What is the minimum depth at which contamination must be for closure procedures?

For closure procedures related to contaminated heating oil tanks, it is essential to address the depth at which contamination is detected. The correct answer indicates that contamination must be found a minimum of three feet below the ground surface to initiate specific closure protocols. This threshold is established based on the understanding that contamination closer to the surface can pose an immediate risk to public health and the environment.

By adhering to this three-foot depth requirement, operators can ensure that contamination is sufficiently evaluated and managed. Contaminated soil at this depth level implies a greater potential for affecting groundwater and necessitates more comprehensive cleanup efforts to prevent environmental degradation. Proper closure procedures are critical for safeguarding against long-term impacts from any remaining contaminants that may leach into the surrounding areas. Therefore, the regulatory framework focuses on this specific depth to promote effective remediation and mitigate risks associated with contamination.