Section AF102 - DEFINITIONSAdd the following definition to section AF102.1 General.
GAS-PERMEABLE LAYER. A gas-permeable layer shall consist of one of the following:
1. A uniform layer of clean aggregate that is not less than four inches (102 mm) thick. The aggregate shall consist of material that will pass through a two-inch (51-mm) sieve and be retained by a 1/4-inch (6.4-mm) sieve.2. A uniform layer of sand (native or fill) that is not less than four inches (102 mm) thick and that is overlain by a soil gas collection mat or soil gas matting installed in accordance with the manufacturer's instructions. The soil gas mat or matting shall be designed for this purpose and condition, and have the capacity to freely transport soil gases to the collection point from the most remote area. Amended by Mass Register Issue 1532, eff. 10/11/2024.