If you’ve not yet heard the Supreme Court decided Rapanos and Carabell, the opinion written by Scalia is one of the worst environmental decisions ever. It eliminates protection for 80% of all wetlands, most class 2 and all ephemeral streams. It reverses all the gains made over the past 20 years in protecting waters of the US from development and pollution. It was a 4-1-4 decision.
Scalia restricts waters of the US to those waters that always contain running water and wetlands that are contiguous with those waters and connected by surface flow only. A hydrological connection is insufficient to create adjacency. Scalia recognizes that these sources may be point sources. But then that shifts the burden to the plaintiff to prove that pollution is reaching the US water from these sources. A nearly impossible task in most cases.
Justice Kennedy voted to remand the cases for further fact finding under the Bayview standard to see if there exists a significant nexus between adjacent non-surface connected waterways. Arguable if there exists a significant nexus (which is yet to be defined clearly). An adjacent waterbody with only a hydrological connection would be considered a water of the US by Kennedy and thus the court would vote 5-4 in favor of such a decision.