Refuse goes in
of air to begin
Refuse continues to spin
and break down for a total
of five to seven days. Materials
unable to break down
are crushed, reducing
volume in landfill.
byproduct is filtered
through screen and
used as daily cover
Aging bioreactor provides landfill with many benefits
crushed inside, reducing the amount of space they take up
in the landfill.
The landfill’s bioreactor is formed from two sections of
repurposed cement kilns that have been welded together.
Ayres Associates conducted a review of the bioreactor
operation as well as a structural inspection of the
device to investigate the problematic areas that cause
shutdowns. Recommendations from the review and
inspection determined that spot welding repairs can
continue to be made to keep the bioreactor running, but
major, cost-prohibitive repairs would be needed to extend
its life long-term.
f the approximately 60 licensed landfills in Wisconsin,
the Highway G Landfill is the only one still using a
bioreactor, a device used to decompose refuse aerobically
(with oxygen) before it is deposited in the landfill where
anaerobic (without oxygen) decomposition takes place.
“We use it every day when it’s not down,” said Mark
Busha, landfill manager. “We use it for volume reduction.”
The bioreactor, about 185 feet long and 12.5 feet in
diameter, acts like a massive clothes dryer, tumbling
refuse for five to seven days before the decomposed
byproduct makes its way to the landfill. Busha said the
“fines” produced in the bioreactor, similar to compost, are
used as daily cover. Materials that don’t decompose get
“It’s showing signs of fatigue,” Busha said. “Once it
becomes too costly to run and the costs outweigh the
benefits, it will be time to get rid of it.”
– Tom Paquin