This biofilm is the result of several physicochemical and biological mechanisms which can together lead to a different color on reservoir internal surfaces, where microorganisms can live and later be eventually liberated to the stored water.
Since the presence of a biofilm is a risk factor, the cleaning and disinfection of reservoir is a preventive measure that should be adopted by water distributors, as recommended by ERSAR (ERSAR Recommendation No. 01/2018).
Manusystems performs the cleaning and disinfection of reservoir using the bi-component product Carela® Bio greenPOWER, tested and authorized in Europe by several competent entities. In Portugal this product was evaluated by the Laboratório Central da EPAL, being included in its list of approved products for reservoir cleaning.
In the disinfection stage, Manusystems uses the product OX-Água 2ª Geração, which is registered in the European system R4BP3 as biocide type 2, 4 and 5. This product was also approved in Portugal by the Laboratório Central da EPAL for reservoir disinfection, being included in its list of approved products for reservoir cleaning.
Manusystems has developed a technical specification for cleaning and disinfection of water reservoir in operation (ET-HRM). It will be made available to all interested parties.
The cleaning and disinfection method for reservoir in operation, in order to maintain its good hygienic condition, is as follows:
- Washing with low pressure water (pressure less than 5 bar) all internal surfaces of the reservoir;
- Spraying the cleaning product Carela® Bio greenPOWER;
- Control of the contact time of the cleaning product;
- Intermediate washing with low pressure water with control of the removal of the product used;
- Spraying the disinfectant product OX-Água 2ªGeração;
- Control of the contact time of the disinfectant product;
- Final washing with low pressure water with control of the removal of the product used;
- Control of the effectiveness of disinfection by ATP testing on reservoir internal surfaces;
- If the results are satisfactory the work is done. Otherwise, steps 5 to 8 should be repeated until compliance is reached.