Trenching Competent Person with hands-on soil classification. The OSHA safety regulations for trenching and other types of excavations require a trained "competent person" to be at the excavation whenever any employees are involved working in or near the hole. Come learn the required OSHA technique for proper hands-on classification of soils that trained competent persons must be able to perform in order to meet the requirements of OSHA for soil types A, B and C. Give your employees every advantage by taking the same national award winning program that has been taught to hundreds of OSH compliance officers in several states since 1989.