In late January, the Environmental Protection Agency (“EPA”) announced that it was seeking public comment on its proposal to revise technology-based effluent limitations guidelines and standards for meat and poultry products facilities that discharge wastewater into waters of the United States. The proposal would strengthen existing requirements for nitrogen pollution and introduce restrictions on phosphorous pollution for the first time. In its proposal, EPA presents three options for how to implement these new requirements. Each option presents both different levels of pollutant reduction, and different levels of cost to regulated facilities. Option 1, EPA’s preferred option, represents the greatest amount of pollution reduction that can occur with the lowest costs to facilities. EPA is requesting comments from the public on all three options.


Effluent limitations for pollutant dischargers are established under the Clean Water Act (“CWA”) and serve as a key part of how the Act works to regulate water quality in the United States. Effluent limits for meat and poultry processing facilities have been in place since the early 1970s, but have only been updated once since they were first established.

The Clean Water Act

The CWA is the primary federal law regulating water quality in the United States. One of the main ways the CWA regulates water quality is by prohibiting the discharge of pollutants from a fixed point source to waters protected by the CWA unless the discharge is authorized by a National Pollutant Discharge Elimination System (“NPDES”) permit. Among other things, a NPDES permit will contain effluent limitations for the pollutants covered under the permit. Under the CWA, “effluent limitations” are defined as “any restriction established by a State or [EPA] on quantities, rates, and concentrations of chemical, physical, biological, and other constituents which are discharged from point sources into [waters protected by the CWA].” 33 U.S.C. § 1362(11). In other words, effluent limitations refer to the amount of pollution that a NPDES permit-holder may legally discharge.

Effluent limitations in NPDES permits are derived from effluent limitation guidelines (“ELGs”) established by EPA. 33 U.S.C. §§ 1314(b); 1316. ELGs are developed on an industry-by-industry basis, and in general are established according to “the degree of effluent reduction attainable through the application of the best practicable control technology currently available[.]” 33 U.S.C. § 1314(b)(1). There are four types of technology-based ELGs applicable to direct dischargers or those who discharge pollutants directly into protected waters: best practicable control technology currently available (“BPT”); best conventional pollutant control technology (“BCT”); best available technology economically achievable (“BAT”); and new source performance standards (“NSPS”).

BPT limitations are typically based “on the average of the best existing performance by plants within an industrial category or subcategory.” EPA NPDES Permit Writers Manual. In other words, BPT is based on the average of the best performing facilities within an industry that are using currently available pollution reduction technology. EPA considers multiple factors when establishing BPT, including the cost of achieving pollution reduction, the age of equipment, and engineering aspects of the technology. While BPT limitations apply broadly to all pollutants, BCT refers to technology-based standards for reducing conventional pollutants. EPA NPDES Permit Writers Manual. Here, “conventional pollutants” refers to pollutants classified as biological oxygen demanding, suspended solids, fecal coliform, and pH. 33 U.S.C. § 1314(a)(4). BCT is established according to a test that requires EPA to consider the industry costs of reducing pollutant discharge. BAT refers to the technology standards established by EPA for controlling the direct discharge of toxic and nonconventional pollutants. EPA NPDES Permit Writers Manual. Here, “toxic pollutants” refers to those pollutants identified by EPA as causing “death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions[,] or physical deformations[.]” 33 U.S.C. § 1362(13). In turn, “nonconventional pollutants” refers to those pollutants which do not fall into either the conventional or toxic pollutant categories. Pollutants such as nitrogen, phosphorus and ammonia are all considered nonconventional pollutants. Often considered the “gold standard” for controlling discharges of toxic and nonconventional pollutants, BAT is based on the best available pollution reduction technologies that are economically achievable for facilities within a particular industry. Finally, NSPS are pollution reduction technology standards established for those facilities that qualify as new sources. 33 U.S.C. §1316(a). When establishing NSPS, EPA will consider that a new facility “has an opportunity to design operations to more effectively control pollutant discharges.” EPA NPDES Permit Writers Manual.

Along with establishing ELGs for effluent limitations to regulate direct dischargers, the CWA also requires EPA to establish pretreatment standards designed to restrict discharges from indirect dischargers. 33 U.S.C. § 1317(b). Unlike direct dischargers, indirect dischargers do not discharge pollution directly into waters regulated by the CWA. Instead, indirect dischargers introduce pollutants into publicly owned treatment works. 33 U.S.C. § 1317(b)(1). Under the CWA, publicly owned treatment works are defined as “systems used in the storage, treatment, recycling, and reclamation of municipal sewage or industrial wastes,” including various sewage collection and water recycling systems. 33 U.S.C. § 1292(2)(A). Much like ELGs, pretreatment standards are technology-based and established on an industry-by-industry basis. In general, pretreatment standards are divided into two categories: pretreatment standards for existing sources, and pretreatment standards for new sources. Much like the BPT, BCT, and BAT, the pretreatment standards for existing sources are based on the best currently available technology designed to prevent pollutants from entering publicly owned treatment works. Meanwhile, pretreatment standards for new sources are based on the best technology available for new facilities with the understanding that new indirect dischargers have the opportunity to incorporate the best available technology into their facilities.

Taking all of this together, effluent limitations in NPDES permits represent the amount of pollution that a NPDES permittee may discharge based on the available pollution reduction technology. Changes to effluent limitations may require existing facilities to update the pollution reduction technologies they use in order to meet new requirements.

Meat and Poultry Products Effluent Limitations

One of the categories of industry that EPA will establish ELGs and pretreatment standards for is the meat and poultry products (“MPP”) industry. The MPP category includes facilities engaged in “the slaughtering, dressing and packing of meat and poultry products for human consumption and/or animal food and feeds.” 40 C.F.R. § 432.1. According to EPA, there are 5,055 MPP facilities in the United States engaged in slaughtering, processing, and rendering meat and poultry that discharge either directly into protected waters or indirectly into POTWs. MPP facilities discharge large amounts of nutrients such as nitrogen or phosphorus that can contribute to a variety of surface water issues including eutrophication and algal blooms.

EPA first adopted ELGs for the MPP industry in 1974 and amended them in 2004. Currently, the MPP ELGs only apply to about 150 of the 5,055 MPP facilities. While nitrogen is regulated under the existing MPP ELGs, phosphorus is not. In a 2021 document titled Preliminary effluent Guidelines Program Plan 15, EPA noted that its study of wastewater discharges from MPP facilities revealed that the MPP industry discharges “the highest phosphorus levels and second highest nitrogen levels of all industrial categories[.]” Based on that study, EPA determined that the MPP ELGs may be appropriate, and announced that it would initiate a rulemaking to revise the ELGs and introduce pretreatment standards for MPP facilities. In late 2022, a coalition of environmental groups filed a lawsuit against EPA alleging that the agency had failed to initiate the announced rulemaking. The groups and EPA reached a settlement agreement directing EPA to issue a proposed rule in December 2023 and a final rule by August 31, 2025. The proposed rule was released and is now available for public comment.

What’s in EPA’s New Proposal?

In its proposal, EPA presents three options for revising the MPP ELGs. Option 1, EPA’s preferred option, represents the greatest amount of pollution reduction with the lowest level of cost to the MPP industry. Option 3 would achieve the greatest amount of pollution reduction, but carries the highest level of cost to the industry. Option 2 falls somewhere in the middle.

Under Option 1, the MPP ELGs would be revised to include new phosphorous limits and stricter nitrogen limits for large direct dischargers. This option would also include new pretreatment standards for large indirect dischargers. EPA defines a large discharger as any of the following: a meat slaughtering or processing facility that produces more than 50 million pounds per year of finished product; a poultry slaughtering facility that produces more than 100 million pounds per year; a poultry processing facility that produces more than 7 million pounds per year; and any rendering facility that produces more than 10 million pounds of product per year. Under Option 1, EPA would revise both BPT and BAT for nitrogen and phosphorus, as well as revise BPT and BCT for fecal coliform. Additionally, Option 1 would include new pretreatment standards for both new and existing sources. The pretreatment standards would be based on BPT and BCT for conventional pollutants including biochemical oxygen demand, total suspended solids, oil, and grease. EPA expects that of the 5,055 MPP facilities, 844 would be impacted by Option 1, with roughly 16 facilities expected to close.

Option 2 is largely similar to Option 1, but would include additional pretreatment standards for nitrogen and phosphorus. These additional limitations would apply to meat and poultry slaughter facilities that process at least 200 million pounds per year, and to rendering facilities that process at least 350 million pounds per year. EPA expects that 22 facilities would close under Option 2.

Finally, Option 3 would include the same restrictions as Options 1 and 2, but would lower the production threshold to include more MPP facilities. Under Option 3, limits for nitrogen and phosphorus would apply to all MPP facilities that produce more than 10 million pounds of product per year. Option 3 would also impose new conventional pollutant pretreatment standards for facilities producing more than 5 million pounds per year, along with new phosphorus and nitrogen pretreatment standards for facilities producing more than 30 million pounds per year. While Option 3 would result in the greatest overall amount of pollution reduction, it also comes with the highest cost. EPA expects that Option 3 would impact 1,618 MPP facilities, with 53 facilities expected to close.

Going Forward

A comment period on the proposed revisions to the MPP effluent limitations is open through March 25, 2024. In addition, EPA has held two public hearings on the proposal in January and is expected to hold at least one additional hearing on March 20. The agency is considering extending the comment period, but as of right now the March 25 cut-off date is still in place.

Once the comment period ends, EPA will review all the feedback it has received before issuing a final rule. Regardless of which option EPA ultimately adopts, at least some MPP facilities will be impacted by the updated ELGs.


To read the EPA’s proposal, click here.

To read the text of the CWA, click here.

For more EPA resources on the proposal, click here.

For more NALC resources on the CWA, click here.