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glossary of terms


The Energy Glossary: Useful Natural Gas Terms

Get to know key natural gas terms that apply to the energy industry, and save some personal energy by referencing definitions right here:

A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    R    S    T    U    V    W   



Advisory Council on Historic Preservation.


Another person that controls, is controlled by or is under common control with, such person. An affiliate includes a division that operates as a functional unit.


A legal representative of buyers, sellers or shippers of natural gas in negotiation or operations of contractual agreements.


Asset Management Agreement


American Petroleum Institutes

Approved Bidders

Prearranged replacement shippers.

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Earth or other material that has been used to refill a ditch or trench. Also, the act of refilling a ditch or trench.


The technique for covering a completed pipeline so that adequate fill material is provided underneath the pipe as well as above it.


A “paper transport” of natural gas by displacement against the flow on a single pipeline, so that the natural gas is redelivered upstream of its point of receipt. *


Best Available Control Technology

Base Load

The minimum amount of electric power or natural gas delivered or required over a given period of time at a steady rate. The minimum continuous load or demand in a power system over a given period of time usually not temperature sensitive. *


Blanket Capacity Replacement


Methane produced by the decomposition or processing of organic matter.

Blanket Certificate

General authorization granted by the FERC under NGA section 7 (c) for the recipient to engage in a FERC jurisdictional activity, such as transportation or sales of natural gas, on behalf of a general class of potential customers, without individual case-by-case review and approval. *

Blasting Mats

Coverings used to contain the debris and rock caused by the use of explosives during excavation.

Blow Down

The process of reducing gas pressures by means of releasing such pressures to atmosphere.


To penetrate or pierce with a rotary tool. A technique to cross roads, water courses ,or other utilities.

British Thermal Unit (BTU)

The amount of heat energy necessary to raise the temperature of one pound of water one degree  Fahrenheit. *

Burner Tip

The end of the transportation of natural gas from the wellhead, and the point of consumption. *


The joining of two ends of a pipe or other material laid end-to-end by full penetration welds

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The maximum amount of natural gas that can be produced, transported, stored, distributed, or utilized in a given period of time under design conditions. *

Capacity Factor

The ratio of the actual sales of capacity during any specified period to the maximum amount of sales the system is capable of delivering during that time.

Capacity Release

The assignment, allocation, or release of firm gas transportation rights to another party authorized under Order No. 636, done on a permanent or temporary basis, and awarded to the highest bidder. *

Capacity, Pipeline

The maximum throughput of natural gas over a specified period of time for which a pipeline system or portion thereof is designed or constructed, not limited by existing service conditions. *

Carbon Dioxide (CO2)

A gaseous substance at standard conditions composed of one carbon atom and two oxygen atoms, produced when fossil fuels are burned, and is thought to be a major contributor to the “greenhouse effect.” Combustion of natural gas emits only about 50% as much carbon dioxide as combustion of coal. *

Carbon Monoxide

A poisonous, combustible gas formed by incomplete combustion of carbon, or reduction of carbon dioxide.


A length of pipe used for encasing a smaller diameter carrier pipe for installation in a well or under a road, etc.

Cathodic Protection

Cathodic protection refers to the method of preventing corrosion in metal structures that involves using electric voltage to slow or prevent corrosion. It is used along natural gas pipelines, as well as in certain bridges or other large metal structures that need to resist corrosion over an extended period of time.


Critical Energy Infrastructure Information. CEII is not releasable for public review.

Certificate of Public Convenience and Necessity

Authorization to sell for resale or to transport natural gas in interstate commerce; or to construct, or acquire and operate, any facilities necessary therefore, subject to FERC jurisdiction under Section 7 of the NGA. May also refer to a similar permit issued by a state commission to a gas utility. *


Code of Federal Regulations

Clean Air Act of 1970

Mandated restrictions on sulfur dioxide and nitrogen oxide emissions from power plants.


Coastal Management Program


Carbon Monoxide, a poisonous, combustible gas formed by incomplete combustion of carbon, or reduction of carbon dioxide.


(1) Any of several processes which either use waste heat produced by electricity generating to satisfy thermal needs or process waste heat to electricity or produce mechanical energy. (2) The use of a single prime fuel source in a reciprocating engine or gas turbine to generate both electrical and thermal energy to optimize fuel efficiency. The dominant demand for energy may be either electrical or thermal. Usually it is thermal with excess electrical energy, if any, being transmitted into the local power supply companies’ lines. *


The combination of one or more gas turbine and steam turbines in an electric generation plant. An electric generating technology in which electricity is produced from otherwise lost waste heat exiting from one or more gas (combustion) turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for utilization by a steam turbine in the production of electricity. This process increases the efficiency of the electric generating unit. *

Combustion Turbine

A fuel-fired turbine engine used to drive an electric generator. Combustion turbines, because of their generally rapid firing time, are used to meet short-term peak demands placed on power systems. *


(1) In the context of futures trading, the fee charged by a futures broker for executing
an order. (2) The Federal Energy Regulatory Commission (3) State Public Utility’s Commission(s). *

Commodity Charge

A charge per unit of service actually delivered to the buyer. *

Commodity Costs (Rates)

Those costs that are allocated on the basis of actual use of service. *


A mechanical device for increasing the pressure of a gas. *

Compressor Stations

Facility that provides energy to move natural gas within a pipeline by increasing the pressure of the gas at the discharge side of the facility compared to the intake side. *

Confidentiality Agreement

A written legal agreement between Iroquois and another party, generally providing that, except in certain circumstances, confidential and proprietary information of either party (such as financial information of a privately held entity) is to be kept confidential and not disclosed by the other party.

Connection The physical junction between two pipeline; usually transmission lines.


The ultimate user of natural gas, as contrasted to a “customer” who may purchase natural gas for resale. *


Capacity Release Offer Report


Connecticut Siting Council

Cubic Foot

The most common unit of measurement of gas volume; the amount of gas required to fill a volume of one cubic foot under stated conditions of temperature, pressure, and water vapor. *

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Diameter Breast Height

DEC Department of Environmental Conservation

DEIS Draft Environmental Impact Statement

Dekatherm A unit of heating value equivalent to 10 therms or approximately 1,000,000 Btu's.

Delivery Point

Point where gas is transferred to the end user from the pipeline.


The rate at which electric energy or natural gas is delivered to or by a system at a given
instant or averaged over a designated period, usually expressed in kilowatts or megawatts (electric);
Mcfs or MMBtus (natural gas). *

Demand Charge

The Demand Charge portion of rate design is expected to recover the costs associated with the level of demand for the particular service and will be paid even if no service is taken by the customer; a reservation charge. Included in demand charges are capital-related costs and the cost of operation and maintenance of generation, transmission, and distribution. *

Demand Costs (Rate)

A cost included in the total cost of service that is allocated to classes of customers on the basis of service entitlements rather than actual use. *

Demand Load The rate of flow of gas required by a consumer or a group of consumers, often an average over a specified short time interval (cf/hr or Mcf/hr). Demand is the cause; load is the effect.

Demand Side Management (DSM)

The term for all activities or programs undertaken by an electric system or its customers to influence the amount and timing of electricity use. Included in DSM are the planning, implementation, and monitoring of utility activities that are designed to influence consumer use of electricity in ways that will produce desired changes in a utility’s load shape, such as, among other things, direct load control, interruptible load and conservation. *

DEP Department of Environmental Protection

Department of Energy (DOE)

A cabinet level department of the Executive Branch of the Federal government. *

Design Day

A 24-hour period of demand which is used as a basis for planning capacity requirements. *

Design Day Temperature

The mean temperature assumed for a design day. *

Directional Drilling A technique of crossing rivers or interstate highways in pipeline construction in which the pipe is buried under the riverbed or roadway at depths much greater than those of conventional crossings. With this technique, a hole in the form of an inverted arc is drilled beneath the river or roadbed and the actual made-up pipeline is pulled through it.


Mains, service connections, and equipment that carry or control the supply of natural gas from the point of local supply to and including the sales meters. *

Distribution Company Gas Company that obtains the major portion of its gas operating revenues from the operation of a retail gas Distribution system, and which operates no transmission system other than incidental connections within its own system or to the system of another company. For purposes of A.G.A. statistics, a distribution companies obtains at least 90 percent of its gas operating revenues from sales to ultimate customers, and classifies at least 90 percent of mains (other than service pipe) as distribution.


Department of State

DOT Department of Transportation

DPUC Department of Public Utility Control


Dekatherms Per Day


Data Universal Numbering System

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Easement An acquired privilege or right, distinct from ownership of the soil, to use a specified area for certain specified uses.


Electronic Bulletin Board


Electronic Data Interchange


Efficiency (E): Relating to heat, a percentage indicating the available Btu input that is converted to useful purposes. It is applied, generally, to combustion equipment. *


Environmental Inspector


One who actually consumes energy, as opposed to one who sells or re-sells it. *

Energy Affiliate

An affiliate of a transmission provider that engages in or is involved in transmission transactions in U.S. energy or transmission markets; or manages or controls transmission capacity of a Transmission Provider in U.S. energy or transmission markets; or buys, sells trades or administers natural gas or electric energy in U.S. energy or transmission markets; or engages in financial transactions relating to the sale or transmission of natural gas or electric energy in U.S. energy or transmission markets.

Environmental Protection Agency (EPA)

A federal agency charged with protecting the environment. *


Environmental Report

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Federal Energy Regulatory Commission (FERC)

A quasi-independent regulatory agency within the Department of Energy having jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas transmission and related services pricing, oil pipeline rates, and gas pipeline certification. With respect to the natural gas industry, the general regulatory principles of the FERC are defined in the Natural Gas Act (NGA), the Natural Gas Policy Act (NGPA), and the Natural Gas Wellhead Decontrol Act. *

FEIS Final Environmental Impact Statement

Firm Service

Service offered to customers under schedules or contracts that anticipate no interruptions, regardless of class of service, except for force majeure. *

Force Majeure

A common law concept borrowed from the French civil law. “Force majeure” means superior or irresistible force that excuses a failure to perform. It has been defined by the United States Supreme Court as a cause that is “beyond the control and without the fault or negligence” of the party excused. Force majeure events also must not have been reasonably foreseeable; e.g., a blizzard in Houston in January may be a force majeure event, but a blizzard in Montana will not qualify. *

Fossil Fuel

Fuel such as coal, crude oil or natural gas, formed from the fossil remains of organic material. *

Fuel Cell

A device that generates direct current to electricity by means of an electrochemical process. *

Fuel Gas A quantity of gas required by a transporter to provide the transportation service. Fuel gas includes, but is not limited to, gas consumed in transporter's mainline compressor station, gathering system booster stations, and processing plants.

Fuel Use Factor

The applicable percentage determined on a monthly basis to account for transportation fuel requirements.

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That state of matter which has neither independent shape nor volume. Gas expands to fill the entire container in which it is held. Gas is one of the three forms of matter: solid, liquid and gas. *

Gas Controller A person or persons assigned the task of monitoring and controlling daily gas system operations and ensuring safety of a pipeline or distribution system.

Gas Generator The section of a gas-turbine that provides the high temperature gases needed to drive the power turbine.

Gas Transported for Others

Natural gas owned by another company received into and transported through any part of a pipeline transmission system under a transportation agreement. *

Gas Turbine

A prime mover in which gas, under pressure or formed by combustion, is directed against a series of turbine blades; the energy in the expanding gas is converted into mechanical energy supplying power at the shaft.

Gas, Natural

A naturally occurring mixture of hydrocarbon and nonhydrocarbon gases (mainly methane, CH4) found in porous geologic formations beneath the earth’s surface, often in association with petroleum. *

Gate Station Generally a location at which gas changes ownership, from one party to another. Neither party is the ultimate consumer. It should be noted, however, that the gas may change from one system to another at this point without changing ownership. Also referred to as city gate station, town border station, or delivery point.

Grading The process of providing a smooth and even work area to facilitate the movement of construction equipment onto and along a right-of-way.


Gas Research Institute

Grid The layout of a gas distribution system in which pipes are laid in both directions in the streets and frequently connected at intersections.

Guidance Manua FERC Guidance Manual for Environmental Report Preparation

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HDD Horizontal Directional Drill. See HORIZONTAL DRILLING

Hoop Stress The tensile stress TENSILE STRENGTH, usually in pounds per square inch (psi), acting on the pipe along the circumferential direction of the pipe wall when the pipe contains gas or liquid under pressure.

Horizontal Drilling

Horizontal Drilling, heralded today as "causing the greatest change in the industry since the invention of the rotary bit," is the most rapidly growing movement in the petroleum industry. Essentially, in addition to the vertical shaft in an oil or gas well, special equipment allows producers to extend horizontal shafts into areas that could not otherwise be reached.

Horsepower (hp) A unit of power; equivalent to 33,000 ft-lb per minute or 550 ft-lb per second (mechanical horsepower), or 0.746 kilowatts.

Hot Tap The connection of branch piping to an operating line, and the tapping of the operating line while it is under pressure.



Hub Service

Combines ITS and PALS into single service.

Hydrostatic Test A strength test of equipment (pipe) in which the item is filled with liquid, subjected to suitable pressure, and then shut in, and the pressure monitored. Also a test to determine whether a container will hold a certain pressure.

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Interruptible Service A level of service that, in accordance with contractual arrangements, can be interrupted by direct control of the system operator or by action of the customer at the direct request of the system operator.

Interstate Pipeline

A natural gas pipeline company that is engaged in the transportation of natural gas across state boundaries, and is therefore subject to FERC jurisdiction and/or FERC regulation under the NGA. *


Iroquois OnLine


Independent Power Producer

Iroquois Iroquois Gas Transmission System, L.P.

Iroquois OnLine

Iroquois OnLine is a web based application that customers use to nominate, confirm, check scheduled quantities, create and view capacity release offers, retrieve and print invoices and obtain OBA and measurement information.

Iroquois' Filing Iroquois' Application for a Certificate of Public Convenience and Necessity and Accompanying ER


Interruptible transportation

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Joint A single length of steel pipe (usually 40 feet).

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Kilowatt (KW) A unit of electrical work equivalent to 1,000 watts, 1.3414 horsepower, or .9478 Btu/sec.



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LAER Lowest Achievable Emission Rate

Land Man A person concerned with the acquisition of leases, clearing of land titles, payment of lease rentals, and other related activities. Also Right of Way Agent.


A pipe that branches away from the central and primary part of the system. *


Local Distribution Company

Liquefied Petroleum Gas (LPG) A gas containing certain specific hydrocarbons, which are gaseous under normal atmospheric conditions, but can be liquefied under moderate pressure at normal temperatures. Propane and butane are the principal examples.

Liquids, Natural Gas (LNG)

Those liquid hydrocarbon mixtures that are gases at reservoir temperatures and pressures, but can be recovered by condensation or absorption. Natural gasoline and liquefied petroleum gases fall in this category. *


Laying additional pipeline beside and connected to an existing pipeline in order to increase the capacity of the system. *

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Maximum Achievable Control Technology

Mains, distribution Pipes transporting gas within service areas to the point of connection with the service pipe.

Marsh Gas Methane (CH4) the primary constituent of natural gas. Results from the partial decay of plants in swamps.

Materials Transportation Bureau (MTB) An independent office reporting to the Secretary of Transportation of the United States Government charged with enforcing the Pipeline Safety Act. MTB, among other functions, receives reports of safety-related incidents from gas system operators and periodically issues revisions and interpretations to the Minimum Federal Safety Standard (49 CFR 192).

Maximum Balance Quantity

The maximum quantity of gas, as set forth on Schedule 2 appended to the Hub Service Contract or the Park and Loan Service Contract between Transporter and Shipper, which Shipper is entitled to maintain as a net aggregate loan under the applicable HUB or Park and Loan Service Contract at any time on its behalf at one or more Loan Points to be made available to or on behalf of Shipper.

Maximum Equivalent Quantity

The Maximum Equivalent Quantity on each day shall be the maximum quantity, as set forth in Schedule 2 appended to the Gas Transportation Contract between Shipper and Transporter which Shipper may request Transporter to make available at one or more delivery points on a primary basis.

Maximum Operating Pressure The maximum actual operating pressure existing in a piping system during a normal annual operating cycle.

Maximum Transportation Rate The maximum rates that an open-access transporter may charge for its services. Section 284.7(c) of the Commission's regulations states that maximum rates for both peak and off-peak periods should ration capacity during peak periods and maximize throughput.


One thousand cubic feet of natural gas. *

MDQ The term MDQ refers to the Maximum Daily Quantity of gas that a buyer, seller, or transporter is obligated to receive or deliver at each receipt or delivery point as specified in an agreement.


Maximum Daily Quantity

Measurement Variance

The applicable percentage determined on a monthly basis to account for lost and unaccounted for gas on transporters system.

Mercaptans A group of organic chemical compounds containing an SH group having distinctive odors in small concentrations is often added to natural or LP gases to warn of leaks. Compare ODORANT

Metering and Regulating Station Facilities installed at a given location for measuring and regulating the flow of gas in connection with distribution system operations other than the measurement of gas deliveries to customers.

Methane (CH4)

The lightest in the paraffin series of hydrocarbons. It is colorless, odorless and flammable; the major portion of marsh gas and natural gas. *

Minimum Federal Safety Standard Part 192

This refers to Title 49, Part 192, of the code of Federal Regulations and contains the legal minimum requirements for gas transportation within the United States.

MLV Mainline Valve

MM Btu

One million British thermal units. *


One million cubic feet of natural gas. *

MP Milepost

MS Meter Station

MW Megawatt

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NAAQS National Ambient Air Quality Standards


North American Energy Standards Board

National Energy Act of 1978 (NEA) A comprehensive energy statute comprised of five separate but intertwined public laws dealing with energy conservation (The National Energy Conservation Policy Act, P.L. 95-619); coal conversion (The Powerplant and Industrial Fuel Use Act, P.L. 95-620); public utility rates (The Public Utility Regulatory Policy Act, P.L. 95-617); natural gas pricing (The Natural Gas Policy Act, P.L. 95-621); and a series of taxes (Energy Tax Act, P.L. 95-618) designed to discourage energy consumption and to accelerate the transition to alternative fuels. The five bills were signed into law on November 9, 1978. The main purpose of the NEA is to reduce oil imports and promote more efficient use of energy in this country.

Natural Gas

A naturally occurring mixture of hydrocarbon and non-hydrocarbon gases found in porous geological formations beneath the earth’s surface, often in association with petroleum. The principal constituent is methane, CH4. *

Natural Gas Act of 1938

A federal statute enacted in 1938 to provide regulatory control over the interstate sale and transportation of natural gas. Under the NGA, the Federal Power Commission was given two major powers: (1) the power to issue certificates of public convenience and necessity authorizing construction and operation of facilities and the provision of services, and (2) the power to regulate rates for (a) sales in interstate commerce of natural gas sold for resale for ultimate public consumption and (b) transportation of natural gas in interstate commerce. The Act specifically provides that the NGA will not apply to other sale or transportation of natural gas or to the local distribution Df natural gas, or to the facilities used for such distribution, or to the production or gathering of natural gas. *

Natural Gas Design Stress The estimated maximum tensile stress in the wall of the pipe in the circumferential orientation due to internal natural gas pressure that can be applied continuously with a high degree of certainty that failure of the pipe will not occur.

Natural Gas Distillate Material removed from natural gas at the "heavy end" portion; that is, aliphatic compounds ranging from C4 to C8.

Natural Gas Liquids The hydrocarbon components: propane, butanes, and pentanes (also referred to as condensate), or a combination of them that are subject to recovery from raw gas liquids by processing in field separators, scrubbers, gas processing and reprocessing plants, or cycling plants. The propane and butane components are often referred to as liquefied petroleum gases or LPG.

Natural Gas pipeline Safety Act of 1968 (Amended b)

The federal law providing jurisdiction by the Federal Government over the transportation of gas, which includes transmission and distribution and gathering operations in urban areas. The Secretary of Transportation, acting through the Materials Transportation Bureau, enforces the Act. Title 49 of the code of federal regulations, Part 192, contains the regulations issued under this Act. Department of Transportation (DOT) contracts with state regulatory agencies for some aspect of enforcement.

Negotiated Rate

Rate to be charged by Iroquois for service to any Shipper under Rate Schedule RTS, ITS, or HUB.  The rate may deviate in either form or level or both from the applicable maximum rate level in Iroquois' Tariff, subject to certain provisions.


National Environmental Policy Act - A law requiring agencies to consider the environmental impacts of major federal actions and to prepare environmental impact statements (EISs) which discuss these impacts and weigh alternatives. The law also requires public participation in the EIS process. *

NGO Non-Governmental Organization

NHPA National Historic Preservation Act

NIP Non-Internet Public

NO2 Nitrogen Dioxide

Nominal Pipe Size (NPS) Designates a method of identifying the size of steel pipe without compromising the actual diameter data. Thus nominal one-inch pipe with the actual external diameter of 1.315 inch (33.40 mm) becomes NPS 1; nominal 14 inch pipe with internal diameter of 13.250 inch (336.55 mm) becomes NPS 14.

Nominal Wall Thickness


Nominated Volume The physical quantity of gas requested, typically in MMBtu/day, for a specific contract or for all contracts at a specific point.


Nitrogen Oxides

NRCS National Resource Conservation Service

NRHP National Registry of Historic Places

NWI National Wetland Inventory

NYSGS New York State Geological Survey

NYSOPRHP New York State Office of Parks, Recreation and Historic Preservation

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Operational Balancing Agreement

Occupational Safety and Health Act (OSHA) A federal law, Public law 91-596, enacted in 1970, comprising federal standards for safety and health for people at work. The regulations issued under this Act can be found in Title 29, Part 1910, and Part 1926 of the Code of Federal Regulations.

OD Outside Diameter

Odorant Any material added to natural or LP gas in small concentrations to impart a distinctive odor. Odorants in common use include various mercaptans, organic sulfides, and blends of both.

Off-Peak Service Service that is provided during periods of relatively low system demand.

Open Access

Non-discriminatory, fully equal access to transportation or transmission services offered by a pipeline or electric utility. *

Open Access Transporter Once an intrastate or interstate pipeline commences self-implementing transportation services under Section 311 of the NGPA, it becomes an open access transporter and must then provide transportation services on an open access, nondiscriminatory basis and comply with the regulations set forth in Part 284 of the Commission'sregulations. In addition, once an interstate pipeline accepts a Part 284 blanket certificate, it is then an open access transporter. A pipeline which is "open" under Section 311 may terminate such service and "close" its system. However, once a pipeline accepts a blanket, it may not terminate open access services without first receiving Commission authorization to abandon its blanket certificate.

Open Season

A period of time in which potential customers can bid for pipeline services, and during which such customers are treated equally regarding priority in the queue for service. *

Operating Costs Recurring costs related to day-to-day operations of a facility that are paid out of current revenue.


The party in control of the physical operation and maintenance of a well or other facility. *

OPS Office of Pipeline Safety


Operator Qualified


Open Season Bid Form

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Park and Loan Service

Partial Looping A method for increasing carrying capacity of a pipeline by constructing pipeline sections parallel to the existing pipeline for a portion of the distance between compressor or pump stations. The new lines are connected to the main pipeline at the beginning and end of each section.

Particulates Minute particles of solid matter, such as cinders and flyash, that are contained in stack gases.




Synthetic chemicals (polychlorinated biphenyls), manufactured from 1929 to 1977, found in electrical equipment, such as voltage regulators and switches, and used to cool electrical capacitors and transformers. The manufacture of PCBs was banned in 1979. *

Peak Day The one day (24 hours) of maximum system deliveries of gas during a year. Peak day data is used to, among other things, determine the allocation of certain costs between classes of service. The Commission'ssometimes requires allocation based on an average of three continuous days of maximum deliveries (i.e., three-day peak). See also DESIGN DAY

Peak Day Curtailment Curtailment imposed on a day-to-day basis during periods of extremely cold weather when customer demands for gas exceed the maximum daily delivery capability of a pipeline or distribution system DISTRIBUTION COMPANY. Peak day curtailment is applied independent of seasonal curtailment and does not affect overall authorized volumes to customers under seasonal curtailment.

PEM Palustrine Emergent

PFO Palustrine Forested

PHMSA Pipeline & Hazardous Materials Safety Administration

PI Points of Intersection

Pig Internal Pipeline Inspection / Cleaning Device; a device used to clean or evaluate the internal surface of a pipeline (the process is called "pigging"). Pigs are usually barrel shaped, made of metal, and covered with metal brushes. They may also be made entirely of plastic and have rubber or plastic cups. They are inserted into the pipeline with a device called a pig-trap, and are pushed through the system by pressure from the fluid already flowing through the line, usually gas. They can detect imperfections and anomalies on the pipeline; also called a go-devil.

Pipe, Coated Pipe that has been covered with a corrosion resistant coating or compound (such as epoxy) to prevent corrosion from soil conditions.


An entity engaged in the transportation of natural gas in interstate or intrastate commerce.
Also, the actual facility itself. *

Pipeline Capacity The maximum quantity of gas that can be moved through a pipeline system at any given time based on existing service conditions such as available horsepower, pipeline diameter(s), maintenance schedules, regional demand for natural gas, etc.

Pipeline Patrol A general inspection of the pipeline right-of-way by foot, airplane, or land vehicle to observe surface conditions and activity along or on the right-of-way and noting changes in vegetation growth for indication of gas leakage.

Pipelines See GAS

Plan FERC Erosion Control, Revegetation and Maintenance Plan

PM Particulate Matter

PPM Parts Per Million

Prearranged Replacement Shipper

Approved Bidder

Procedures FERC Wetland and Waterbody Construction and Mitigation Procedures

Psig Pounds per Square Inch of Gas

PSS Palustrine Scrub Shrub

Public Convenience and Necessity That which is necessary or desirable in the public interest. The Commission'smust find a particular facility or service "necessary or desirable in the public interest" as a condition for granting a Certificate of Public Convenience and Necessity.

Public Interest Usually intended to mean the interest of the public, generally, as opposed to the interest of an individual or company.


Present Value

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RACT Reasonably Achievable Control Technology


The unit charge or charges made by an energy company or utility to customers for energy. *

Rate Adjustment Provisions A provision in a tariff that provides for adjustments in rates or total charges because of changes in specified items of cost, such as fuel price, purchased gas, tax, etc.

Rate Base

The value of property upon which a utility is given the opportunity to earn a specified rate of return as established by a regulatory authority. The rate base generally represents the value of property used by the utility in providing service and may be calculated by anyone or a combination of the following accounting methods: fair value, prudent investment, reproduction cost, or original cost. The rate base may include a working capital allowance covering such elements as cash, working capital, materials and supplies, prepayments, minimum bank balances and tax offsets. The rate base may be adjusted by deductions for accumulated provision for depreciation, contributions in aid of construction, accumulated deferred income taxes, and accumulated deferred investment tax credits. *

Rate Case A proceeding before a regulatory Commission'sinvolving the rates to be charged for a public utility service.

Rate Design

The development of electricity prices for various customer-classes to meet revenue requirements dictated by operating needs and costs within current regulatory and legislative policy goals. *

Rate of Flow The volume or units of a material passing a given point in a pipeline system per unit of time.

Rate of Return

The profit a regulated utility is given the opportunity to earn. The allowed rate of return is the percentage determined by the jurisdictional state or federal commission based on standards including the cost of capital in other sectors with comparable risk. The achieved rate of return is the actual result the utility obtained over any given period. In the utility industry, rate of return usually refers to the rate of return on rate base. *

RCNM Roadway Construction Noise Model


Retail Choice Program

Receipt Point

The point on a pipeline’s system at which it receives natural gas into its system. *


The governmental function of controlling or directing economic entities through the process of rulemaking and adjudication. *

Release Notice

The notice that a Releasing Shipper provides to Transporter via EBB in accordance with the provisions of Section 28.6 of Iroquois' Tariff.

Releasing Shipper

Any Shipper that has executed a Gas Transportation Contract for Firm Reserved Service with Transporter and that elects to release rights to it's firm capacity on a temporary or permanent basis.


The degree to which the performance of the elements of a system results in power being delivered to consumers within accepted standards and in the amount desired. The degree of reliability may be measured by the frequency, duration, and magnitude of adverse effects on consumer service. *

Replacement Shipper

Any Shipper that executes a Gas Transportation Contract in the form prescribed by Iroquois' Tariff, acquiring capacity rights from a Releasing Shipper.

Right-of-Way A strip of land, the use of which is acquired for the construction and operation of a pipeline or some other facility; the land may be owned outright or an easement taken for a specific purpose.


Right of First Refusal

ROW Right-of-Way. A strip of land, the use of which is acquired for the construction and operation of a pipeline or some other facility; the land may be owned outright or an easement taken for a specific purpose.


Reserved Transportation Service

RTU Remote Telemetry Unit

Rupture-Pipeline A failure in the pipeline for various reasons such as third party damage, corrosion, etc., where a complete loss to atmosphere of the gas or other media is sustained.

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Supervisory Control and Data Acquisition - A system of remote control and telemetry used to monitor and control the transmission system. *

SCFWH Significant Coastal Fish and Wildlife Habitats

Seasonal Curtailment A level of service that contractually restricts or limits service during certain periods of the year.

SEQRA State Environmental Quality Review Act


One who contracts with a pipeline for transportation of natural gas and who retains title to all natural gas while it is being transported by the pipeline. *

SHPO State Historic Preservation Officer

SIP State Implementation Plan

SO2 Sulfur Dioxide

SPCC Plan Spill Prevention, Containment, and Countermeasure Plan

SPDES State Pollution Discharge Elimination System


An affiliate, usually with majority control.


One who contracts with a pipeline for transportation of natural gas, and who retains title to all natural gas while it is being transported.

SWPPP Stormwater Pollution Prevention Plan

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T&E Threatened and Endangered


A document filed by a regulated entity with either a federal or state commission. It lists the rates the regulated entity will charge to provide service to its customers as well as the terms and conditions that it will follow in providing service. *

Temperature Ambient

The temperature of the air, atmosphere, or other fluid (medium) that completely surrounds the apparatus, equipment, or the work piece under consideration. For devices that do not generate heat, this temperature is the same as the temperature of the medium at the point of device location when the device is not present. For devices that do generate heat, this temperature is the temperature of the medium surrounding the device when the device is present and generating heat. Allowable ambient-temperature limits are based on the assumption that the device in question is not exposed to significant radiant-energy sources such as sunlight or heated surfaces.

Tensile Strength The resistance to being pulled apart laterally; resistance to length-wise stress.


The proposed commencement and termination dates of service.


A unit of heating value equivalent to 100,000 British thermal units (Btu) (0.1 MMBtu). *

THPO Tribal Historic Preservation Officer

Throughput Total of transportation volumes and tariff sales; all gas volumes delivered.

Tie In To make a connection to an existing pipeline or piping.

Title Transfer

The equal quantity of gas deposited and withdrawn at the same meter on the same day.

Transportation The act of moving gas from a designated receipt point to a designated delivery point GATE STATION pursuant to the terms of a contract between the transporter and the shipper. Generally it is the shipper's own gas that is being moved.

Transportation Agreement An agreement between a shipper and transportation company that defines the terms and conditions of the transportation services and transportation transfer to be provided.

Transportation Service The act of moving gas from a receipt point to a delivery point GATE STATION pursuant to a contract between the shipper and the transporter. To the extent the shipper has paid for guaranteed, high-priority capacity in the pipeline, that shipper is entitled to firm service.


The pipeline company that transports natural gas for a shipper. *

TSCA Toxic Substances Control Act

Turbine Station A compressor station in which the power is supplied by a turbine.

Turbine, Steam or gas An enclosed rotary type of prime mover in which heat energy in steam or gas is converted into mechanical energy by the force of a high velocity flow of steam or gas directed against successive rows of radial blades fastened to a central shaft.

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ULSD Ultra Low Sulfur Diesel

Uncased Crossing In pipeline construction, a road crossing bored or open-cut without a casing pipe.

USACE United States Army Corps of Engineers

USDA United States Department of Agriculture

USDOT United States Department of Transportation

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

USGS United States Geological Survey

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Valve A mechanical device for controlling the flow of fluids and gases; types such as gate, ball, globe, needle, and plug valves are used.

Vent A device installed on a pipeline that will allow gas to escape into the atmosphere under controlled conditions.

Venting The planned release of natural gas to the atmosphere during depressurization or purging.

VOC Volatile Organic Compound

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Wall Thickness Specified wall thickness of pipe without adding an allowance to compensate for the underthickness tolerances permitted in approved specifications.


* The definitions denoted with an asterisk were obtained from the Interstate Natural Gas Association

of America.

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