The Division of Food Safety is required by state law to sample bottled water produced in Wisconsin each year and to issue a report. For specific results and data from recent reports, go the bottom of this page.
There is no such thing as naturally pure water. In nature, all water contains some impurities. As water flows in streams, accumulates in lakes, and filters through layers of soil and rock in the ground, it dissolves or absorbs the substances that it touches. Some of these substances are harmless. In fact, some people prefer mineral water precisely because minerals give it an appealing taste. However, at certain levels, just like man-made chemicals, minerals may be considered contaminants that can make water unpalatable or even unsafe.
Man-made contaminants may also affect water that is bottled. These contaminants may be substances discharged from factories, applied to farmlands, or used by consumers in their homes and yards. Microbiological and chemical contaminants can enter water supplies. These materials can be the result of human activity or can be found in nature. For instance, chemicals can migrate from disposal sites and contaminate sources of drinking water. Coliform bacteria from human and animal wastes may be found in drinking water if the water is not properly treated or disinfected. These bacteria are used as indicators that other harmful organisms may be in the water. If coliform bacteria are found in a water sample, further testing is conducted to see if there are any fecal or pathogenic bacteria present.
Water naturally contains less than 1 milligram of nitrate-nitrogen per liter. When higher levels are present, it indicates that the water has been contaminated. Common sources of nitrate contamination include fertilizers, animal wastes, septic tanks, municipal sewage treatment systems, and decaying plant debris. State and federal laws set the maximum allowable level of nitrate-nitrogen in public drinking water at 10 milligrams per liter.
Naturally occurring contaminants can also be found in drinking water. Some contaminants come from erosion of natural rock formations. Groundwater, which moves slowly through the pores or cracks in underground layers of rock, dissolves minerals as it travels. Dissolved solids are minerals or salts that have been dissolved in the water while in the aquifer. Dissolved solids
can be calcium, magnesium, salt, iron or other minerals.
Fluoride can be added to water supplies to promote healthy teeth. It can also be present in water from the erosion of natural deposits or discharge from fertilizer and aluminum factories.
Water can also pick up naturally occurring radium or man-made radionuclides as it flows to the water source. The radioactive gas radon-222 occurs in certain types of rock and can leach into ground water. All rock contains some radium, usually in small amounts. Testing for radionuclides is a relatively recent change in DATCP requirements. The testing process for water samples begins with a screening for "gross alpha particle activity" which measures the total amount of one type of radioactivity given off by the water. If high levels of gross alpha activity are found, further testing for radium is conducted. Radioactivity levels are measured in "picocuries" per liter of water (abbreviated "pCi/L").
In Wisconsin, most of the community water supplies which exceed the radium standard draw water from a deep sandstone aquifer and are located in a narrow band which stretches from Green Bay to the Illinois state line. In addition, a few high radium levels have been found in groundwater from sandstone formations in west central Wisconsin and in granite formations in north central Wisconsin. In all cases, the radium was present in the rock and water long before the first well was drilled.
For more information about Wisconsin Groundwater Standards, see the Department of Natural Resources' summary. For the complete text of pertinent state law, see the Legislature's website.
On May 13, 1996 new bottled water regulations from the federal Food & Drug Administration took effect. The new regulations were aimed at alleviating consumer confusion about the many different types of bottled water on the market by providing standard definitions for the terms "artesian water," "ground water," "mineral water," "purified water," "sparkling bottled water," "spring water," "sterile water," "well water," and others.
Bottled water, like all other foods regulated by FDA, must be processed, packaged, shipped and stored in a safe and sanitary manner and be truthfully and accurately labeled. Bottled water products must also meet specific FDA quality standards for contaminants. Since 1996, mineral water must also meet the bottled water standards. Mineral water had previously been exempt from standards that applied to other bottled water.
The FDA has established the following definitions:
Bottled Water—Water that is intended for human consumption and that is sealed in bottles or other containers with no added ingredients except that it may contain safe and suitable antimicrobial agents.
Artesian Water or Artesian Well Water—Water from a well tapping a confined aquifer in which the water level stands at some height above the top of the aquifer.
Ground Water—Water from a subsurface saturated zone that is under a pressure equal to or greater than atmospheric pressure.
Mineral Water—Water containing not less than 250 parts per million total dissolved solids, originating from an underground water source. No minerals may be added to this water.
Purified Water—Water that has been produced by distillation, deionization, reverse osmosis, or other processes and that meets the definition in the United States Pharmacopoeia, 23d Revision, January 1, 1995.
Sparkling Bottled Water—Water that, after treatment and possible replacement of carbon dioxide, contains the same amount of carbon dioxide that it had at emergence from the source.
Spring Water—Water derived from an underground formation from which water flows naturally to the surface of the earth.
Well Water—Water from a hole bored, drilled, or otherwise constructed in the ground, which taps the water of an aquifer.
In addition to defining these terms, the regulation addresses various other labeling concerns. For example, water bottled from municipal water supplies must be clearly labeled as "from a community water system" or, alternatively, "from a municipal source", unless it is processed sufficiently to be labeled as "distilled" or "purified" water.
The regulation also requires accurate labeling of bottled water marketed for infants. If a product is labeled "sterile" it must be processed to meet FDA's requirements for commercial sterility. Otherwise, the labeling must indicate that it is not sterile and should be used in preparation of infant formula only as directed by a physician or according to infant formula preparation instructions.
Bottled Drinking Water Reports
The annual Bottled Drinking Water Report is produced annually and is required by state law. Each report includes a summary, background information and tables containing data about the bottlers surveyed and water samples taken. The samples are analyzed by state laboratories and checked that they meet state and federal drinking water standards. You will need a PDF reader to view the reports.
Links to additional information on bottled water.
Drinking Water Inspectorate
Answers to basic questions from the drinking water regulator in England and Wales.
U.S. Environmental Protection Agency
Groundwater and drinking water information including training information and a children's page.
Water Quality Help Guide
A detailed site with summaries about many potential drinking water contaminants from Wilkes University.
Interpreting Drinking Water Analysis
An academic paper that contains a list of technical definitions and a summary of the Safe Drinking Water Act from Rutgers University.
Bottled, Filtered or Tap: Which Water is Healthiest?
A June 2000 article from the LA Daily News covering a range of drinking water choices.