U.S. EPA’s Preliminary Effluent Guidelines Program Plan 16

On December 18, 2024, the U.S. Environmental Protection Agency (U.S. EPA) published in the Federal Register the Preliminary Effluent Guidelines Program Plan 16 (Preliminary Plan 16). The comment period ended January 17, 2025. Preliminary Plan 16 addresses U.S. EPA’s latest efforts to develop and refine limits surrounding industrial wastewater discharges including effluent limitation guidelines (ELGs). ELGs are technology-based limits intended to regulate industrial wastewater discharges from certain industries directly into waters of the U.S. or indirectly to publicly owned treatment works (POTWs). The purpose of ELGs is to achieve economically feasible control on pollutants from industrial discharges.

Trump’s Regulatory Freeze Pending Review Executive Order

It is notable that President Donald Trump enacted an Executive Order titled Regulatory Freeze Pending Review. In layman’s terms, proposed regulations such as Plan 16 are postponed from publication until reviewed by the Trump administration or a designated official. The administration could choose to amend Plan 16 and open it up for public comment again.

Preliminary Plan 16

Under the Clean Water Act, Section 304(m), U.S. EPA is required to publish biennial plan ELGs. Preliminary Plan 16 builds on this commitment, following the Effluent Guidelines Program Plan 15 (Plan 15) published on January 31, 2023 (See ALL4’s article on Plan 15). Plan 15 continued U.S. EPA’s scrutiny on per- and polyfluoroalkyl substances (PFAS) and Preliminary Plan 16 is no exception to that. Highlights of the components of Plan 16 are included in the following sections.

New Studies

U.S. EPA conduct preliminary studies for industries based on recent rulemakings, public comments, and ranking in U.S. EPA’s ranking analysis. U.S. EPA has identified the following industrial categories for detailed studies, including:

• Battery Manufacturing – focusing on industrial processes used for electric vehicles
• Centralized Waste Treatment – focusing on PFAS
• Oil and Gas Extraction – focusing on treatment technologies that can reduce the discharge of pollutants from the agricultural and wildlife water use
• PFAS Processors (facilities that process raw PFAS into commercial products) – developing a more complete understanding of facilities that receive PFAS feedstocks

Updates to Ongoing Studies

Preliminary Plan 16 also provides updates on the following ongoing U.S. EPA studies:

• Steam Electric Power Generating (40 CFR Part 423):
  • Zero discharge limits established for flue gas desulfurization (FGD) wastewater, bottom ash (BA) transport water, and combustion residual leachate (CRL)
    • Zero discharge is the absence of pollutants
  • Non-zero numeric limits established for mercury and arsenic for specific CRL discharges, and new limits on legacy wastewater
    • Non-zero numerical is numerical limit above 0
    • Legacy wastewater is the wastewater that has accumulated over time from previous coal combustion processes before regulations were enacted over that specific wastewater
  • Introduces a subcategory for units ceasing coal combustion by 2034

• Meat and Poultry Products (40 CFR Part 432):
  • U.S. EPA proposed stricter effluent limits on nitrogen, phosphorus, chlorides, and E. coli, plus new pretreatment standards for indirect dischargers to POTWs with nutrient removal
  • Public comments closed on March 25, 2024, and final action is expected by August 2025

• Organic Chemicals, Plastics, and Synthetic Fibers (40 CFR Part 414):
  • U.S. EPA intended to publish a proposed rule in fall of 2024
    • While this date has come and gone, U.S. EPA continues to explore ELGs in this sector, specifically to address wastewater discharges of PFAS

• Metal Finishing and Electroplating (40 CFR Parts 433 and 413):
  • U.S. EPA has learned that:
    • It is possible to successfully mitigate hexavalent chromium emissions using commercially available chemical fume suppressants that do not contain any PFAS
    • Trivalent chromium, which does not require the use of chemical fume suppressants
    • Granular activated carbon can be used to treat perfluoro octane sulfonic acid (PFOS) in wastewater and PFAS in metal finishing and electroplating wastewater
    • Membranes, ion exchange, and PFAS destruction techniques may be able to treat PFAS in wastewater from chromium finishing facilities, including membranes, ion exchange, and PFAS destruction techniques
  • U.S. EPA intends to publish a proposed rule by the spring of 2026

• Landfills (40 CFR Part 445):
  • PFAS identified in over 95% of landfills evaluated
  • U.S. EPA plans to propose revised ELGs in 2027

Facilities which operate in the industries provided in Preliminary Plan 16 should review publications in the Federal Register to see how it could affect you. Keep an eye out for ALL4’s article when the final plan is published.

ALL4 has extensive experience with the Clean Water Act, tracking regulatory developments, permitting strategy, and ELG applicability and compliance. If you have any questions or would like to discuss how ALL4 can help you with the items above, please reach out to Evan Mia at emia@all4inc.com.