What is "scum" in the context of a septic tank?

In the context of a septic tank, scum refers to the layer of fats and oils that floats on the surface of wastewater. This layer forms as a result of the solid waste breaking down and the lighter materials, such as grease and oils, rising to the top due to their lower density. Scum accumulates over time and is an important aspect of how septic systems manage waste.

Understanding scum is crucial for septic system maintenance, as excess scum can lead to clogs in the system and can affect the overall functionality of the septic tank. Hence, recognizing scum and its role helps in ensuring the long-term efficiency of the septic system.