432 cow freestall barn at Mallories Dairy, Silverton Oregon. The center of the feed lane is depressed 3º to carry drainage away.
The secret to success with flush cleaning is high flow rate. This high volume pop up valve is discharging 6-7,000 gpm. This is the only way to flush sand and other heavy bedding.
20 minutes after flushing, the grooves have drained the floor dry.
The slurry collection ditch at the low end of the freestall leads to the rock trap on the left. The slurry flows through the separators by gravity. The solids stack to the right, the liquid flows under the drain pipes.
The separated liquid flows on through twin settling basins before proceeding to the main liquid retention pond in the background. Recycle water for flush cleaning comes from these settling basins. The steel fixture in the foreground directs the flow to the left or right settling basin.