What must backwash or pool draining water go through before entering the sanitary sewer line?

The requirement for backwash or pool draining water to go through an air gap before entering the sanitary sewer line is critical for ensuring that contaminants from the pool do not enter the wastewater system. An air gap is a physical separation between the water in a pipe and the potentially polluted water from another source. This separation prevents any backflow that could occur, which is vital for maintaining public health and the integrity of the water supply system.

By implementing an air gap, it acts as a safeguard against cross-contamination. The design effectively ensures that no pool water can flow back into the clean water supply, thereby protecting it from chemicals, debris, or pathogens that may be present in the pool water. In many local regulations, this is a mandated practice, emphasizing the importance of environmental and public health standards.

Other options, such as filtration systems or chemical treatments, focus on purifying or treating water rather than preventing contamination during discharge. While those processes are important in their own right, they do not address the immediate need to safely manage the release of water into the sanitary sewer system without risking the safety of the water supply.