Lets states team up with federal or state agencies to clean up polluted water from abandoned mines using formal agreements. Each agreement must lay out a plan to improve water quality, include long‑term monitoring and operations, go through a public comment process, and get joint approval from the Interior Department and the Environmental Protection Agency within 120 days. Approved agreements become part of the state’s existing mine cleanup plan.

It also updates related planning requirements and clarifies how state liability is handled for these mine drainage projects. The authority created by this Act ends on September 30, 2032 unless renewed.