California ICC UST Inspector Practice Exam 2026 – Your All-In-One Guide to Exam Success!

Statistical inventory reconciliation (SIR) is a method used in the quantitative release detection of underground storage tanks (USTs) to monitor inventory and detect potential releases. The frequency of conducting SIR is critical to ensure the integrity and safety of storage tanks.

Conducting SIR at least once per month is the standard required to effectively analyze inventory discrepancies and identify any potential leaks in a timely manner. Monthly assessments allow for consistent monitoring and provide enough data points to detect small changes that could indicate a release. This frequency strikes a balance between practicality and the need for prompt identification of potential issues, allowing for quick corrective actions if necessary.

Other frequencies, such as annually or biannually, may not provide sufficient oversight to detect leaks before they can cause significant environmental harm or regulatory issues. Conducting SIR weekly, while more frequent, may not always be feasible for all facilities and could lead to unnecessary resource expenditure if not justified by the site's risk profile. Thus, the monthly frequency is established as the minimum standard for effective monitoring under the quantitative release detection method.