Passage Summary: Even though rain is clean and should make the bay water cleaner by diluting it, the bay actually becomes much more polluted right after it rains.

Reasoning: Rainwater is pure and should dilute pollution, yet pollution levels in the bay spike immediately after heavy rain.

Analysis: This paradox requires us to find a reason why 'pure' rain would lead to 'impure' bay water. Since the rain itself isn't the source of the pollution, the rain must be acting as a catalyst or a transport mechanism for pollution from somewhere else. Look for an answer that explains how rainfall interacts with the surrounding environment—such as washing urban runoff, chemicals, or sewage from the land into the water—to overwhelm the dilution effect.