When thousands of Milwaukee residents suffered from severe intestinal illness as a result of a parasite in the city's water system this spring, concerns about water quality surfaced around the country.
The culprit in Milwaukee was cryptosporidium, a parasite that can often withstand normal municipal disinfection procedures. In the late 1980s, waterborne outbreaks of cryptosporidiosis occurred in Oxfordshire-Swindon, England, and Carrollton County, Ga.While improved sanitary engineering and drinking water disinfection practices have virtually eradicated diseases like typhoid and cholera in the United States, this most recent outbreak points out that safe drinking water remains a challenge for public officials, says the National Consumers League.
Many different contaminants can enter our water supply, either through negligence or by accident. Contamination can occur from septic tank leaks or agricultural waste runoff. Sometimes factories discharge or illegally dump chemicals or heavy metals.
Until recently, lead pipe was widely used for service lines and connections that carry water into homes, and lead-based solder was used in plumbing systems.
Micro-organisms from both human and animal wastes that end up in our water supply may cause diarrhea and hepatitis. These waterborne diseases can be a particular problem to infants and young children, persons with AIDS, the elderly or those receiving chemo-therapy.
What is being done to deal with these and other water quality problems? The Safe Drinking Water Act requires the EPA to set standards for drinking water contaminants. The EPA has recently proposed new concentration levels for disinfectants and their byproducts, taking into consideration the effectiveness of alternative disinfectants.
For millions of Americans, the answer to the question "Is my water safe?" is a definite yes. However, if you suspect you have water quality problems, you can work with county health officials. Public water supplies are rigorously tested, and those test results are available to the general public. You can also research your distribution system to see if there are any lead pipes, asbestos-cement pipes or iron pipes used in distributing water.
Some consumers, for peace of mind or because they prefer the taste of the water, purchase home drinking water systems.
The choices for such systems can be confusing, says the Water Quality Association; there are hundreds of system manufacturers producing thousands of products. Most of these products fall into one of the following categories:
- Activated carbon/adsorption: generally a faucet-mounted system with filter cartridges that must be changed.
- Filtration: do a good job of removing particulate matter but may not remove taste and odor producers.
- Combination adsorption and filtration.
- Distillation: work by heating, vaporizing and condensing water to remove most chemicals, bacteria and viruses.
- Reverse osmosis: use pressure to force water molecules through a membrane, causing contaminants to be left behind.
- Softening: exchange sodium for calcium and magnesium in water to boost cleaning ability and reduce mineral buildup.
- Ultraviolet disinfection: use UV light to kill bacteria and viruses.
Some consumers are also turning to bottled water as an alternative. American consumers drink on average eight gallons of bottled water per person per year. But, points out the National Consumers League, doubts about the safety and quality of bottled water have arisen as well. It cites reports that indicate 25 percent of bottled water on the market is actually tap water and that some bottled water might contain levels of harmful contaminants that are not allowed in tap water.
In response, the Food and Drug Administration has proposed new regulations for that industry. Under the current proposal, nutrients such as iron, sodium and calcium that are present in significant amounts will have to be disclosed. The rules also set standard definitions for words used to describe the source of bottled water. (These definitions now differ from state to state.) The FDA will establish new limits on approximately 50 chemicals and other contaminants, including lead, that may be present.
"With two federal regulatory agencies setting new standards for both tap and bottled water, the thirst of American consumers for safer drinking water may finally start to be quenched," says the league.
Bottled water definitions
Here are standardized definitions proposed by new FDA regulations:
- Artesian: Water drawn from a well that taps a confined aquifer in which the water level stands above the natural water table.
- Distilled: Water that has been produced by a process of distillation in a way that leaves it free of dissolved minerals.
- Purified: Water produced by distillation, deionization, reverse osmosis or other suitable processes and that meets the U.S. Pharmacopeia's most recent definition of "purified" water.
- Spring: Water obtained from an underground formation from which water flows naturally to the surface.
- Well: Water that comes from a hole bored, drilled or otherwise construction in the ground to tap an aquifer.
- Mineral: Water that comes from a source tapped at one or more bore holes or springs originating from a geologically and physically protected underground water source.
Under the proposed regulations, water that actually comes from municipal water systems would have to be labeled as such, unless it has been taken from the municipal system and then treated in a way that would enable it to be labeled distilled or purified.