Which of the following is a sign that a septic tank needs pumping?

A septic tank that requires pumping typically exhibits specific signs that indicate it is full or malfunctioning. Foul odors are a prominent indicator; this can suggest that septic waste is nearing the surface or escaping the tank. Slow drains often accompany this issue, as the buildup of solids in the tank prevents proper drainage through the plumbing system. Furthermore, a backup in the plumbing—where wastewater does not properly leave the home—signals that the septic system is overwhelmed, likely due to a full tank that needs to be emptied.

While high water bills, wet grass, and increased insect activity may relate to the overall functionality or condition of the septic system, they are not definitive indicators of the tank needing to be pumped. A high water bill could result from increased water usage that doesn't directly correlate to the septic tank's status. Wet grass may indicate leaks in the system rather than a full tank, and increased insect activity might suggest other issues rather than specifically needing a pump.