Rule 15-18-77-5.4.2 - Definitions1. Aggregate System - any subsurface disposal system that utilizes gravel, crushed stone, tire chips or other approved aggregate media.2. Conventional Subsurface Aggregate Disposal System - any gravity-fed subsurface disposal field utilizing a loose aggregate media ranging from 36 to 12 inches in depth. a. Standard Subsurface Disposal 25 in. to 36 in.b. Shallow Subsurface Disposal 12 in. to 24 in.3. Tire Chips - Coarse aggregate made from recycled tires to substitute volume trically for mineral aggregate for use as media in a conventual subsurface disposal field.15 Miss. Code. R. 18-77-5.4.2