Division of Spill Prevention and Response


SIR: Statistical Inventory Reconciliation

Federal and state laws require underground storage tank systems (USTs) to have leak detection. One of the available leak detection methods is Statistical Inventory Reconciliation (SIR). In this method, a trained professional uses sophisticated computer software to conduct a statistical analysis of inventory, delivery, and dispensing data.

SIR can allow the owner or operator of an UST facility to meet leak detection requirements without an extensive outlay of capital, using only the equipment that most facilities have readily at hand—a tank stick and a tank chart used for inventory control. The SIR analysis itself is usually provided as a service by vendors who charge a monthly fee based on the number of tanks.

Qualified Vendors for Statistical Inventory Reconciliation (SIR)

Please see the National Work Group On Leak Detection Evaluations' web page for a complete listing of vendors who meet performance standards to perform Statistical Inventory Reconciliation (SIR) as an approved form of release detection. However, the SIR method must be third party approved.

Please note that not every method will work on every tank system. Check with the vendor on the specifics of your system before you begin using SIR. UST systems without totalizers, compartmentalized tanks, or manifolded piping systems may not be able to use SIR.