The Billings Department of Public Works commissioned a new composting facility in August of 2024, to reduce the cost of landfilling compostable material and to meet sustainability goals. The aerated static pile (ASP) composting facility has capacity to process up to 25,000 tons of material annually and is expected to extend the life of the current municipal landfill by at least 10 years.
The primary materials being composted are yard waste along with biosolids that come from municipal sewage treatment. Before this composting facility was in operation these materials were all disposed of at the municipal landfill. 鈥淭his composting facility should extend the lifespan of our landfill by as much as a decade,鈥� said Kyle Foreman of the Billings Department of Public Works. 鈥淎nd it’s a big step towards someday being able to accept food waste from residents and restaurants.鈥�
Rising costs of landfilling, combined with landfill capacity issues and the city鈥檚 sustainability goals were all important factors motivating the city鈥檚 investment in composting infrastructure. Instead of spending money to throw these materials away, the city will now be producing thousands of tons of valuable 鈥淐lass A鈥� biosolids compost annually.
The engineered aeration system and the overall process ensures that the composting material always has the optimum amount of oxygen. This speeds up the process, minimizes odors and dramatically reduces material handling costs compared to conventional turned windrow composting. In addition it negates methane emissions that would have otherwise occurred had the material been landfilled.
The composting equipment was designed and provided by Green Mountain Technologies (GMT), a leading compost engineering company based in Washington State, who worked with local general contractor COP Construction and Great West Engineering.
The specialized compost aeration infrastructure and equipment includes computerized data and control systems that can automatically adjust aeration levels to optimize the process. The composting aeration pad is divided into nine separate zones, each of which can be independently controlled. Proper aeration levels are a key factor in minimizing odors and producing high value compost products.
The aeration system zones are all connected to one aeration blower, with specialized valves from GMT that are opened and closed by GMT鈥檚 鈥淲ebMACs鈥� control system to track data and determine the aeration levels of each zone. WebMacs optimizes aeration levels to control temperatures across multiple zones. Optimized aeration reduces the need for mechanical turning of the material, speeds up the process and ensures low operating costs of the facility, while eliminating odors and anaerobic gas emissions such as nitrous oxide and methane.
鈥淭his is a huge step towards sustainability for Billings and a project I鈥檓 really proud to be a part of,鈥� said Peter Haun, Montana-based engineer and project manager at GMT. 鈥淭o my understanding there really aren’t many other projects like this in Montana. This project solves two problems by composting two waste streams together, reducing their GHG emissions and creating valuable compost products.鈥�
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