Treating wastewater to protect the environment and public health is our mission. We take it one step further by creating resources from the wastewater for sustainability. Part of cleaning the water involves extracting the human waste or solids. Solids are full of good stuff for the soil like carbon, nitrogen, and phosphorus, but they need to be treated first. To continue the treatment process,
we send the solids to big, heated tanks called anaerobic digesters. There, microorganisms
feast on solids for about a month. During that time, they’re killing harmful bacteria, breaking down pollutants, and releasing methane gas. We capture that gas and use it as a renewable fuel source to power the treatment plant and generate electricity. This process is completely transformative. In the end, we have finished biosolids. King County’s biosolids are a fantastic,
endlessly renewable soil amendment called Loop. Recycling the carbon and nutrients in
Loop back into the soil isn’t just the right thing to do, it makes sense. It’s safe, sustainable,
and plants love it.