Prince William County had been composting about 30,000 tons of yard, tree and garden debris at their Manassas, VA facility since 1994. Because of increasing demand and a desire to also recycle food waste, Prince William County released an RFP in 2015 for a newly constructed facility at their existing site. Especially important in the RFP were substantial material throughput as well as rigorous odor control. Freestate Farms, using an ECS advanced composting solution as a key portion of their solution, was awarded the public private partnership contract.
ECS worked with Freestate Farms and Prince William County to design an aerated static pile composting system that included both primary and secondary composting stages. The primary stage features reversing aeration—this helps destratify the temperature profile of the pile and create favorable bio-oxidation conditions to minimize VOCs and odors—as well as LFT (low friction trench) aeration floors, which provide uniform airflow to the pile, capture leachate, and require low amounts of maintenance. Odor control during the primary composting process is achieved by creating a Best Management Practice mix, adding bio-layer cover to the top of the composting material, and routing exhaust process air (from negative aeration) through a biofilter. The secondary stage was designed with a single direction positive aeration and an ECS sparger aeration floor to further cure the product.
“ECS has been tremendous to work with throughout the process, including original conceptualization and design, construction, and now commissioning. They understood our particular needs and worked with us, our engineer, and our contractor to design and construct a system that we believe will meet, if not exceed, expectations." – Douglas Ross, CEO
Food Waste, Green Waste
ECS Technologies Employed
Reversing Aerated Static Pile
CompTroller™ Automated Control & Monitoring System
Low Friction Trench (Primary) and Sparger (Secondary) Aeration Floor