Which of the following systems has a leaching bed as a way to dispose waste?

• A. Class 2 System
• B. Class 4 System
• C. Class 3 System
• D. Class 5 System

Answer: (B)

A leaching bed is the soil absorption field of an on-site system, where effluent from the treatment unit is distributed through perforated pipes in a bed of gravel or sand and allowed to infiltrate the soil. This disposal method relies on the soil to filter and treat the water as it percolates downward, making it a natural, ground-based disposal approach. That drainage field approach is what defines a Class 4 system, so it’s the best fit for the question. Other system classes use different disposal strategies that don’t involve a leaching bed, such as alternative treatment or storage methods, so they don’t match this description.