Definitions, Sources and Explanatory Notes  Category:
			Natural Gas StorageTopic:
	        Underground Storage - All Operators  Definitions  Key Terms
  DefinitionAGA Eastern Consuming Region
  All States east of the Mississippi River less Mississippi and Alabama,
 plus Iowa, Nebraska and Missouri.AGA Western Consuming Region
  All States west of the Mississippi River less the Producing
Region and Iowa, Nebraska and Missouri.AGA Producing Region
  Alabama, Arkansas, Kansas, Louisiana, Mississippi, New Mexico, Oklahoma, and Texas.Base (cushion) Gas
  The volume of gas needed as a permanent inventory to maintain adequate reservoir
pressures and deliverability rates throughout the withdrawal season. All native gas is 
included in the base gas volume.Natural Gas
  A gaseous mixture of hydrocarbon compounds, the primary one being methane.Net Withdrawals
  The amount by which storage withdrawals exceed storage injections.Storage Additions
  Volumes of gas injected or otherwise
added to underground natural gas reservoirs or liquefied natural
gas storage.Storage Withdrawals
  Total volume of gas withdrawn from
underground storage or from liquefied natural gas storage
over a specified amount of time.Underground Storage Injections
  Gas from extraneous sources put into underground storage reservoirs.Underground Gas Storage
  The use of sub-surface
facilities for storing gas that has been transferred from its original
location. The facilities are usually hollowed-out salt
domes, natural geological reservoirs (depleted oil or gas
fields) or water-bearing sands topped by an impermeable cap
rock (aquifer).Underground Storage Withdrawals
  Gas removed from underground
storage reservoirs.Working (top storage) Gas
  The volume of total natural gas storage capacity that contains natural gas available for withdrawal.  For definitions of related energy terms, refer to the
   EIA Energy Glossary.  Sources  1979 and prior data from the American Gas
  Association, Committee on Underground Storage, *The Storage of Gas in the United
  States and Canada*. 1980 to current data from  Form EIA-191M, "Monthly Underground Gas Storage Report"
; 
  Form EIA-191A, "Annual Underground Gas Storage Report"
;  Form EIA-176, "Annual Report of Natural and Supplemental Gas Supply and Disposition"
.
  Background on "Natural Gas Monthly" dataNatural Gas Survey Forms and Instructions  Explanatory Notes  Net storage withdrawals data through 2006 include underground storage and liquefied natural gas storage.
  Data for January 2007 forward include underground storage only.Gas in storage at the end of a reporting period may not equal the quantity
  derived by adding or subtracting net injections or withdrawals during the
  period to the quantity of the gas in storage at the beginning of the period.
  This is due to changes in the quantities of native gas included in base gas
  and/or losses in base gas due to migration from storage reservoirs.Totals may not equal sum of components due to independent rounding.Geographic coverage is the 50 States and the District of Columbia. Prior to January 2013, Alaska data were not included in U.S. totals.Positive net withdrawals indicate the volume of withdrawals in excess of 
  injections.  Negative net withdrawals indicate the volume of injections in
  excess of withdrawals.