35 Ill. Adm. Code 704.106
Classification of Injection Wells
Section 704
Section 704.106
Classification of Injection Wells
Injection wells are classified
as follows:
a) Class I Injection Wells. Any of the following is a Class I
injection well:
1) A well used by a generator of hazardous waste or the owner or operator
of a hazardous waste management facility to inject hazardous waste beneath the
lowermost formation containing a USDW within 402 meters (one-quarter mile) of
the well bore.
2) Any other industrial and municipal disposal well that injects
fluids beneath the lowermost formation containing a USDW within 402 meters
(one-quarter mile) of the well bore.
3) A radioactive waste disposal well that injects fluids below
the lowermost formation containing a USDW within 402 meters (one-quarter mile)
of the well bore.
b) Class II Injection Wells. Any well that injects any of the
following fluids is a Class II injection well:
1) Fluids that are brought to the surface in connection with
natural gas storage operations, or conventional oil or natural gas production,
and which may be commingled with waste waters from gas plants that are an
integral part of production operations, unless those waters are classified as a
hazardous waste at the time of injection;
2) Fluids injected for enhanced recovery of oil or natural gas;
and
3) Fluids injected for storage of hydrocarbons that are liquid at
standard temperature and pressure.
c) Class III Injection Wells. Any well that injects fluids for the
extraction of minerals, including the following:
1) The mining of sulfur by the Frasch process;
2) The in-situ production of uranium or other metals. This
category includes only in-situ production from ore bodies that have not been
conventionally mined. Solution mining of conventional mines, such as stopes leaching,
is included as a Class V injection well; and
3) Solution mining of salts or potash.
d) Class IV Injection Wells. Any of the following is a Class IV
injection well:
1) A well used by a generator of hazardous waste or of
radioactive waste, by the owner or operator of a hazardous waste management facility
or by the owner or operator of a radioactive waste disposal site to dispose of
hazardous wastes or radioactive wastes into a formation that contains a USDW
within 402 meters (one-quarter mile) of the well.
2) A well used by a generator of hazardous waste or of
radioactive waste, by the owner or operator of a hazardous waste management facility,
or by the owner or operator of a radioactive waste disposal site to dispose of
hazardous waste or radioactive waste above a formation that contains a USDW
within 402 meters (one-quarter mile) of the well.
3) A well used by a generator of hazardous waste or the owner or
operator of a hazardous waste management facility to dispose of hazardous waste
that cannot be classified under any of subsections (a)(1), (d)(1), or (d)(2) (e.g.,
a well that is used to dispose of hazardous waste into or above a formation that
contains an aquifer that has been exempted pursuant to 35 Ill. Adm. Code
730.104).
e) Class V Injection Wells. Any injection well that is not classified
as a Class I, II, III, IV, or VI injection well. Section 704.281 describes
specific types of Class V injection wells.
f) Class
VI Injection Wells.
1) An
injection well that is not experimental in nature which is used for geologic
sequestration of carbon dioxide beneath the lowermost formation containing a
USDW;
2) An
injection well that is used for geologic sequestration of carbon dioxide which
has been granted a permit that includes alternative injection well depth
requirements pursuant to Section 730.195; or
3) An
injection well that is used for geologic sequestration of carbon dioxide which has
received an expansion to the areal extent of an existing Class II enhanced oil
recovery or enhanced gas recovery aquifer exemption pursuant to Section
704.123(d) and 35 Ill. Adm. Code 730.104.
BOARD NOTE: Derived from 40 CFR
144.6 (2017).