Supreme Court Extends Clean Water Act Coverage

The U.S. Supreme Court issued an opinion last week that clarifies the scope of the Clean Water Act to include groundwater discharges that are “functionally equivalent” to surface water discharges. The ruling represents a win for clean water by closing a potential loophole that would have allowed dischargers to evade permit requirements by simply discharging into groundwater, even though pollution may quickly reach a navigable water.  

The case addresses a wastewater discharge to groundwater by Maui County, Hawaii. Evidence in the case showed that pollutants from the wastewater eventually reach the Pacific Ocean. Environmental groups sued the county because it did not have a permit for a discharge of pollutants under the Clean Water Act. They argued that even though the discharges were made to groundwater, they required a permit because the pollution reached a navigable water. Maui County and the federal government responded that the Clean Water Act’s scope did not include groundwater. 

The decision was an unusual 6-3 vote in favor of environmental protection. The interpretation of Congress’s intent regarding the Clean Water Act’s scope and goals was a refreshing reminder of the Act’s importance and nonpartisan popularity. It was also a refutation of the U.S. EPA’s statement that sided with Maui County and adopted a limited interpretation of the Agency’s regulatory duty under the CWA. 

How might this decision affect Iowa waters? 

Iowa has potential discharges to groundwater that may be affected, such as leaks from unlined ponds. As other commentators have noted, the decision did not directly overturn lower court decisions about coal ash ponds at power plants. Coal ash ponds are often unlined, which has led to groundwater contamination, and they are typically located close to surface waters that could become polluted.

Iowa has numerous coal ash ponds, many of which are close to floodplains. Previous litigation in other states has generally found coal ash ponds did not meet the definition of a “point source,” so their release of pollutants still might may not be regulated under the Clean Water Act. 

The ruling may also have implications for another industry in Iowa: concentrated animal feeding operations. CAFOs are defined as point sources in the Clean Water Act, so any discharge of pollutants may require a permit. Earthen lagoons may have some degree of seepage and could be subjected to the “functional equivalent” test of the court decision. Most CAFOs in Iowa do not have Clean Water Act discharge permits today. 

Because the decision created new criteria to require a Clean Water Act permit, it will almost certainly lead to new lawsuits around the country. The resulting lower court interpretations will determine how big an impact the Maui decision will have. For now, IEC is celebrating this win for clean water. 

1. water quality