The Laboratories and Water Quality Control Department is accredited according to standard NP EN ISO/IEC 17025 - 'General requirements for the competence to carry out tests and/or calibrations' for the collection, preservation, and transport of water samples for human consumption and natural water for the production of water for human consumption.

These operations are carried out by duly trained and qualified technicians from the Technical Support Unit. All types of water may experience bigger or smaller changes as a result of physical, chemical or biological phenomena, which may occur between the moment in which the water sample is collected and the moment in which it is tested in the laboratory.

These changes are related to the sample's chemical and biological nature, its eventual exposure to light, the nature of the recipient used for sample collection, temperature, etc., and may affect the final analyses as well as their interpretation. Hence, special care is required in the collection and techniques used for preservation, transport, and handling of water samples to be tested in order to minimise these changes.

Sampling, preservation, transport, and handling of samples strictly follow the technical requirements within the normative references that apply to this activity.