EPA Ends 20-Year Air Emissions Study, Easing Dairy Farm Uncertainty

US Dairy Farmers Welcome Closure of Outdated Regulatory Agreement

The US Environmental Protection Agency (EPA) has decided not to finalise air emissions estimation methodologies developed under its 2005 Animal Feeding Operations Air Compliance Agreement and will move to terminate the agreement.

Announced on October 30, 2026, the decision brings an end to more than two decades of uncertainty for dairy and other livestock operations that participated in the National Air Emissions Monitoring Study (NAEMS).

The National Milk Producers Federation (NMPF) welcomed the announcement, describing it as an important step towards regulatory clarity for American dairy farmers.

Why EPA Abandoned the Emissions Methodologies

The original agreement was established in 2005 to develop scientifically credible methods for estimating air emissions from animal feeding operations.

The NAEMS monitored 25 animal feeding operations across 10 states between 2005 and 2007, collecting data on ammonia, hydrogen sulfide, particulate matter and volatile organic compounds.

However, EPA concluded that the monitoring data were now too old and limited to support reliable emissions-estimation methodologies for today's livestock operations.

Changes in barn designs, herd sizes, manure management practices and farm technologies have made the original dataset less representative of modern production systems.

NMPF Raises Concerns Over Dairy Emissions Models

NMPF had previously challenged the proposed dairy emissions models, highlighting their reliance on monitoring data from only five dairy farms.

The federation's technical analysis identified substantial variations in per-cow emission estimates based on herd size, negative emissions estimates under below-freezing conditions, and limited consideration of improvements in feed, genetics, manure management and emissions-control technologies.

EPA's latest decision reflects concerns about the age and representativeness of the underlying data.

Nearly 14,000 Farms Affected by the Agreement

According to EPA, approximately 2,600 animal feeding operations, representing nearly 14,000 farms, were covered by the 2005 Air Compliance Agreement.

The agency will work to notify the affected operations and terminate the agreement in accordance with its provisions.

Importantly, the decision does not change EPA's implementation of the Clean Air Act or remove other applicable environmental requirements for livestock operations.

EPA also plans to continue working with the US Department of Agriculture, land-grant universities and agricultural producers on practical, science-based approaches to understanding and reducing farm air emissions.

What This Means for the Dairy Industry

The decision provides greater regulatory clarity to dairy farmers who have waited for a final outcome from a study initiated more than 20 years ago.

It also highlights a wider challenge for agricultural environmental policy: emissions models must be supported by current, representative data that reflect differences in farm size, production systems and evolving technologies.

NMPF has indicated that it will continue collaborating with government agencies, universities and dairy cooperatives to support environmental improvements across the sector.

Industry takeaway: Ending an outdated emissions study brings regulatory certainty, but the need for credible, modern and science-based environmental measurement remains an important priority for the dairy industry.

Source: Read full story here 03 Nov, 2026 Edited and Reported by

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