The town of Lahaina in Maui has become the center of a Clean Water Act (CWA) dispute that is tremendously important to agriculture, and the case will be heard by the Supreme Court this week.

The legal issue is whether pollutants are subject to CWA federal permitting controls and penalties if they reach surface waters (Waters of the US) via groundwater. This issue is important to agriculture as many environmental advocates want field tile discharge containing nitrogen and other materials to be subject to CWA permitting if that discharge goes to surface waters.

The facts in the Maui case now before the Supreme Court involve Lahaina’s sewage treatment system, which injects treated wastewater deep underground.  A substantial portion of the treated wastewater flows in groundwater into the ocean along some of Maui’s most famous beaches.

Environmental advocates want Lahaina to be subject to CWA penalties for failure to get a permit for these discharges and related “damages.” The 9^th Circuit Court of Appeals agreed with this argument. Three former EPA Administrators (both Democrat and Republican) support this view. The EPA has issued new guidance that holds that discharges through groundwater are not subject to the CWA. Several agricultural organizations filed a brief with the court in defense of Lahaina’s position.  A decision from the court is not expected until June.