Why Compost?

Composting is a controlled, aerobic (oxygen-required) process that converts organic materials into a nutrient-rich, biologically-stable soil amendment or mulch through natural decomposition. The end product is compost. Microorganisms feed on the materials added to the compost pile during the composting process. They use carbon and nitrogen to grow and reproduce, water to digest materials, and oxygen to breathe.

You can compost at home using food scraps from your kitchen and dry leaves and woody material from your yard.

Protects the climate by reducing methane emissions from landfills.
Reduces waste.
Recycles organic materials into a valuable soil amendment – compost.
Recovers organic materials and keeps them local.
Creates green jobs.
Extends municipal landfill life by diverting organic materials and saving space in landfills.
Reduces solid waste management costs because food scraps are one of the largest and heaviest portions of the waste stream, making their recovery increasingly cost-effective compared to disposal.

Food waste on the right turns into compost on the left.

Composting Definitions

Composting is the controlled, aerobic (oxygen-required) biological decomposition of organic materials by microorganisms. Organic (carbon-based) materials include grass clippings, leaves, yard and tree trimmings, food scraps, crop residues, animal manure and biosolids.

Compost is a dark, crumbly, earthy-smelling, biologically-stable soil amendment produced by the aerobic decomposition of organic materials.

Benefits of Compost Use

Compost Use for Stormwater Management

In the United States, our soils suffer from topsoil loss and erosion, which can lead to water quality issues and reduce the productivity of agricultural land. Compost adds much-needed organic matter to soil to enhance soil health. Compost has other uses as well in green infrastructure and stormwater management. Additionally, the use of compost sustains green jobs throughout the organics recovery cycle.

Markets and applications for compost include agricultural and horticultural, landscape and nursery, vegetable and flower gardens, sod production and roadside projects, wetlands creation, green infrastructure, soil remediation and land reclamation, sports fields and golf courses, sediment and erosion control, and stormwater management.

Compost Enriches and Builds Healthy Soil

Adds organic matter to the soil and increases the nutrient content and biodiversity of microbes in soil.
Conserves water and reduces water use by helping soils retain moisture.
Helps prevent soil erosion by reducing soil compaction and runoff.
Reduces reliance on chemical fertilizers and pesticides.
Improves plant growth and promotes higher yields of agricultural crops.
Improves water quality by filtering stormwater and reducing nutrient and sediment runoff.
Helps regenerate poor soil and remediate (clean up) soils that have been depleted by overuse or contain contaminants.

Compost Aids Climate Adaptation and Resilience

Improves a community’s ability to adapt to adverse climate impacts by helping soil absorb water and prevent runoff of pollutants during floods. It also helps soil hold more water for longer, mitigating the effects of drought.
Sequesters carbon in the soil, helping reduce greenhouse gas emissions.
Strengthens sustainable, local food production by using locally generated food scraps and other organic materials to create a valuable soil amendment that supports plant growth.

Total Municipal Solid Waste Landfilled

In 2019, 66.2 million tons of wasted food were generated in the food retail, food service and residential sectors in the United States. Only 5% of that wasted food was composted.

In the U.S., food is the single most common material sent to landfills, comprising 24.1 percent of municipal solid waste. When yard trimmings, wood and paper/paperboard are added to food, these organic materials comprise 51.4 percent of municipal solid waste in landfills.

When food and other organic materials decompose in a landfill where anaerobic (without oxygen) conditions are present, bacteria break down the materials and generate methane, a powerful greenhouse gas. Municipal solid waste landfills are the third largest source of human-related methane emissions in the U.S, accounting for approximately 14% of methane emissions in 2021. Wasted food is responsible for 58% of landfill methane emissions.

When we send food and other organic materials to landfills or combustion facilities, we throw away the valuable nutrients and carbon contained in those materials. By composting our food scraps and yard trimmings instead and using the compost produced, we can return those nutrients and carbon to the soil to improve soil quality, support plant growth and build resilience in our local ecosystems and communities.