Treatment levels vary too. Nitrogen levels in the ground water may be high if there is, or was farming in an adjacent area or if there is a waste water treatment facility discharge or reuse point in near proximity. Nitrogen standards for Arizona are established at 10 milligrams per liter of water. Above this limit, there is an increased change of stomach or esophageal cancer developing. As an example, it has been reported that Coca-Cola bottled in Japan contain as much as 80 milligrams per liter of nitrogen.
Japan also has the highest incidence of stomach cancer in the world.
Every caver knows the wisdom of taking extra drinking water into a cave. The crystal clear waters of a cave pool can be very inviting to the tired, thirsty caver. The information presented here is not an indictment of all caves and all of the water found within all caves. It is merely a statement of precaution to those cavers who are inexperienced or perhaps just like to express the romantic adventurous side of their character, by drinking the crystal clear waters found deep within the earth. Absolutely no rights of distribution by sale or other transfer of ownership or by rental, lease or lending, preparation of derivative works, or reproduction, in whole or in part, is granted.