With the recent E. Coli contamination in the City of Brighton’s municipal water supply affecting nearly 34,000 customers, we are reminded again of the importance of clean drinking water to our health and well being.
Water naturally contains different amounts of dissolved inorganic and organic compounds. These include:
Microorganisms
Common microorganisms that can contaminate drinking water are Giardia and E. Coli There are many types of E. coli, but among those that concern health officials are E. coli strains that can cause diarrhea, stomach cramps and vomiting — with occasional complications that include kidney failure, according to the Centers for Disease Control and Prevention.
Chlorination and filtration are effective controls for most bacteria. However, a tiny one-celled parasite not readily killed by chlorination, Giardia lamblia, deserves special discussion. Giardia has become an increasingly common problem in rural and mountain communities with inadequate filtration systems.
Giardia is mostly found in surface waters such as mountain streams and lakes, not groundwater. Because one cannot see, taste, or smell giardia, it is best not to drink water directly from mountain streams or lakes.
Minerals
The more minerals present, the harder the water. Soft water may contain sodium and other minerals or chemicals; however, it contains very little calcium, magnesium or iron. Many people prefer soft water because it makes soap lather better, gets clothes cleaner and leaves less of a ring around the tub. Some municipalities and individuals remove calcium and magnesium, both essential nutrients, and add sodium in an ion-exchange process to soften their water.
The harder the water, the more sodium that must be added in exchange for calcium and magnesium ions to soften the water. This process can have drawbacks from a nutritional standpoint.
Flouride
Fluoride is found naturally in Colorado water supplies in different amounts. The dental benefits of fluoridated water are well documented. Fluoride concentrations of 1.0 milligrams per liter or greater will reduce the incidence of dental cavities. However, concentrations over 2.0 milligrams per liter can darken tooth enamel causing fluorosis.
Lead
Lead is a toxic heavy metal known to turn up in drinking water. A 1986 EPA survey estimated that 40 million Americans (one in five) were using drinking water that contained potentially hazardous levels of lead. This finding led to changes in the Safe Drinking Water Act to require the use of “lead-free” pipe, solder, and flux in the installation or repair of home and commercial plumbing connected to public water systems.
Acute lead poisoning can cause severe brain damage and death. The effects of chronic, low-level exposure, however, are more subtle. The developing nervous systems of fetuses, infants, and children are particularly vulnerable. Recent studies show that lead exposure at a young age can cause permanent learning disabilities and hyperactive behavior. Low-level lead exposure also is associated with elevated blood pressure, chronic anemia, and peripheral nerve damage.
Natural water usually contains very little lead. Contamination generally occurs in the water distribution system or in the pipes of a home or facility. Lead pipes, brass faucets and lead solder used to join copper pipes are the culprits. If your home was built before 1986 when the nationwide ban on lead pipes and lead solder went into effect, it is likely to have lead-soldered plumbing.
The severity of lead contamination depends in part on how “corrosive” your water is. Soft or acidic water is more likely to corrode plumbing and fixtures, leaching out lead. According to the EPA, about 80 percent of public water utilities deliver water that is moderately or highly corrosive.
Organic Chemicals
The term “organic chemical” includes such products as pesticides, herbicides, petroleum products and industrial solvents. Hundreds of different organic chemicals have been found in drinking water from accidental spills, improper disposal or non-point movement through soils to groundwater. Today, municipalities are required to monitor more than 50 organic chemicals under the Safe Drinking Water Act.
As with other contaminants, the danger from organic chemicals in water is hard to assess. In high doses these chemicals may cause various problems including increased risk of cancer, impaired nervous system or damage to the heart. In low doses, organic chemicals may have cumulative effects, but less is known about their nature or magnitude.
References
Drinking Water Quality and Health, Colorado State University http://www.ext.colostate.edu/pubs/foodnut/09307.html
E.P.A. Lead in Your Drinking Water. Washington D.C.: Environmental Protection Agency, Public Information Center, 1993. Available at www.epa.gov/safewater/Pubs/lead1.htm.
Fundingsland, S. and D. Lundstrom. Drinking Water and Health. Pub. 27, HEA, NDSU Extension Service, North Dakota State University, Fargo, ND 58105, June, 1988.
Steiner, G. Cancer Incidence Rates and Environmental Factors: An Ecological Study. Journal of Environ, Pathology, Toxicology, Oncology. 2002; 21(3)205-12.
National Academy of Sciences. Risk Assessment of Radon in Drinking Water. Washington D.C.: National Academy Press. 1999. Available at http://books.nap.edu/html/radon/.
