An Arizona dairy farm is turning cow manure into renewable natural gas

BUCKEYE, Ariz. - It all starts here - with 25,000 dairy cows at Butterfield Dairy Farm in Buckeye.

"Me and my three sons built this dairy, there was no contractor here, they did it all," said owner Thomas De Jong.

The De Jong family bought land in Buckeye in 2003. They finished their first dairy in 2008 and their second in 2018, but the owner says his family has been in the dairy business since 1620.

Now, Thomas and his three sons - Tommy, Jake and Andrew - are taking their farming to the next level with a plant that's turning manure into renewable natural gas.

The farm is working with Avolta, a renewable energy company.

"From the renewable natural gas that we produce here, it could power 6,000 homes," said De Jong.

The manure is flushed out of the barn and is collected in what resembles a sewage system.

Manure is flushed out at Butterfield Dairy Farm.

The manure is taken to its first stop to be dewatered. 

"The manure coming out of here has a lot of water," said Avolta owner Gov Siegel. "That’s too much water that we need to process, so we’re dewatering that manure."

Manure with the water removed.

The dewatered product is then sent to a giant tank that's the size of two football fields. It's 16 feet deep and full of liquid manure.

"We use a heating process to break that manure down, and one of the most beneficial byproducts of that is this renewable natural gas," said Siegel.

A look inside the giant manure tank.

The next step involves purifying the gas to remove most of the carbon dioxide and convert it into usable methane gas.

"Ultimately removing most of the carbon dioxide, getting it to that pipeline quality spec so it goes into local utilities here," Siegel explained.

The byproducts from broken-down manure are purified into usable methane gas.

Methane gas is used to cook, heat homes and power vehicles.

"We’re helping dairy farmers with manure management, water management," Siegel said.

"This is good for the environment," De Jong said. "Good for the farm…and good for us."