Source: There are a variety of water-borne diseases associated with microorganism contamination from bacteria, protozoa, and viruses. The most common source of microorganisms in drinking water wells is sewage contamination. Other potential sources include surface water infiltration into shallow wells, waste water treatment facilities, livestock areas, and landfills. The presence of Coliform bacteria and, in particular, fecal Coliform bacteria, may indicate there are other disease-causing microorganisms as well. Two protozoa that have been implicated in recent outbreaks of illness in the US are Cryptosporidium and Giardia lamblia.

Health Effects: Typical symptoms of water-borne diseases are severe diarrhea, cramps, nausea, headache, fatigue, and sometimes jaundice. Diarrhea and vomiting can cause rapid and dangerous levels of dehydration in seniors, children, and those with immune deficiencies.

Maximum Contaminant Level: The presence of Coliform bacteria in drinking water is cause for concern and confirmation testing. The presence of fecal Coliform is cause for immediate cessation of human consumption and disinfection of the water source. See Bacteria Testing Flow Chart.