How many clean groundwater samples are required to be considered clear in Risk-Based Cleanup?

In Risk-Based Cleanup (RBC) processes, the standard requirement often specified for groundwater samples to be deemed clear is three consecutive clean samples. This is crucial because it helps ensure that the absence of contamination is not due to temporary fluctuations in groundwater quality or sampling errors.

Collecting three samples establishes a more reliable baseline for the absence of pollution, confirming that the site has returned to acceptable environmental standards over a consistent timeframe. Such an approach minimizes the risk of premature conclusions regarding the cleanup status, providing greater confidence in the results that determine the safety and health of the groundwater. This practice is part of a comprehensive risk assessment strategy used to evaluate and manage potential hazards associated with contaminants in the environment.