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Water Analyses - Microbiology PDF Print E-mail

Analytical Methods, Practical Detection Limits (PDL), Containers Preservation, and Holding Times for Selected Analytes

These bacteria analyses are recommended for drinking water, discharge water, swimming pools and spas. The holding times in the table below are regulatory limits. Standard Methods recommends 6 hours from collection to the start of the analysis. Chlorinated water must be collected in a container, which contains sodium thiosulfate.

Determination Std. Methods 22th ed. 1995 PDL Container Preservation Holding Time Max.
Drinking Water
Total coliform 9223B 0/100mL Plastic/Glass Cool to 4°C 30 Hours
Fecal coliform 9223B 0/100mL Plastic/Glass Cool to 4°C 30 Hours
E. Coli 9223B 0/100mL Plastic/Glass Cool to 4°C 30/6 Hours
HPC 9215B 0/100mL Plastic/Glass Cool to 4°C 24 Hours
BOD-5 5210B 2 mg/L Plastic/Glass Cool to 4°C 24 Hours
Surface Water






E. Coli 9223B(B) <1/100mL Plastic/Glass Cool to 4°C 6/8 Hours(A)

(A) - 6 hours from collection to the laboratory and 8 hours from collection to incubator, recommended and for regulatory use. 34 hours from collection to incubator for routine monitoring.

(B) - Using IDEXX Colilert Quanti-Tray procedure.

From Standard Methods for the Examination of Water and Waste Water, 19th edition, APHA, AWWA, and WEF, Washington, D.C., 1995.

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