Some contaminants may cause aesthetic problems with drinking water, such as the presence of unpleasant tastes or odors, or cosmetic problems, such as tooth discoloration. Since these contaminants do not cause health problems, there are no legally enforceable limits on their presence in drinking water.
Certain substances may interfere with the appearance of drinking water, causing tastes and odors that people find unappealing, or they might lead to cosmetic issues like tooth discoloration. Despite these aesthetic concerns, there are currently no legal regulations limiting their levels in tap water.