Why does my tap water smell like rotten eggs?

Regardless of where you live in Australia, local water authorities continuously receive complaints about the quality of water being received by local households. In the vast majority of circumstances, these changes are completely harmless. This is regardless of whether the colour of the water has changed or the smell is noticeably different. One such complaint is that the water is smelling like rotten eggs. But why does this happen?

First off, how is your water treated?

Before understanding why your water might smell like rotten eggs, you first need to understand the process it goes through before reaching your tap. As you are likely aware, the local council responsible for managing your water will need to put certain chemicals in the water to make it safe for consumption. These chemicals, notably chlorine, act by killing off harmful bacteria, as well as adding helpful vitamins and nutrients.

This is all a part of a long and complex filtration system that can vary depending on the part of Australia you live in and where the water supply is coming from. However, before it becomes available in your tap, the vast majority of these chemicals will have been removed, leaving behind safe, healthy drinking water.

smelly water

So, what could be causing the eggy smell?

As explained, the process of filtering water is long and complex, and there are a few key reasons why your water might smell like rotten eggs. By far the most common reason your water smells this way is because there is hydrogen sulfide gas in the supply. This could be down to four reasons:

1. There‘s an issue with your water heater

Often, people find that the smell of eggs is only present in water coming from the hot water tap. This means that the hydrogen sulfide gas is entering the supply as a result of what your water heater is doing to it. This problem can be fixed, but not by yourself. Instead, the best thing to do is call up a local boiler specialist and they can remedy the situation.

2. Your water softener is adding it in

If you find that the smell is present in both the hot and cold water and you also use a water softener, then this could be the root cause. In some cases, the water softener solution isn’t right and it is inadvertently adding the hydrogen sulfide gas in. You can remedy this yourself by replacing the water softener solution.

3. A problem with the water supply

You can usually tell if there is a problem with the actual water supply if the smell is apparent in both the hot and cold water and diminishes over time. Or you might find the smell comes and goes over time as the taps are left running. Either way, this is not an issue you can fix yourself and it could be serious for a number of households in the area. If you believe this to be the case, then you should contact your local council immediately and inform them.

4. It’s because of the groundwater

Groundwater is the water that’s present below the Earth’s surface and locked in the surrounding soil. It could be the case that this groundwater is responsible for diluting the water supply with hydrogen sulfide. Again, this is a serious issue that needs remedying so take necessary steps to contact your local water supplier.

If you’re really not sure which one of these issues might be responsible for your water smelling like rotten eggs, then it could be best to contact a local plumber. They can assess the situation professionally and make the most informed decision possible.


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