Contamination of supposedly safe drinking water is not rare. In Pittsfield, Mass. an estimated 8000 people once fell ill with diarrhea when the parasite giardia got into the town's water supply.

      In May 1988, the California Dept. of Health Services reported that pregnant women who said they drank purified bottled water had fewer miscarriages than one would expect from birth statistics. The findings were later confirmed by three studies involving Silicon Valley and other San Francisco areas.
          In the four studies, the rate of miscarriages in women who reported drinking no tap water during pregnancy ranged from zero to 7.7 percent. The rates for women who drank some tap water ranged from 8.4 to 13.1 percent. The rate of birth defects in the children of tap water drinkers was 2.6 to 6.2 percent, while the rate for those who drank no tap water was zero to 1.6 percent. The expected rate was 2 to 3 percent.

      Twenty percent of all municipal systems have detectable levels of contaminants; 63 percent of rural household water supplies are considered unsafe because of bacteria, affecting about 39 MILLION people. Thirty- four states have reccommended wells be closed because of contamination by organic chemicals.

      A 1988 National Wildlife Federation report of an 18-month examination of 15,000 pages of EPA computer printouts for fiscal 1987 showed 36,763 water systems committing 101,588 violations of the Safe Drinking Water Act.
      Seventy percent of the contaminant violations were for exceeding bacteriological standards, 20 percent involved inorganic chemicals or substances like metals or arsenic, 0.6 percent were organic chemicals such as pesticides, 0.9% were radioactivity violations and 7.7% were turbidity, or sediment, violations.

      Environmental Defense Fund science associate David Fanning: "There are more than 60,000 toxic chemicals now being used in American industry and agriculture. The fact that we don't find all sixty thousand means we aren't looking for them. Seventeen different pesticides and herbicides have been found in drinking water in 23 states, including Kansas, Nebraska, Illinois, Missouri and Minnesota."

            Of the 2,110 contaminants found in some concentration in water systems, 2,090 were organic, and 190 were known or suspected to be health-damaging.

      All purification methods have both drawbacks and advantages.
      Distillation: volatile chemicals such as PCB's, solvents and chloroform can slip through the process.
      Reverse osmosis: some membranes don't work well with microbe contamination.
      Activated charcoal: some large microbes can pass through the filters.

      A combination of reverse osmosis/carbon filtering appears to be effective in eliminating 95-100% of all water contaminants.

      Be aware that solvents and other chemicals have been found in some bottled water brands, though the chemicals are almost always in quantities well below recognized danger levels. * Check for method of purification on label before buying *.