City of Phoenix CASE STUDY

The City of Phoenix was searching for a financially feasible sustainable approach to diverting the city's green and food waste. The solution had to work on an existing 20-acre parcel of land, have a high throughput, work in the dramatic desert climate, and not negatively impact the surrounding community.

Composting proved to be the lowest cost solution meeting these criteria. They reached out next to GMT for feedstock feasibility analyses, pilot testing, permitting, and compost equipment.

To better understand the feedstocks, GMT designed a small pipe on grade system that was installed prior to the 2014 Super Bowl. Food waste from the event was mixed with green waste and aerated on the pilot aeration pad. Based on the results, GMT designed a large Turned Aerated Pile (TAP) composting system capable of handling 120,000 T/year. The facility utilizes below grade spargers, reversing aeration, and biofiltration for maximal process, and odor control. At present, the facility is only built out to half of the overall capacity and processing exclusively green waste as a result of subsequent political changes.