What is the minimum distance a drainage system must be from a source of contamination?

The minimum distance of 5 feet for a drainage system from a source of contamination is established to ensure that contaminants can’t easily migrate into the drainage system. This distance acts as a protective barrier, helping to prevent the potential for harmful substances, such as sewage or other pollutants, to enter clean water sources or potable water lines.

By adhering to this separation distance, the risks of cross-contamination are minimized, which is crucial for public health and safety. The distance reflects considerations of soil absorption rates, potential flooding, and the physical properties of different contaminants and how they can spread. Regulations often take into account various site-specific variables, including soil type and drainage patterns, but the 5-foot requirement is a general guideline that aligns with best practices in plumbing to protect water quality.

While the other distances might seem plausible, they either exceed what is necessary for effective protection or may not be specifically mandated for all types of sources and systems, which is why the 5-foot distance is the commonly accepted standard in plumbing codes.