The Clean Water Act in Practice: Implementation in Massachusetts Under the Supreme Court’s County of Maui Decision

In April 2020, in County of Maui v. Hawaii Wildlife Fund, the U.S. Supreme Court held that the Clean Water Act requires a permit when the addition of pollutants into navigable waters through a non-point source (such as groundwater) is the “functional equivalent” of direct discharges from a point source. Following the Maui decision, many activities, from stormwater management systems, wastewater management systems, and leaking infrastructure like storage tanks, may be subject to regulation and permitting under the CWA, leaving the regulated community and permitting agencies with many questions about future implementation.

In January 2021, the U.S. Environmental Protection Agency issued a guidance memorandum on the application of the Maui decision, and Massachusetts has seen a variety of cases that have touched on the application of Maui to the CWA. The panelists, including Mintz Member, Jeff Porter, have worked directly on these cases and issues, and they will provide an up-to-date review of the CWA’s application under Maui, starting with a general overview of the state of the law, followed with specific and recent Massachusetts-based example cases.