Which method is not typically used to determine the spread of contamination?

Taste and odor testing is not typically used to determine the spread of contamination because it relies on subjective sensory perception rather than objective analysis. While taste and odor can indicate possible contamination, they are not definitive methods for identifying the presence or extent of pollutants or pathogens in water. In many cases, contaminants may be present without any noticeable taste or odor, which means relying on this method could lead to false security or missed threats.

In contrast, laboratory analysis, visual observation, and environmental sampling are established methods for assessing contamination. Laboratory analysis provides quantitative and qualitative data about specific contaminants through chemical and biological testing. Visual observation helps to identify obvious signs of contamination, such as discoloration or unusual particles in water. Environmental sampling involves collecting water samples from various sources, allowing for a comprehensive assessment of contamination levels across a distribution system. Thus, while taste and odor may provide initial indications, they do not form a reliable basis for determining the spread of contamination.