In lakes and impoundments, or portions thereof, which exhibit natural thermal stratification, all applicable narrative and numerical criteria, with the exception of the numerical criteria for temperature, apply only to the epilimnion. Numerical temperature criteria apply at all depths (epilimnion, metalimnion, and hypolimnion) of lakes and impoundments exhibiting natural thermal stratification. In lakes and impoundments, or portions thereof, not exhibiting natural thermal stratification, the applicable narrative and numerical criteria apply at all depths.
117 Neb. Admin. Code, ch. 6, § 002