EPA versus Colorado: National Unity versus State Flexibility

In 1981 Colorado comprehensively revised its Water Quality Control Act in legislation commonly referred to as Senate Bill 10. Subsequently, the Environmental Protection Agency (EPA) commenced a review of the adequacy of Colorado's delegated National Pollutant Discharge Elimination System (NPDES) permit program under the federal Clean Water Act, in view of the 1981 Colorado legislation. That review process generated additional amendments to the Colorado Act and continues at present. EPA' s review uncovered a conflict between