Which contaminant category includes bacteria and other microorganisms that threaten health in water?

• A. Glyphosate
• B. Atrazine
• C. Lead
• D. Microbes

Answer: (D)

The main idea here is recognizing biological contaminants. Bacteria and other microorganisms fall under the biological (or microbial) contaminant category in water. These living organisms can cause illness and are a primary health concern in drinking water, spreading through sources like fecal contamination, runoff, or compromised water systems. Microbial contamination is typically addressed with disinfection (such as chlorination or UV treatment), proper filtration, and safeguarding the water source.

The other options represent chemical or inorganic contaminants: glyphosate and atrazine are pesticides that can contaminate water as chemical residues, while lead is a metal that can enter water through old pipes or corrosion. These require different controls, such as source water protection, treatment to remove chemicals, and corrosion control, rather than the disinfection strategies used for microbes.