Decision on Ammonia Regulation in Maryland

By Mia Hoetzlein-Sirman, Staff Writer

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Assateague Coastal Trust brought a case in Montgomery County, Maryland in March of 2021, arguing that Maryland was not appropriately regulating ammonia pollution or effluent discharge. Animal feeding operations, particularly poultry farms, produce significant amounts of ammonia as the chickens are kept indoors and in close quarters, which increases the amount of ammonia-producing bacteria.[1] Ammonia production impacts the environment since it is released as a gas but then falls into the waterways as nitrogen.[2] Nitrogen in waterways causes decreased water quality through the increased growth of algae and aquatic plants in nitrogen-polluted water.[3] This decreases the amount of oxygen in the waterways which decreases biodiversity, kills aquatic animals, and reduces the health of the Chesapeake Bay and the waterways that feed into it.[4] The impact of nutrient pollution is in direct opposition to the Maryland policy of fully restoring the Chesapeake Bay’s health by 2025.[5]

The EPA and Maryland regulate discharge by concentrated animal feeding operations (CAFOs) which are animal feeding operations (AFOs) that either hold many animals or release a significant number of pollutants into waterways.[6] Maryland also has Maryland Animal Feeding Operations (MAFOs) which are the size of CAFOS but do not release pollutants into surface water, instead, they release pollutants into groundwater.[7] These are regulated solely by Maryland. All AFOs must apply for general discharge permits which regulate the amount of waste that is permitted by the operations.[8] The AFOs must submit a notice of intent and a “Required Plan” which is a nutrient-management plan that lays out the management of the operation, identifies environmental risks, and develops solutions to these risks.[9] This mirrors the federal process for CAFOs.

In 2019, the Maryland Department of the Environment worked with the EPA to reissue the general permits for AFOs as the statute requires the permit to be renewed every five years.[10] Similar to previous general permits, the 2019 version prohibited discharges of pollutants to waterways, required state discharge permits if there was discharge, and continued submissions of the Required Plans and statements of intent.[11] However, there were new guidelines specifically pertaining to air pollution caused by poultry farms.[12] The facilities had to be operated in a manner to reduce odors as much as possible and if there was a concern regarding air quality the Natural Resources Conservation Service standards should be used to address the problem.[13] Additionally, the Required Plan had to identify the waterways near the operations that could be impacted by the potential air pollution.[14]

Assateague Coastal Trust brought suit and stated that the renewed permit failed to comply with state and federal regulations as it did not mention water quality-based effluent limitations and did not regulate ammonia regulations or if it did the regulation was not enough.[15] The Montgomery County Circuit Court held that the 2019 general permit needed to be revised to include solutions to these issues.[16]

The Maryland Supreme Court granted a writ of certiorari and held in favor of the Maryland Department of the Environment (The Department).[17] The Department argued that although they did not have uniform water quality-based effluent limitations, the technology-based effluent limitations they had in place worked as efficiently.[18] This was because the water quality standards were based on site-specific conditions thus, they were responsive to how close operations were to waterways. The court also rejected Assateague’s argument regarding the ammonia regulations because the Department added ammonia regulations to the general permit for the first time showing they were making an effort to regulate.[19] Thus, the court held that the regulations in the 2019 general permit complied with the Clean Water Act of the EPA and with Maryland state laws and reversed the circuit court decision.[20]

This decision is important in regard to the balance of the interests of Maryland citizens, the health of the Chesapeake Bay, and the interests of the large corporations producing this pollution. As the dissent states, the counties with the largest number of AFOs are the poorest counties in Maryland with the highest concentration of minorities.[21] Thus, the environmental impact of this falls disproportionately on poor minorities.[22] The EPA considers nutrient pollution one of the most costly and challenging environmental problems as too much nitrogen in the air and water causes algae blooms.[23] These algae blooms take the oxygen from the water causing aquatic life to die and even making humans sick through contact with polluted water.[24] Nutrient pollution is a primary pollutant of the Chesapeake Bay.[25] The Clean Water Act specifically references reducing this pollution in the Chesapeake Bay.[26] Although the 2019 general permit is compliant with state and federal guidelines it seems that the Department should have recognized the necessity of formulating stricter ammonia regulations in light of Maryland’s goal of restoring the Chesapeake Bay health by 2025.



[3] Id.



[6] Md. Dep’t of the Env’t v. Assateague Coastal Tr., No. 11, 2023 Md. LEXIS 335 (Aug. 9, 2023)


[8] Id.

[9] Id.

[10] Id.

[11] Id.

[12] Id.

[13] Id.

[14] Id.

[15] Id.

[16] Id.

[17] Id.

[18] Id.

[19] Id.

[20] Id.

[21] Id.

[22] Id.

[23] Id.

[24] Id.

[25] Id.

[26] Id.

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