For what reason can any commercial pool be immediately closed?

A commercial pool can be immediately closed for a hazardous chemical imbalance. This situation poses a significant health risk to patrons, as improper chemical levels can lead to recreational water illnesses or other health hazards. Maintaining proper water chemistry is crucial to ensure the safety and comfort of swimmers, which is why any indication of a hazardous chemical imbalance warrants immediate closure of the facility.

While other factors like a broken main drain grate, unsatisfactory water clarity, and structural damage can be serious and may lead to operational limitations or risk, they do not present the same immediate health threat as a chemical imbalance. Issues like a broken main drain could pose risks related to entrapment or safety, but they do not necessarily compromise water quality in the same urgent manner as a hazardous chemical imbalance does. Therefore, the urgency and potential health implications associated with a chemical imbalance justify the immediate closure of the pool.