What could an increase in chlorine demand indicate regarding water quality?

An increase in chlorine demand often suggests the presence of contaminants in the water, which can indicate pollution. Chlorine is used as a disinfectant to kill bacteria and other pathogens in treated water. When chlorine demand rises, it generally means that there are increased levels of substances that react with chlorine, such as organic matter or microbial contaminants. This can reflect poor water quality, as the additional chlorine is needed to achieve the same level of disinfection in the presence of more pollutants. In this context, an increase in chlorine demand can be a warning sign that the water supply is compromised or has been exposed to pollution sources, which is critical information for maintaining safe and clean drinking water.