What type of condition must the excavation be in before filling with back fill material?

Before filling an excavation with backfill material, it is essential for the condition of the excavation to be dry and stable. This condition ensures that the backfill material can be compacted adequately, which is important for providing structural integrity and preventing future settlement around the installed underground storage tank (UST).

When an excavation is dry, there is less chance of water-related issues, such as soil displacement or weakening of the soil structure, which can occur in wet and muddy conditions. Stability in the excavation is also critical because unstable or loose material can lead to collapses during the backfilling process or in the future, impacting the safety and functionality of the UST system. Therefore, ensuring that the excavation is dry and stable prior to backfilling helps to maintain a safe and effective installation process.