Babcock Laboratories, Inc. (Babcock Labs) wishes to inform you about the requirements for repeat testing following a positive test for Total Coliform per the Revised Total Coliform Rule, beginning July 1, 2021. If directed by the State Board, repeat analyses to a previous positive Coliform test may require Coliform and E. coli be determined on a density basis. If required to do so, Babcock Labs utilizes the IDEXX Quanti-Tray® system to determine and report the Coliform and E. coli density (MPN) under SM 9223B. The need for Quanti-tray® enumeration MUST be clearly communicated at the time of sample submission.

To alert the laboratory, please note on your Chain of Custody that the sample(s) being submitted are resample(s) for a positive bacti/microbiology Coliform analysis. The laboratory cannot guarantee the appropriate Coliform and E. coli MPN will be reported if the Chain of Custody does not clearly specify the need for MPN by Quanti-tray.

If you have any questions, please visit: https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/rtcr.html or contact your Project Manager.