The U.S. Supreme Court recently decided to hear two environmental cases in its 2011-2012 term, which begins in October. The two cases will have consequences for waterbodies that may be subject to the public trust and for property owners and facilities operators who are given administrative compliance orders under federal environmental laws.

The first case, PPL Montana, LLC v. State of Montana, USSC No. 10-218, addresses the public trust doctrine and involves a dispute over the ownership three Montana rivers: the Missouri, Madison and Clark Fork Rivers. The State of Montana claims ownership of those waterways in trust for current and future residents as an incident of state sovereignty. PPL Montana, which operates hydroelectric plants on the three rivers, argues the waterways are private property. The issue turns on whether, under federal law, the rivers were “navigable” when Montana was admitted to the Union. The matter was first litigated in Montana state courts, with the Montana Supreme Court ruling that each of the rivers was “navigable” and that title vests in the State of Montana. In its petition to the U.S. Supreme Court, PPL Montana asserts that the Montana court used the wrong legal standard for navigability and improperly considered contemporaneous evidence to find the three disputed rivers were navigable.