King County wins grant to plan manure
digester for power
Cow power on the Enumclaw Plateau is getting a
boost thanks to a $93,900 federal grant for King County’s
efforts to help family-run dairies, improve manure management and
generate new energy sources. King County Executive Ron Sims said
the U.S. Department of Agriculture Rural Business Enterprise Grant
will be used to address the technical challenges of developing and
building a system to collect and process the tens of thousands of
gallons of manure that dairy cows produce each day on the Enumclaw
Plateau.
The heart of any system is a manure “digester”
that converts methane gas from cow manure into electricity. The
digester also creates a marketable biosolid that is an excellent
composting material. The remaining liquid that is separated from
the gas and solids during processing will continue to be used as
fertilizer for farmers’ crops but with significantly less
odor.
Sims said the federal grant funding will be used
to identify which system is most appropriate for the Enumclaw Plateau,
to map out a system to aggregate the manure and to identify the
best site for such a facility. The work is expected to be completed
by the end of the year.
Dairy cow manure is currently stored in lagoons
or large tanks on individual farms and later sprayed onto fields
as a fertilizer. This practice can lead to complaints from neighbors
about excessive odors. Runoff from sprayed fields can also deteriorate
local ground water and create problems for fish.
King County has had a number of important partners
during this initial stage of the manure digester project, including
the dairy farmers of the Enumclaw Plateau, Energy Northwest and
its team, Washington State University, Seattle City Light, the USDA’s
Natural Resource Conservation Service in Renton, the King Conservation
District, and the Department of Community Trade and Economic |
