What is the required depth of a grease trap's water seal?

The required depth of a grease trap's water seal is typically mandated to be at least 2 inches. This depth is essential for the effective functioning of the grease trap, as it helps to ensure that there is an adequate barrier between the fats, oils, and grease (FOG) that need to be separated from the wastewater and the outlet flow. A sufficient water seal depth minimizes the risk of FOG escaping back into the drainage system, which can lead to blockages and maintenance issues within plumbing systems.

Additionally, a 2-inch water seal is necessary to provide enough floatation for the grease and FOG while still allowing the heavier solids to settle to the bottom of the trap. This balance is crucial for the grease trap to operate effectively, as it optimally separates the different components of the wastewater.

Inadequate water seal depths could result in overflow issues or ineffective trapping, potentially violating local plumbing codes and regulations meant to protect the performance of municipal sewer systems.