Would you actually fill a tank with water prior to placing the backfill?

• A. Yes
• B. No
• C. Only if required by code
• D. Only for pressure tests

Answer: (A)

The main idea is preventing floatation and movement of the tank during backfill. After the tank is set in the trench, filling it with water adds downward weight so buoyant forces from groundwater or moist soil won’t lift or shift the tank as you place and compact the backfill around it. This helps the tank stay in the correct position and reduces the risk of future movement or misalignment. The other options aren’t as correct because skipping the water can allow buoyancy to lift or shift the tank, some codes may mandate certain steps but the practical, standard approach is to fill to prevent movement, and using water only for pressure testing addresses a different purpose unrelated to stabilizing the tank during backfill.