Proficiency testing (PT): Microbiological parameters in drinking water

Distribution Schedule 2019

Round Registration
Final Report

February 2019 18/01/2019 04/02/2019 01/03/2019 18/03/2019
Final Reports in the Customer Area

May 2019 03/05/2019 20/05/2019 14/06/2019 01/07/2019
Final Reports in the Customer Area

September 2019 06/09/2019 23/09/2019 18/10/2019 04/11/2019
Deadline reporting results: 18/10/2019

Scope of the Interlaboratory Proficiency Testing

The scope of this interlaboratory proficiency testing is the evaluation of the performance of laboratories for the quantitative (CFU/Volume) determination of water microbiological parameters (ex. drinking water, mineral water, groundwater).

Target organisms (microorganisms)

  • Total aerobic count at 22°C (1 - 1000 ufc/mL)
  • Total aerobic count at 37°C (1 - 1000 ufc/mL)
  • Enumeration of Coliform bacteria (1 - 1000 ufc/100mL)
  • Enumeration of Enterococci (1 - 1000 ufc/100mL)
  • Enumeration of Escherichia coli (1 - 1000 ufc/100mL)

  • Enumeration of Pseudomonas Aeruginosa (1 - 1000 ufc/100mL)
  • Enumeration of Clostridium perfringens (1 - 1000 ufc/100mL)
  • Enumeration of Staphylococcus aureus (1 - 1000 ufc/100mL)

  • Enumeration of Legionella pneumophila (1 - 10 000 ufc/L)
  • Enumeration of Legionella spp (1 - 10 000 ufc/L) New 2019!

Note: Measurement methods for the determination of the Colony Forming Units (CFU/Volume).

Proficiency test item:

Test sample to be prepared from the vials containing the microorganisms according to instructions reported in the Guide Line of the proficiency testing.

  • 1 x 10L of the test material for the determination of all parameters except Legionella pneumophila, Legionella spp, Clostridium perfringens, Staphylococcus aureus and Pseudomonas Aeruginosa. New 2019!

  • 1 x 1L of the test material for the enumeration of Clostridium perfringens.
  • 1 x 1L of the test material for the enumeration of Staphylococcus aureus.
  • 1 x 1L of the test material for the enumeration of Pseudomonas Aeruginosa.

  • 10 x 10L of the test material for the enumeration of Legionella pneumophila. New 2019!
  • 10 x 10L of the test material for the enumeration of Legionella spp. New 2019!
ANALYSIS: The test sample should be analysed under the same conditions and with the same procedures used for the routine samples in the laboratory including the quality control procedures.

Participants are free to choose a suitable method for the determination of the Colony Forming Units (CFU/ml).

For each measurand shall be reported the result of a replica.

ADDITIONAL RESULTS: Each participant can submit up to 5 results* for the same analyte, thus obtaining an evaluation of laboratory performance for different operators, instruments and/or test methods (e.g. operator 1/operator 2, instrument A/instrument B, etc..).

  • Request a quote

    Download and complete the Application Form, selecting for each matrix, the measurands and the period in which you want to participate. Send it by email ( or by FAX (0039 0656562874).


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*: Only one result submitted by the laboratory will be included in the statistical treatment of data for the calculation of the Assigned Value and statistics of data of the analyte, to avoid that a single laboratory has a different statistical weight, depending on the number of its submitted results. The additional results are evaluated by assigning z-score values, using the Assigned Value and the Standard Deviation for Proficiency Assessment obtained from statistical treatment.