Which fixture may be indirectly connected to a storm drainage system?

An indirectly connected fixture is one that discharges wastewater into the drainage system in a manner that prevents any possibility of backflow, thus not allowing harmful substances to contaminate the potable water supply or flood into other areas. A drinking fountain is designed to provide potable water, and it can be considered suitable for indirect connection to a storm drainage system through methods such as an air gap. This ensures that the drinking water remains uncontaminated and that any overflow is safely drained away without risking backflow into the drinking source.

In contrast, fixtures like toilets, showers, and bathtubs are directly connected to the sanitary sewer system, which is designed for wastewater and sewage. These connections involve a different set of plumbing standards and considerations, which typically do not allow them to connect to storm drainage systems due to the risk of contamination and the nature of their waste.