Is it Safe to Drink from the Hot Water Tap?Cat McCarthy
Growing up, my sisters and I weren’t allowed to swim in the irrigation channel like the other kids in town because of my Dad’s extensive fear of us getting amoebic meningitis from the water. We also had to hold our nose in swimming pools or in dams/lakes (I still blame this reason for never being able to pass stage 2 in swimming lessons…).
Fast forward 20 odd years and I married a plumber with an extensive fear of us getting legionella by getting dripped on by an air conditioner.
Are their fears irrational? Or should we be cautious around stagnant and/or warm water, including what comes out of our hot water tap while the water is heating up?
What is Amoebic Meningitis?
Amoebic Meningitis is a rare but usually fatal disease, caused by a single sell organism living in damp soil or fresh water. It travels through the nose (via contaminated water) to the brain. It can cause symptoms within 5 days of infection, including headaches, high fever, nausea, neck stiffness, vomiting, confusion and coma. The outcome in most cases is death, and it’s a particularly nasty disease as it mostly affects children and young people.
How Can You Prevent Getting Amoebic Meningitis
Dad was right; you can get it from swimming holes and natural water bodies that are warm. The Department of Health in WA state that you should ‘Never allow water to go up your nose or a child’s nose and do not sniff water into your nose when bathing, showering or washing your face’.
You should also make sure you run the hose or sprinkler for a few minutes until cool water flows through it before any child plays in it. Children should only play in fresh water that is cool/cold, never stagnant and warm.
If a spa or pool is dirty, warm or not chlorinated properly it can also attract the amoeba. Chlorine levels should be monitored, including shell pools or wading pools. Baby pools should be clean from ‘slime’ and emptied after each use.
The amoeba can not grow in salty water, so this is the safest place to swim, with chlorinated swimming pools and spas next, then cold and flowing fresh water.
In Melbourne, our drinking water has been treated by fluoridation, chemical treatment and disinfection, pH correction, filtration and has substances added to it including chlorine (the full list can be found here).
When installing hot water systems and tempering valves, Plumbers need to work within the parameters of lowering the temperature setting to reduce the risk of scalding and save energy and increasing the temperature enough to decrease the risk of bacteria growth in the tank.
Legionella bacteria thrive in temperatures between 20-45°C, with their ideal range being 37-43°C. Australian plumbing regulations require water heaters (the hot water tank) to be set at a minimum of 60°C to prevent bacterial growth. At this temperature, 90% of Legionella bacteria die in just 2 minutes, and raising it to 70°C eliminates them almost instantly.
However also as per Australian plumbing regulations, a tempering valve must be installed on all hot water systems to ensure water that is heated up to 60°C must leave the tap at 50°C (to prevent scalding) and thermostatic mixing valves are also used in nursing homes and childcare centres. As 50°C is near the danger zone of 43°C, the valves must be regularly maintained by a plumber and flushed to ensure the bacteria doesn’t grow.
What is Legionella, or Legionnaire’s Disease?
Another bacteria type disease found in damp soil or water, Legionella is a severe form of pneumonia. Like Amoebic Meningitis, it can be fatal if not treated on time. The signs and symptoms are also similar to Amoebic Meningitis, however can be more ‘flu-like’ including muscle soreness, dry cough and shortness of breath.
How Can You Prevent Getting Legionella?
Legionella can affect people of all ages and is mostly prevalent in:
Potting Mix and Soil
Gardeners should use gloves whenever they can, be careful not to inhale potting mix, keep mix out of the sun and wash hands thoroughly with soap after gardening.
Evaporative Air Conditioners
Evaporative coolers need to be cleaned and maintained regularly to ensure the covers are cleaned, filters replaced, hoses are flushed, they are disinfected, and slime is removed to ensure a bacteria breeding ground isn’t forming in your system. Heating and Cooling companies can provide this service. Portable evaporative coolers should be cleaned thoroughly and dried when not in use.
Hot Water Systems
Hot water systems must be serviced regularly by a plumber to ensure the tank, tempering valve and thermostatic mixing valves are operating at a safe temperature.
You should always let your hot water run first (from your taps and shower) and not use any warm water that comes out, until it gets to temp (remember what I said earlier about bacteria loving water between 20-43°C?). Don’t want to waste that water? Collect it with a jug or bucket and use on your garden or to water your indoor plants.
Nebulisers, humidifiers, water fountains and spas should also be kept clean and disinfected to control any bacterial growth.
So, Should I Drink the Water From a Hot Water Tap?
Whilst technically it’s safe to do so (if your hot water system is performing optimally) and the risk of contracting legionella and amoebic meningitis is extremely low, there’s always a risk if your water hasn’t been treated properly, your hot water system isn’t maintained, and your water is warm.
What does our plumbing family personally do?
- We don’t drink from the hot water tap (or brush our teeth/wash our faces with that water)
- Our kids know to run the hose and sprinkler and not use the water until it gets cold.
- The splash pool is emptied and scrubbed after each used in summer.
- We don’t get under the shower until it is hot (the warming water is collected in a bucket and feeds the plants)
- We get our evaporative cooler serviced regularly.
Some of these measures are VERY cautious and risk adverse, however amoebic meningitis is such an awful disease and almost always fatal, so we do everything we can to avoid it. Give us a call at McCarthy Plumbing Group if you need any clarification on water temperatures and how you can ensure your hot water system is working optimally.