Ohio Valley Environmental Coalition v. Horinko

The Environmental Protection Agency (EPA) (defendant), pursuant to its authority under the Clean Water Act (CWA), approved the state of West Virginia’s antidegradation implementation procedures that were designed to prevent the degradation of state waters. The antidegradation procedures provided the main stems of the Monongahela River and the Kanawha River from mile point 72 to the confluence with the Ohio River (the river segments) would only receive tier-one protection. Tier-one protection was afforded to water segments that failed to meet minimum uses. The EPA stated that there were two basic categories for how the states could identify high-quality waters that should be afforded tier-two protection. The approaches to classifying waters as tier one or two included a pollutant-by-pollutant approach or a water-body-by-water-body approach. Under the pollutant-by-pollutant approach, the state would make a classification for each pollutant in a given body of water and classify the body of water as tier two only for those pollutants for which water quality was better than the applicable criteria. Under the water-body-by-water-body approach, states would weigh a variety of factors to judge a water body segment’s overall quality. West Virginia designated the rivers using a water-body-by-water-body approach. The only evidence the EPA provided as to why the river segments were classified as tier one was the fact that both river segments were on a list prepared by the state of West Virginia of impaired waters for submission to the EPA as required by the CWA for any water that failed to meet quality standards for at least one pollutant parameter. The Ohio Valley Environmental Coalition (OVEC) (plaintiff) challenged the EPA’s approval of the antidegradation policy, arguing that there was insufficient evidence to conclude that the rivers were not entitled to tier-two protection.