Which of the following must be done to a tank during abandonment?

When a septic tank is abandoned, removal or crushing the tank is crucial for several reasons. First, leaving a tank in place creates a risk of structural failure over time, which could lead to ground subsidence or pollution of nearby groundwater. A buried tank that deteriorates can potentially release contaminants into the environment, posing health hazards.

Additionally, local regulations often dictate that abandoned septic tanks must be properly decommissioned to ensure public safety and environmental protection. This typically involves either completely removing the tank from the ground or crushing it to eliminate the possibility of it becoming a hazard. By ensuring that the tank is dealt with properly, installers help to mitigate potential environmental issues and comply with legal requirements.