Approved Backfill Calculator
The use of proper backfill is critical to long term underground storage tank performance. Only approved backfill is allowed when installing fiberglass storage tanks and the backfill must meet ASTM C-33 for quality and soundness. To verify that your backfill material meets our specifications, use the Approved Backfill Calculator.
An important characteristic of good backfill is hardness or stability when exposed to water and loads. Materials like crushed concrete, soft limestone, sandstone, sea shells or shale cannot be used as backfill because they break down over time.
To begin: Select the backfill material you wish to verify. Then enter the required data from your provider’s sieve analysis and if your material meets our specification, you will receive a confirmation email from our Tank Technical Support department.