Introduction | Waterborne Pathogens and the Diseases They Cause | Microbial Water Contamination and Human Exposure | Drinking Water Treatment | Improvements ... and What You Can Do
For more than 100 years, the water industry has relied on methods that detect and count “indicator” bacteria such as coliform (normally found in the human intestine). Fecal coliform monitoring has helped reduce the risk of waterborne diseases in our water supply, but it can’t detect many harmful microbes such as enteric viruses, parasites, or toxic algae.
Microbiologists and other scientists are leading efforts to develop risk-based testing and regulation of our water supply. New scientific tools and techniques can improve detection of microbial and chemical contaminants in water and assess their actual risks.
Courtesy of Microbial Ecology/Biogeochemistry Research Laboratory, Ames Research Center, NASA
In the not-too-distant future, miniature gene chips will monitor water supplies and automatically alert water facilities when contamination occurs. This and other new tools for detection and risk assessment are discussed in a recent report by the American Academy of Microbiology (a division of the American Society for Microbiology).
In the meantime, there are steps you can take to help ensure the safety and quality of your water.
All community water utilities are required to provide customers with an annual Consumer Confidence Report on the quality of their drinking water, and to disclose if they exceeded state or federal pollutant limits or standards. These reports also inform consumers of basic information, such as the source of their drinking water and what standards the utility is required to meet.
If your drinking water is supplied by a public utility, you should automatically receive a report once a year. You can also request a copy from your water utility at any time, or check their Web site for an online report.
Some people use home water treatment devices, most often pitchers or filters mounted on faucets, for extra protection against contamination. Others turn to bottled water.
Home treatment devices are not tested or regulated by the federal government, so the Environmental Protection Agency (EPA) does not recommend using them as a substitute for public water treatment.
The principal function of most home filter devices is to improve the taste of drinking water. Because these devices remove residual chlorine in tap water, the filtered water is theoretically more prone to microbial growth if allowed to sit for long periods. Therefore, these products should be used according to the manufacturer’s directions.
Home treatment devices should list exactly what kinds of contaminants they act on and whether they remove or just reduce their levels.
Not all home water filtration or treatment devices remove or reduce microbial contaminants. Those that do target the reduction or removal of protozoal cysts (such as Cryptosporidium). The EPA says most home filters do not work against potentially harmful bacteria such as E. coli O157:H7.
Photo courtesy of NSF International.
Home water treatment devices and bottled water are tested and certified by NSF International, an independent non-profit organization.
Bottled water is regulated by the Food and Drug Administration, which sets specific standards for contaminant levels. Is bottled water safer than tap water? It depends.
A 1999 Natural Resources Defense Council study found that 25% of bottled water was actually tap water. In fact, one brand of “Spring Water” was found to be “actually from an industrial parking lot next to a hazardous waste site.”
In general, bottled water brands that performed well in the NRDC study also got a clean bill of health in an August 2000 Consumer Reports’ rating of bottled water.
Call the EPA’s Safe Drinking Water Hotline for general questions or concerns about water safety or the Safe Drinking Water Act at 1-800-426-4791 weekdays from 9 a.m. to 5:30 p.m. Eastern Time. If you have questions or concerns about your drinking water, feel free to contact your local water supplier.
American Academy of Microbiology Reevaluation of Microbial Water Quality: Powerful New Tools for Detection and Risk Assessment, learn how advances in science and technology can further reduce microbial contamination and improve water quality. (The American Academy of Microbiology is an honorific leadership group within the American Society for Microbiology.)
American Water Works Association Find out what water utility supplies your water and view a sample Consumer Confidence Report. Bottled Water: Pure Drink or Pure Hype? Natural Resources Defense Council’s 1999 study on bottled water.
Bottled Water NSF International’s Certified Bottled Water Product Listings shows which bottled water meets FDA criteria. For definitions of different kinds of bottled water, see NSF’s Bottled Water Certification Program. Consumer Confidence Reports: Final Rule Details from the EPA on what these reports must include.Home Water Treatment Devices NSF International’s Certified Product Listing provides information on specific products. Home filtration devices were rated by Consumer Reports in its October 1999 issue (updated August 2000.) The August 2000 report also rates brands of bottled water. Online reports are available only to Consumer Reports Web site subscribers, but back issues are available in most public libraries.
Introduction | Waterborne Pathogens and the Diseases They Cause | Microbial Water Contamination and Human Exposure | Drinking Water Treatment | Improvements ... and What You Can Do
|
 
|
