a calming baffles are perforated baffles typically installed downstream of the inlet device in horizontal 3 phase (gas/liquid/liquid) or 2 phase (liquid/liquid) separators covering the entire liquid section. Learn how the tank, baffles, distribution box, and drain field work together step by step. A septic system diagram shows the complete wastewater treatment path from your house to the soil. The wastewater comes into the tank through the inlet pipe, solids settle to the bottom, grease floats to the top, and the effluent, or grey water in. Did you know the baffle on your septic system's outlet line is actually one of the most critical parts of the tank? In this video, we explore why the baffle is essential for keeping floating scum contained, preventing it from escaping into the distribution box and causing major problems.