[Title 40 CFR 146.5]
[Code of Federal Regulations (annual edition) - July 1, 2009 Edition]
[Title 40 - PROTECTION OF ENVIRONMENT]
[Chapter I - ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)]
[Subchapter D - WATER PROGRAMS (CONTINUED)]
[Part 146 - UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND]
[Subpart A - General Provisions]
[Sec. 146.5 - Classification of injection wells.]
[From the U.S. Government Printing Office]
40PROTECTION OF ENVIRONMENT222009-07-012009-07-01falseClassification of injection wells.146.5Sec. 146.5PROTECTION OF ENVIRONMENTENVIRONMENTAL PROTECTION AGENCY (CONTINUED)WATER PROGRAMS (CONTINUED)UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA ANDGeneral Provisions
Sec. 146.5 Classification of injection wells.
Injection wells are classified as follows:
(a) Class I. (1) Wells used by generators of hazardous waste or
owners or operators of hazardous waste management facilities to inject
hazardous waste beneath the lowermost formation containing, within one
quarter (\1/4\) mile of the well bore, an underground source of drinking
water.
(2) Other industrial and municipal disposal wells which inject
fluids beneath the lowermost formation containing, within one quarter
mile of the well bore, an underground source of drinking water.
(3) Radioactive waste disposal wells which inject fluids below the
lowermost formation containing an underground source of drinking water
within one quarter mile of the well bore.
(b) Class II. Wells which inject fluids:
(1) Which are brought to the surface in connection with conventional
oil or natural gas production and may be commingled with waste waters
from gas plants which are an integral part of production operations,
unless those waters are classified as a hazardous waste at the time of
injection.
(2) For enhanced recovery of oil or natural gas; and
(3) For storage of hydrocarbons which are liquid at standard
temperature and pressure.
(c) Class III. Wells which inject for extraction of minerals
including:
(1) Mining of sulfur by the Frasch process;
(2) In situ production of uranium or other metals. This category
includes only in-situ production from ore bodies which have not been
conventionally mined. Solution mining of conventional mines such as
stopes leaching is included in Class V.
(3) Solution mining of salts or potash.
(d) Class IV. (1) Wells used by generators of hazardous waste or of
radioactive waste, by owners or operators of hazardous waste management
facilities, or by owners or operators of radioactive waste disposal
sites to dispose of hazardous waste or radioactive waste into a
formation which within one quarter (\1/4\) mile of the well contains an
underground source of drinking water.
(2) Wells used by generators of hazardous waste or of radioactive
waste, by owners or operators of hazardous waste management facilities,
or by owners or operators of radioactive waste disposal sites to dispose
of hazardous waste or radioactive waste above a formation which within
one quarter (\1/4\) mile of the well contains an underground source of
drinking water.
(3) Wells used by generators of hazardous waste or owners or
operators of hazardous waste management facilities to dispose of
hazardous waste, which cannot be classified under Sec. 146.05(a)(1) or
Sec. 146.05(d) (1) and (2) (e.g., wells used to dispose of hazardous
wastes into or above a formation which contains an aquifer which has
been exempted pursuant to Sec. 146.04).
(e) Class V. Injection wells not included in Class I, II, III, or
IV. Specific types of Class V injection wells are also described in 40
CFR 144.81. Class V wells include:
(1) Air conditioning return flow wells used to return to the supply
aquifer the water used for heating or cooling in a heat pump;
(2) Cesspools including multiple dwelling, community or regional
cesspools, or other devices that receive wastes which have an open
bottom and sometimes have perforated sides. The UIC requirements do not
apply to single family residential cesspools nor to non-residential
cesspools which receive solely sanitary wastes and have the capacity to
serve fewer than 20 persons a day.
(3) Cooling water return flow wells used to inject water previously
used for cooling;
(4) Drainage wells used to drain surface fluid, primarily storm
runoff, into a subsurface formation;
[[Page 780]]
(5) Dry wells used for the injection of wastes into a subsurface
formation;
(6) Recharge wells used to replenish the water in an aquifer;
(7) Salt water intrusion barrier wells used to inject water into a
fresh water aquifer to prevent the intrusion of salt water into the
fresh water;
(8) Sand backfill and other backfill wells used to inject a mixture
of water and sand, mill tailings or other solids into mined out portions
of subsurface mines whether what is injected is a radioactive waste or
not.
(9) Septic system wells used to inject the waste or effluent from a
multiple dwelling, business establishment, community or regional
business establishment septic tank. The UIC requirements do not apply to
single family residential septic system wells, nor to non-residential
septic system wells which are used solely for the disposal of sanitary
waste and have the capacity to serve fewer than 20 persons a day.
(10) Subsidence control wells (not used for the purpose of oil or
natural gas production) used to inject fluids into a non-oil or gas
producing zone to reduce or eliminate subsidence associated with the
overdraft of fresh water;
(11) Radioactive waste disposal wells other than Class IV;
(12) Injection wells associated with the recovery of geothermal
energy for heating, aquaculture and production of electric power.
(13) Wells used for solution mining of conventional mines such as
stopes leaching;
(14) Wells used to inject spent brine into the same formation from
which it was withdrawn after extraction of halogens or their salts;
(15) Injection wells used in experimental technologies.
(16) Injection wells used for in situ recovery of lignite, coal, tar
sands, and oil shale.
[45 FR 42500, June 24, 1980, as amended at 46 FR 43161, Aug. 27, 1981;
47 FR 4999, Feb. 3, 1982; 64 FR 68573, Dec. 7, 1999]