Which test would you use to measure the concentration of bacteria in water?

The Total Coliform Test is specifically designed to detect and quantify the presence of coliform bacteria in water, which is an indicator of microbial safety. Coliforms are a group of bacteria found in the environment, including fecal matter, and their presence in water typically signals potential contamination by pathogens that can pose health risks. This test is crucial in assessing water quality, especially for drinking water and recreational water bodies, since it reflects the overall levels of microbial contamination.

In contrast, other tests mentioned don't directly measure bacterial concentrations. The Total Phosphorus Test evaluates the amount of phosphorus in water, which is important for understanding nutrient levels and potential eutrophication, but it does not give information about bacterial populations. The Ammonia Test measures the concentration of ammonia, indicating organic pollution or nutrient enrichment but, like phosphorus, does not assess bacteria. The Chemical Oxygen Demand Test evaluates the amount of oxygen required to chemically oxidize organic material in water, serving as an indicator of organic pollution levels but again does not directly relate to bacterial concentration.

Thus, for measuring bacteria in water, the Total Coliform Test is the most appropriate choice, as it directly targets and quantifies specific microorganisms that are critical for assessing water quality in the context of human health.