Which type of measurement will best indicate the concentration of contaminants in water?

Quantitative analysis is the best measurement for indicating the concentration of contaminants in water because it provides specific numerical values that represent the amount of a particular contaminant present in a given volume of water. This type of analysis uses precise methods such as chemical assays, spectrophotometry, or titration to determine how much of a substance is present, allowing for accurate monitoring and assessment of water quality.

In the context of water treatment, having exact measurements of contaminant levels is crucial for regulatory compliance and ensuring that the water treatment processes are effectively removing harmful substances. Quantitative data allows operators to make informed decisions regarding treatment adjustments and to evaluate the effectiveness of treatment systems.

Other methods, while important in their own contexts, do not provide the same level of detail regarding the concentration of contaminants. Qualitative analysis identifies the presence or absence of contaminants but does not quantify them. Microbial testing focuses specifically on the presence of microorganisms rather than other types of contaminants, and physical testing measures characteristics such as turbidity or color, which do not provide concentration data.