Section 240.1805  Definitions


"Act", for the purposes of this Subpart, means the Illinois Underground Natural Gas Storage Safety Act [415 ILCS 160].


"Downhole" means the portion of an underground natural gas storage facility from the first flange attaching the wellhead to the pipeline equipment and continuing down the well casing to and including the storage reservoir. (Section 5 of the Act)


"Emergency Abatement Order" or "EAO" means an order issued by the Department under Subpart H.


"Fault" means a fracture surface or zone of fractures in Earth materials along which there has been vertical and/or horizontal displacement or movement of the strata on opposite sides relative to one another.


"Fluid" means any material or substance that flows or moves, whether semisolid, liquid, gas, or steam.


"Gas Storage Operator", "Operator" or "Owner" means any entity that owns or operates an underground gas storage field.


"Gas Storage Well" means a well drilled for input and/or withdrawal of natural gas or manufactured gas in a gas storage field.


"Natural Gas Incident" or "Incident" means an event that involves a release of stored natural gas from the downhole portion of an underground natural gas storage facility located in this State that:


results in the unintentional estimated gas loss of 3,000,000 cubic feet or more;


results in the unintentional estimated gas loss of 500,000 cubic feet or more that occurs within ⅛ mile of a dwelling used as a residence, place of business, or place of public assembly;


results in death;


causes personal injury necessitating in-patient hospitalization;


causes property damage in excess of $50,000; or


results in an emergency shutdown of an underground natural gas storage facility.


Activation of an emergency shutdown system for reasons other than an actual emergency does not constitute an incident.


"Observation Well" means a well drilled to monitor subsurface conditions in oil and gas projects or gas storage fields.


"Person" means an individual, firm, joint venture, partnership, corporation, company, limited liability company, firm, association, municipality, cooperative association, or joint stock association.  "Person" includes a trustee, receiver, assignee, or personal representative of the person.  (Section 5 of the Act).


"Produced Fluid" means liquids regardless of chloride and total dissolved solids content, that is produced in conjunction with oil or natural gas production or natural gas storage operations.


"Release" means the escape of natural gas from an underground natural gas storage facility, regardless of whether the escape is underground or to the atmosphere.


"Secretary of Transportation" means the U.S. Secretary of Transportation or his or her designee.


"Sole Source Aquifer" means an aquifer that:


is the sole or principal drinking water source for an area; and


if contaminated, would create a significant hazard to public health as defined in 42 USC 300h-3(e) and further defined in the Sole Source Aquifer Designation Decision Process, Petition Review Guidance (USEPA; 1987; this incorporation by reference includes no later editions or amendments).


"Stored Natural Gas" means natural gas that is:


transported by pipeline into an underground natural gas storage facility for the purpose of storage prior to transmission back to the pipeline; and


stored within the underground gas storage field.


"Underground Natural Gas Storage Facility" means a facility that stores natural gas in an underground natural gas storage field incident to natural gas transportation, including:


a depleted hydrocarbon reservoir;


an aquifer reservoir;


a solution-mined salt cavern reservoir; and


associated material and equipment used for injection, withdrawal, monitoring, or observation wells, and wellhead equipment, piping, rights-of-way, property, buildings, compressor units, separators, metering equipment, and regulator equipment.


An underground natural gas storage facility is subject to regulation by the Illinois Department of Natural Resources and has not been preempted by the United States Government pursuant to 49 USC 60104(c).


"Underground Gas Storage Field" means an area of land that is contained within the lowest closing structural contour for which gas can be stored in a subsurface stratum.


"Violation" means a failure to comply with any provision of the Act or any Department order or rule under the Act. (Section 35 of the Act)


(Source:  Amended at 43 Ill. Reg. 11524, effective September 24, 2019)