What three factors does Statistical Inventory Reconciliation (SIR) analyze for leak detection?

Statistical Inventory Reconciliation (SIR) is a critical method used in leak detection for underground storage tanks that focuses on specific factors to ensure compliance and safety. The correct answer identifies the three main elements that are essential in understanding tank operations and evaluating the possibility of leaks.

By analyzing inventory levels, SIR examines the amount of fuel in the tank at any given time. This is vital for tracking any discrepancies and managing stock levels effectively. The delivery factor is crucial as it includes the amounts added to the tank, which helps in determining if the inventory matches what should be present based on deliveries. Lastly, the dispensing factor considers how much fuel is taken from the tank, giving insight into withdrawals and usage patterns. These three factors — inventory, delivery, and dispensing — together provide a comprehensive overview that helps identify potential leaks through discrepancies that arise from various operational activities.

The other choices incorporate factors that are either irrelevant or do not fit within the standard practice of SIR. For instance, maintenance is important for the overall integrity of the storage system but does not directly contribute to the statistical analysis used solely for leak detection. Similarly, disposal, while a crucial aspect of environmental management, falls outside the parameters of SIR's intended focus, reinforcing why inventory, delivery,