What is a critical requirement for access openings located at a high water table?

Access openings located at a high water table have a critical requirement to be water-tight. This is essential because high water tables can lead to groundwater infiltration into sewage systems, potentially causing significant issues such as system failure, contamination of groundwater, and unpleasant odors. A water-tight access opening ensures that no water can enter the system from outside, maintaining the system's integrity and functionality. By preventing groundwater from compromising the sewage system, it promotes proper operation and protects the environment.

While painting for visibility, having a cover, or being removable for inspection might be considerations in different contexts, they do not specifically address the unique challenges presented by high water tables in sewage systems. Therefore, the primary focus when dealing with high water tables is ensuring that the access openings do not allow external water to enter.