This could lead to drug residues in the carcass if the precipitate is carried in the water offered to market weight pigs at a later date. Iron is not itself considered a major safety concern, however low levels of iron in water can cause problems by supporting the growth of iron bacteria. These types of bacteria can cause foul odours and even plug water systems due to accumulation of dead and decaying bacteria. Iron levels of 0.3 ppm can stain laundry and bathroom fixtures. Settling tanks can be used to lower the iron content of water.
Water hardness has no effect on animal health.
Hardness is caused by an accumulation of multi-valent metal cations such as calcium and magnesium. Hardness affects the cleansing ability of water and results in a build-up of scale in water systems. This, in turn, can impair the water delivery system and lead to problems associated with reduced water intake. Nitrates and nitrites in water are considered serious potential hazards. Most nitrate problems are caused by decomposition of organic material and from runoff from heavily fertilized fields.