How to regulate stormwater discharges from impervious areas such as parking lots remains a hotly disputed environmental issue. Most recently, U.S. EPA Region 9 rejected a petition filed by environmental advocacy groups under the federal Clean Water Act calling for regulation of stormwater discharges into the Alamitos Bay/Los Cerritos Channel watershed in Los Angeles County from “privately-owned commercial, industrial, and institutional sites.”  This petition is one of a number of so-called Residual Designation Authority (RDA) petitions that have been filed around the country demanding that the U.S. EPA regulate stormwater discharges from commercial properties with large areas of impervious surface, like office parks, shopping centers, and apartment complexes.  If successful, these RDA petitions would impose costly regulatory requirements (including retrofitting stormwater treatment systems) on commercial property owners and developers.  Industrial and institutional properties, like warehouses, hospitals and college campuses could also be affected.

Section 402(p)(2)(E) of the Clean Water Act and 40 C.F.R § 122.26(a)(9) provides the U.S. EPA with authority to regulate certain otherwise unregulated stormwater discharges if itdetermines that those discharges are contributing to violations of water quality standards or are a significant contributor of pollutants. The U.S. EPA’s regulations expressly allow for third parties like environmental advocacy groups to file petitions seeking exercise of this RDA. 40 C.F.R. § 122.26(f)(2).

In this most recent case, three environmental groups filed an RDA petition demanding that U.S. EPA Region 9 require privately-owned commercial, industrial, and institutional sites in the Alamitos Bay/Los Cerritos Channel watershed to apply for Clean Water Act NPDES permits.  U.S. EPA Region 9 demurred on the grounds that other regulatory programs were already in place to address water quality impairments from stormwater discharges, and that these programs, including permitting requirements on municipal separate stormwater sewers, should be allowed adequate time to take effect before considering additional regulatory requirements.

This RDA petition was one of three filed last year targeting specific watersheds around the country. The two other petitions were filed in U.S. EPA Region 3 – one regarding the Back River watershed in Baltimore, MD and the other regarding Army Creek in New Castle County, DE.  U.S. EPA Region 3 has not responded to either of those petitions yet.

While environmental groups are increasingly turning to RDA petitions to force additional regulation of stormwater discharges from non-industrial sources, that strategy has yielded mixed results to date. The Conservation Law Foundation (CLF) first employed this approach in Vermont, where it secured a court order compelling the Agency for Natural Resources to implement an RDA stormwater permitting program.  In re Storwater NPDES Petition, 910 A.2d 824 (2006).  In another instance, CLF relied on the RDA provisions to provide a regulatory framework for a consensual stormwater management program implemented in a portion of the Long Creek watershed in Portland, ME.

Subsequent efforts with RDA petitions have proven less successful. CLF has filed several RDA petitions to force regulation of stormwater discharges from commercial properties into the Charles River watershed outside of Boston, MA.  U.S. EPA’s New England Region declined to act on these RDA petitions.  In response, CLF filed a Clean Water Act citizen suit last February seeking to compel U.S. EPA to take the actions demanded in the RDA petitions. Conservation Law Found. v. U.S EPA, Civil Action No. 1:16-cv-10397 (D. Mass.)  The government has moved to dismiss the case, but a decision on that motion is likely months away. (CLF filed a similar citizen suit in Rhode Island, which the government has also moved to dismiss).

In 2014, environmental groups filed RDA petitions in U.S. EPA Regions 1, 3 and 9 seeking broad residual designations for stormwater discharges in each of those regions. Each of those regions declined to take any action in response to any of those petitions.

The U.S. EPA’s approach with respect to RDA petitions appears consistent with its approach to the previously proposed national post-construction stormwater regulations.  In 2010, in connection with the settlement of a citizen suit involving water quality impacts in the Chesapeake Bay, the U.S. EPA agreed to propose regulations to manage stormwater discharges from commercial sites after they are developed or re-developed.  After four years of extensive rulemaking efforts, U.S. EPA announced that it would not move forward with these post-construction regulations, but would instead rely on existing regulatory programs, as well as providing additional incentives and technical assistance, to address stormwater impacts from commercial sites.

While that may seem like a sensible approach – both with respect to the previously proposed national post-construction regulations and the more recent watershed-specific RDA petitions – environmental advocacy groups continue to argue that the U.S. EPA has a non-discretionary duty to take regulatory action. The question then becomes whether these groups can convince a court to adopt their view that U.S. EPA lacks discretion to determine what if any administrative actions should be implemented to address stormwater impacts from commercial properties.