Why would be unwise to pass a law stating that if any toxic substances were shown to be in a municipality drinking water the water could not be distributed and used by its citizens?

Passing a law that prohibits the distribution of drinking water upon the detection of toxic substances could lead to severe public health crises and social instability. Such a blanket ban might result in immediate scarcity of safe drinking water, disproportionately affecting vulnerable populations and increasing the risk of waterborne diseases. Additionally, the law could create unnecessary panic and undermine public trust in water management systems, complicating efforts to address contamination issues effectively. A more nuanced approach, focusing on remediation and communication, would be wiser.