KDHE Home - Laboratories - Environmental Microbiology
| Environmental Microbiology |
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Robert Flahart Ph.D. This website is intended to help all persons and
agencies that are involved in collecting and submitting drinking
water, surface water, or waste water specimens for analysis to
the Environmental Microbiology (EM) Laboratory of the
Kansas Health and Environmental Laboratories. The site includes
a detailed guide for submitting samples, interpreting the results,
and describes the methods and assays performed in the EM Laboratory.
This information should help you to understand what is involved
in analyzing water samples and the relevant EPA and State Regulations.
A list of the people in KHEL and KDHE to contact for information
about various samples is also provided. It has been said that
test results are no better than the quality of the sample, the
sampler, and the laboratory and its personnel running the tests. Emerging infectious diseases in the United States and the rest of the world reinforce the need to carefully monitor drinking water. It is not practical to assay for each possible waterborne infectious diseases because of the time and cost required to run the numerous tests necessary to detect all possible disease-causing organisms. Scientists have found a more economical method to handle the problem by testing for "surrogate" or "indicator" organisms whose presence indicates that conditions are ripe for transmitting disease-causing organisms. Most of these organisms are common to the intestinal flora in humans and animals. The ideal indicator organisms must be detectable in all types of water, must be found in sewage and polluted waters when pathogens are present, and must be present in greater numbers than the pathogens. The most common organisms meeting these criteria are coliforms. They are capable of living in humans and animals, but some can live on plants, leather, wood, rope, or jute, and may produce a biofilm inside water distribution systems. Tests for the general group called fecal coliforms are being replaced by tests for their more notorious member, E. coli, as a more accurate indicator organism. This organism only grows in the intestines of humans and animals and therefore is the best indicator of fecal contamination.
In addition to drinking water samples, the Environmental Microbiology laboratory analyzes surface waters from lakes, rivers, and streams. Public water supplies draw their water from both surface and subsurface waters so it is important that we keep these waters safe. Laboratory staff analyze surface water for fecal coliforms using a filter technique that traps bacteria on a membrane so that the number of organisms (colony-forming units or CFUs) in the raw water to be counted. In a normal year, the Environmental Microbiology laboratory will analyze over 4,000 specimens of surface water. The world's water supply is 97.5% seawater and 2.5% fresh water. Two-thirds of the fresh water is locked in icecaps and glaciers so that less than 1% of all water is useable. Because of this limited availability monitoring and maintaining drinkable fresh water is vital for our future on earth.
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