Pandemic and Legionella

During the pandemic, many facilities including hotels remained closed for extended periods. This situation caused water systems to remain unattended and stagnant for a long time, potentially creating suitable environments for the proliferation of Legionella bacteria. The list of actions to be taken during normalization and the reopening phase of businesses is provided. The required actions may be more than those written here.

Actions to be Taken

  1. All COLD WATER TANKS should be emptied, cleaned with a brush, and their walls whitewashed with chlorinated water.

  2. Eliminate short circuits inside cold water tanks (proximity of supply and suction lines).

  3. Clean the interiors (inner surfaces) of all HOT WATER TANKS (boilers) (removal of lime scale and sediment).

  4. Perform hot water shock treatment on all HOT WATER TANKS (Heat the hot water tanks from the drain valve until water temperature reaches at least 60 ºC. Wait at least 1 hour and then flush for 5 minutes).

  5. Remove all FILTERS connected to the water system for detailed cleaning and disinfection.

  6. Remove all SHOWER HEADS, shower hoses, faucet aerators, and garden irrigation sprinklers for detailed cleaning and disinfection.

  7. Perform detailed cleaning and disinfection of all COOLING TOWERS.

  8. Perform detailed cleaning and disinfection of all pool BALANCE TANKS and FILTER SANDS.

  9. Perform CHLORINE SHOCK by adding chlorine to cold water tanks. The free chlorine level to be reached is 3 ppm. Flush 3 ppm chlorinated water from all cold water outlets such as taps, showers, WC reservoirs, etc., and let it stand for 24 hours.

  10. Increase the water temperature inside boilers to ≥ 60 ºC, and flush hot water at pencil thickness from all showers and taps (bath, hairdresser, kitchen, etc.) for 5 minutes each. Perform THERMAL SHOCK.

  11. Increase the water temperature inside boilers to ≥ 60 ºC, measure and record the temperature at the lower drain valve as ≥ 60 ºC.

  12. After shock treatments, maintain free chlorine levels at 0.2-0.5 ppm and water temperatures at 60 ºC.

  13. Take Legionella samples 2 days after shock treatments.

  14. Keep records and document all performed procedures.