One of the issues many rural residents face with their private well water supply is a rotten egg odour coming from the water.
There are two main causes of this, and the first thing to check is your hot water. If the odour is new, meaning it wasn’t something you noticed in the water a few months ago, then do a quick and free water test – plug the drain and run your hot water into the sink – let it fill up a few inches and give it the smell test. Is there odour? How strong is it?
Then repeat the test, but this time with cold water. If you have odour on the hot water, but not the cold water, this problem could be fixed very quickly and easily by your plumber, or a handy home owner. You likely need to replace the anode rod on your hot water tank. There are a number of factors in well water that can cause the problem, but the fix is pretty simple.
If you have odour on both hot and cold water, the issue is likely either sulfur in the water (h2s gas) or can, in some cases, be from the iron content. Treating the water presents a few options, all of which will involve oxidation of some sort – meaning taking the gases from the water and making them react to form solids which can then be filtered out.
Common solutions involve chlorine injection – a process by which chlorine is dosed into the water, allowed to react (usually for about 10 minutes in a contact or “retention” tank,) then filtered out by a media that would remove both the chlorine and the sediment. This usually clarifies the water as well and has long-been a relatively low-cost way to treat iron and sulfur issues.
We prefer to inject hydrogen peroxide instead of chlorine. It is much nicer to work with, is a stronger oxidizer, and doesn’t need to be removed – instead the home owner just keeps some simple test strips in their kitchen and periodically checks to ensure there’s a little hydrogen peroxide left at the tap. If there is, then it’s doing its job and everything should be fine. Because the hydrogen peroxide doesn’t need to be removed, we can focus more attention on the sediment and give even better filtration to the whole home – resulting in the clearest, cleanest water supply possible, and longer life for hot water tanks, faucets and appliances.
Iron filters are another way, but really would only work if the rotten egg odour is not caused by the presence of SRB’s, or “Sulfur Reducing Bacteria.” If they are the root cause, then chemical injection oxidation may be the best way to go. The nice thing about iron filters is that they are much lower maintenance. Usually they are set to regenerate and backwash about once a week (depending on filter size and water usage) and typically can contain an entire year’s worth of regenerant in their tank – meaning you don’t have a lot of maintenance. The main down-side to chlorine or other chemical injection systems is that you need to store, handle and sometimes mix/dilute chemicals in the home.
To find out more on treating sulfur in well water, or troubleshooting rotten egg odour, contact a water treatment professional.