Lead in drinking water, although rarely the sole cause of lead poisoning, can significantly increase a person's total exposure, particularly infants who drink baby formulas and concentrated fruit juices that are mixed with water. The major health concern involves infants 6 months or younger since their digestive system is too immature to break down nitrates. Since a high level of nitrates in water does not impart taste, color or odor, the only way to determine it's level is to have the water analyzed. The average citizen takes in 75 to 100 mg of nitrates each day, mostly from vegetables such as beets, lettuce and spinach. Nitrate is an essential nutrient and hence, a major component of animal wastes and decomposing organic matter.
Chemical fertilizers are another source of nitrogen.
Nitrates can build up in the soil and leach into groundwater. It does not exist in a gaseous state and natural inorganic phosphorus deposits occur primarily as phosphate in the mineral apatite. Phosphate is usually not readily available for uptake in soils. Thus, if sufficient phosphorus is available, elevated concentrations of nitrates will lead to algal blooms and perhaps fish kills. The major concern with turbid water is the fact that it greatly decreases the effectiveness of chlorination and disenfection.