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Animal Sewage in New York, By the Numbers

Last week, Cornell Professors Michael Van Amburgh and Karl Czymmek published a blog attempting to dispute one of the figures referenced in the recent lawsuit brought on behalf of Riverkeeper and others by Earthjustice. In the suit, we challenge the weak, unenforceable and secretive permit that regulates the largest dairies in the state.

There is no doubt that fertilizer use is one of the foremost sources of water pollution in the United States. So Riverkeeper is encouraged that our lawsuit has motivated an increase in public discourse regarding regulation of animal wastes. Such a robust discussion will lead to stronger, smarter regulation in the future. While we welcome the professors’ differing opinion regarding how animal and human wastes should be compared, we respectfully disagree.


Photo: CC, US Department of Agriculture

Everyone acknowledges the vast quantity of animal sewage produced at dairies.

The professors seem to agree with environmental plaintiffs (and the federal Environmental Protection Agency on which we relied) that a mature dairy cow can produce 120 pounds of sewage per day. With more than 530 concentrated animal feeding operations, or “CAFOs,” in New York housing at least 200 cows each, that means the local dairy industry’s waste stream is larger than 4.6 billion pounds per year! That enormous amount of animal sewage, which contains harmful pathogens and excessive amounts of nutrients, must be handled and disposed of properly. That’s what our lawsuit seeks to accomplish.

The correct comparison of animal and human wastes should be based on environmental threat.

To put the dairy cow waste stream in perspective, our CAFO lawsuit compares cow sewage, nearly all of which is spread on fields without treatment, to the amount of sewage sludge produced by humans after it has been processed by a sewage treatment system. EPA estimates that a family of four produces roughly one pound of sewage sludge per day. Doing the math, every single one of the 530 CAFOs throughout the state produces and land applies at least the same amount of sewage as the City of Albany’s roughly 96,000 residents produce after treatment. This is an apt comparison because these are the equivalent quantities of wastes that are then disposed of into the environment. Comparing pollution threat to pollution threat, our numbers are correct.

The professors argue that we should instead compare the volume of cow-produced sewage to the volume of human waste before treatment. However, attempting to compare wastes at that point disregards the critical step of wastewater treatment for human waste, which dewaters and removes dangerous pathogens before exposing the sewage sludge to the environment, reducing its pollution potential.

Riverkeeper has long supported the beneficial use of manure for crop fertilization. When applied at proper rates, use of manure as fertilizer helps sustain farmers, provide a local food source, and protect open space—all while protecting water quality. However, since waste manure is spread on fields without prior treatment and is often over-applied, the environmental and human health risks posed by mishandling that waste are actually greater than those risks from an equivalent volume of treated human sewage.

It is important to note that our numbers are not actually in conflict with the professors’. We agree on the amount of waste produced by these facilities. Instead, the dispute is over the appropriate comparison between animal and human waste that will help policy makers understand the issue. Theirs is but a different lens through which to view the same problem. Even if we measure by the professors’ numbers, the “waste from the 200 cow example herd compares to 9,444 people [before treatment].” These figures are hardly less eye popping than ours. According to their calculations, the 530 CAFOs in the state are producing at least as much sewage as 5 million people, or over a quarter of New York State’s population. The facilities housing these cows would be comparable to 530 cities the size of Rensselaer, which has a population of 9,340 as estimated by the U.S. Census Bureau.

Therefore, no matter whose numbers we choose to use, the fact remains that that these large dairies must be properly regulated to protect our waters. To do so, the water quality permit must contain pollution prevention safeguards and be reviewed and enforceable by the Department of Environmental Conservation and by the public whose waters could be affected by disease-causing animal sewage.

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