In the wake of actions taken on August 5, 2015 by contractors for the United States Environmental Protection Agency (EPA) that resulted in the Gold King Mine Spill, western states that rely on water from the Animas River, the San Juan River, and the Colorado River may be left with long-term clean-up and monitoring issues as well as multiple legal challenges stemming from the spill.

Last week, the State of New Mexico filed an original jurisdiction lawsuit in the United States Supreme Court against the State of Colorado. This action is separate from the claims New Mexico previously filed in its May 23, 2016 lawsuit in the United States District Court for the District of New Mexico against the EPA, Gina McCarthy, Environmental Restoration, Kinross Gold, and Sunnyside Gold Corp., among others.

Although the majority of the claims asserted by New Mexico in the two lawsuits are strikingly similar, the suit against Colorado asserts that, in addition to Colorado’s direct role in the Gold King Mine Spill, “Colorado is directly responsible for the hazardous conditions that preceded the catastrophe.” New Mexico asserts that the long history of neglect and harmful actions undertaken by the State of Colorado are directly responsible for the conditions that led to the Gold King Mine Spill. As these two cases move forward through the courts the parties will likely be addressing the issues of long-term clean-up and monitoring plans to protect the water supply for several western states.

Additional lawsuits are likely to be filed by other parties over the next year. In the meantime, state agencies and water users already addressing severe drought issues may also wish to consider how to manage keeping up with multiple lawsuits that could impact their interests and how future storm events may raise additional concerns for the rivers impacted by the Gold King Mine Spill.