Indoor Air sciences CSMI Practice Exam

Which of the following water sources is classified as Category 3?

1. Melting snow

2. Broken aquarium

3. Overflowing toilet tub

4. Flood waters from streams

The correct answer is: Overflowing toilet tub

The classification of water sources into categories is essential for understanding potential health risks and appropriate remediation actions. Category 3 water is defined as "black water," which is heavily contaminated and poses significant threats to human health. Among the options provided, an overflowing toilet tub contains waste material, including feces, and various contaminants, which categorize it as black water. This type of water can carry harmful bacteria and pathogens that can cause severe health issues. In contrast, the other options represent less hazardous water. Melting snow is typically clean and not contaminated, thereby falling under Category 1. A broken aquarium potentially introduces some bacteria but is generally not considered as hazardous as Category 3 sources. Flood waters from streams may carry a variety of contaminants, but without specific further context about the water's condition, they are usually classified as Category 2 or potentially a mix, rather than definitively as Category 3. Thus, the overflowing toilet tub is correctly identified as Category 3 due to its nature of containing highly polluted substances.