FIELD WORK

Coliform bacteria

Fecal coliform bacteria are naturally present in the human digestive tract but are rare or absent in unpolluted waters. Coliform bacteria should not be found in well water or other sources of drinking water. Their presence in water serves as a reliable indication of sewage or fecal contamination. Although coliform. bacteria themselves are not pathogenic, they occur with intestinal pathogens that are dangerous to human health. This presence/absence total coliform test detects all coliform bacteria strains and may indicate fecal contamination.

The coliform test in this kit will indicate if you have above or below 200 coliform colonies per
100ml of well or river water. Even if the result of the coliform test for your well water is negative, this is not proof that your water is safe to drink. You should always have a professional lab test your drinking water for the presence of coliform bacteria.

See chart for significant levels.

Collection procedure river site testing.

  • Remove the cap of the sampling container.

  • Wear protective gloves. Rinse the bottle 2 3 times with the stream water.

  • Hold the container near the bottom and plunge it (opening downward) below the water surface.

  • Turn the submerged container into the current and away from you.

  • Allow the water to flow into the container for 30 seconds.

  • Cap the full container while it is still submerged. Remove it from the river immediately.

    Significant levels of coliform bacteria

    Fecal coliform bacteria per 100 ml water

    Desirable Permissible Water Use
    0 0 Potable and well water
    (for drinking)
    <200 < 1,000 Primary contact
    (for swimming)
    < 1MO <5000 Secondary contact (for
    boating, & fishing)

    *For specific requirements consult your province, or local health department.

    Coliform bacteria procedure

  • Pour the water sample into the large test tube containing a tablet (3599) until it is filled to the 10 ml line. Don't worry if you overfill or underfill a little.

  • Replace the cap on the test tube.

  • Stand the tube upright, with the tablet flat on the bottom of the tube.

  • Incubate by storing the tube upright, at room temperature, out of direct sunlight, for 30.to 36 hours. Store the tubes where the temperature will be fairly constant and between 21' to 27' C. Do not disturb, handle, or shake tubes during the incubation period.

  • Compare the appearance of the tube to the picture on the Coliform color chart. Record the result as negative or positive

    Reactions

    negative:
    -Liquid above get is clear.
    -Gel remains at bottom of tube.
    -Indicator remains red or turns yellow with no gas bubbles.
    -Indicates less than 200 total coliform colonies per 100 ml of water.

    positive:
    -Many gas bubbles present.
    -Gel rises to surface.
    -Liquid below get is cloudy.
    -Indicator turns yellow.
    -Indicates more than 200 total coliform colonies per 100 ml of water.

    Coliform test disposal

  • One tube at a time, remove the cap and add approximately I mL M teaspoon or 20 drops) of household chlorine bleach and immediately recap.

  • Let the tubes stand upright for about 4 hours.

  • Dispose of the closed tubes in the a ash. Do not open tubes.

    NEVER re use tubes after coliform bacteria testing.