B-1.1, r. 3 - Safety Code
407. The owner must take samples or cause them to be taken and have them analysed to determine the Legionella pneumophila concentration in CFU/L:
(1) at the time of re-starting, after winterizing;
(2) at least once every 30 days, during the operation period;
(3) between 2 and 7 days, following the application of the decontamination procedure.