When Dan Flood built his 16- by 18-foot compost facility nearly two years ago, he used left-over pre-cast concrete blocks from his bunker silo.

The 6-foot long blocks cost $27 each, so for less than $500 Flood had a permanent structure to handle mortalities on his 105-cow dairy near Oakfield, Wis. “I’d already paid for the blocks, and I wanted to make a compost site, so this made perfect sense,” Flood says. Asphalt from an old roadbed provides flooring, and to keep the operating cost low, Flood uses spoiled silage for a carbon source.

“The site works great,” he adds.