The Native American tribes that hunted the plains between the Mississippi River and the Rocky Mountains for most of the last millennium are often held up as models of wastelessness (a word I just invented) for, among other things, their innovation in using virtually every part of the animal. Those of us who saw Dances with Wolves will recall how this idea was juxtaposed against the wastefulness of modern American society, when a misty-eyed Kevin Costner gazed over an entire herd of buffalo slaughtered by white men for only their hides.
Now, hundreds of years after the plains hunters set their example, modern society is gradually coming to grips with the fact that it needs to move back to a system in which virtually nothing is wasted. But the task may in some ways be more daunting than it was for the Lakota, given that there may be 50 times more people in North America than there were 200 years ago. More importantly, much of the population alive today in the United States grew up during a time of relative abundance with little consideration for waste or excess presenting a difficult cultural hurdle to overcome.
Enter the ingenuity of American business. The George DeRuyter & Sons Dairy in Outlook, Washington maintains a herd of about 4,500 cows. Cows in Washington state are some of the most productive in the country, producing up to 10 gallons of milk per day. But they also produce a lot of waste the average dairy cow generates over 100 pounds of waste per day. This can have a detrimental impact on the environment in a number of ways, but given that manure is rich in nutrients, it also presents a number of opportunities.
The DeRuyter Dairy takes advantage of these opportunities, and in many ways is a model for manure management (and optimization). Having visited there last month, I saw it all first hand. Here are the various products that the dairy produces from the waste stream:
1. Carbon Credits
The manure is collected via a drainage system into an anaerobic digester tank. There, it breaks down over a period of 21 days, releasing methane gas that is captured by a piping system. Methane is a potent greenhouse gas (21 times more powerful than carbon dioxide), making its capture and destruction eligible for carbon credits which in the case of the DeRuyter project are purchased by Terrapass.
2. Electricity
Methane is also the main constituent in natural gas, meaning that it can be used as fuel. So the dairy uses this gas to power two internal combustion engines that generate renewable electricity for sale to the grid.
3. Phosphorus
After 21 days, two products come out of the back side of the digester tank. One is effluent (fluid) that DeRuyter sends to a series of processing tanks, one of which captures phosphorus from the waste stream. Phosphorus (in this case, natural organic phosphorus) is a chemical element used in a variety of everyday products.
4. Liquid Fertilizer
The remaining effluent, still rich in nutrients, is used by the farm as valuable fertilizer for the fields also managed by the farm.
5. Solid Fertilizer
The other substance that emerges from the digester tank is a solid known as digestate. The dairy uses a novel in-bag composting system to stabilize this digestate so that it can be bagged and transported for sale as a solid fertilizer in stores.
This begins to look a lot like the lesson that the Lakota have taught us to use everything and waste nothing. If we are going to move to a zero waste society, someday all farms and truly all operations and businesses of any kind will have to look like this. Welcome to the Farm of the Future.
Brought to you by terrapass.com
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