What is a major source of error when obtaining water quality information?

Improper sampling is a major source of error when obtaining water quality information because it directly affects the representativeness and reliability of the test results. When sampling, it is crucial to ensure that the water collected reflects the overall quality of the source. Factors such as the location of the sample, the time of day, and the method of collection can all influence the results. For example, a sample taken from a location with localized pollution can give a misleading indication of the water quality for the entire system if the sample is not representative.

By ensuring that sampling procedures are followed correctly, including using appropriate containers, collecting samples at various times, and selecting locations carefully, one can obtain more accurate data that better reflects the overall water quality. This is essential for making informed decisions regarding water treatment and management.