18 AAC 70.040 - Procedures for applying water quality criteria

In applying the appropriate water quality criteria for any waterbody or portion of a waterbody, the department will use the following procedures:

(1) if a waterbody is protected for more than one use class under 18 AAC 70.050 or 18 AAC 70.230(e), the most stringent water quality criteria for all the included use classes will apply;

(2) at the boundary between waters protected for different use classes under 18 AAC 70.050 or 18 AAC 70.230(e), the water quality criteria for the more stringent use class will apply; and

(3) in estuaries, where the fresh and marine water quality criteria differ within the same use class, the standard will be determined on the basis of salinity; however, the marine water quality criteria will apply for

(A) dissolved oxygen if the salinity is one part per thousand or greater; and

(B) fecal coliform bacteria if the salinity is 10 parts per thousand or greater;

(4) if both a narrative and a numeric criterion apply under 18 AAC 70.020(b), compliance with the numeric criterion satisfies the narrative criterion unless the department finds that the potential for cumulative or synergistic effects or other reasons specific to a particular situation require a more stringent criterion to protect the designated use.

Notes

18 AAC 70.040

Eff. 11/1/97, Register 143; am 9/19/2009, Register 191

Authority:AS 46.03.020

AS 46.03.070

AS 46.03.080