A Type B dispersal bed receives effluent from what type of treatment unit?

• A. Level I treatment unit
• B. Level II treatment unit
• C. Level III treatment unit
• D. Level IV treatment unit

Answer: (D)

The main idea is that a dispersal bed’s ability to function properly depends on the quality of the effluent feeding it. A Type B dispersal bed is designed to receive the cleaner, more treated effluent produced by the most advanced treatment units, so it won’t clog or fail under fine media and controlled infiltration conditions. Level IV treatment units provide the highest level of treatment, delivering effluent with significantly reduced solids, BOD, and pathogens. Feeding Type B with this high-quality effluent helps maintain adequate infiltration rates and long-term performance, whereas lower-level units don’t remove as much material and could lead to clogging and reduced effectiveness in a Type B bed. Hence, Level IV is the appropriate source for a Type B dispersal bed.