Waste Not, Want Not: Creating Usable Materials from Cow Manure while Reducing Methane

October 15, 2014


At Ben & Jerry’s, we think the key to delicious ice cream starts with happy cows and happy farmers, and we know there are some things on the farm that can have a negative impact on our environment when handled incorrectly. From the cows themselves to the feed they eat, dairy farming unfortunately stands out as a source of greenhouse gas emissions, and ultimately contributes to climate change. But like many things, what’s really important is how we manage the emissions source, and how we turn a problem into a productive solution.

The two major sources of GHG emissions on dairy farms both stem from the cow herself. Yes, cow “gas” from both ends, along with manure, releases a significant amount of methane gas into the air, and this gas is a key contributor to climate change. But luckily, there are good solutions. Enter Chris Wagner, owner of Green Dream Farm, and a Ben & Jerry’s Caring Dairy farmer.

Chris has worked with Andrea Asch, the Director of Natural Resources and the Caring Dairy Caring Dairy program here at Ben & Jerry’s. Together, they’ve proven that with a little innovation and a lot of determination, greenhouse gas emissions can be reduced with a manure separator, turning a liability into an asset. The manure separator, a joint project between Ben & Jerry’s, Green Dream Farm, and NativeEnergy, who work on carbon offsetting and insetting, is now up and running at Wagner’s farm. Through a process of separating the liquids and solids in manure, the amount of methane created is dramatically reduced. Over ten year’s time, the project is estimated to keep enough methane gas out of the atmosphere to equal 10,000 tons of CO2. That’s the equivalent of keeping 5,000 cars off the road for a year!


So how does it work? The liquid manure is separated from the solid material, and is then used on the fields as a valuable fertilizer. The separated solids are composted, creating a nice, clean bedding material for cows, which is then used on Chris’s farm. On top of that, Chris’s 360-cow operation can support bedding for up to nearly 900 cows. He’s then able to sell excess bedding materials to surrounding farms as supplemental income, all while reducing his own expenses and the CO2 that would be emitted were he to truck bedding to his farm. Saving money and doing good—now that makes for a happy farmer!

This entire process benefits the farm, the environment, and most of all, the cows! As Chris put it, “It’s nice, fluffy bedding that the cows like laying down in, and that’s what it’s all about.”


This separator can be used on many small farms throughout Vermont and the St. Albans Dairy Cooperative, which Ben & Jerry’s relies on for much of its dairy supply. The success of this first project we hope will become a repeatable model used on other Caring Dairy farms we source milk from around the globe. Projects like this are truly helping to create happy cows, happy farmers, and a happier planet.