Does the Manure Generated by Large Dairy Farms Cause Significant Water Pollution?


General Reference (not clearly pro or con)

[Editor's Note: Animal feeding operations (AFOs) and confined animal feeding operations (CAFOs) are animal farming operations where dairy cows (and other livestock aimals) are housed. Animals in AFOs and CAFOs are fed on site rather than being allowed to graze or otherwise find food in pastures, fields, or on rangeland. There are approximately 450,000 AFOs in the United States.

Concentrated animal feeding operations (CAFOs) are large scale AFOs that house thousands of animals. The
"regulatory definitions of large CAFOs, medium CAFO, and small CAFOs" (25 KB) are maintained by the US EPA.]


Peter Lane Taylor, a writer and TV producer, stated in his article "Florida Dairy Farms and Springs Protection: Got Solutions?," published on the Florida Springs website (accessed June 17, 2008):

"Cows are prolific producers of manure and urine. In an average day of grazing, milking, and just mooing about, one dairy cow can generate over 100 pounds of manure and urine...

In areas and facilities where cows are milked, fed, and staged between the various phases of the milking process, wastes are removed through pressure-washing, and in some cases, even bulldozing. Once flushed from these facilities, the wastes - now a semi-solid sludge - are directed into holding ponds to await their final disposal through one of two techniques.

In the first of these techniques, the mixture is spread in a thin layer over a large field by truck so that the nutrients can be absorbed as fertilizer by a variety of nitrogen absorbing plants like alfalfa and other grasses. In the second, cow manure mixture is further diluted with water and sprayed over a large area by a center-pivot irrigation system. In reality, neither of the techniques is full proof; a percentage of the nutrients bypasses the root system and enters the underground aquifer."

June 17, 2008 - Peter Lane Taylor 

The Congressional Research Service wrote in its Sep. 20, 2006 report "Animal Waste and Water Quality: EPA's Response to the Waterkeeper Alliance Court Decision on Regulation of CAFOs," that:

"The primary pollutants associated with animal wastes are nutrients (particularly nitrogen and phosphorus), organic matter, solids, pathogens, and odorous/volatile compounds. Animal waste also contains salts and trace elements, and to a lesser extent, antibiotics, pesticides, and hormones. Pollutants in animal waste can impact waters through several possible pathways, including surface runoff and erosion, direct discharges to surface waters, spills and other dry-weather discharges, leaching into soil and groundwater...

Although agricultural activities are generally not subject to requirements of environmental law, discharges of waste from large concentrated animal feeding operations (CAFOs) into the nation's waters are regulated under the Clean Water Act (CWA)."

Sep. 20, 2006 - Congressional Research Service (CRS) 
Animal Waste and Water Quality: EPA's Response to the Waterkeeper Alliance Court Decision on Regulation of CAFOs (125KB)  

The California Farm Bureau Federation wrote in its article "How Much Water Does It Take to Make a Glass of Milk?," published on www.cfbf.com (accessed Aug. 20, 2009):

"When you add together the amounts of water needed to provide food and water for the cows, to keep the dairy barns clean, and to process the milk, it takes 48.3 gallons of water to produce one eight-ounce glass of milk."

Aug. 20, 2009 - California Farm Bureau Federation 



PRO (yes)

The US Environmental Protection Agency provided the following testimony on Sep. 6, 2007 during the Senate Environmental and Public Works Committee hearing "An Examination of the Potential Human Health, Water Quality and Other Impacts of the Confined Animal Feeding Operations Industry":

"AFOs [animal feeding operations] annually produce more than 500 million tons of animal manure...

An ongoing trend toward fewer but larger farm operations, together with greater emphasis on intensive production methods, increases environmental and public health risks by concentrating more manure nutrients and other animal waste impacts within smaller geographic areas. In addition, many large operations do not have sufficient land to effectively use the manure they generate as fertilizer. Animal waste and wastewater can enter water bodies from spills or breaks of waste storage structures (due to accidents or excessive rain), and over-application of manure to crop land...

Improperly managed manure has caused acute and chronic water quality problems and is a significant component of water body impairments. Manure and wastewater from CAFOs can contribute pollutants such as excessive amounts of nitrogen and phosphorus, organic matter, sediments, pathogens, heavy metals, hormones, and antibiotics to the environment."

Sep. 6, 2007 - U.S. Environmental Protection Agency (EPA) 



People for the Ethical Treatment of Animals (PETA) published the following information on the homepage of its Milk Sucks website (accessed May, 20 2008):

"[N]ot only is milk a waste of energy and water, the production of milk is also a disastrous source of water pollution. A dairy cow produces 120 pounds of waste every day -- equal to that of two dozen people, but with no toilets, sewers, or treatment plants.

In Lancaster County, Pa., manure from dairy cows is destroying the Chesapeake Bay, and in California, which produces one-fifth of the country's total supply of milk, the manure from dairy farms has poisoned vast expanses of underground water, rivers, and streams. In the Central Valley of California, the cows produce as much excrement as a city of 21 million people, and even a smallish farm of 200 cows will produce as much nitrogen as in the sewage from a community of 5,000 to 10,000 people, according to a U.S. Senate report on animal waste."

[Editor's Note: A 1998 EPA study showed that US dairy cows produced 54 billion pounds of manure (553KB) - 2.6 times the amount produced by the human population.]


May 20, 2008 - People for the Ethical Treatment of Animals (PETA) 



The Pew Charitable Trusts' Commission on Industrial Farm Animal Production wrote in its Apr. 28, 2008 report "Putting Meat on the Table: Industrial Farm Animal Production in America," that:

"Application of untreated animal waste on cropland can contribute to excessive nutrient loading, contaminate surface waters, and stimulate bacteria and algal growth...

Beyond nitrogen and phosphorus, waterborne chemical contaminants associated with ifap [industrial farm animal production] facilities include pesticides, heavy metals, and antibiotics and hormones...

It is also recognized that ammonia emissions from livestock contribute significantly to the eutrophication and acidification of soils and waters...

The large concentration of animals on the typical industrial farm presents a major waste management problem. The volumes of manure are so large that traditional land disposal methods can be impractical and environmentally threatening. Excess nutrients in manure contaminate surface and groundwater resources. Today, over a million people are estimated to take their drinking water from groundwater that shows moderate or severe contamination with nitrogen-containing pollutants mostly due to the heavy use of agricultural fertilizers and high rates of application of animal waste."

Apr. 28, 2008 - The Pew Charitable Trusts 



The Association of Metropolitan Water Agencies provided the following testimony on Sep. 6, 2007 before the United States Senate Committee on Environment and Public Works Hearing, "An Examination of the Potential Human Health, Water Quality, and Other Impacts of the Confined Animal Feeding Operation Industry":

"[C]oncentrated animal feeding operations [CAFOs] are very different from small family farms…a CAFO is a large farm that generally holds more than 700 dairy cattle...

[T]he typical manure disposal practices of CAFOs - which commonly involve holding waste in huge leak-prone cesspools and field application techniques that lead to increased runoff - pose serious dangers to the quality of nearby drinking water supplies. Waste from family farms, on the other hand, is usually generated and released in much smaller volumes, so it is more readily controlled.

As the number of CAFOs in the United States continues to grow, industry representatives have increasingly argued that they deserve an exemption from pollution cleanup liability under CERCLA. Legislation has been introduced in both houses of Congress that would specifically exclude manure and its components from the law's definition of a 'hazardous substance' under section 101(14) and from the definition of a 'pollutant or contaminant' under section 101(33)...

For a number of years there have been cases of components of untreated manure from CAFOs having harmful effects on public drinking water supplies across the country...

[In one specific example] Dairy cows in CAFOs upstream from Lake Waco created 5.7 million pounds of manure per day that was over-applied to land and made its way into the lake. The state found that nearly 90% of the controllable phosphorus in the river came from CAFOs in the watershed, and an independent researcher who conducted much of the state's analysis found that dairy waste applied to fields supplied up to 44% of the lake's phosphorus. From 1995 to 2005, the city spent $3.5 million on phosphorus-related water pollution, and has spent a total of approximately $70 million to improve water treatment. To recoup costs the city filed suit against 14 large industrial dairies in 2003 and eventually reached a settlement with the defendants."

Sep 6, 2007 - The Association of Metropolitan Water Agencies 



CON (no)

The American Farm Bureau Federation stated the following in a Sep. 6, 2007 statement, presented by Chris Chinn, to the Senate Committee on Environment and Public Works:

"Many people outside of agriculture and the livestock industry have concerns about the environmental and health impacts of livestock operations. Some have gone so far as to demonize livestock operations, calling them factory farms and industrial livestock production…

It is often overlooked, but the vast majority of farmers who operate CAFOs are involved in a family-based business, are highly educated college graduates, community leaders, and experts in science and technology. Most are trained in humane animal husbandry and environmental sciences and spend great amounts of time, money and other resources ensuring that their operations do not harm the environment...

CAFOs are regulated by the Clean Water Act. They must either have zero discharges, or obtain a National Pollutant Discharge Elimination System (NPDES) permit. Contrary to the assertions of some, it would be incorrect to presume that all or even most CAFOs experience actual discharges to navigable waters...

In particular, we note that any animal feeding operation (pork, poultry, beef, dairy or horse) of almost any size faces potential enforcement and severe penalties for even a single discharge from the operation to waters of the United States...

Farmers and ranchers understand their roles in improving and maintaining the health and safety of the nations' environmental resources. Farmers are sensitive to the environment because they own and manage two-thirds of the nation's land. They are doing their part to promote the principles of environmental stewardship by being good caretakers of the nation's soil, air and water resources."

Sep. 6, 2007 - American Farm Bureau Federation 



Dairy Farming Today, an organization that provides information about dairy production, stated the following in their "Being Green" article, posted on their website (accessed June 6, 2008):

"Dairy cows need to drink plenty of clean water to stay healthy and produce quality milk, so farmers take water protection and conservation practices seriously.

The proper recycling of cow manure plays a central role in protecting nearby lakes, rivers and streams. Farmers store manure and spread it on their crop fields according to a Nutrient Management Plan that takes into account the types of soil found on the farm, the terrain of the fields and the amount of nutrients needed by the crops. Other water protection measures include building fences along streams and planting trees along rivers."

June 6, 2008 - Dairy Farming Today 



Larry Serpa, Director of Member Relations and Milk Procurement for Land O'Lakes Dairy Foods, wrote in his Nov. 3-4, 2001 article "Dairies Can Coexist with Environment," published in the Visalia Times-Delta, that:

"We cannot allow...environmentalists to dictate their 'no impact - no growth' mentality in our rural communities. Everything we do from driving a car to a weekend backyard barbecue has some impact on the environment...

Local dairy farmers are doing their part...to minimize and eliminate environmental impacts...

[P]lans call for storing waste more carefully to eliminate runoff, and leaving sufficient land available for the safe field applications to manure. At modern dairies, manure isn't waste at all - it's a vital crop nutrient, used safely and efficiently to grow the feed crops necessary to support the dairy…

No one wants to degrade the land, especially not the families who live and work on their dairies."

Nov. 3-4, 2001 - Larry Serpa 




[Editor's Note: In our effort to find additional "con" statements to the question we spent many hours researching online, and were unable to find suitable "con" responses.

We also directly contacted three major dairy industry organizations involved with environmental research. On June 12, 2008 we emailed the Community Alliance for Responsible Environmental Stewardship (CARES) and made a follow up telephone call a few days later. On June 13, 2008 we emailed the National Milk Producers Federation (NMPF) and made a follow up call the subsequent week. On June 17, 2008 we emailed Paul Martin, the Director of Environmental Services for the Western United Dairymen, and made two follow up telephone calls to his office. As of July 3, 2008, none of these organizations have yet provided us with their response.]