(a)

1. (1) For all waters with specific aquatic life use designated in Appendix A, aquatic biota should not be impacted.
2. (2) Aquatic biota should be representative of streams that have the ability to support the designated aquatic life use, taking into consideration the seasonal and natural variability of the aquatic biota community under naturally varying habitat and hydrological conditions; the technical and economic feasibility of the options available to address the relevant conditions; and other factors.

(b)

1. (1)

   1. (A) (b)(1)(A) An aquatic biota assessment should compare biota communities that are similar in habitat and hydrologic condition, based upon either an in-stream study including an upstream and downstream comparison, a comparison to a reference water body within the same ecoregion, or a comparison to community characteristics from a composite of reference waters.
   2. (B) Such a comparison should consider the seasonal and natural variability of the aquatic biota community.

2. (2)

   1. (A) It is the responsibility of the Division of Environmental Quality to evaluate the data for an aquatic biota assessment to protect aquatic life uses designated in Appendix A.
   2. (B) Such data may be used to develop permit effluent limitations or conditions.