If a tank has a liquid depth of 60 inches, how many inches must the outlet baffle extend below the liquid level?

The correct answer is that the outlet baffle must extend 24 inches below the liquid level in a septic tank with a liquid depth of 60 inches. This requirement is in place to ensure proper separation of solids and liquids within the tank and to facilitate effective wastewater treatment.

By having the outlet baffle extend below the liquid level by 24 inches, it helps prevent the floating scum layer from escaping the tank, which can disrupt the treatment process and lead to the clogging of the outlet pipe. This dimension allows for adequate depth to maintain effective hydraulic conditions within the tank.

Extending the baffle the right distance ensures that only the clarified liquid above the solids is drawn off, thus maintaining the quality of effluent that exits the tank while trapping solids and preventing their movement into the drain field.

Overall, this dimension is critical for the system's performance and longevity, aligning with the health and safety standards set forth by regulations governing private sewage systems.