Fascinating! Royal Dairy in Royal City, Washington, cleans and reuses its water more than 10 times before the water leaves the farm. The dairy has also cut its nitrate pollution and lowered its greenhouse gas emissions, all thanks to a new kind of wastewater filtration system powered by worms.
Called vermifiltration, every day, half a million gallons of farm wastewater is pumped through a gigantic bed of earthworms. The worms, wiggling in wood chips and shavings, feast on the liquid manure and wastewater, removing nutrients and harmful chemicals from the stream. The water then percolates through a layer of crushed rock, collects at the bottom of the worm bed, and travels out an exit pipe to use on the farm once more.
Source: The Bullvine, July 18, 2022. Link.
Also see: A vermifilter system for reducing nutrients and organic-strength of dairy wastewater, Science Direct, August 2021. Link.
Vermifiltration is an emerging low-cost and environmentally sustainable technology for the treatment of wastewater and recovery of nutrients.”