August 2004 Newsletter

Dairies Can Help Reduce Greenhouse Gas Emissions

Friday, July 23, 2004
By Cookson Beecher, Washington State Staff Writer

LYNDEN, Wash. — As dairy farms grow larger, scientists continue to send out warnings about the harmful environmental effects of methane and nitrous oxide released from dairy farms and other livestock operations. According to scientific reports, greenhouse gases such as methane and carbon dioxide damage the ozone layer, which in turn leads to global warming.

During the recent groundbreaking of the first commercial dairy anaerobic digester to be built in Washington state, visitors to the Vander Haak Dairy in Whatcom County, Wash., learned about some of the research being done on the subject.

According to a 1974 study, about 65 percent of the methane in the atmosphere comes from agriculture, with a significant part coming from dairy cows. That’s important for dairy operators to understand, say scientists, because methane is about 23 times more potent as a greenhouse gas than carbon dioxide.

In 2004, the U.S. Environmental Protection Agency estimated that agriculture contributed approximately 7 percent of the U.S. greenhouse gas emissions, most of that as methane. The intergovernmental Panel on Climate Change estimates that the concentration of methane in the atmosphere has increased by more than 150 percent in the last 250 years.

Pointing to Washington state as an example, the panel said that if half of the state’s 250,000 dairy cows were on farms with anaerobic-digester systems, up to 100 million pounds of methane – about 3.15 million tons carbon equivalent – could be captured each year.

The upside to using closed systems of anaerobic digestion to decrease greenhouse gas emissions is that a wide range of environmental benefits is realized. Examples are elimination of most methane emissions into the atmosphere, water-quality protection, nutrient conservation, renewable energy production, and the elimination of most odor problems.

In addition, the process creates byproducts that can generate new income streams for the farmers. This, in turn, will help farmers stay in farming and protect the land from development.

Marlin Statema, president of Ferndale, Wash.-based Andgar Corp., project manager for the methane digester at the Darryl Vander Haak Dairy in northwest Washington, said the digester represents a technological approach to an environmental and neighborhood problem.

“It’s neighbor-friendly,” he said, referring to the elimination of most odors. “It’s environmentally friendly, and it’s profitable. We wouldn’t advise a farmer to do this unless it was profitable.”

Andgar has plans to build a similar, but much larger, system on a California dairy with 6,500 cows. If that happens, it will likely be the largest anaerobic digester for handling dairy waste in the U.S. While most dairies use lagoon systems to store manure, those lagoons emit large amounts of methane and nitrous oxide.

In contrast, a closed anaerobic digester system eliminates most of those emissions. It also produces renewable energy, which can be used to power the farm. This “green energy” can also be sold to local power companies and used to provide electricity to households.

This spring, a Marin County dairy became the latest California farm to generate electricity from cow manure. Capital Press reported in May that the Straus Family Creamery’s new $280,000 methane digester converts manure from its cows into electricity, which helps power the farm and creamery.

But even though California dairies have a total of nearly 2 million cows, the generator at Straus’ dairy is only one of five in that state.

But there are signs that this picture will be changing.

In a recent “Dairyline” column by Lee Mielke, a dairy official reported that the San Joaquin Valley Air Pollution Control Board has decided to require dairy operators to acquire air pollution permits. To do that, they must make “significant investments” to achieve what the board considers a reduction in pollution. That would include covering lagoons or installing digesters.