1. (a) A person may not conduct an operation that causes or contributes to a violation of the water quality standards set by this chapter.
2. (b) The water quality standards set by this chapter specify the degree of degradation that may not be exceeded in a waterbody as a result of human actions. The water quality standards are set by the antidegradation policy in 18 AAC 70.015, the water quality criteria in 18 AAC 70.020(b), and the limits in 18 AAC 70.030, applied in accordance with the remainder of this chapter.
3. (c) Except as specified in an authorization issued under 18 AAC 15, 18 AAC 60, or 18 AAC 72, the water quality standards and limits set by or under this chapter do not apply to a treatment works authorized by the department under 18 AAC 60 or 18 AAC 72, except that the water quality criteria and limits set by or under this chapter must be met in adjacent surface water and groundwater at and beyond the boundary of the treatment works.

4. (d) Where the department determines that the natural condition of a water of the state not subject to 33 U.S.C. 1251 - 1387 (Clean Water Act) is of lower quality than the water quality criteria set out in 18 AAC 70.020(b), the natural condition supersedes the criteria and becomes the standard for that water. When establishing water quality-based effluent limits based on natural conditions in a permit, certification, or other written decision, the department will follow the procedures set out in the

   1. (1) department's Guidance for the Implementation of Natural Condition-Based Water Quality Standards, dated November 15, 2006, and adopted by reference; or
   2. (2) monitoring requirements for groundwater, set out under 18 AAC 60.

(Eff. 11/1/97, Register 143; am 12/28/2006, Register 180; am 1/8/2025, Register 253)

Authority: AS 46.03.010, AS 46.03.070, AS 46.03.110, AS 46.03.020, AS 46.03.080, AS 46.03.710, AS 46.03.050, AS 46.03.100, AS 46.03.720