Regulatory Alert: AAAE Responds to EPA's Fact Sheet Guidance for Airports on Industrial Stormwater Discharges

AAAE submitted comments to the U.S. Environmental Protection Agency (EPA) on March 28 in response to a request for input on the agency's fact sheet guidance on the 2021 multi-sector general permit (MSGP), which outlines the terms and conditions for authorizing certain airports to discharge industrial stormwater. AAAE emphasized that EPA's suggested best management practices (BMPs) for managing stormwater discharge must be feasible, effective, and voluntary in nature because airports need flexibility to implement the types of BMPs that appropriate to the facility's size, location, and prior history, among other things. 

In addition, AAAE raised concerns that EPA's use of the MSGP guidance document is an inappropriate tool for addressing potential PFAS exposure to stormwater discharge at airports. While the guidance is not mandatory, AAAE is concerned that EPA may be laying the foundation to require airports and other permit holders to implement stormwater control measures that minimize such exposure. AAAE acknowledged the challenges associated with PFAS and instead urged the agency to work with FAA and the airport community on standalone guidance that will help the industry successfully transition away from AFFF, which FAA requires airports to use.

MSGP Background. In accordance with the Clean Water Act, EPA implements the National Pollutant Discharge Elimination System (NPDES) program, which requires permits for any person or organization, including airports, to discharge industrial stormwater into waters of the United States. The MSGP provides operators with coverage for such stormwater discharge for three states, Washington, D.C., many Tribal areas, and U.S. territories, where EPA is the NPDES permitting authority. However, many states use the MSGP as a model for developing their own industrial stormwater discharge permits, reflecting its importance. 

PFAS and the NPDES MSGP. Last year, EPA issued the 2021 MSGP that remains in effect for five years. The permit does not contain any requirements for permit holders regarding PFAS, despite many requests to EPA from members of the public and some state environmental agencies. However, at the same time the final MSGP was released, EPA issued sector-specific fact sheet guidance documents outlining practices that could be used by operators to minimize PFAS in stormwater discharges. The “Sector S“ fact sheet specifically applies to air transportation facilities and airports. In January, EPA issued a request for feedback on their fact sheet guidance documents, including the applicable provisions relating to the mitigation of PFAS exposure to stormwater discharges. 

Summary of AAAE's Response to EPA. In response to the January solicitation, AAAE submitted comments to EPA that focused on two underlying themes. First, EPA's MSGP and fact sheet guidance documents are not appropriate tools to address potential PFAS exposure to stormwater discharge because the agency lacks the regulatory authority in this area. Moreover, many of the BMPs identified by the agency were either not helpful or inappropriate, suggesting that EPA was more interested in addressing potential historical impacts of AFFF usage rather than minimizing exposure to stormwater discharge. 

We instead urged EPA to work with FAA and the airport community in a more productive manner on standalone guidance that would help airports navigate the transition from AFFF to a PFAS-free firefighting foam, which is expected to be available in 2023. This should include EPA providing more practical transition-related guidance for airports on: (1) the proper disposal of PFAS and PFAS-containing products like AFFF; and (2) effective methods for cleaning ARFF vehicles. Greater clarity in these areas would be major steps toward addressing our communities' concerns.

Second, AAAE reiterated our continued support for EPA providing voluntary guidance and a list of BMPs for airports to consider implementing as part of their stormwater management programs. However, we emphasized that not all BMPs are appropriate for all airports, and EPA's guidance documents must provide airports with viable options and as much flexibility as possible regarding the types of measures that are recommended to be implemented.

What's Next? EPA will adjudicate the comments that have been submitted and update, as appropriate, the “Industrial Stormwater Fact Sheet Series“ guidance documents, including the “Sector S“ fact sheet that applies to airports. The current MSGP does not expire until February 2026, although the proposed 2026 MSGP will be released and adjudicated much earlier.