The city of Fayetteville, Arkansas, received a National Pollutant Discharge Elimination System permit from the Environmental Protection Agency (EPA) for the discharge of sewage into a stream that ultimately reaches the Illinois River, twenty-two miles upstream from the Oklahoma border.

The EPA permit limited the effluent discharge to comply with Oklahoma water quality standards, but the EPA stated that those standards would be violated only if the discharge would cause an actual, detectable violation of Oklahoma standards. Oklahoma appealed the permit, arguing that the permit violated Oklahoma water quality standards, which allow no degradation of water quality. Explain whether the permit should be granted.