What is the minimum distance that the water table should be from the ground surface year-round for leak detection to be valid?

The minimum distance that the water table should be from the ground surface year-round for leak detection to be valid is critical for ensuring the effectiveness of leak detection systems. A distance of 20 feet is generally recognized as necessary because it allows for an adequate buffer zone. This buffer helps to prevent contamination from groundwater, which can interfere with leak detection technologies and potentially mask the presence of leaks.

If the water table is too close to the ground surface, fluctuations in water levels due to seasonal changes or rainfall can affect the reliability of the monitoring systems. This can lead to false positives or negatives in detecting leaks, as water above the tank or piping can create confusing readings. Establishing a minimum distance of 20 feet ensures that any detected leaks can be measured accurately without interference from groundwater fluctuations, thereby maintaining the integrity and safety of the UST systems. Maintaining this distance is part of best practice regulations and guidelines for UST management and leak detection effectiveness.