Which of the following is a common sign of a water quality issue?

A common sign of a water quality issue is an unpleasant odor. Water that has an unusual or foul smell can indicate the presence of contaminants or bacteria, which may pose health risks. For example, a sulfur-like odor might suggest hydrogen sulfide gas, often associated with natural sources or the breakdown of organic material, and it can also indicate the presence of certain metals. Similarly, a musty odor could suggest algae growth or organic pollution. Detecting any offensive smell in drinking water serves as an important alert to potential problems requiring further investigation and treatment.

In contrast, clear water typically indicates that there are no visible particles or suspended solids present, which is a sign of good water quality. A chlorine taste can arise from disinfection processes and, while it can be an indication of adequate sanitation, it doesn’t inherently suggest a water quality problem as long as it stays within acceptable limits. Neutral pH, typically around 7, is considered ideal for drinking water, and deviations from this range can indicate issues, but neutral pH itself does not directly signify a water quality problem.