original passage: The leaching of highly water soluble tannins from decaying vegetation and leaves along a stream may produce what is known as a blackwater river. Water flowing out of bogs has a characteristic brown color from dissolved peat tannins. The presence of tannins (or humic acid) in well water can make it smell bad or taste bitter, but this does not make it unsafe to drink.
original sentence: The presence of tannins (or humic acid) in well water can make it smell bad or taste bitter, but this does not make it unsafe to drink.
sentence2: Would it be advisable, for health reasons, for a utility to use a dog's sensitive nose to try to detect even a faint odor in drinking water before allowing it to be delivered to houses?
sentence1: The leaching of highly water soluble tannins from decaying vegetation and leaves along a stream may produce what is known as a blackwater river. Water flowing out of bogs has a characteristic brown color from dissolved peat tannins. Tannins, also known as humic acid, can be found in well water, yet despite giving it a bitter taste and bad smell, they do not raise any safety concerns.