CHAPTER 6 OVERVIEW OF FEDERAL UNDERGROUND INJECTION CONTROL PROGRAM

• Jurisdiction: United States

Environmental Regulation of the Oil and Gas Industry
(Feb 1993)
CHAPTER 6
OVERVIEW OF FEDERAL UNDERGROUND INJECTION CONTROL PROGRAM
Elizabeth H. Temkin and Mary C. Larson
Ballard Spahr Andrews & Ingersoll
Denver, Colorado

I. OVERVIEW OF FEDERAL UNDERGROUND INJECTION CONTROL PROGRAM

A. Nature and Scope of Regulations

1. The only federal environmental scheme directly regulating groundwater discharges is the Underground Injection Control ("UIC") Program, enacted under the Safe Drinking Water Act of 1974, as amended ("SDWA"). 42 U.S.C. § 300f et seq.

2. The SDWA is aimed at protecting all underground sources of drinking water (USDW's). The UIC program is a critical component of this effort.

a. The UIC Program prohibits all subsurface well injection unless authorized by permit or rule. 42 U.S.C. § 300h(b)(1)(A).

b. No well injection will be authorized if it will endanger a USDW. 42 U.S.C. § 300(b)(1)(B).

(1) An injection is presumed to "endanger" a USDW if it could result in the movement of contaminated fluids into a USDW, causing the USDW to violate the national primary drinking water standards ¹ or otherwise adversely affect human health. 42 U.S.C. § 300h(d); 40 C.F.R. § 144.1(g).

B. Key Definitions

1. There are several key definitions which are critical to the scope of the UIC program.

a. "Well injection" means the subsurface emplacement of fluids through a bored, drilled, or driven well; or through a dug well, where the depth of the dug well is greater than the largest surface dimension. A small pit which is barely deeper than wide can constitute a "well" within the meaning of the SDWA. 40 C.F.R. § 144.3. EPA

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applies UIC regulations only to wells used for underground storage or disposal of fluids.

b. The term "fluid" is defined broadly to mean any material or substance which flows or moves, whether in a semi-solid, liquid, sludge, gas, or any other form or state. 40 C.F.R. § 144.3.

c. A "USDW" is any non-exempt aquifer² or portion thereof which (1) supplies any public water system³ ; or (2) contains sufficient groundwater to supply a public water system and (i) currently supplies drinking water for human consumption, or (ii) contains fewer than 10,000 mg/1 total dissolved solids. 40 C.F.R. § 144.3. The definition of a "USDW" is broad enough to include virtually all actual and economically viable sources of public drinking water.

d. Ordinarily, subsurface well injection is permitted only into "exempt aquifers". An aquifer may be designated as exempt if it has no real potential to be used as a drinking water source because it is contaminated, contains commercially exploitable minerals or hydrocarbons, or has a total dissolved load exceeding 3,000 mg/1. 40 C.F.R. §§ 144.3; 144.7; 146.4.

e. The term "contaminant" means any physical, chemical, biological, or radiological substance or matter in water, and can include such substances as salt and brine.

II. INJECTION WELL CLASSIFICATIONS AND STANDARDS

A. Classes of Injection Wells. Injection wells are generally categorized by use of the well, types of fluids injected, and/or the location of the injection zone with respect to USDW's:

1. Class I wells are used to inject hazardous, non-hazardous or municipal wastes below the lowermost USDW.

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40 C.F.R. § 146.5(a). Both a UIC permit and RCRA disposal facility permit may be required for injection of hazardous waste. 40 C.F.R. §§ 146.5 (a); 265.430; 270.60(b); 52 Fed. Reg. 45,788, 45,791 (Dec. 1, 1987).

2. Class II wells are used to inject fluids brought to the surface in oil and gas production, fluids used in enhanced recovery operations, and fluids stored in hydrocarbon storage wells⁴ ("Class II fluids"). 40 C.F.R. § 146.5(b). EPA lists eleven fluid categories which can be injected into Class II wells. See Attachment 1.

a. Class II fluids do not include fluids which are hazardous wastes under RCRA. Class II fluids must either fall within the production and exploration exemption under RCRA ("E&P exempt wastes"), be unlisted or non-characteristic under RCRA. 42 U.S.C. § 6921(b)(2)(A); 40 C.F.R. § 261.4(b)(5).

(1) The E&P exemption is based on the waste's relationship to oil and gas production activities and not toxicity. E&P exempt wastes are wastes intrinsically derived from primary field operations associated with exploration, development, or production of oil, gas, or geothermal energy. 42 U.S.C. § 6921(b)(2)(A); 40 C.F.R. § 261.4(b)(5). E&P wastes are typically generated prior to the transfer of custody, or the point of production separation and dehydration.

b. Class II fluids generally encompass E&P exempt wastes, but may include other non-hazardous fluids produced at the wellhead, such as those used for enhanced recovery operations or stored in hydrocarbon storage so long as they are not listed or characteristic under RCRA.

(1) Tank bottoms produced at a production facility rather than at a refinery are E&P exempt. Tertiary recovery fluids injected

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for the purpose of enhancement, rather than disposal, are also E&P exempt.⁵

(2) Although fluids produced from gas wells and gas plants (which are considered production facilities) are E&P exempt, the gathering line system between the well and the gas plant is not exempt because of the custody transfer which ordinarily occurs at the wellhead.

(3) EPA intends to clarify issues such as whether spilled fluids and other wastes produced during transport to the gas plant fall within the E&P exemption in early 1993. ⁶

3. Class III wells are used for injecting fluids for the extraction of minerals, such as Frasch process sulphur mining, salt mining, and in situ mineral extraction. 40 C.F.R. § 146.5(c).

4. Class IV wells are used to dispose of radioactive or hazardous waste into or above a USDW. All Class IV wells are banned, except in conjunction with agency-approved CERCLA and RCRA remedial cleanup. 40 C.F.R. §§ 146.5(d); 144.13.

5. Class V wells include all injection wells which do not fall within one of the four classes listed above, and generally inject non-hazardous fluid into or above a USDW. 40 C.F.R. § 146.5(e).

a. The Class V injection well category includes over 30 different types of injection wells, including drainage systems (horizontal wells), sewage-related wells, and oil field waste disposal wells such as air scrubber waste disposal wells and water softener regeneration brine disposal wells. See Attachment 2.

b. Certain

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