6 Colo. Code Regs. § 1007-1-18.2
"Aquifer" means a geologic formation, group of formations, or part of a formation capable of yielding a significant amount of ground water to wells or springs. Any saturated zone created by uranium or thorium operations would not be considered an aquifer unless the zone is or potentially is:
"As expeditiously as practicable considering technological feasibility", for the purposes of Criterion 6A, means as quickly as possible considering: the physical characteristics of the tailings and the site; the limits of available technology; the need for consistency with mandatory requirements of other regulatory programs; and factors beyond the control of the licensee. The phrase permits consideration of the cost of compliance only to the extent specifically provided for by use of the term available technology.
"Available technology" means technologies and methods for emplacing a final radon barrier on uranium mill tailings piles or impoundments. This term shall not be construed to include extraordinary measures or techniques that would impose costs that are grossly excessive as measured by practice within the industry (or one that is reasonably analogous), (such as, by way of illustration only, unreasonable overtime, staffing, or transportation requirements, etc., considering normal practice in the industry; laser fusion of soils, etc.), provided there is reasonable progress toward emplacement of the final radon barrier. To determine grossly excessive costs, the relevant baseline against which cost shall be compared is the cost estimate for tailings impoundment closure contained in the licensee's approved reclamation plan, but costs beyond these estimates shall not automatically be considered grossly excessive.
"Byproduct Material" is the same as in definition (2) of 1.2.2 and means the tailings or wastes produced by the extraction or concentration of uranium or thorium from any ore processed primarily for its source material content, including discrete surface wastes resulting from uranium solution extraction processes. Underground ore bodies depleted by such solution extraction operations do not constitute "byproduct material" within this definition.
"Certificate of designation" means the approval pursuant to article 20 of title 30, CRS., or section 25-15-204(6).
"Closure" means the activities following operations to decontaminate and decommission the buildings and site used to produce byproduct materials and reclaim the tailings and/or waste disposal area.
"Closure plan" means the Department approved plan to accomplish closure.
"Compliance period" begins when the Department sets secondary ground-water protection standards and ends when the owner or operator's license is terminated and the site is transferred to the State or Federal agency for long-term care.
"Dike" means an embankment or ridge of either natural or man-made materials used to prevent the movement of liquids, sludges, solids, or other materials.
"Disposal area" means the area containing byproduct materials to which the requirements of Criterion 6 of Appendix A to this Part 18 apply.
"Disposal site" means all land that is subject to transfer to a government agency after termination of the license.
"Existing portion" means that land surface area of an existing surface impoundment on which significant quantities of uranium or thorium byproduct materials had been placed prior to September 30, 1983.
"Facility" in this part means the physical location at one site or address and under the same administrative control at which:
"Factors beyond the control of the licensee" means factors proximately causing delay in meeting the schedule in the applicable reclamation plan for the timely emplacement of the final radon barrier notwithstanding the good faith efforts of the licensee to complete the barrier in compliance with paragraph (1) of Criterion 6A. These factors may include, but are not limited to:
"Final radon barrier" means the earthen cover (or approved alternative cover) over tailings or waste constructed to comply with Criterion 6 of this Appendix (excluding erosion protection features).
"Ground water" means water below the land surface in a zone of saturation. For purposes of Appendix A to this Part 18, ground water is the water contained within an aquifer as defined above.
"Leachate" means any liquid, including any suspended or dissolved components in the liquid that has percolated through or drained from the byproduct material.
"Licensed site" means the area contained within the boundary of a location under the control of persons generating or storing radioactive materials under a Department license.
"Liner" means a continuous layer of natural or man-made materials, beneath or on the sides of a surface impoundment, which restricts the downward or lateral escape of byproduct material, hazardous constituents, or leachate.
"Milestone" means an action or event that is required to occur by an enforceable date.
"Monitoring" means observing and making measurements to provide data to evaluate the performance and characteristics of a site.
"Operation" means that a uranium or thorium mill tailings pile or impoundment is being used for the continued placement of byproduct material or is in standby status for such placement. A pile or impoundment is in operation from the day that byproduct material is first placed in the pile or impoundment until the day final closure begins.
"Point of compliance" is the site specific location in the uppermost aquifer where the ground-water protection standard must be met.
"Reclamation plan", for the purposes of Criterion 6A of Appendix A of this Part 18, means the plan detailing activities to accomplish reclamation of the tailings or waste disposal area in accordance with the technical criteria of Appendix A of this Part. The reclamation plan must include a schedule for reclamation milestones that are key to the completion of the final radon barrier including as appropriate, but not limited to, windblown tailings retrieval and placement on the pile, interim stabilization (including dewatering or the removal of freestanding liquids and recontouring), and final radon barrier construction. (Reclamation of tailings must also be addressed in the closure plan; the detailed reclamation plan may be incorporated into the closure plan.)
"Residual radioactive material" means:
The term residual radioactive material is used only with respect to materials at sites subject to remediation under title I of the Uranium Mill Tailings Radiation control Act of 1978, as amended.
"Surface impoundment" means a natural topographic depression, man-made excavation, or diked area, which is designed to hold an accumulation of liquid wastes or wastes containing free liquids, and which is not an injection well.
"Third-party contractor" or "Third-party agreement" means a legal or contractual mechanism whereby an applicant or licensee voluntarily agrees to pay for the services, solely selected and supervised by the Department, of qualified persons not Department staff nor under contract directly to the Department.
"Uppermost aquifer" means the geologic formation nearest the natural ground surface that is an aquifer, as well as lower aquifers that are hydraulically interconnected with this aquifer within the facility's property boundary.
"Uranium milling" means any activity that results in the production of byproduct material as defined in Part 18.
6 CCR 1007-1-18.2