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Boise households have composted millions of pounds of material to date. Without your efforts, all of that material would have been dumped and buried in the landfill. Instead, it’s being turned into a valuable and useful new product that will improve the soil in landscapes across the city.

So what happens to the material that has been collected?


Compost Cart with Leaf Bags


1. Pickup from your curb

Compost carts are collected weekly from across the city. There are nearly 70,000 households that are participating in the compost program. Once a collection truck is filled, it transports that material to the city-owned 20-Mile-South Farm composting site.

Truck Unloading Compost Material


2. Drop and sort

Compostable material from the trucks is then placed on the ground, where any obvious plastics or other improper material are removed.

Grinding Process


3. Grinding

Compostable material, everything from watermelons, grass, coffee grounds, and tree limbs are ground into nickel-size pieces.

Compost Piles


4. Windrows

The freshly ground material is placed into long rows, called windrows. The windrows are six to eight foot-high, and about one hundred feet in length. Once in windrows, the composting process begins.

Windrow Turning Machine


5. Turning

The piles are regularly watered and a machine called a windrow turner rolls over each windrow every few days, based on the soil moisture and temperature readings, with large spines that mix and turn the material. This aids in the composting process by adding oxygen and moisture.

Finished Compost


6. Finished Compost

As the composting process proceeds, the internal temperature inside the windrows is between 130 - 160 degrees. The compost is continually monitored for heat and moisture levels to ensure proper composting. The entire process takes around 100 days.


Back to homes and parks around Boise

Once finished compost has been sampled and tested, it is available for residents to pick up free of charge. Additionally, it is used to improve landscapes in parks and greenspaces across the city.