A recent state appellate court decision sharply limited the bases on which Clean Water Act permittees may challenge permitting requirements imposed to comply with a federal Chesapeake Bay “Total Maximum Daily Load” (“TMDL”), often described as a watershed-wide “pollution diet.” The decision directly impacts municipalities with separate stormwater sewer (“MS4”) permits, as well as certain agricultural and other industrial concerns with stormwater requirements.

The Maryland Court of Appeals opinion affirmed water pollution (“NPDES”) permits issued to authorize discharges from two municipal separate storm sewer systems (“MS4s”) to the Chesapeake Bay watershed. Md. Dep’t of the Envt. v. County Comm’rs of Carroll County, Nos. 5 & 7, Sept. Term 2018 (Md. Aug. 6, 2019). The court held that state permits issued by the Maryland Department of the Environment (MDE) are required to conform to the Chesapeake Bay Total Maximum Daily Load (TMDL) issued by the federal Environmental Protection Agency and the Maryland Watershed Implementation Plan (WIP) promulgated by MDE and approved by EPA. The permittee may not challenge permit conditions necessary to meet the requirements of the TMDL or the WIP through judicial review of the permit, but instead must have already sought review in federal court of the TMDL. Moreover, EPA’s interpretation of the TMDL is entitled to Chevron deference.…
Continue Reading Maryland Court of Appeals Limits Bases for Challenging CWA Permits under the Chesapeake Bay TMDL