Some lakes with many roads around them that are salted will have increasing salt concentrations as the road salts move into the lake with rains. Turbidity measures the eye appeal of the water and are usually the result of high phytoplankton or silt concentrations. Turbidity greater than 5 NTU's indicate water both unappetizing in appearance and potential hazards. High silt may harbor high concentrations of bacteria colonies. Silt load also has an impact on respiration of gill organisms.
Dark color impedes light penetration.
Some water from bogs may have a high turbidity due to dissolved materials in the water. High hardness may result in scaling in hot water heaters or pipes and is the main reason to have a water softener. Hardness is the result of the type of rocks the water has to come in contact with. Iron is an essential element in human metabolism. High concentrations impart taste to beverages.