What factor may indicate a risk of tank infiltration?

A sinkhole or settling around the tank is a significant indicator of potential tank infiltration risk because it suggests that the soil structure has changed, which could compromise the stability of the septic tank and its ability to contain waste. When there are depressions or ground settling, it can often mean there has been some form of erosion or collapse of the soil above the tank, potentially leading to structural failures in the tank itself. This could allow wastewater to leak into the surrounding soils, contaminating groundwater and posing environmental health risks.

Level ground surrounding the tank indicates stability, which typically means there are no significant changes that would threaten the tank's integrity. Dry soil in nearby areas may not strongly correlate to infiltration risk since dry soil can indicate low water saturation, and does not generally point to structural weaknesses. Low vegetation growth is often indicative of dry soil or poor soil condition, and while it may suggest a lack of nutrient availability, it does not directly relate to the risk of tank infiltration.