Why does King County use biosolids on land and crops?
Biosolids enrich the soil with essential nutrients that are released gradually as plants need them. These nutrients include not only organic nitrogen, phosphorus, and potassium, but also minor elements such as chromium, calcium, copper, iron, magnesium, manganese, selenium, sulfur, zinc and others that are necessary for plant growth. Biosolids also add organic matter, which improves the structure of the soil and helps the soil absorb and retain moisture. Recycling biosolids on land captures nutrients that would otherwise be lost and maintains the productivity of soil, one of our most vital resources. Biosolids are a valuable resource that can be used productively rather than treated as a waste to be dumped and buried at considerable cost.
