On October 21 and November 3, EPA Regions 3 and 9 denied petitions from eNGOs for the agency to use its “residual designation authority” (RDA) to expand the universe of stormwater discharges that are regulated by the Clean Water Act (CWA) in specific watersheds in Maryland and California. See 33 U.S.C. § 1342(p)(2)(E); 40 C.F.R. §§ 122.26(a)(1)(v), (a)(9)(i)(D). This was an important decision by EPA, and any resulting litigation could have significant implications for businesses or activities with significant swaths of impervious surfaces, from which stormwater discharges may occur.
Stormwater can wash sediment, nutrients, metals and other pollutants into surface waters. Impervious surfaces like roofs, parking lots and sidewalks alter the land’s natural infiltration capability, potentially increasing stormwater discharges. Under the existing CWA stormwater regulatory program, generally only stormwater discharges associated with industrial and construction activity and from municipal storm sewer systems require NPDES permits. Various eNGOs have been applying significant pressure on EPA and the states to increase the universe of regulated sources of stormwater (e.g., new and redevelopment) and require design and/or performance standards for those properties. This effort includes urging EPA through rulemaking to revise the stormwater regulations at 40 C.F.R. Part 122 and litigation to force EPA to permit these sources of stormwater. See e.g., Conservation Law Foundation v. U.S. EPA, Case No. 15-00165 (D. R.I.) (litigation pending).
EPA Regions 3 and 9 agreed that nonregulated commercial, industrial and institutional sites entail significant areas of impervious surface on which a variety of pollutants may collect, and that the data submitted by the eNGOs, along with analyses conducted by the EPA and the states, demonstrate that, taken as a monolithic category, these sources contribute to water quality impairments in the receiving waters at issue in the RDA petitions. Notwithstanding those findings, EPA Regions 3 and 9 denied the petitions on the grounds that effective state programs already are in place to address the water quality impairments in the watershed, and that these existing programs should be afforded adequate time for implementation before pursuing a new, resource-intensive regulatory program.
If eNGOs challenge EPA’s actions in federal district court, they may argue that EPA has a duty to require NPDES permits for these sources of stormwater after it has identified that they have an impact on water quality, even if some of those facilities or activities do not individually impact water quality in any material way. Any resulting decision from that litigation will be important, as the underlying legal rationale would be applicable to watersheds nationwide and have implications for any source with large amounts of impervious surface that discharges stormwater into those watersheds.