In a well-operating system, where are most scum and solids removed from?

In a well-operating On-Site Sewage Facility (OSSF) system, most scum and solids are typically removed from the first chamber. This is because the first chamber, or primary treatment chamber, is where the incoming sewage first enters the system. During this stage, heavier solids settle out to the bottom as sludge, while lighter materials, such as fats and oils, float to the top, forming scum.

The design of most OSSF systems emphasizes the separation of solids and scum in this initial stage, allowing for more efficient treatment of the wastewater as it progresses to subsequent chambers. Effective retention of solids and scum in the first chamber helps to prevent clogging and reduces the load on later treatment stages, ultimately leading to a more effective and efficient processing of wastewater. Thus, removal from the first chamber is critical for maintaining system functionality and preventing issues down the line.