Section 331.11 - Classification of Injection Wells(a) Injection wells within the jurisdiction of the commission are classified as follows.(1) Class I: (A) wells used by generators of hazardous wastes or owners or operators of hazardous waste management facilities to inject hazardous waste, other than Class IV wells;(B) other industrial and municipal waste disposal wells which inject fluids beneath the lower-most formation which within 1/4 mile of the wellbore contains an underground source of drinking water (USDW); and(C) radioactive waste disposal wells which inject fluids below the lower-most formation containing a USDW within 1/4 mile of the wellbore.(2) Class III. Wells which are used for the extraction of minerals, including:(A) mining of sulfur by the Frasch process; and(B) solution mining of minerals which includes sodium sulfate, sulfur, potash, phosphate, copper, uranium and any other minerals which can be mined by this process.(3) Class IV. Wells used by generators of hazardous wastes or of radioactive wastes, by owners or operators of hazardous waste management facilities, or by owners or operators of radioactive waste disposal sites to dispose of hazardous wastes or radioactive wastes into or above a formation which within 1/4 mile of the wellbore contains a USDW.(4) Class V. Class V wells are injection wells not included in Classes I, II, III, or IV. Generally, wells covered by this paragraph inject nonhazardous fluids into or above formations that contain USDWs. Except for Class V wells within the jurisdiction of the Railroad Commission of Texas, all Class V injection wells are within the jurisdiction of the commission and include, but are not limited to: (A) air conditioning return flow wells used to return to the supply aquifer the water used for heating or cooling in a heat pump;(B) closed loop injection wells which are closed system geothermal wells used to circulate fluids including water, water with additives, or other fluids or gases through the earth as a heat source or heat sink;(C) large capacity cesspools or other devices that receive greater than 5,000 gallons of waste per day, which have an open bottom and sometimes have perforated sides;(D) cooling water return flow wells used to inject water previously used for cooling;(E) drainage wells used to drain surface fluid, primarily storm runoff, into a subsurface formation;(F) drywells used for the injection of wastes into a subsurface formation;(G) recharge wells used to replenish the water in an aquifer;(H) salt water intrusion barrier wells used to inject water into a freshwater aquifer to prevent the intrusion of salt water into the fresh water;(I) sand backfill wells used to inject a mixture of water and sand, mill tailings, or other solids into mined out portions of subsurface mines;(J) septic systems designed to inject greater than 5,000 gallons per day of waste or effluent;(K) 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;(L) wells used for the injection of water for storage and subsequent retrieval for beneficial use as part of an aquifer storage and recovery project;(M) motor vehicle waste disposal wells which are used or have been used for the disposal of fluids from vehicular repair or maintenance activities, such as an automotive repair shop, auto body shop, car dealership, boat, motorcycle or airplane dealership, or repair facility;(O) aquifer remediation wells, temporary injection points, and subsurface fluid distribution systems used to inject nonhazardous fluids into the subsurface to aid in the remediation of soil and groundwater; and(P) subsurface fluid distribution systems.(b) Class II wells and Class III wells used for brine mining fall within the jurisdiction of the Railroad Commission of Texas.(c) Baseline wells and monitor wells associated with Class III injection wells within the jurisdiction of the commission are also subject to the rules specified in this chapter.30 Tex. Admin. Code § 331.11
The provisions of this §331.11 adopted to be effective May 13, 1986, 11 TexReg 1980; amended to be effective June 28, 1996, 21 TexReg 5443; amended to be effective April 28, 1997, 22 TexReg 3526; amended to be effective June 25, 2000, 25 TexReg 5906; amended to be effective November 23, 2000, 25 TexReg 11433; amended to be effective July 12, 2001, 26 TexReg 5019; amended to be effective March 29, 2006, 31 TexReg 2690; Amended by Texas Register, Volume 41, Number 20, May 13, 2016, TexReg 3522, eff. 5/19/2016; Amended by Texas Register, Volume 47, Number 22, June 3, 2022, TexReg 3266, eff. 6/9/2022