Do I Need a NPDES Permit for Groundwater Discharge?
In late 2023, US EPA issued new draft guidance concerning when a NPDES permit is required to discharge pollutants to groundwater. The new guidance followed a 2020 Supreme Court decision in the case Maui v. Hawaii Wildlife Fund, and varies greatly from the interpretive statement below.
Original Article Published May 2019 and Updated September 2019
US EPA recently clarified its stance on whether the Clean Water Act’s National Pollutant Discharge Elimination System (NPDES) permit program covers point-source discharges to groundwater. Examples of a point-source discharging to groundwater include leaks from an underground pipeline or a remediation well.
In an interpretive statement posted to the Federal Register on April 23, EPA states its conclusion:
“The (Clean Water Act) is best read as excluding all releases of pollutants from a point source to groundwater from NPDES coverage, regardless of a hydrologic connection between the groundwater and jurisdictional surface water.”
Is This a New Interpretation from EPA?
Yes and no. While this is EPA’s first official interpretation on this issue, generally, a NPDES permit is not required for common activities that result in discharge to groundwater.
These activities include aquifer recharge, leaks form sewage collection systems, septic system discharges, spills and accidental releases, or coal ash impoundment seepage. In fact, the word “groundwater” is completely absent from the legal text that authorizes the National Pollutant Discharge Elimination System (NPDES) requirements.
That said, two ongoing court cases are challenging EPA’s view of point-source discharges to groundwater. Because of conflicting or confusing interpretations offered in the past, EPA felt a need to clarify its position in writing in advance of the Supreme Court taking up the appeals.
In both cases, the courts determined that NPDES requirements may apply when a pollutant released from a point source to groundwater migrates to navigable waters. While these decisions are being elevated for Supreme Court consideration, EPA will apply the court’s decisions to the Fourth and Ninth Circuits. For all other areas, EPA’s new interpretation applies.
EPA Protections for Groundwater
This does not mean that groundwaters are not protected under the Clean Water Act or other EPA regulations. Under the CWA, all states may regulate nonpoint source pollution—meaning, broadly speaking, any water pollution not covered by Section 402 of the Clean Water Act (i.e., the NPDES permitting requirements).
Other EPA programs also provide protection for groundwater. The Safe Drinking Water Act (SDWA) boasts an underground injection control (UIC) program and a sole source aquifer (SSA) program to protect groundwater. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requires reporting of hazardous substance releases, including those that can reach groundwater.
The Resource Conservation and Recovery Act (RCRA) requires facilities that generate hazardous waste to take steps to prevent releases to the environment, including secondary containment requirements and release reporting.
Clean Water Act & NPDES Training
Identify your responsibilities under the many US EPA water programs that impact industrial facilities—from oil spill reporting to NPDES permits, stormwater regulations, and more. The Clean Water Act and Safe Drinking Water Act Regulations Online Course is open for enrollment now!
The instructor was very dedicated to providing a quality experience. She did her best to make sure students were really comprehending the information.
Inventory Control Specialist
Lion's training was by far the best online RCRA training I've ever taken. It was challenging and the layout was great!
Hazardous Waste Professional
I really enjoyed this training. Even after years on both sides of the comprehension coin, I find myself still learning! The quality of the delivery exceeded much of the training I have received in the past.
Excellent. I learned more in two days with Lion than at a 5-day program I took with another provider.
The instructor had knowledge of regulations and understanding of real-world situations. The presentation style was engaging and fostered a positive atmosphere for information sharing.
Safety & Environmental Compliance Officer
Best instructor ever! I was going to take my DOT training w/a different provider, but based on this presentation, I will also be doing my DOT training w/Lion!
Hazardous Waste Professional
I really enjoy your workshops. Thank you for such a great program and all the help Lion has provided me over the years!
Hazardous Material Pharmacy Technician
I was able to present my scenario to the instructor and worked thru the regulations together. In the past, I attended another training firm's classes. Now, I have no intention of leaving Lion!
Senior Environmental Engineer
I used the IT support number available and my issue was resolved within a few minutes. I don't see anything that could have made it better.
The instructor was probably the best I ever had! He made the class enjoyable, was humorous at times, and very knowledgeable.
Mary Sue Michon
Download Our Latest Whitepaper
Shipping papers are a crucial part of safely shipping hazardous materials. See the top 5 mistakes shippers make on shipping papers, and how to avoid them.