When potholing, utility crews use a transportable vacuum excavator. To start with, check holes, normally measuring 6 to twelve inches deep, are made together the road wherever they decide to dig or get started building. They excavate soil with large-speed suction straight down until the utility line is partly uncovered. https://f004.backblazeb2.com/file/DigitalAsset/Bess-Utility-Solutions-Hayward/Potholing-Utilities-Hayward-CA.html