ARSD 74:52:03:20. Effluent limits for internal waste streams

If permit effluent limits or standards imposed at the point of discharge are impractical or infeasible, effluent limits or standards for discharges of pollutants may be imposed on internal waste streams before mixing with other waste streams or cooling water streams. In those instances, the required monitoring shall also be applied to the internal waste streams. Limits on internal waste streams shall be imposed only when the statement of basis sets forth the exceptional circumstances which make such limits necessary, such as when the final discharge point is inaccessible, the wastes at the point of discharge are so diluted as to make monitoring impracticable, or the interferences among pollutants at the point of discharge make detection or analysis impracticable.