Disease Reporting and Surveillance

Pyrethrin Scheduled Review

The American Horse Council submitted written comments to the Environmental Protection Agency’s (Agency) Proposed Interim Decision (PID) involving application methods for the insecticide pyrethrin and two synergists, MGK-64 (MGK) and Piperonyl butoxide (PBO).  After decades of use, we know these products to be safe, effective and absolutely essentially to the management of key insect pests in barns and animal spaces, critical to animal welfare and rider safety while in use, worker exposure is far less then presented in your documentation, and non-worker exposures are almost eliminated due the biosecurity and safety concerns ever-present at these facilities.  The AHC collaborated on comments submitted with several other entities in supporting the continued safe and wise use of these products.

The Proposed Interim Decision mentions the EPA’s conclusion that cancellation of these products would not result in significant loss of efficacy or economic impacts for users. We empathically disagree with this assumption and we have successfully relayed our concerns. The comments received by the EPA resulted in their decision to delay any decision.  

Health Canada, the Canadian equivalent of the EPA, has now banned indoor structural broadcast applications to control flies and mosquitoes in livestock and poultry housing facilities and pressurized products used in metered-release devices. While this has no direct effect on US regulations, there is concern this may set an international precedent for an EPA decision.

Proposed Regulation of PFOA and PFOS as CERCLA Hazardous Substances

In fall of 2022 the EPA released a notice of proposed rulemaking to designate PFOA and PFOS as CERCLA Hazardous Substances. The Comprehensive Environmental Response, Compensation, and Liability Act, aka CERCLA or “Superfund”, authorizes the EPA to specify substances as hazardous and would require facilities across the country to report any PFOA or PFOS above the designated threshold and hold them liable for all costs associated with the clean up.

While this was not brought to the attention of the AHC until after the comment period has closed, many comments were submitted on behalf of agriculture stakeholders.

What are PFOA/PFOS, and where are they found?

PFOA or PFOS, are known as “forever chemicals. They are ubiquitous in everyday commercial products such as waterproofed clothing (and horse blankets), nonstick cooking products, firefighting foam, and more. Scientific studies have shown that exposure to PFAS in the environment may be linked to harmful health effects in humans and animals.

Because there are thousands of different PFOA/PFOS chemicals, and they are found in so many different consumer, commercial, and industrial products, it is challenging to study and assess the potential human health and environmental risks. It is not yet fully understood what level of PFOA/PFOS exposure is unsafe, and what the long-term health impacts may be.

Unbeknownst to farmers, sludge and fertilizer from wastewater treatment plants were not able to filter out PFOA/PFOS, resulting in it being spread onto crops and pasture lands during routine field work.

PFOA/PFOS Thresholds, Testing, and Impacts of a CERCLA ruling

In March 2023 the EPA released proposed thresholds for PFOA/PFOS found in water and soil. These thresholds are considered extremely low and currently are set below what is considered testable levels.

In September 2025 the EPA announced that it would retain the designation of PFOA and PFOS as hazardous substances under CERCLA. In November 2025, EPA plans to propose a rulemaking to include PFAS requirements in National Pollutant Discharge Eliminations System Permit applications. This would have potential down steam effects on horse operations currently being regulated as CAFOs.

Large-Scale Equine Facilities

Over the last several years the American Horse Council has been monitoring situations involving long-term/permanent equine holding facilities and the pressures placed on them due to environmental regulations in their state. California, in particular, has placed undue pressure on equine facilities bordering waterways, to the degree that several facilities may close down. Water Management and Environmental Protection laws in these cases are the product of state regulatory action. The singular Federal language of note used in the enforcement of these regulations concerns the definition of a concentrated animal feeding operation, or CAFO. CAFO’s are described as small, medium, or large, with large facilities being designated as permanently housing 500 animals or more throughout the year.

 As state regulations change with the environmental needs of communities in rural areas, oftentimes large horse CAFOs are expected to meet waste management, water runoff, and large-scale infrastructure requirements that are uncommon and often unnecessary to meet the needs of equine operations. Unfortunately, the designation of large CAFOs is unlikely to be changed at the federal level. As such, the horse industry needs to take active action at the state level to prevent burdensome regulatory action or pursue equine specific exemptions in States with existing environmental regulations.

AHC staff have taken steps to prioritize the development of strategies and actions that can be taken on behalf of the industry at large. This includes educational materials for horse owners and peer organization outreach to raise awareness of the hostile actions being taken by environmental groups towards agricultural interests.

The Environmental Protection Agency (EPA) announced in March 2025, that it will once again revise the definition of “Waters of the United States” (WOTUS). This definition determines which waterways fall under federal regulation through the Clean Water Act. The Clean Water Act originated from the 1948 Federal Water Pollution Control Act and was significantly amended in 1972 to regulate pollutants entering U.S. waters. CAFOs rely on the WOTUS definition to determine whether they require permits. The 2023 Supreme Court case Sackett v. EPA complicated matters when the Court ruled that the previous WOTUS definition was unclear and inconsistent. The Court established that only waters with a “relatively permanent” connection to navigable waters should qualify under WOTUS.

Currently, the AHC is working to understand how regulations and enforcement differ in each state, the number of equine operations currently designated as CAFOs, and identify courses of action to ensure that CAFO regulations for equine operations are written using equine specific research.

EPCRA and Ammonia

The Emergency Planning and Community Right-to-Know Act (EPCRA) was authorized by Title III of the Superfund Amendments and Reauthorization Act (SARA Title III) in 1986 in response to concerns regarding the environmental and safety hazards posed by the storage and handling of toxic chemicals. The purpose of EPCRA is to help protect communities during accidental releases of toxic chemicals by requiring the notification of chemical releases to emergency personnel.

In 2018 Congress enacted legislation titled the Fair Agriculture Reporting Method (FARM) Act that excluded air emissions of ammonia from manure from the reporting requirements of CERCLA. Historically, substances listed as exempt from CERCLA reporting are also listed as exempt from EPCRA reporting.

As regulatory language has not explicitly listed exempting air emissions of manure related ammonia from EPCRA, EPA has the discretion to enforce reporting. The most recent administration has begun requiring EPCRA reporting of ammonia, regardless of origin, and is inclusive of manure related emissions. Any emission of ammonia of 100 lbs or more in one 24 hour period must be reported. Any facility with 500 or more horses on the property could potentially reach this threshold within a 24 hour period. This is regardless of an operation’s CAFO status and would be inclusive of breeding farms, show facilities, racetracks, and more.

An EPCRA report would need to be submitted to local emergency responders every day the threshold is reached. For example, a racetrack would need to report every day during the season.

The National Association of SARA Title III Program Officials (NASTTPO) has come out in support of exempting naturally occurring manure originating ammonia from EPCRA reporting. As there is no remediation protocol or need to manage ammonia released from manure, EPCRA reporting of this substance creates undue strain on NASTTPO officials receiving reports, and the operations owners making the reports on a daily basis. Further, as EPCRA reporting of this substance has been ambiguously enforced, confusion exists at multiple levels about what is required at this point.

AHC supports language that reduces unnecessary reporting, as well as encourages further research into manure protocols specific to horse manure emissions.

EPA Greenhouse Gas Emissions

In June 2023 the EPA submitted a Notice of Request for Public Comment on Updates to Technical Guidelines for Quantifying Greenhouse Gas (GHG) Emissions and Carbon Sequestration at the Entity-scale for Agriculture and Forestry. This document updates the 1990-2018 U.S. Agriculture and Forestry Greenhouse Gas Inventory.

The proposed document is well over 600 pages. AHC has signed on to comments with other members of the Animal Agriculture Coalition requesting an extension of the comment period.

At first glance the proposed document could have major remediation implications for horse operations, especially those permitted as CAFOs. Similar to other effluent and emissions regulations, horse operations are listed as falling under regulatory purview but lack horse specific science based evidence for rule making.

AHC is working to ensure that environmental rulemaking is considering horses fairly – calling for updated research and consideration of common husbandry practices as well as the variability of operations compared to other livestock.