Clean and healthy water should be colorless and odorless. Hence, it must be disturbing to suddenly find your water smell like sewer gas. Not only does it feel disgusting, but it will also make you worry about your family’s health. How can this happen, and what can you do about it?
First, it is best to inspect where the smell is coming from. You can take an empty glass and fill it with the water directly flowing from your faucet. If the water is odorless, colorless, and tastes normal, then the smell might be coming from your drain. This is most often the case.
It is the bacteria in your drains that produce the foul smell of hydrogen sulfide gas. These bacteria grow in the food waste, soaps, and other materials from your sink. The hydrogen sulfide gas will fill your drain so that sometimes you can smell it if you get close to your sink. When the faucet is turned on, the water flows into the sink drain, forcing all the gas to go upward. This smelly gas will get to your nose.
You can smell the stench of hydrogen sulfide when it reaches a level of at least 0.5 parts per million (ppm). When it gets to 1 ppm, the smell will be musty. At the level of 2 ppm, it will smell like rotten eggs.
Your water heater could also cause your water to smell like sewer gas. The anaerobic bacteria from the water source will create a reaction when it meets with the sulfur, magnesium, and anodes in the heater. This usually occurs when the water heater is off for a long period, like when you leave your house for a vacation.
Is It Dangerous?
Since the smell is not coming from your tap water, you can be sure that it is not dangerous. Hydrogen sulfide can indeed be toxic at a high level, but there is likely an extremely low level of gas in the drain. You can use water as you usually do. However, it should be a big concern if the water itself has an abnormal color, smell, or taste.
What to Do
If the water is the culprit, you need to contact a technician or water testing lab and ask for an inspection. This issue needs to be resolved as soon as possible to avoid health problems with your family.
If the smell is coming from the water heater, you will need to turn it on at high temperature for a few hours and then open the faucet. This will effectively flush out the bacteria inside your pipes. The smell should disappear after a while.
If the problem is the drain pipe under your sink, you need to clean it up. Use liquid soap and a long, thin brush to clean up the sludge inside the drain pipe. Turn your faucet on and let it run for a minute or so to flush it down until the smell disappears.
There is no need to panic when you suddenly notice a foul smell when turning on your faucet. If handled accordingly, this problem will be gone soon without having to call a professional technician. In any case, make sure you resolve the problem as soon as possible before it creates other issues.