What is a major concern when decommissioning an underground storage tank?

A major concern when decommissioning an underground storage tank is ensuring that samples meet Department of Environmental Quality (DEQ) requirements. This process involves taking soil and groundwater samples for testing to determine if any leakage or contamination has occurred. Meeting these regulatory standards is crucial to ensure that any potential environmental hazards are identified and managed properly. This aspect not only protects the local ecosystem but also ensures compliance with environmental laws, which is essential to avoid legal repercussions and to safeguard community health. Proper sampling also helps in making informed decisions about additional remediation efforts that may be necessary if contamination is found.

While the other options may have relevance in different contexts, they do not highlight the immediate and critical concern of environmental safety and compliance during the decommissioning process. For example, installing a new tank is not pertinent to the decommissioning itself, improving soil conditions may be a subsequent step after decommissioning but is not inherently part of the process, and calculating the tank's remaining capacity does not address the environmental impact of the decommissioning activities.