What are the conditions that rule out the direct contact pathway?

The determination that contamination deeper than 3 feet rules out the direct contact pathway is based on the principle that the risk of exposure through direct contact decreases significantly as depth increases. Direct contact typically involves interaction with contaminated soil or materials at or near the surface, such as during excavation or when individuals walk on or disturb contaminated areas.

When contamination is located deeper than 3 feet, it is generally less accessible to individuals, reducing the likelihood of direct physical contact with hazardous substances. This depth can also provide a natural barrier that limits the potential for migration of contaminants to surface levels where people might interact with them.

While the other options may indicate contamination issues or environmental concerns, they are not specifically indicators that eliminate the direct contact pathway in the same way that depth does. For instance, surface contamination may present a significant direct contact risk, contamination near groundwater could lead to a migration risk, and exceeding regulatory limits highlights a compliance issue rather than a physical exposure pathway.