2025 Lookahead: Resiliency Planning in Stormwater

Though the vast majority of industrial facilities in the United States with stormwater discharge maintain stormwater permit coverage issued by their State, the United States Environmental Protection Agency (U.S. EPA) Multi-Sector General Permit (MSGP) serves as a guide to states when it is time to renew their own permits (every five years). While many states issue one MSGP, some states, such as Alabama, New Jersey and North Carolina, issue multiple general permits specific to individual industry categories.

Multiple states renewed their own MSGP in 2024, including Rhode Island, which followed U.S. EPA’s lead in adding resiliency planning requirements to their permit. Connecticut also issued a draft MSGP with very similar requirements (a second draft Connecticut MSGP is now out for public comment and still contains resiliency planning requirements). The resiliency planning requirements in U.S. EPA and Connecticut MSGPs do not require facilities to implement prescriptive additional stormwater control measures (Rhode Island’s MSGP does state that facilities “must implement” measures), but facilities must document existing measures in their SWPPP as well as “considerations made to select and design control measures…to minimize pollutants discharged via stormwater” (2021 U.S. EPA MSGP), including (emphasis added):

• Reinforce materials storage structures to withstand flooding and additional exertion of force;
• Prevent floating of semi-stationary structures by elevating to the Base Flood Elevation (BFE) level or securing with a non-corrosive device;
• Delaying delivery of exposed materials when a storm is expected or store materials as appropriate;
• Temporarily store materials and waste above the BFE level;
• Temporarily reduce or eliminate outdoor storage;
• Temporarily relocate any mobile vehicles and equipment to higher ground;
• Develop emergency procedures for major storms and conduct training.

States with stormwater general permits set to expire and/or expected to be renewed in 2025 include Alaska, Minnesota, Mississippi, North Dakota, Tennessee, Vermont (expired 7/12/24, draft issued), and Wisconsin. In renewing their permits, these states may adopt similar provisions regarding resiliency as the 2021 U.S. EPA MSGP.

If this weren’t enough, in December 2024, U.S. EPA issued a proposed 2026 MSGP for public comment (public comment period ends on February 11, 2025). Among other changes, the proposed 2026 MSGP includes even more onerous and robust revisions to the consideration of stormwater control measure enhancements for major storm events, including:

• New considerations based on whether a facility has been exposed to major storm events under “current conditions” (defined as the 100-year flood) or may be exposed to major storm and flood events based on best available data;
• Removing the word “temporarily” from considerations pertaining to storing materials and waste above the BFE level, reducing or eliminating outdoor storage, and relocating mobile vehicles and equipment to higher ground;
• Changing references to “base flood elevation” to “flood level,” with a definition;
• Adding a control measure to identify emergency contacts for staff and contractors, and;
• Adding several definitions including:
  • “Adaptive measures refers to structural improvements, enhanced/resilient pollution prevention measures, and/or other control measures, actions, or strategies that mitigate the effects of impacts from stormwater discharges from major storm and flood events. They may include but are not limited to: building or modifying infrastructure, utilization of models…monitoring and inspections…and repair/retrofit.”
  • “Impacts” is defined as “an effect on a component of the stormwater collection system and/or related operation that may include destruction, damage, or ineffective operation such as bypass, upset or failure, overflow, increased inflow and infiltration or discharges of pollutants, and effluent limit exceedance. Impacts may be economic, environmental, or public health related.”
  • “Best available data refers to both the most current observed data and available forward-looking projections…such as data on observed and projected precipitation and storm events, sea level rise, storm surge, stream gauges…expected service life, and inspection and maintenance schedules.”

Similar to the 2021 U.S. EPA MSGP, the proposed 2026 U.S. EPA MSGP does not require facilities to implement additional controls if they are determined to be unnecessary. However, facilities are required to consider the benefits of control measures that reduce risk to their facility and the impact of pollutants in stormwater discharges caused by major storm events.

If you have general industrial stormwater permit coverage and operate in a state that is either under U.S. EPA jurisdiction or has a permit due for renewal in 2025, keep an eye out for inclusion of resiliency planning measures and how they may impact your facility. If you need help evaluating resilient pollution prevention measures, tracking developments in stormwater permitting, obtaining stormwater permit coverage, or developing your facility’s SWPPP, please reach out to Lizzie Smith, ALL4’s Water Tech Team Lead, at lsmith@all4inc.com or 770-999-0269.