EPA issues wastewater treatment plant effluent standards

The U.S. Environmental Protection Agency (EPA) has developed effluent limitation guidelines (ELGs) as national regulatory standards to control wastewater discharges of pollutants into surface waters and publicly owned treatment works (POTWs). To date, the EPA has issued ELGs for 59 industrial categories. The wastewater treatment plant effluent standards apply to about 40,000 facilities that discharge directly into surface waters and 129,000 facilities that discharge to POTWs.

Notably, ELGs are not based on environmental risk or the impact on receiving waters. Instead, the EPA bases them on the performance and cost of demonstrated wastewater control and treatment technologies for specific regulated pollutants.

This blog post explores how the EPA develops these standards and how partnering with a team of wastewater engineers can help meet compliance requirements. 

An overview of wastewater treatment plant effluent standards

The U.S. EPA reviews, revises and updates effluent limitation guidelines annually, as required by the Effluent Guidelines Program plan. The plan identifies industries selected for regulatory revisions and new industries identified for regulation.

The most recent update for effluent guidelines, Effluent Guidelines Program Plan 15, was published in January 2023. It focused on the EPA's 2021 PFAS strategic roadmap to revise the effluent limitation guidelines for PFAS in wastewater discharges. The preliminary effluent guidelines program plan 16 (Preliminary plan 16) has been announced, underlining the agency's intent to conduct several new detailed studies of industrial categories.

Types of pollutants in effluent

The Clean Water Act categorizes pollutants in effluent into three main types:

• Conventional pollutants. These include biochemical oxygen demand (BOD), total suspended solids (TSS), fecal coliform, pH and any additional pollutants (oil and grease) that are defined as conventional pollutants.

• Toxic pollutants. The EPA has identified 65 toxic pollutants and classified 126 specific substances as priority toxic pollutants.

• Nonconventional pollutants. All other pollutants not classified as conventional or toxic fall under this category.

The following are the several levels of control for regulated pollutants as defined under the Clean Water Act (CWA). At these levels of control, technology-based numeric limitations for specific pollutants are set. 

The following table highlights planning and implementing wastewater treatment plant effluent standards.

Adhering to the wastewater treatment plant effluent standards is critical for industries. Partnering with an expert can help determine the most effective and economical technology to limit pollutants in the effluent.

How Fehr Graham can help communities comply with wastewater treatment plant effluent standards

At Fehr Graham, we are committed to strengthening wastewater infrastructure across communities. Our team of licensed and certified engineers devise custom, industry-specific treatment solutions to help your business meet effluent standards.