(a) All Class I wells shall be situated such that they inject into a formation that is beneath the lowermost Under ground Source of Drinking Water within one-quarter (1/4) mile of the well or within two (2) miles for Class I hazardous waste injection wells, and the discharge zone has sufficient permeability, porosity, thickness, and extends over a sufficient area to prevent migration of fluids into any underground source of drinking water.
(b) Class I wells shall be limited to areas that are determined by the administrator to be geologically suitable for the prevention of migration of fluids into underground source of drinking waters. In determining geological suit ability, the administrator shall consider the following information submitted by the applicant: - (i) An analysis of the structural and stratigraphic geology, hydrogeology, and the seismicity of the region;
- (ii) An analysis of the local geology and hydro-geology of the well site, including, at a minimum, detailed information regarding the stratigraphy, structure, and rock properties, aquifer hydrodynamics, and mineral resources; and
- (iii) A determination that the geology of the area can be described confidently, and, for hazardous waste wells only, that the waste fate and transport can be accurately predicted through the use of models.
(c) The operator shall demonstrate to the satisfaction of the administrator that: - (i) The confining zone is free from faults or fractures over an area sufficient to prevent the migration of fluids into a underground source of drinking water, and contains at least one formation of sufficient thickness and characteristics capable of preventing vertical propagation of fractures; and
- (ii) The confining zone is separated from the base of the lowermost underground source of drinking water by at least one (1) sequence of permeable and less permeable strata that will provide an added layer of protection in the event of fluid movement through an unlocated borehole or fault; or
- (iii) Within the area of review, the piezometric surface of the fluid in the receiver is less than the piezometric surface of the lowermost underground source of drinking water considering density effects, injection pressures, and any significant pumping of the overlying aquifer; or
- (iv) There are no underground source of drinking waters present.
(d) The administrator may approve a site which does not meet the above requirements, if the operator can demonstrate that because of the site's geology, nature of the waste, or other considerations, it would not cause endangerment to any underground source of drinking waters.
020-13 Wyo. Code R. § 13-12