MUSTR requires that how many soil borings be taken near the bottom of the UST?

The requirement for taking two soil borings near the bottom of the Underground Storage Tank (UST) stems from the need to ensure adequate assessment and characterization of the surrounding soil for potential contamination. By obtaining two soil borings, operators can achieve a more comprehensive understanding of the subsurface conditions. This approach allows for better identification of any potential leaks or releases of hazardous substances from the UST, as well as a more thorough evaluation of the soil's characteristics, which can influence remediation strategies.

Having just one soil boring may not provide sufficient information about the variability of the soil composition or the extent of any contamination, while three or four would exceed the standard requirements without necessarily yielding significantly greater insights. Consequently, the requirement for two borings strikes a balance between practicality and thoroughness in assessing environmental risks associated with UST systems.