[Code of Federal Regulations]
[Title 40, Volume 20]
[Revised as of July 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR146.62]

[Page 721-722]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 146_UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS--Table of Contents
 
 Subpart G_Criteria and Standards Applicable to Class I Hazardous Waste 
                             Injection Wells
 
Sec.  146.62  Minimum criteria for siting.

    (a) All Class I hazardous waste injection wells shall be sited such 
that they inject into a formation that is beneath the lowermost 
formation containing within one quarter mile of the well bore an 
underground source of drinking water.
    (b) The siting of Class I hazardous waste injection wells shall be 
limited to areas that are geologically suitable. The Director shall 
determine geologic suitability based upon:
    (1) An analysis of the structural and stratigraphic geology, the 
hydrogeology, and the seismicity of the region;
    (2) An analysis of the local geology and hydrogeology of the well 
site, including, at a minimum, detailed information regarding 
stratigraphy, structure and rock properties, aquifer hydrodynamics and 
mineral resources; and
    (3) A determination that the geology of the area can be described 
confidently and that limits of waste fate

[[Page 722]]

and transport can be accurately predicted through the use of models.
    (c) Class I hazardous waste injection wells shall be sited such 
that:
    (1) The injection zone has sufficient permeability, porosity, 
thickness and areal extent to prevent migration of fluids into USDWs.
    (2) The confining zone:
    (i) Is laterally continuous and free of transecting, transmissive 
faults or fractures over an area sufficient to prevenet the movement of 
fluids into a USDW; and
    (ii) Contains at least one formation of sufficient thickness and 
with lithologic and stress characteristics capable of preventing 
vertical propagation of fractures.
    (d) The owner or operator shall demonstrate to the satisfaction of 
the Director that:
    (1) The confining zone is separated from the base of the lowermost 
USDW by at least one sequence of permeable and less permeable strata 
that will provide an added layer of protection for the USDW in the event 
of fluid movement in an unlocated borehole or transmissive fault; or
    (2) Within the area of review, the piezometric surface of the fluid 
in the injection zone is less than the piezometric surface of the 
lowermost USDW, considering density effects, injection pressures and any 
significant pumping in the overlying USDW; or
    (3) There is no USDW present.
    (4) The Director may approve a site which does not meet the 
requirements in paragraphs (d) (1), (2), or (3) of this section if the 
owner or operator can demonstrate to the Director that because of the 
geology, nature of the waste, or other considerations, abandoned 
boreholes or other conduits would not cause endangerment of USDWs.