National City, CA Landscaping Rules: Composting (2026)

Section 7.08.050 of the National City Municipal Code, in Chapter 7.08 (Environmental Conditions) of the Property Conservation and Community Appearance Code, is the only composting rule in that chapter. It makes it a violation to operate, maintain or permit any horticultural, agricultural or botanic compost pile, pit, bin or heap that in any way produces odor that exceeds the odor threshold upon the residential property of any other person. The test is measured at the neighbor's property, not at the property where the compost sits. Chapter 7.08 prints no minimum distance from a lot line, no maximum size and no bin construction requirement, so the standard a resident has to meet is a result: no over-threshold odor reaching someone else's residential lot.

The code defines the measuring stick in Section 7.10.010.E. The odor threshold is the lowest concentration of odorous matter that produces an olfactory response in normal human beings, and it is determined under American Society for Testing Materials Test Method D 1391-57 (reconfirmed to 1967) or in an equivalent manner acceptable to the code conformance officer. Section 7.04.030 defines the code conformance officer, abbreviated CCO, as the officer of the city who applies the Property Conservation Code.

Other sections in Title 7 sit next to the compost rule. Section 7.08.010.A separately makes prolonged odor emission a violation when it noticeably exceeds the odor threshold on an adjacent residential property, and it defines prolonged as more than five minutes in any hour. Section 7.10.030 makes it unlawful to bury or burn garbage or rubbish on property under a person's control. Section 7.10.010.B defines garbage as organic refuse and waste of fruit, vegetable and animal matter prepared and intended for human consumption and not so used, and Section 7.10.140 makes it unlawful to keep garbage or refuse that yields odor exceeding the threshold within any dwelling unit on the same or adjacent properties. The junk chapter, at Section 7.12.010, excludes trimmings from lawns, shrubbery or trees from the definition of junk when they are used for mulch or like agriculture purposes.