What is required for pool backwash or draining water before it enters the sanitary sewer line?

The requirement for an air gap is pivotal in preventing contamination of the sanitary sewer system. An air gap is a vertical space between the outlet of a pipe or faucet and the flood level of the receiving vessel, in this case, the sanitary sewer line. This physical separation ensures that any backwash or water drained from the pool does not flow back into the sewer system, which could pose health risks from contaminants commonly found in pool water, such as chlorine and other chemicals.

The use of an air gap is a critical component of plumbing codes designed to protect public health and safety by preventing cross-connections. This method is an effective way to ensure that wastewater does not mix with clean water supplies. Therefore, when backwashing or draining pool water, maintaining an air gap is essential to comply with regulations and to promote safe wastewater management.