BSCES - "Residual Designation Authority: Preparing for the Next Wave of Stormwater Permitting"

Rosalie T. Starvish, P.E., CMS4S

Residual Designation Authority (RDA), although not well-known at this time, is a provision in the Clean Water Act that engineers, planners, attorneys, developers and economists should become familiar with in the near future.  On July 10, 2013, Conservation Law Foundation (CLF), in concert with other environmental action groups, filed legal petitions requesting that RDA be applied in thousands of watersheds throughout  New England (USEPA Region 1), the Mid-Atlantic (USEPA Region 3) and the Southwest (USEPA Region 9).  If EPA agrees with the petition, RDA could impact existing development in watersheds of impaired waterbodies throughout New England (2,000+ segments in 6 states), the Mid-Atlantic (4,500+ segments in 4 states and Washington, D.C.), and the Southwestern United States (1,400+ segments in 4 states).

What is RDA?  RDA allows EPA (or a state-delegated authority) to designate certain stormwater discharges as requiring National Pollutant Discharge Elimination System (NPDES) permits where either:

  • stormwater controls are needed to address pollutants of concern, or
  • discharges (or a category of discharges within a geographic area) are causing or contributing to a violation of a water quality standard within waters of the United States.

Recent applications of RDA in New England have generally resulted in new permitting and management obligations for the existing built environment, thus regulating discharges from targeted areas of concentrated impervious surfaces, including buildings, roadways, sidewalks and parking lots.

Where has RDA been applied?  To date, RDA petitions have been filed four times in New England since 2003.  First, CLF petitioned the Vermont Agency of Natural Resources to apply RDA within the watersheds of five impaired brooks in the Burlington area.  Although the final RDA determination in VT followed years after the initial petition was filed, approximately 400 property owners in these five watersheds are now subject to NPDES requirements, including stormwater permitting, management, and fees, due to RDA actions.

In March 2008, another RDA petition was filed by CLF.  This time CLF petitioned EPA directly, requesting that RDA be applied to stormwater discharges within the Long Creek watershed in South Portland, Maine.  A Record of Decision (ROD) was issued by EPA in coordination with Maine Department of Environmental Protection requiring NPDES permitting in accordance with a community-supported watershed management plan (WMP) finalized in 2009.  The estimated cost of implementation for the watershed-wide retrofits and Best Management Practices (BMPs) included in the WMP was projected to be $14 million.  Today, all parcels with one acre or more of impervious surfaces, including municipal and State roadways and Maine’s largest shopping mall within the 3.5-square-mile watershed, are required to maintain NPDES permit coverage for post-construction stormwater discharges within the Long Creek watershed.  Permit obligations also include paying annual fees of $3,000 per impervious acre and providing easements for structural retrofits or stream restoration efforts identified in the WMP.  The fees are paid to Long Creek Watershed Management District (LCWMD) that administers the permit and executes contracts to conduct routine maintenance (e.g., street sweeping, catch basin cleanouts, etc.), water quality monitoring, and structural stormwater upgrades.  An economy of scale is realized through the administration of these collective and centralized maintenance, monitoring and stormwater efforts; however, there is no guarantee that these efforts will eventually restore the watershed to its assigned water quality standards, which is the primary objective of both RDA actions and the Long Creek efforts.

In November 2008, under threat of a RDA petition from environmental groups in MA, EPA issued a preliminary determination (i.e., ROD) indicating that NPDES permits would be required for designated stormwater discharges in the headwaters of the Charles River watershed within the municipalities of Milford, Bellingham, and Franklin.  Although no RDA-specific permit has been finalized at this time, EPA provided a Draft General Permit for Designated Discharges in the Charles River Watershed within the Municipalities of Milford, Bellingham and Franklin, published in 2010.  This Draft General Permit was developed in hopes of restoring the river by using the General Permit as a tool, in combination with existing NPDES permits, to encourage a similar collective watershed-based Stormwater Management Plan (SMP) and Phosphorus Reduction Program (PRP).  According to the Draft General Permit, all parcels with two acres or more of impervious surfaces will be required to participate in the SMP and PRP to meet the pollutant loading reduction goals.  By initiating restoration in the headwaters of the Charles River, additional RDA efforts in lower segments over time could eventually address impairments, in hopes of restoring the entire river through the heart of Boston.  A recent study commissioned by EPA estimated a total capital cost of $180 million for implementation of controls to achieve the required phosphorus reductions in the three headwaters communities alone.  Applying this price tag to the remaining impaired segments of the Charles River, it is clear that additional RDA efforts could represent billions of dollars in additional capital and maintenance costs.

Most recently, the July 2013 RDA petition has widely expanded the potential application of RDA into thousands of watersheds within three separate geographic areas: New England, Mid-Atlantic, and Southwestern United States.  The petition requests that EPA regulate non-de minimis, non-NPDES permitted stormwater discharges from commercial, industrial, and institutional sites that contribute to violations of water quality standards in certain impaired waters.  The number of impaired watersheds listed in the petition is significant in New England alone, leaving both stormwater practitioners and regulators stymied with numerous questions.  How will thousands of watersheds and millions of discharges be permitted?  Where will the money to study impairments and design improvements for restoration come from?  Will the requirements and costs be similar to current RDA efforts in New England?  How will RDA be applied in the Mid-Atlantic (USEPA Region 3) and Southwestern United States (USEPA Region 9)?

How do RDA efforts compare?  In working with both public and private landowners in these areas already affected by RDA, GZA GeoEnvironmental, Inc. understands that these recent petitions are only the first step to potential additional NPDES permitting.  However, our past experience in New England has provided insight as to what the additional steps might entail, who may be impacted, and how much it will cost.  The events which unfolded, specifically in the Long Creek and Charles River watersheds after RDA appeared, were of a similar nature, but did not result in similar outcomes.  For example, the Long Creek and Upper Charles River stakeholder processes occurred over multiple years and included multiple municipalities and many commercial property owners.  The proposed solutions supported by EPA for both Long Creek and the Upper Charles River included collective, watershed-wide planning and pollutant reductions.  Identifying regulated parcels and/or designated discharges in both watersheds is based on a minimum amount of impervious surfaces (i.e., one acre versus two acres of impervious area).

On the other hand, although both Long Creek and Upper Charles River efforts encourage collective planning for restoration, the differences between the two RDA actions are significant.  For example, the entirety of the Long Creek watershed was targeted in ME with advance warning provided to landowners from CLF and EPA regarding the potential RDA action to allow a proactive, collaborative, community-supported approach.  Only a portion of the Charles River watershed was targeted in MA thus leaving the three headwater communities wondering why they were targeted and provided little to no advance warning to collaborate or even understand the potential impacts of the RDA action.  The permits resulting from the two RDA efforts are also different.  The Long Creek permit, which was issued in response to the petition, occurred in parallel with the collective plan (i.e., during WMP finalization) and formation of the LCWMD to implement the goals of the community-supported WMP.  Conversely, since 2010, no apparent progress has been made to finalize the Draft General Permit for the Upper Charles or to identify or form a unifying organization, like LCWMD, to administer the General Permit and its anticipated requirements. 

What’s next?  EPA must eventually issue a ROD in response to the RDA petition filed in July 2013.  The details of the ROD and requirements of the final permit and timeframes for compliance applicable to affected commercial, industrial, and institutional property owners have yet to be determined. For example, EPA must define what will be considered a “non-de minimis discharge,” such as one or two acres of impervious surfaces (or perhaps some other measure or enforceable threshold for stormwater discharges).  With no anticipated timeframe for EPA’s response to the most recent petition, landowners await EPA’s ROD, which will determine if commercial, industrial, and institutional sites are required to obtain NPDES permits in order to continue discharging stormwater runoff from existing development in thousands of watersheds in the three targeted regions of the country.  In the meantime, environmental action groups continue to pressure regulators to increase the scope and complexity of requirements to manage stormwater runoff from existing development and restore impaired watersheds, while engineers, planners, attorneys, developers and economists struggle to understand where all of the money will come from if response to this RDA petition is required in accordance with the Clean Water Act.

For more information, please contact Robyn Saunders ( or 207-358-5114) or Rosalie Starvish, P.E. ( or 413-726-2119) at GZA GeoEnvironmental, Inc.  They will be providing more information regarding their RDA experiences at a presentation at the NEWEA Annual Conference in Boston, MA on Monday, January 27, 2013.