The City of Napa’s contractor, Napa Recycling and Waste Services, had for years been composting mostly yard wastes using a simple static pile composting process. The City wanted to upgrade its compost facility to process more yard waste along with the addition of food waste and digestate. The system had to comply with the rigorous permit conditions required by the Bay Area Air Quality District and the California Water Board. The City wanted a robust system that would minimize fugitive odors and be capable of composting 50% additional feedstocks once their permitted amount was increased.
ECS designed and supplied a 20 zone positively aerated, bio-layer Covered Aerated Static Pile system (CASP). The zones are arranged in two 10 zone “fan groups,” each of which is aerated with a single large, highly efficient fan. Sparger pipes are embedded below the concrete aeration floor to uniformly distribute air. In addition to controlling the airflow to each zone and logging comprehensive process data, the CompTroller controls pile surface irrigation systems that can further reduce emissions. ECS also provided extensive technical support throughout the long permitting process.
Food Waste, Yard Waste, and Digestate
ECS Technologies Employed
Aerated Static Pile System
CompTroller™ Automated Control & Monitoring System
Positive Aerated System
Sparger Aeration Floor