Microbiology

In addition to routine certifications, the Microbiology Department is certified in the latest coliform test, which is EPA Method 1604. This test method utilizes a sensitive and differential membrane filter (MF) medium, using MI agar or MI broth, for the simultaneous detection and enumeration of both total coliforms and Escherichia coli (E.coli) in water samples in 24 hours or less on the basis of their specific enzyme activities. There are many benefits to using MI media, such as:

• Improved accuracy; Low false-positive and false-negative rates
• Positive results can be obtained in 16 hours (24 hour incubation required before negative results can be recorded)
• Does not require confirmation procedure, therefore, notification of positive results to the client occurs much quicker
• Useful with different types of water
• The target organisms (Total Coliforms and Escherichia coli) can be enumerated. Numerical data can be used to monitor the severity of drinking water contamination, the quality of drinking water source water, the deterioration of the water quality in the distribution system, and the progress in remediation, situations where Presence-Absence determinations are not helpful.

The department is also equipped to analyze water samples for fecal coliforms and heterotrophic plate count providing enumerated results. A petroleum degrading bacteria test is also available for determining the presence or absence of PDB's in water samples.

The department continues to investigate new methods and techniques to better serve the needs of our clients and the community.