Once the bin is at the curb, what happens to it? Most commercial composters use one of three methods. The choice comes down to space, volume, climate, and budget.
Windrow composting
Long parallel rows of organic material, typically 4 to 8 feet tall, built outdoors on a hard pad. A specialized turner drives over each row on a schedule to mix in oxygen and even out moisture. It is the workhorse method for regional volumes and works well in climates with real seasons.
Aerated static pile (ASP)
Material is built into a pile over a network of perforated pipes that either push or pull air through it. Because oxygen is delivered mechanically, the pile doesn't need to be turned. ASP is faster than windrow and uses less land, with a higher up-front infrastructure cost.
In-vessel composting
The entire active phase happens inside an enclosed drum, silo, or concrete trench with computer-controlled temperature, airflow, and moisture. It's the most expensive option per ton, but it processes material the fastest and is the easiest to site near neighbors because odor and leachate are fully contained.
