Boil-water alerts, sometimes called boil-water advisories, can occur with public drinking water supplies at certain times if it is considered that there is a risk to drinking water, e.g. after a storm or power outage. If these happen, you should boil water before consuming it and follow issued guidelines to avoid the risk of illness. Alternatively, you can access alternative drinking water supplies. Here is a brief guide on what to do.

What is a boil-water alert?

A boil-water alert is a public announcement, usually issued by a local public health officer, advising residents to boil water accessed from their main water supply before consuming it. Boil-water alerts can occur in any area supplied with safe drinking water when there is a risk that the water could be contaminated by pathogens such as E.Coli.

When boil-water alerts have been issued, it is strongly advisable to bring water to the boil for at least one minute before using when drinking, preparing food, brushing your teeth or cleaning products in contact with food or drink (e.g. washing up). Dishwashers and other machinery that boils water are still OK to use but standard water filter systems won't necessarily remove the pathogens, so boiling is still recommended.

Typically, boil-water alerts last for 24-48 hours although they can be longer. Local public health authorities will notify residents when water is safe to consume again.

What causes water contamination?

Central drinking water supplies are available because of treatment processes that remove microbiological contaminants from the supply before it reaches households and public facilities. However, contaminated water can enter the system in certain circumstances such as:

• storms or floods, where treatment facilities can get damaged or flooded with untreated water;
• power outages which can compromise treatment plantations;
• insufficient maintenance of treatment facilities;
• sudden loss of pressure in the water system;
• ongoing water leaks in the central supply;
• inadequate water disinfection processes.

Where has experienced a boil-water alert?

Boil-water alert notices are not uncommon, even in countries with a good central supply of drinking water. Sometimes they will be issued as a precautionary measure, sometimes because a more serious problem has been detected.

Examples of places that have issued boil-water alerts in recent years are:

• Dublin, Ireland – problems linked to bad weather and issues with a treatment plant meant that alerts were issued in October and November 2019 affecting 600,000 residents.
• New South Wales, Australia – flooding caused by Cyclone Uesi has affected water supplies in many areas including Sydney over the past month. 14 local councils have issued boil-water alerts since the start of the year.
• Texas,USA – flooding in 2018 led to high levels of silt and debris entering water supplies in Austin, Texas. The local authorities issued an alert as well as instructing households to limit water use.

What to do in the event of a boil-water alert

The first thing to remember is don't panic. Public health authorities will often issue warnings as precautionary to be on the safe side. Even if there is an issue with contamination, it is unlikely to be major and the worst that is likely to happen to anyone consuming supplies is diarrhea, nausea or vomiting.

However, this is unpleasant enough so it's worth taking steps to avoid unnecessary illness. You should:

• boil all water that might be consumed – even water for washing up the dishes – for a minimum of one minute on the boil (or 3 minutes if at high altitude)
• store any boiled water in the fridge for later use. It won't be in danger of recontamination
• use soap or hand sanitizer when washing your hands
• take care when bathing or showering not to consume any of the water. Don't use tap water for brushing your teeth during a boil-water alert
• sterilize all baby equipment in boiling water for 2 minutes
• avoid giving pets tap water.
• Use an alternative water source such as bottled water or a decentralized supply

Discover how BOSAQ can provide premium quality off-grid drinking water through solutions such as the Q-Drop system. This will ensure that you have a continuous supply of sustainably sourced drinking water that isn't at risk of contamination.