• Support or batter excavation sides before anyone enters the tank excavation.
• Use a lift plan for placing precast sections or heavy crate pallets.
• Inspect geomembrane wrapping for punctures before and during backfilling.
• Follow the designer backfill specification for material type and compaction.
• Secure lightweight geocellular crates against wind displacement during installation.
• Dewater the excavation to keep the formation dry for tank placement.
• Ensure safe access and egress is provided within the excavation at all times.
• Check for buried services before excavating the tank formation area.
• Obtain temporary works approval if traffic loads will cross the excavation.
• Record installation details including membrane integrity checks for handover.

• DON'T enter unsupported excavations for attenuation tank installation.
• DON'T lift precast tank sections without an approved lift plan in place.
• DON'T puncture the geomembrane with tools, boots, or sharp aggregate.
• DON'T backfill with materials that differ from the designer specification.
• DON'T place heavy plant or traffic loads over the tank without design approval.
• DON'T leave lightweight crate systems unsecured in windy conditions on site.
• DON'T compact backfill directly against geocellular crates without protection.
• DON'T allow water to accumulate in the excavation during tank placement.
• DON'T skip buried service checks before starting the excavation work.
• DON'T deviate from the installation sequence in the method statement.

See also: Below Ground Drainage Installation | Excavation Safety Awareness