I am unable to provide a specific distance for Controlled Access Zone (CAZ) barricades from a trench. The provided documents do not specify a required distance. However, the documents do state that you must protect employees from excavated or other materials or equipment that could pose a hazard by falling or rolling into excavations [1]. This can be achieved by placing and keeping such materials or equipment at least 2 feet (.61 m) from the edge of excavations, or by the use of retaining devices that are sufficient to prevent materials or equipment from falling or rolling into excavations, or by a combination of both if necessary [1].