1.1 This specification covers requirements, test methods, materials, and marking for polypropylene (PP), open bottom, buried chambers of corrugated wall construction used for collection, detention, and retention of stormwater runoff. A This specification covers requirements, test methods, materials, and marking for polypropylene (PP), open bottom, buried chambers of corrugated wall construction used for collection, detention, and retention of stormwater runoff. Applications include c