Ariz. Admin. Code § 18-11-209

Current through Register Vol. 30, No. 45, November 8, 2024

Section R18-11-209 - Variances

A. Upon request, the Director may establish, by rule, a discharger-specific or water segment-specific or water segments-specific variance from a water quality standard if requirements pursuant to this Section are met.

B. A person who requests a variance must demonstrate all of the following information:

1. Identification of the specific pollutant and water quality standard for which a variance is sought.

2. Identification of the receiving surface water segment or segments to which the variance would apply.

3. A detailed discussion of the need for the variance, including the reasons why compliance with the water quality standard cannot be achieved over the term of the proposed variance, and any other useful information or analysis to evaluate attainability.

4. A detailed description of proposed interim discharge limitations and pollutant control activities that represent the highest level of treatment achievable by a point source discharger or dischargers during the term of the variance.

5. Documentation that the proposed term is only as long as necessary to achieve compliance with applicable water quality standards.

6. Documentation that is appropriate to the type of designated use to which the variance would apply as follows. For a water quality standard variance documentation must include a demonstration of at least one of the following factors that preclude attainment of the use during the term of the variance:

a. Naturally occurring pollutant concentrations prevent attainment of the use;

b. Natural, ephemeral, intermittent or low flow conditions or water levels prevent the attainment of the use, unless these conditions may be compensated for by the discharge of sufficient volume of effluent discharges without violating state water conservation requirements to enable uses to be met;

c. That human-caused conditions or sources of pollution prevent the attainment of the water quality standard for which the variance is sought and either (1) it is not possible to remedy the conditions or sources of pollution or (2) remedying the human-caused conditions would cause more environmental damage to correct than to leave in place;

d. Dams, diversions or other types of hydrologic modifications preclude the attainment of the use, and it is not feasible to restore the water body to its original condition or to operate such modification n a way that would result in the attainment of the use;

e. Physical conditions related to the natural features of the water body, such as the lack of a proper substrate, cover, flow, depth, pools, riffles, and the like, unrelated to water quality, preclude attainment of aquatic life protection uses;

f. Actions necessary to facilitate lake, wetland, or stream restoration through dam removal or other significant reconfiguration activities preclude attainment of the designated use and criterion while the actions are being implemented.

7. For a waterbody segment-specific or segments-specific variance, the following information is required before the Director may issue a variance, in addition to all other required documentation pursuant to this Section:

a. Identification and documentation of any cost-effective and reasonable best management practices for nonpoint source controls related to the pollutant or pollutants or water quality parameter or parameters and water body or waterbody segment or segments specified in the variance that could be implemented to make progress towards attaining the underlying designated use and criterion; and

b. If any variance pursuant to subsection (B)(7)(a) previously applied to the water body or waterbody segment or segments, documentation must also demonstrate whether and to what extent best management practices for nonpoint source controls were implemented to address the pollutant or pollutants or water quality parameter or parameters subject to the water quality variance and the water quality progress achieved.

8. For a discharger-specific variance, the following information is required before the Director may issue a variance, in addition to all other required documentation pursuant to this Section: Identification of the permittee subject to the variance.

C. The Director shall consider the following factors when deciding whether to grant or deny a variance request:

1. Bioaccumulation,

2. The predicted exposure of biota and the likelihood that resident biota will be adversely affected,

3. The known or predicted safe exposure levels for the pollutant for which the variance is requested, and

4. The likelihood of adverse human health effects.

D. The variance shall represent the highest attainable condition of the water body or water body segment applicable throughout the term of the variance.

E. A variance shall not result in any lowering of the currently attained ambient water quality, unless the variance is necessary for restoration activities, consistent with subsection (B)(6)(a)(vi). The Director must specify the highest attainable condition of the water body or waterbody segment as a quantifiable expression of one of the following:

1. The highest attainable interim criterion,

2. The interim effluent condition that reflects the greatest pollutant reduction achievable.

F. A variance shall not modify the underlying designated use and criterion. A variance is only a time limited exception to the underlying standard. For discharge-specific variances, other point source dischargers to the surface water that are not granted a variance shall still meet all applicable water quality standards.

G. Point source discharges shall meet all other applicable water quality standards for which a variance is not granted.

H. The term of the water quality variance may only be as long as necessary to achieve the highest attainable condition and must be consistent with the supporting documentation in subsection (E).

I. The Director shall periodically, but not more than every five years, reevaluate whether each variance continues to represent the highest attainable condition. Comment on the variance shall be considered regarding whether the variance continues to represent the highest attainable condition during each rulemaking for this Article. If the Director determines that the requirements of the variance do not represent the highest attainable condition, then the Director shall modify or repeal the variance during the rulemaking.

J. If the variance is modified by rulemaking, the requirements of the variance shall represent the highest attainable condition at the time of initial adoption of the variance, or the highest attainable condition identified during the current reevaluation, whichever is more stringent.

K. Upon expiration of a variance, point source dischargers shall comply with the water quality standard.

Ariz. Admin. Code § R18-11-209

Former Section R9-21-209 renumbered and amended as Section R9-21-210, new Section R9-21-209 adopted effective January 29, 1980 (Supp. 80-1). Former Section R9-21-209 renumbered as Section R9-21-208, Tables I and II amended as Appendix B (now shown following R9-21-213 and Appendix A), former Section R9-21-210 renumbered as Section R9-21-209 and amended effective January 7, 1985 (Supp. 85-1). Former Section R9-21-209 renumbered and amended as Section R9-21-210, former Section R9-21-208 renumbered and amended as Section R9-21-209 effective August 12, 1986 (Supp. 86-4). Former Section R9-21-209 renumbered without change as Section R18-11-209(Supp. 87-3). Section repealed effective February 18, 1992 (Supp. 92-1). New Section made by final rulemaking at 29 A.A.R. 302, effective 2/20/2023.