DEPARTMENTS - Microbiology

At Analytical Balance, we take pride on our Microbiology department. Our principal microbiologist has over 30 years of experience in laboratories and runs one of the finest programs in the State. Below is a list of the bacteria methods we run. While we test your samples of drinking water, waste water, ground water, pools and spas please note that the Massachusetts DEP only certifies methods for drinking water. While these methods cover a wide scope, please contact us with any other requirements you might have. If we cannot assist you in house, we can normally suggest someone who can.

Method Description Enumeration Available** Method
Total Coliform & E. coli: Membrane Filter /MI Agar Yes EPA 1604
Total Coliform & E. coli: Idexx Colisure® No SM 9223
Heterotrophic Plate Count (HPC) Yes SM 9215B
New Main (Total Coliform/E. coli by MI plus HPC) Yes Multiple methods
Fecal Coliform: Membrane Filter/mFC Agar Yes SM 9222D
Enterococci: Membrane Filter/mEI Agar Yes EPA 1600
E. coli in fresh water: Membrane Filter/mTec Agar (usually for ponds and fresh water beaches) Yes EPA 1603
Enterococci: Idexx Enterolert® No ASTM D6503-99
Pseudomonas: Membrane Filter/M-PA Agar/confirmation* Yes SM 9213E (mod.)
Total Coliform & E. coli: Membrane Filter/LES Agar / multi-tube confirmation Yes SM 9222B/G
Yeast & Mold: Potato Dextrose Agar Yes SMDP 8.10C
Culture Speciation for Enterobacteriacae and other Gram negative bacteria* n/a BioMerieux API

* Massachusetts DEP does not certify for these methods.

** Enumeration allows us to give you a count of the number of colonies (bacteria) found per 100 mL of sample. For health and Maximum Contaminant Level purposes, the Mass DEP does not consider counts, only whether it is present or absent. Whether a sample has a count of 1 or 200, it is considered a violation. However, it may be beneficial to know the count to judge the severity of the situation. For instance, a count of 1 will probably clear with a chlorination of the well, but a count of 200 might indicate a damaged well or persistent contamination.