metric tons/year

24,000

Technologies Used

Client Needs

EnviroWaste’s Hampton Downs facility had been in operation for several years mostly composting yard waste and using a low aeration rate micro-porous fabric covered aerated static pile. They had the opportunity to add high-energy food waste and increase the overall tonnage. The operators recognized they needed a high aeration rate composting system to maintain BMP process conditions during the first few weeks enabling increased throughput and a high level of odor control. With the tremendous reduction in volatile solids during primary composting, the low aeration rate system could then be successfully be repurposed for secondary composting.

ECS Solution

ECS worked with the EnviroWaste team to develop a detailed facility design of a bio-layer covered aerated static pile (CASP). The phase I CASP included six bunkers, and a control and aeration system sized for six more bunkers in phase II. Given the high energy feedstocks and the need for rapid stabilization, a reversing aeration system (automatically switching between positive and negative to minimize temperature variability) was employed that ducted all negative exhaust air to a biofilter. The aeration system and biofilter were designed to accommodate the addition of six more bunkers.

Compared to the previous microporous covered compost system with low flow, this new approach utilized a high aeration primary composting step followed by a low flow secondary step (using existing infrastructure). Other improvements the operators observed include:

Much better control over the process – able to compost a more aggressive and wider range of feedstocks,
much better termperature control
The custom zone sizes were a better match for their operational needs
less hassle – no need to remove and reapply covers
smaller footprint with faster cycle time (previously ~6-8 weeks, down to ~3 weeks with ECS)
Less cost, much less concrete using the ECS system than the previous system
“You can significantly increase your throughput….[the two] systems work really well together” – HD Operator

NZ Herald Article