Bacteriological Analysis

The bacteriological quality of drinking water can be used to indicate whether a water supply is vulnerable to contamination.  This test looks for the presence of "coliform" bacteria, which are found in the intestinal tract of warm-blooded animals, in surface water, and in decaying vegetation.  A positive means that the safety of the water supply cannot be assured and that an investigation of the supply should be made.  In many cases, the investigation may reveal something as simple as the well was of new construction, and simply needs to be disinfected again.  Call the Environmental Health (EH) Division for assistance if your water supply tests positive.

    Test Results:

• ND:         "Not Detected" - Water quality of the sample met the state drinking water standard at the time of sampling.
• POS:        "Positive" - Coliform bacteria were present in the sample.  A resample and investigation is recommended.
• EC-POS:  "E.coli Detected" - E.coli is a type of coliform bacteria which may indicate sewage contamination when present in drinking water.  The safety of the drinking water supply cannot be assured and an investigation should be made.

Partial Chemical Analysis:

This routine test performed by the Michigan Department of Environmental Quality Laboratory analyzes drinking water for seven parameters.  The following table lists them and a guideline for the test results.   Gasoline, oil and other chemicals are not analyzed for in this routine test.   Nitrate, nitrite, and fluoride have state established maximum contaminant levels for public supplies, which are recommended for private residential supplies.

Partial Chemical Analysis - Test Results in Milligrams per Liter (Mg/L)

*    Exceeds State Drinking Water Standards
**  Boiling the water will increase the Nitrate and Nitrate concentrations

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