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EPA ends 20-year effort to set factory farm air emissions methods

EPA ends 20-year effort to set factory farm air emissions methods

Rule Changes

The agency said its 2005–2007 monitoring data can't support national models, closing a safe-harbor deal that covered about 14,000 facilities.

6 days ago: EPA abandons emissions methods

Overview

Updated 5 hours ago

For two decades, the Environmental Protection Agency (EPA) tried to build a way to measure air pollution from large livestock farms. On October 30, 2026, it said the data it collected between 2005 and 2007 cannot support reliable national methods, and it stopped trying.

The decision closes a 2005 agreement that gave about 2,600 livestock operations, representing nearly 14,000 facilities, protection from Clean Air Act enforcement while they funded a monitoring study. The legal duty to get permits when emissions cross federal thresholds remains. Without EPA methods, though, regulators have no standard way to decide which farms cross them.

Why it matters

Large farms still need Clean Air Act permits above certain emissions levels, but the EPA has declined to produce the method for measuring them.

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Key Indicators

14,000
Facilities covered by the 2005 agreement
About 2,600 animal feeding operations joined, representing nearly 14,000 facilities.
25
Farms monitored in the EPA study
The National Air Emissions Monitoring Study collected data at 25 farms in 10 states from 2005 to 2007.
20
Years of effort
The EPA began the monitoring effort in 2005 and ended it in 2026.
12,700
Estimated annual deaths from farm emissions
Research cited by Ars Technica attributes about 12,700 U.S. deaths a year to air pollution from livestock operations.
10
States in the monitoring study
The study covered farms in 10 states.

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People Involved

TH
Tarah Heinzen
Legal director, Food & Water Watch
Active; tracking the EPA's factory farm proceedings

Organizations Involved

Environmental Protection Agency (EPA)
Environmental Protection Agency (EPA)
Federal agency
Ended its effort to develop farm air emissions methods

The federal agency responsible for enforcing the Clean Air Act and other environmental laws.
Food & Water Watch
Food & Water Watch
Advocacy group
Critic of the EPA's decision

A nonprofit advocacy group that campaigns on food, water and agriculture policy.
OA
Office of Air and Radiation
EPA office
Determined it cannot develop emissions methods

The EPA office that administers the Clean Air Act and issued the October 2026 determination.

Timeline

2002 October 2026

8 events Latest: 6 days ago
Tap a bar to jump to that date

  1. EPA abandons emissions methods

    Latest Decision

    The Office of Air and Radiation says 2005–2007 data cannot support national methods, ending the 20-year effort.

  2. Public comment period closes

    Rulemaking

    The EPA receives 13 public comments on the draft methods.

  3. EPA releases draft methods

    Rulemaking

    The agency publishes draft emissions estimating methodologies for livestock and poultry operations.

  4. Inspector General criticizes delay

    Oversight

    The EPA's Office of Inspector General faults the agency for slow-walking the emissions methods.

  5. Science board faults draft models

    Review

    The EPA Science Advisory Board finds the models rely on limited data and flawed methods for national extrapolation.

  6. EPA signs air compliance agreement

    Agreement

    About 2,600 operations join, covering nearly 14,000 facilities, and fund a monitoring study in exchange for deferred enforcement.

  7. Monitoring study begins

    Study

    The National Air Emissions Monitoring Study collects data at 25 farms in 10 states through 2007.

  8. Science panel calls for farm emissions data

    Report

    A National Academy of Sciences report calls for reliable emissions estimation methods for animal feeding operations.

Scenarios

1

No federal farm emissions method is finalized

Likely Resolves by End of 2028

Discussed by: EPA Office of Air and Radiation; Food & Water Watch

The EPA's October 30 memo says the 2005–2007 data cannot be fixed within the agreement's framework. Unless a court or Congress forces a new study, the agency has no path to publish methods, and the Clean Air Act's permit thresholds for livestock farms stay unmeasured at the federal level.

2

Environmental groups sue to force EPA emissions methods

Possible Resolves by End of 2027

Discussed by: Food & Water Watch; environmental law analysts

Food & Water Watch has filed dozens of suits over CAFO pollution. A challenge to the October 30 determination would argue the EPA cannot abandon a statutory duty because its data is old. A court could order a new study or a different method.

3

States adopt their own farm emissions limits

Possible Resolves by End of 2028

Discussed by: State air regulators; Food & Water Watch

California already uses its own models to enforce livestock emissions rules. Other states could follow, creating a patchwork where federal methods are absent. The trigger would be a state legislature or air board adopting numeric limits for animal feeding operations.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

January 2005

The 2005 Air Compliance Agreement

After a 2002 National Academy of Sciences report called for better emissions data, the EPA offered livestock operators a voluntary deal. About 2,600 operations signed, covering nearly 14,000 facilities. They funded a monitoring study, and the EPA paused enforcement while it worked on methods.

Then

The study monitored 25 farms in 10 states from 2005 to 2007.

Now

The methods were never finalized, and the agreement became the basis for two decades of deferred enforcement.

Why this matters now

The October 2026 decision formally closes this deal, but its safe harbor had already shaped the rules for large livestock farms.

2012

The 2012 Science Advisory Board review

The EPA's Science Advisory Board reviewed the draft emissions models built from the monitoring study. It found the models relied on limited data, missed regional and housing differences, and used flawed methods for national extrapolation.

Then

The board recommended revising the models and postponing regulation.

Now

The EPA kept working on the methods for another 14 years without finalizing them.

Why this matters now

The 2026 memo cites the same limitations the board identified in 2012.

2017

The 2017 Inspector General report

The EPA's Office of Inspector General reviewed the agency's progress on the 2005 agreement. It faulted the agency for slow-walking the process and recommended steps to complete the monitoring study.

Then

The EPA said it planned to publish final methods in fiscal year 2018.

Now

It did not. Draft methods arrived in 2024, and the effort ended in 2026.

Why this matters now

The report shows the delay was documented years before the agency abandoned the project.

Sources

(8)
+2
Ars Technica U.S. Environmental Protection Agency Farms.com Society of Environmental Journalists npj Clean Air InsideEPA Agribusiness Wire U.S. Environmental Protection Agency