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Exploring Environmental Regulation of Agriculture

Recently the U.S. Environmental Protection Agency (EPA) grabbed attention when it attempted to clarify the Clean Water Act by defining the term “waters of the United States.” Many in agriculture have raised concerns about the definition and how it would impact farming and property owners, adding a new chapter to the long-running debate regarding environmental regulation of agriculture and land use. This article begins the exploration of environmental regulation, voluntary conservation and farming in America in an attempt to better understand the overall issues involved in this frequent and intense debate. The most direct environmental regulatory issue for agriculture involves water, and it provides the point of departure for this series with a look at the Clean Water Act. Further installments will discuss other environmental issues as needed or as they arise.

Historical and Legal Background

The Clean Water Act is home to Congress’ long-standing goals to restore and maintain the chemical, physical and biological integrity of the Nation’s waters by eliminating the discharge of pollutants into navigable waters; a goal that was intended to have been reached by 1985. The original law—the Federal Water Pollution Control Act—dates to 1948 with the most substantial revisions in 1972 when Congress established a comprehensive national program giving the law its current operational form and substance (background and historical information can be found here and here). It was renamed the Clean Water Act in 1977.

At its core, the Clean Water Act makes the “discharge of any pollutant by any person” unlawful. Discharging a pollutant means any addition of a pollutant into the waters of the United States from any point source. A point source is any discernible, confined and discrete conveyance (such as a pipe, ditch, channel, container, etc.) and includes a concentrated animal feeding operation but does not include agricultural stormwater discharges and return flows from agricultural irrigation. The term pollutant does include, however, agricultural waste discharged into water. The Environmental Protection Agency (EPA) primarily regulates point source water pollution and does so through a permitting system designed mostly for industrial facilities and municipal water treatment plants, but that now includes confined animal feeding operations (CAFO) above a certain size. Anyone discharging waste through a point source must receive a permit to do so and be subject to technology-based limits on discharges.

Certain aspects of crop agriculture have been explicitly excluded from point-source pollution regulation and most of agriculture falls under a category outside of direct regulatory reach. In 1977, Congress revised the definition of point source so that it would not include return flows from agricultural irrigation and in 1987 Congress revised the Act to exclude agricultural stormwater discharges. Beginning in 1994, the EPA undertook a process that led to requiring permits for confined animal feeding operations (CAFO) above a certain size.

Pollutants from agriculture are typically considered to be nonpoint-source pollution (NPS). Unlike point-source pollution, NPS pollution comes from, as the name implies, widely dispersed and thus not discrete or confined sources, which makes it difficult to contain and regulate. Because of this reality the Clean Water Act of 1972 focused regulatory efforts on point-source pollution, but amendments to the CWA in 1987 introduced a focus on NPS pollution by requiring the states to develop and implement programs to control nonpoint sources of pollution, including runoff from land. Although Congress did not define NPS in the statute, EPA has defined it as “water pollution caused by rainfall or snowmelt moving over and through the ground and carrying natural and human-made pollutants into lakes, rivers, streams, wetlands, estuaries, coast waters, and ground water.”

Water quality standards form the basis for trying to control nonpoint-source pollution. Each water body has a designated use, such as recreation or water supply, and water quality criteria are set to meet and maintain the specific designated use. When a river or a body of water fails to meet the criteria for its designated use, the state must develop a Total Maximum Daily Load (TMDL) program. In short, the TMDL program identifies point source polluters along the river and further restricts their effluent. The TMDL program also identifies nonpoint sources of pollution and creates a plan for reducing the NPS pollution. After developing a TMDL program, states have the prerogative to implement it with those that do receiving financial assistant from the EPA (more on TMDLs can be found here).

To help ensure that states are creating TMDL plans, every state is required to submit an assessment of the state’s waters every two years. Any water body that does not meet the water quality standard is designated as “impaired.” Figure 1 is a map that shows the most recent assessment of the rivers in Illinois—­­red rivers are impaired, and blue ones meet their water quality standard. According to the assessment, 3,119 miles of waterway in Illinois are considered impaired, meaning that they do not meet the water quality standard for their designated use due to pollution.

* Figure 1



Critics of farming struggle with agriculture’s treatment by environmental law but acknowledge the challenges inherent in attempting to regulate nonpoint source pollution. There are important and vast differences between pollution emitted from discrete sources like pipes and that which runs off of the land largely due to the confluence of natural events like rainfall and the use of the land. Farming highlights this problem as it is conducted on a large scale, across hundreds of millions of acres, millions of fields and farms, and miles of rivers and streams. Runoff comes in a myriad varieties from a nearly uncountable number of potential sources.

Consider, for example, the Upper Mississippi Water Basin (UMWB), which covers most of Minnesota, Wisconsin, Iowa, and Illinois and some of Missouri. It contains 30,700 miles of rivers and streams that drain 189,000 square miles of land, of which over two-thirds is used for agriculture. According to the 2012 Census of Agriculture, 295,000 farms produce food and fiber in the UMWB, with an average farm size of 300 acres. The sheer size and scope inherent in such numbers, identifying the exact source of a pollutant found in water is virtually impossible.

Perhaps the most well-known nonpoint-source water pollution issue in the UMWB is the “dead zone” in the Gulf of Mexico. Nutrients, primarily nitrogen and phosphorus, reach the Gulf through the Mississippi River causing hypoxia – a condition where dissolved oxygen in the water decreases to a point where the waters are unable to sustain life. Research has found that Midwestern agricultural watersheds are a major source of the nutrients in the Gulf and that fields may lose as much as 18-45 pounds of nitrogen per acre in a year. The main drivers of this problem are precipitation and the system of drainage used across the landscape, including tiles in farm fields and manipulation of streams and rivers (i.e., dredging and channelization). Of these, however, the amount and timing of precipitation is the biggest factor in how much nutrients reach the Mississippi River, with larger amounts in wet years than in dry years and more during the January to June months. Moreover, short-term, intense events like flooding or above-normal precipitation can account for the bulk of nutrients that reach the river because streams lose their ability to naturally process and retain the nutrients and merely pass them through. In other words, Spring is the peak time for nutrients to leave fields and enter the waterways, especially during wet years when there is flooding and large quantities of water moving across the land and through the tile, stream and river systems.

Spring is, of course, a critical time for farming as it is the time of intense activity surrounding the planting of crops; farmers who cannot plant their crops on time risk much lower yields and lost income. Drainage tile has long been put in place throughout much of the Midwest – some of the work dates as far back as the 1860’s. Tiles help remove excess moisture from water-clogged fields so that farmers can plant on time and so those crops can get a successful start even in wet years; but as excess water leaves the fields it can take important and costly nutrients with it. In the UMWB, about 75% of farmland (64 million acres) is estimated to contain some tiling.


This brief, initial look at environmental regulation of farming highlights some of the significant challenges inherent in the issue, providing background and some context to the current controversy over the waters of the U.S. proposed rule. Attempting to regulate such diverse sources, spread out over large land areas and impacting millions of miles of waterways is likely create insurmountable administrative burdens. Further complicating this matter are the unique challenges associated with agricultural runoff and the unpredictability of natural weather events like snow melt and rainfall, particularly during critical months for farming. Current efforts are underway that seek to address these problems, but much work and innovative solutions will be needed. Future articles will seek to explore in more depth these and other issues concerning farming, regulation and conservation.