Water contaminated by sewage and agricultural waste is best described as?

• A. Nutrient Runoff
• B. Harmful Algal Blooms
• C. Sewage Runoff
• D. Raw Sewage

Answer: (C)

The key idea is identifying how the pollution enters water. When water is contaminated by sewage and agricultural waste, describing it as sewage runoff captures both the source of the waste (sewage and manure) and the transport path (runoff from land into a water body, especially after rain). This wording acknowledges that the contamination comes from waste carried by rainfall or irrigation rather than being a specific form of pollution alone.

Nutrient runoff focuses only on nutrients like nitrogen and phosphorus and doesn’t necessarily name the sewage component or the transport method. Harmful algal blooms describe a consequence of high nutrient levels, not the contaminant or its mode of entry. Raw sewage would mean untreated sewage, but it doesn’t explicitly include agricultural waste or runoff as the mechanism.