In groundwater or surface water, which is not a parameter you should test for to indicate groundwater pollution?

• A. Potassium
• B. Nitrate
• C. Chloride
• D. Lead

Answer: (A)

Potassium isn’t used as a pollution indicator because its presence in groundwater or surface water is often natural and highly variable, coming from rocks, soils, and agricultural use. This makes it a poor signal for contamination since elevated levels don’t reliably distinguish polluted water from background mineral content. In contrast, substances like nitrate, chloride, and lead are monitored because their levels more clearly reflect specific pollution sources—nitrate from fertilizers and septic waste, chloride from salinity or runoff, and lead from corrosion or industrial sources. So potassium isn’t a reliable parameter for indicating groundwater pollution, which is why it isn’t commonly tested for in this context.