Which of the following is a common sign that a septic tank needs to be pumped?

Pumping a septic tank is essential to maintain its function and prevent system failure. When assessing the need for pumping, several signs can indicate that the system is overloaded or that solids are building up inside the tank.

The presence of lush grass above the tank can suggest that the tank is leaking or that effluent is surfacing, which typically occurs when the tank is full. This is a visual cue of potential issues related to the tank's contents.

Unpleasant odors near the system are another strong indication that the septic tank may need attention. These odors signal that sewage or effluent is escaping from the tank or the lines leading to it, which can happen when the tank is full or the absorption field is compromised.

Slow draining toilets are also a key sign, as they point to potential blockages or backups in the plumbing that can arise from a full septic tank. When solids accumulate beyond the tank's capacity, it can hinder the normal flow of wastewater.

Each of these signs—lush grass, unpleasant odors, and slow drainage—indicates a failing septic system that requires pumping. Therefore, recognizing all these indicators is crucial for maintaining a healthy septic tank, making "all of the above" the appropriate choice.