Lion's office will be closed at 3:30 PM ET on Friday, May 23 and all day on Monday, May 26. Online training support is available from 8:30 AM to 5 PM ET. Contact support@lion.com.
Search

New NPDES Guidance on Discharges to Groundwater

Posted on 11/27/2023 by Roger Marks

US EPA recently released a draft copy of new guidance intended to help the regulated community comply with NPDES permitting requirements for discharges of pollutants to groundwater.

The newly drafted guidance is meant to clarify when a NPDES permit is required to discharge pollutants to a water of the United States (WOTUS)—including some discharges that travel through groundwater before reaching a WOTUS.

New NPDES Guidance on Discharges to Groundwater

Why NPDES Guidance? Why Now?

The new NPDES draft guidance stems from a 2020 Supreme Court decision in the case County of Maui v. Hawaii Wildlife Fund. That legal fight centered on whether a wastewater treatment plant needed a NPDES permit to discharge pollutants into underground injection wells.

The wells led the plant’s discharges to groundwater, which carried the pollutants to the Pacific Ocean. Because the Pacific is a WOTUS, citizen groups argued that the treatment plant should have obtained a NPDES permit before discharging pollution.

The Court agreed with those groups, partly, deciding that discharging pollution to groundwater sometimes requires a NPDES permit. Sometimes, the Court reasoned, discharging pollution to groundwater is “functionally equivalent to discharging pollution directly to a WOTUS.

The purpose of EPA’s draft guidance is to help facilities determine when a discharge to groundwater meets this “functional equivalent” standard (and therefore requires a NPDES permit). 

EPA will accept public comments on the new Maui/NPDES draft guidance until December 27, 2023. 

When is a NPDES Permit Required?

The Clean Water Act NPDES permitting program requires any person to obtain a permit before discharging "any pollutant to navigable waters from any point source." To determine when a NPDES permit is required to discharge pollutants to groundwater, the facility first must determine if the discharge will eventually reach a water of the United States. 

If the pollutants will reach a WOTUS, the facility must determine whether that discharge is “functionally equivalent” to a direct discharge to the navigable water. This determination must be based on a variety of factors which EPA gives details about in the draft guidance. 

In addition to outlining general principles for an “overall approach” to NPDES permitting decisions with respect to groundwater pollution, EPA’s draft guidance provides a list of considerations included in the Supreme Court’s Maui decision. 

Factors for determining NPDES applicability (i.e., "functional equivalence") for a discharge to groundwater that reaches a WOTUS include: 

  • Transit time and distance traveled to reach the WOTUS (The draft guidance calls this the “most important factor in most cases, an in many cases the only factor that need be considered…”).
  • The manner or area in which the pollutants enter the water of the US. 
  • The nature of material through which the pollutant travels. 
  • The amount and concentration of pollution. 

From EPA's draft guidance:

“If the operator does not seek permit coverage for a functionally equivalent discharge, the operator may be subject to administrative or judicial enforcement proceedings and associated liability under the CWA (including civil and criminal penalties.”

US EPA, Applying the Supreme Court's Maui Decision... ("Maui Draft Guidance")

Last Complete EPA Regulations Training of the Year

Get in on our final Complete Environmental Regulations Webinar of the year to catch up with rapidly evolving EPA rules and policies under the Clean Air Act, Clean Water Act, TSCA, EPCRA, CERCLA/Superfund, and other major programs.

This unique and deeply-detailed training spans two days (December 14–15) and prepares professionals to identify relevant environmental programs and provisions for their facility and take the right steps to achieve compliance. 

Find a Post

Compliance Archives

Lion - Quotes

Lion's course was superior to others I have taken in the past. Very clear in the presentation and the examples helped to explain the content presented.

George Bersik

Hazardous Waste Professional

Lion courses are the standard to which all other workshops should strive for!

Brody Saleen

Registered Environmental Health Specialist

Very well structured, comprehensive, and comparable to live training seminars I've participated in previously. I will recommend the online course to other colleagues with training requirement needs.

Neil Luciano

EHS Manager

I have attended other training providers, but Lion is best. Lion is king of the hazmat jungle!!!

Henry Watkins

Hazardous Waste Technician

I like the consistency of Lion workshops. The materials are well put together and instructors are top notch!

Kevin Pylka

Permitting, Compliance & Environmental Manager

If I need thorough training or updating, I always use Lion. Lion is always the best in both instruction and materials.

Bryce Parker

EHS Manager

Lion's training was by far the best online RCRA training I've ever taken. It was challenging and the layout was great!

Paul Harbison

Hazardous Waste Professional

The course is well thought out and organized in a way that leads to a clearer understanding of the total training.

David Baily

Hazmat Shipping Professional

One of the best trainings I have ever received!

Brandon Morfin

EH&S Manager

The instructor did an excellent job presenting a very dry subject; keeping everyone interested and making it enjoyable.

Marc Bugg

Hazardous Waste Professional

Download Our Latest Whitepaper

The definitive 10-step guide for new hazardous materials shipping managers. Quickly reference the major considerations and details that impact hazmat shipping compliance.

Latest Whitepaper

By submitting your phone number, you agree to receive recurring marketing and training text messages. Consent to receive text messages is not required for any purchases. Text STOP at any time to cancel. Message and data rates may apply. View our Terms & Conditions and Privacy Policy.