Twin Falls County, ID Landscaping Rules: Composting (2026)

Solid waste rules in County Code Title 4, Chapter 2 define private composting narrowly: producing compost not for sale, on a parcel under five acres, capped at ten cubic yards at any particular time, and used only on the premises where it is produced. Section 4-2-3(D) then makes clear that private composting is affirmatively allowed and that compostable material does not have to be hauled to the county's official disposal sites like other solid waste, so long as the material is actually being actively composted and the operation otherwise complies with applicable law.

The code draws a sharp line between this small residential exemption and larger operations: agricultural composting, meant for on-site or nearby farm use, must comply with local zoning and be approved by the Idaho Department of Agriculture, while commercial composting facilities producing compost for sale off-site must be approved by the South Central Public Health District and also comply with zoning. Both of those larger categories remain "solid waste" subject to disposal-site rules if not actually composted, and the private exemption only covers material genuinely being decomposed on the same property, not stockpiled yard debris awaiting pickup.

A pile that exceeds the ten-cubic-yard, five-acre threshold, or is not being actively composted, falls back under the general solid waste storage and disposal rules of section 4-2-3, including the fourteen-day storage limit that otherwise applies to accumulated waste.