5 Colo. Code Regs. § 1002-64.6
The Division may grant a variance from any provision of these regulations in a particular case where it determines that the public health or water quality benefits that will be created by compliance with the subject provision do not bear a reasonable relationship to the costs required to achieve compliance, except that in no case shall the Division grant a variance such that any resultant requirement or standard is less stringent than required by federal regulation. Any such variance shall be reasonably consistent with the protection of public health and of water quality.
Any person who requests a variance from a provision of these regulations shall bear the burden of developing and supplying the Division with such information as the Division deems necessary to adequately demonstrate the existence of conditions which warrant issuance of a variance. A variance may be requested at any time. Any such request shall be made in writing. The Division shall notify the applicant of the adequacy of information contained within the applicants request within 45 days of receipt of the variance request. The Division shall either issue or deny a variance request within 90 days of receipt of a complete and adequate variance request. Any such variance issued by the Division shall be made in writing. No person shall be considered to have obtained a variance until said person is in receipt of the Division's written statement granting such variance. Any such written statement shall identify the provision of these regulations from which a variance has been awarded, and shall prescribe any requirements with which the recipient of the variance must comply in lieu of the provision for which a variance has been issued. The Division shall prescribe such requirements as are reasonably consistent with the protection of the public health and of water quality.
All variances awarded by the Division in any one month shall be reported to the Water Quality Control Commission at its subsequent regular meeting.
5 CCR 1002-64.6