What is required for backfill material around an underground container?

The requirement for backfill material around an underground container is that it must be free of rocks and abrasives. This is crucial because rocks and abrasive materials can damage the container during the backfilling process or over time due to the pressure and movement of the surrounding soil. By ensuring that the backfill is smooth and devoid of sharp objects, the integrity of the underground container can be maintained, reducing the risk of leaks or structural failure. Proper backfill material also helps to provide adequate support and drainage around the container, which are essential for the safe storage of LP gas. Using inappropriate materials, like those containing gravel or varying soil types, could compromise both the safety and effectiveness of the installation.