Most companies and institutions have a collective drinking water installation that subministers water to third parties. The owner of a drinking water installation or building is responsible for the quality of the water, from the meter to the water taps. 

How can you reduce the risk of contamination in drinking water installations?

• Keep hot water systems as hot as possible without scaling risk:
  • The European Centre for Disease Prevention and Control recommends 50°C–60°C, 122°F–140°F;
  • Maintain circulation throughout the hot water system;
• Keep cold water temperatures as cold as possible, including all cold-water storage;
• Flush 10% distal outlets from representative locations (sinks and showers) on a weekly basis; Rotate room locations to ensure different rooms are flushed each week;
  • Flush the cold-water line from the outlet for two minutes, then flush the hot water line until maximum temperature is reached, followed by a two-minute flush;
  • Temperatures should be checked at 30 and 60 seconds;
• Flush oversized storage tanks and infrequently used equipment attached to the system at least once per week to prevent stagnant water;
• Rarely used ice machines should be drained and shut down;
• If supplemental disinfection is present at the facility, continue operating supplemental disinfection. Refer to your manufacturer for service instructions;
• Supplement disinfection systems should be operated within normal limits. Refer to your manufacturer’s guidelines; 
• Disinfection residual levels should be checked as previously performed or weekly;
• Continue operation/maintenance for non-chemical treatment systems such as, UV systems;
• Perform preventative maintenance and check the inventory;
• Maintain documentation for flushing and maintenance procedures;
  • Documentation ensures that each necessary action is taken to reduce risks caused by low occupancy.
     

Legionella

Common bacteria in drinking water are Legionella. They appear naturally wherever it is moist, in soil and in water. Legionella bacteria are as inevitable as all other types of bacteria. The numbers of Legionella in drinking water are so small that the bacteria pose no threat. But in stagnant water, however, legionella bacteria grow and reproduce very rapidly in drinking water installations!  

For companies and institutions of a collective drinking water installation, it is recommended to perform a legionella risk assessment and have a management plan. As legionella can cause Legionnaires’ disease, it is important that you, as an owner of a large installation, take the necessary measures to limit legionella in water pipes.

Legionnaires’ disease

Legionnaires’ disease is a pneumonia caused by the legionella bacteria. There is no vaccine, but the disease can be treated with specific antibiotics if applied as soon as possible. There is also a milder form, legionella flu or Pontiac fever, which develops like a ‘normal’ flu.

How do people get infected?

People risk getting infected by inhaling very small droplets (as mist or aerosol) of water containing high counts of Legionella bacteria. These droplets appear mostly in showers, hot tubs, steam baths, fountains, and cooling towers. Most people do not get sick from drinking water with Legionella, and it is not transferable from person to person. Some people, however, are more at risk of getting sick, like the elderly, people with low resistance due to illness, people who use anti-immune drugs and smokers.

How do we at WEB Aruba prevent Legionella?  

Besides the periodic sampling program WEB Aruba has a yearly sampling program to detect legionella in its water supply and distribution network. If high counts of legionella are detected, we act immediately. We also have a structural maintenance program for flushing and disinfection of water pipes. Part of the maintenance is a monthly fixed program to take samples of the entire production and distribution network, including the reservoirs. The water samples are subjected to bacteriological and chemical analyses. If WEB Aruba detects any sample exceeding the guidelines, the system or pipes will be flushed and, if necessary, disinfected.