Color makes water unpleasant for drinking and cooking and, like iron and manganese, causes staining. Organic matter very often contributes to tastes and odors. Even very small amounts of it can result in a musty odor and an "off" taste. A major cause of taste and odor problems is metabolites produced by actinomycetes, algae, or other microorganisms.
If water has a distinctive "rotten egg" odor, hydrogen sulfide gas is present in the water supply. Even very low concentrations will result in strong obnoxious odors. In addition to this, the water rapidly tarnishes silver and is corrosive to plumbing metals.
For a pleasant taste, water should have some dissolved minerals. Distilled
water without minerals tastes "flat." However, high concentrations of minerals
make water taste salty or metallic, and the taste can easily be detected
in foods and beverages prepared with highly mineralized water. The presence
of dissolved oxygen can improve taste. Faucet aerators will put oxygen
in the water and can help remove obnoxious gases.