible party (RP) - The individual or party responsible for the remediation of a release.

Resource Conservation and Recovery Act (RCRA) - The primary federal law governing the disposal and management of solid and hazardous wastes.

Root zone - The zone of the soil profile penetrated by plant roots.

RP - Responsible Party

Salt - A general term most often used for sodium chloride.

Saltwater - Any water containing sodium chloride greater than NDDEQ action levels.

Saltwater disposal well (SWD) - Also known as an SWD, saltwater disposal wells are designed to dispose of produced water into an underground formation.

SAR - Sodium Adsorption Ratio

SDS - Safety Data Sheet

Secondary containment - Secondary containment is berms or other vertical walls around tanks that are designed to mitigate the spreading of any materials released from primary containment.

SEP - Supplemental Environmental Project

Should - Not required by law but will be considered during any enforcement action.

SHPO - State Historic Preservation Office

Sodium adsorption ratio (SAR) - Also known as SAR. A ratio of sodium to calcium and magnesium. This laboratory analysis is used to determine the sodicity level present in soil.

Soil series - Soil series is classification system of soils that are similar in color, texture, structure, chemistry, and other characteristics. Often, but not always, similar landscape positions nearby will be of the same soil series. The USDA soil survey information is available on the USDA's Web Soil Survey.

Source water - Source water is water from an aquifer used in the advanced recovery of crude oil from an oil producing formation. Source water is typically pumped from a formation that is too high in TDS to be considered freshwater, such as the Lodgepole or Dakota formations.

Supplemental environmental project (SEP) - An environmentally beneficial project that is not otherwise legally required by the NDDEQ but may be completed as part of the settlement of an enforcement action.

TDS - Total Dissolved Solids

Technologically enhanced naturally occurring radioactive material (TENORM) - TENORM is material that naturally contain radioactive elements, but those elements have been concentrated due to industrial or technological processes. TENORM containing materials in the oil and gas industry include used filter socks, pipe or equipment scale, tank sludge, and contaminated soils.

TENORM - Technologically Enhanced Naturally Occurring Radioactive Material

Tertiary containment - The third layer of protection in a spill containment system, designed to contain spills that escape both primary and secondary containment. In the oil and gas industry, tertiary containment is used to describe a berm or shallow ditch around the outside of well pads.

Total dissolved solids (TDS) - Also known as TDS, total dissolved solids is a measure of all dissolved substances in a liquid. Dissolved substances may includes minerals, salts, metals, and small organic compounds.

Total petroleum hydrocarbons (TPH) - Total petroleum hydrocarbons is a mixture of hydrocarbons derived from crude oil. In laboratory analysis, total petroleum hydrocarbon tests typically cover the gasoline range organic, diesel range organic, and oil range organic ranges.

TPH - Total Petroleum Hydrocarbons

USDA - United States Department of Agriculture

USFS - United States Forest Services

UST - Underground Storage Tank

Volatile organic compound (VOC) - An organic chemical that easily evaporates into air at room temperature. VOCs contribute to poor air quality and include, but are not limited to, benzene, toluene, ethylbenzene, and xylenes (BTEX).

Waters of the state - All waters within the jurisdiction of this state, including all streams, lakes, ponds, impounding reservoirs, marshes, watercourses, waterways, and other bodies or accumulations of water on or under the surface of the earth, natural or artificial, public or private, situated wholly or partly within or bordering upon the state, except those private waters that do not combine or effect a junction with natural surface or underground waters just defined. N.D.C.C. § 61-28-02(15).