Positive Coliform Sample


Follow-Up Sampling After A Positive Routine Coliform Sample

  • Four (4) repeat samples must be collected within 24 hrs after being notified of the positive sample results. All repeat samples must be collected on the same day. If more than one routine sample has been submitted during the month, only three (3) repeats are required. (18 AAC 80.415)

  • Repeat samples must be taken from different locations within the distribution system. One repeat sample must be collected from the same place as the original contaminated sample. The others should be collected from other points in the distribution system. If the source is a well, one sample must be collected from the well prior to any treatment, according to the Ground Water Rule.

  • If coliforms are detected in any repeat sample, you will have violated the coliform MCL (maximum contaminant level), and the State should be contacted immediately for assistance. If any sample was positive for fecal coliforms, it is an acute MCL violation and a Boil Water Notice may be required. Public notice is required for any MCL violation. (18 AAC 80.1000)

  • Five (5) routine samples must be collected during the month following the original routine positive sample. Sampling should be spaced throughout the month and from different sampling points on the distribution system.

For More Information, Contact the Drinking Water Program at:

Anchorage: (907) 269-7656 Fax (907) 269-7655
Fairbanks: (907) 451-2108 Fax (907) 451-2188
Juneau: (907) 465-5350 Fax (907) 465-5362
Kenai: (907) 262-5210 Fax (907) 262-2294
Mat-Su: (907) 376-1850 Fax (907) 376-2382