Sanitation District harvests Napa’s sewage sludge for fertilizer
The dredging is taking place in a vast sewage treatment pond. And the material being removed is biosolids, which is another way of saying sewage sludge. About 3,500 tons of biosolids will be piped from the pond this summer to be dewatered. It is ultimately trucked a short distance and spread over a NapaSan field where a farmer grows sorghum.