The past several months have witnessed multiple attempts by environmental groups bring currently unregulated entities that discharge stormwater into the Clean Water Act (CWA) National Pollution Discharge Elimination System (NPDES) permitting program. CWA section 402(p) and EPA’s regulations provide a mechanism to require NPDES permits for additional sources of stormwater discharges that EPA or a state determine “contribute to a violation of a water quality standard or [are] a significant contributor of pollutants to waters of the United States.” Multiple groups have sued EPA to force the Agency to exercise this “residual designation authority” and require privately-owned commercial, industrial, and institutional sites to obtain NPDES permits for their stormwater discharges. If successful, these suits could pull a range of operations—from privately-owned universities and mixed-used developments to warehouses and retailers—into the NPDES stormwater program for the first time.
A recent decision by the First Circuit in Conservation Law Foundation v. Pruitt ended one set of these lawsuits by holding that EPA’s approval of a total maximum daily load (TMDL) does not constitute an exercise of the Agency’s residual designation authority. In a consolidated appeal from decisions by district courts in Rhode Island and Massachusetts, the court rejected the argument that the approvals of TMDLs in those states amounted to determinations that specific sources—or groups of sources—were required to obtain NPDES permits for their stormwater discharges. The court explained that approval of the TMDLs constitutes nothing more than EPA’s determination that they “meet the requirements of § 303(d)” of the CWA.
The panel further explained that the TMDLs at issue also failed to identify sources with the level of specificity necessary to constitute an exercise of EPA’s residual designation authority. These TMDLs only “address[ed] discharges at the abstract level of source type”; they did not identify specific sources or categories of sources required to obtain permits. In the court’s view, requiring permits from vaguely identified source types listed in a TMDL would expand the NPDES program for stormwater discharges beyond what Congress intended when it inserted the stormwater provisions into the CWA in 1987. Congress could not have intended that “every storm water-related TMDL that the EPA approves” would expand the universe of stormwater dischargers required to obtain permits.
In closing the door on residual designation through TMDLs, the First Circuit emphasized that EPA will typically exercise this authority in response to citizen petitions. Two sets of law suits—one brought in Maryland and the other in California—concern EPA’s denial of citizen petitions requesting that EPA exercise its residual designation authority. Both sets of cases argue that EPA has a mandatory duty to make a final determination regarding the effects of stormwater discharges on water quality once the Agency is presented with a residual designation petition. These plaintiffs further argue that EPA does not have the authority to consider the efficacy of other stormwater management programs when evaluating these petitions.
If these suits, or similar actions, succeed, swaths of non-industrial operations would suddenly be pulled into the NPDES program. By bringing this litigation, these environmental groups are seeking the regulation of stormwater discharges from any site primarily used for commercial activity, heavy or light industrial activity; or institutional functions (e.g., schools or hospitals). In short, up and down the supply chain—from manufacturers and warehouses to distributors and retail outlets—businesses currently beyond the reach of federal stormwater regulation could find themselves having to contend with NPDES compliance obligations.