Class B biosolids applied to Bremerton’s forest are relatively dry. Before application, at least 99 percent of the pathogens have been removed. After 30 days, no measurable pathogens remain. Still, public access remains closed to this area.
When the city of Bremerton started applying processed sewage sludge to its forestland west of Gorst, the trees began to grow dramatically faster.
One can see the result 20 years later in tree rings when the Douglas firs are cut down: skinny rings before the application, fat rings ever since.
Some people consider biosolids – produced from sewage sludge – to be a prime fertilizer, rich in nitrogen, phosphorus and organic material.
Others raise questions about an array of low-level compounds found in the material, from toxic industrial chemicals to pharmaceutical drugs to personal health care products.