This is a question we get all the time here at Magnolia Plumbing. The rotten egg smell comes from hydrogen sulfide gas, which occurs naturally in groundwater but can also be produced by sulfur bacteria or chemical reactions inside water heaters. In certain cases, it can also be caused by pollution.
Fortunately, the rotten egg smell does not mean your water is unsanitary, except in the rare case that the gas is caused by sewage. However, hydrogen sulfide gas in the air can be harmful in high concentrations. When removing the gas from the water (which is possible – we’ll get into how to do it in a bit), it’s important to vent the gas outside so it doesn’t collect in low-lying places like well pits or basements or in enclosed areas like well houses. If you’re worried you have hydrogen sulfide gas, don’t enter the space where it might be – call a Magnolia Plumbing technician to inspect the area.
How can I find the problem, and how do I fix it?
Having water that smells like rotten eggs is no fun, but it’s very fixable. The first thing you need to do is figure out where the rotten egg smell is coming from:
- If the rotten egg smell only comes out of hot water faucets, there’s probably a problem with the water heater.
- If the smell is coming from both faucets, but only comes from water that has been treated by a water softener, the problem is most likely sulfur bacteria in the water softener.
- If the smell comes on strong when either the hot or cold faucets are first turned on, but it diminishes after a little while, you probably have sulfur bacteria in the well or distribution system.
- If the smell is strong when you first turn the faucets on and doesn’t go away, there’s probably hydrogen sulfide gas in the groundwater.
Once you’ve located the source of the problem, call Magnolia Plumbing! We can take care of the rotten egg smell in your water in a variety of ways, including:
Water heater maintenance
- Many water heaters have a magnesium anode attached to a plug on the top . The plug can be removed by turning off the water, releasing the pressure and unscrewing the plug. Once removed, the magnesium anode can be replaced by an aluminum/zinc alloy which should solve the problem.
- The water heater can also be disinfected with a chlorine bleach solution and flushed, which should kill all the sulfur bacteria that produce the rotten egg smell. This should only be done professionally, because if you don’t kill all the bacteria the problem could return before long.
- If all else fails, the water temperature in your water heater can be increased to 160 F for a few hours to kill the bacteria. Note that this solution should only be attempted by a licensed Magnolia plumber, who can monitor the water heater pressure and reset the thermostat back to normal before it presents serious scalding risks and high energy costs.
Groundwater treatment
If the rotten egg smell is coming from your groundwater, the problem may be harder to eliminate permanently without digging a new well. However, there are several treatment options available:
- Installing an activated carbon filter is effective for low level hydrogen sulfide problems, usually less than 1mg/L. Since the carbon filter can remove substances in addition to hydrogen sulfide gas, it is difficult to predict how long the filter will last before it needs to be replaced – some large carbon filters have been known to last for years, while some small filters may last for only weeks or even days.
- An oxidizing filter is better for hydrogen sulfide levels up to 6mg/L. Oxidizing filters should be periodically recharged before the filtration material is exhausted.
- For serious hydrogen sulfide problems, you’ll need to install an oxidation-filtration system. These will inject a chemical such as chlorine into the water supply line that can change the hydrogen sulfide to sulfur, which can be removed by a particulate filter.
Rotten egg smell in water is a common problem in the Maryland, Virginia and Washington, DC area, but it doesn’t have to be. If your water smells like rotten eggs, call the DC plumbers at Magnolia Plumbing today!