In most areas, you will need a permit for excavation work, even for projects that only involve grading or yard leveling. Permit requirements depend on your local government and the scope of the project, but they are especially common for significant digging or work that could affect utilities or public property. These permits help protect the local topography and prevent drainage issues. An experienced excavation company will typically know whether permits are needed and can often handle the process of pulling and closing them for you. You can also verify permit requirements by contacting your local building department and describing your project.

Most residential basements are 8 to 10 feet deep. You can dig deeper depending on building codes, but it does become more difficult. You’ll likely need to install stronger foundation walls and additional supports to handle the increased load. Depending on the water table, you may also need a water management system. Clay soil can support a deeper foundation than sandy soil. A structural engineer will be able to tell you the maximum, feasible depth.

Septic drain lines (or leach lines) are typically buried between 18 and 36 inches underground, and should be at least 6 inches below the surface. These pipes are perforated and surrounded by filtering materials like sand or gravel. Burying the lines at this depth helps minimize odors and allows bacteria and other biological processes in the soil to effectively treat the wastewater. Burying lines too close to the surface can cause issues unless the soil is very compact and stable.

Most states do not require excavation companies to hold specific licenses, but many require at least a contractor’s license. Additionally, heavy equipment operators require a special commercial equipment license to operate machinery required for excavation. You can use Angi’s contractor licensing tool to confirm that an excavation company you’re considering hiring is fully licensed. You should also make sure that the excavation team is fully insured before allowing them to work on your property.