The poop on farm use of human waste
Human waste is getting some good press lately.
Watertown is moving forward with plans to overhaul the wastewater treatment plant – so it can turn sewage sludge into energy. The city recently got a grant from the New York State Energy Research and Development Authority. Watertown water officials say they’re going to close down the sludge incinerator, and replace it with a system that will produce methane gas on site.
Sewage is also finding its way to North Country farm fields.
Unloading biosolids at the Grasslands facility in Chateaugay, NY. Photo: Casella Organics
Potsdam-based Casella Resource Solutions has found some success selling fertilizer from human waste to North Country farmers. In a story late last year, NCPR’s Natasha Haverty spoke with dairy farmer Dave Vincent of Chateaugay. At first, Vincent was leery of the “biosolid”(sewage) fertilizer, so he applied only a little bit, and sent samples from those fields to a lab at the University of Maine. He liked what it found, and put down 400 tons of it down last year. He says it's like handling "dry dirt,” and, “It kind of breaks up like sawdust when it’s being spread, it spreads real nice."
So what is sewage sludge?
This is how the Environmental Working Group describes it, “Sewage sludge is the thick, malodorous slurry left behind in a sewage treatment plant after its load of human and industrial chemical wastes has been treated and the wastewater discharged.”
Sludge News(ha!), which advocates against the use of sludge on farm fields, explains that, “…though the aim of sewage treatment is to produce clean water, it is never to produce “clean” sludge. Indeed, the “dirtier” the sludge-the more complete its concentration of the noxious wastes-the more the treatment has done its job.”
The Contrary Farmer chimes in
One of my all-time favorite farmers and writers, Gene Logsdon, is a proponent of using human and animal waste on the fields. His latest book is called “Holy Shit: Managing Manure to Save Mankind.”
He says manure, whether human, pet, or farm animal, should be seen as a resource, not a burden to society.
In a recent blog post he says, “Because of our cultural attitudes toward bodily waste, society is spending billions of dollars trying to make the stuff disappear when in fact it is worth billions of dollars as plant food. If it were white and smelled like roses, there would not be a problem.”
Oh, I do love this guy:
“Right now, advertising is doing a good job of convincing pet owners that it is okay to let their dogs lick them on the face but the same people throw their hands up in horror at the idea of composting the dog’s manure for garden fertilizer. In case you think this is not much of a problem, there are something like 70 million pet dogs in this country and most of their manure is going into landfills or down the toilet hole. And another 70 million pet cats.”
Logsdon concludes, “What makes this wastefulness so pathetic is that at the same time we are throwing the stuff away, the price of phosphorus fertilizers is rising.”
Poop is different than sewage sludge.
As a former crop inspector for the National Organic Program in Ohio, I cringed when I heard that story about human sewage being used in fertilizer. Sewage sludge is not allowable on organic-certified fields(See (e)(2).)
When the organic standards were being debated in the late 1990s, the Environmental Protection Agency’s top sludge regulator urged the department to allow “high quality biosolids” (sewage sludge,) to be used in organic food production.
In response, the Environmental Working Group questioned the “safety and advisability” of using sewage(pdf) sludge in any food production system.
“The large amount of human waste in sewage treatment plants means that the sludge contains high concentrations of phosphates and nitrates, desirable components of fertilizer. However, the industrial wastes that are present in sewage cause highly toxic materials such as industrial solvents, heavy metals, and even nuclear waste to be left behind in sludge. When sewage sludge is applied to the fields, both the nutrients and the toxic chemicals are released to the environment. There are many of these toxic chemicals, and they are often found at high concentrations.”
And from Sludge News, “Sludge is thus inevitably a noxious brew of vastly various and incompatible materials unpredictable in themselves and in the toxicity of their amalgamation, incalculably but certainly wildly dangerous to life.”
Hyperbole? Perhaps. But it sure makes Watertown’s plan to turn sludge into methane gas look like a good option.
Tags: agriculture, farming, sewage, sludge, small business, waste, waste disposal