U.S. EPA celebrates Sonoma County’s first methane digester

SAN FRANCISCO – The U.S. Environmental Protection Agency, along with the California Energy Commission, Western United Resource Development and the Petaluma City Council, today celebrated with St. Anthony Farm as it brought online Sonoma County’s first methane digester that will convert manure from the dairy’s 240 cows into electricity.

The Petaluma, Calif. digester will use bacteria to break down manure and produce biogas, which is converted into renewable electricity in an adjacent generator.

“Using biogas decreases greenhouse gas emissions, produces renewable energy, and safeguards local air and water quality,” said Wayne Nastri, the U.S. EPA’s administrator for the Pacific Southwest region. “The EPA is pleased to see the St. Anthony dairy digester come on-line -- it’s good for the environment and farmers.”

At the heart of the system is a 27,000 square foot covered manure lagoon digester. Flushed manure from St. Anthony Farm’s organic dairy, along with wastewater from the creamery, will be pumped daily to the new 2.3 million gallon lagoon. The covered lagoon provides favorable conditions for natural microbial action necessary to convert the organic matter into 17,000 cubic feet per day of methane rich biogas.

The gas will then be channeled into a pipeline where it’s transported into a 80KW generator, which will operate approximately 12 hours per day. The electricity generated will provide a substantial portion of the electric requirements of the dairy milking center and the creamery. The heat from the generator engine and exhaust system will also be captured and used to produce hot water for St. Anthony Farm.

Biogas is made up of methane and carbon dioxide. Because methane is more than 20 times as potent as carbon dioxide at trapping heat in the atmosphere, capturing biogas provides significant environmental benefits. Farmers and project developers can also increase their incomes by using biogas for on-site electricity generation or delivery to a local electric utility.

Under the EPA’s AgStar Program, the EPA provided technical assistance to Western United Resource Development. AgStar is a voluntary program that encourages the use of waste methane recovery systems on dairy and swine farms. Each year, these systems have reduced methane by about 1.5 million metric tons of CO2 equivalent, while providing enough renewable energy to power over 20,000 average American homes. The program also assists countries throughout the world in developing biogas recovery projects through the Methane to Markets Partnership.

Since 1952, St. Anthony Farm has been operated by the St. Anthony Foundation to provide a place for the homeless and impoverished to begin a recovery process from alcohol and drug addiction. Located on a lush 315-acre farm outside of Petaluma, program participants work on the farm while participating in a social model 12-step based rehabilitation program. In 1999, St. Anthony Farm became a certified organic (QAI) and North Coast Excellence Certified dairy. Each day more than 1,800 gallons of organic milk produced at the farm are made available to consumers through the Clover-Stornetta organic line. St. Anthony Farm’s organic garden produces fresh vegetables and fruit for farm residents and other local food programs.