St. Louis County, MO Landscaping Rules: Composting (2026)

Section 607.1005 of the St. Louis County Waste Management Code governs residential (backyard) yard by-product composting. It opens by requiring that all residential compost be maintained using accepted composting methods, then lists specific requirements. Composting must prevent the harborage of rodents and pests and must inhibit the generation of odors. The pile or bin must sit at least three (3) feet behind the front of the main residential structure, so a heap cannot go in a front yard or beside the street-facing wall of the house.

Location is also tied to water. Composting must be placed so that leachate does not discharge onto adjacent property, and it cannot be located in natural or man-made storm water channels. Chapter 607 defines leachate as liquid that has percolated through waste or come in contact with it and extracted, dissolved or suspended materials from it, so a soggy, unmanaged pile draining toward a neighbor's lot or a drainage swale fails this standard. Where a pile abuts adjacent property, it must be made site-proof to the neighboring owners, and any enclosed compost structure must comply with local zoning regulations.

Four materials are prohibited outright: meat scraps, bones, fatty foods (the code names cheese and cooking oils) and pet feces. The section is built around yard by-product, which Chapter 607 defines as source separated leaves, grass clippings, yard and garden vegetation, tree limbs six (6) inches or less in diameter, and Christmas trees. Stumps, roots, shrubs with intact root balls and waste from decorative or ceremonial items are outside that definition.

Composting under this section is for private use only. There can be no commercial provision of material to be composted and no commercial use of the finished product. Every owner and operator is responsible for all property under his or her control meeting the section, which puts the duty on the landowner or occupant in charge of the lot.

A backyard pile that follows these standards needs no license. That is why Section 607.310 carves out an exception for yard by-products handled as provided in Section 607.1005 from its ban on depositing waste at unlicensed sites. A yard by-product compost facility, by contrast, is a non-residential premises that accepts material generated off-site, and it needs a license from the Director of the Department of Health under Section 607.1010 plus a plan and application fee under Section 607.1015.