Hydrogen sulfide gas (H2S) can give water a “rotten egg” taste or odor. This gas can occur in wells anywhere and be:
- It occurs naturally due to degradation and chemical interactions with soil and rocks.
- Produced by certain “sulfur bacteria” in the groundwater, well, or plumbing system.
- Sulfur bacteria or chemical processes within water heaters produce it.
- From pollution (this is rare).
May help other bacteria grow
Sulfur bacteria make a slime that may aid in the growth of other bacteria, such as iron bacteria. The slime can block wells, pipes, and irrigation systems.
Gas may be harmful
While sulfur bacteria are not dangerous, large volumes of hydrogen sulfide gas in the air may be. Removing the gas from the water or exhausting it into the atmosphere is critical. Venting keeps gas from accumulating in low-lying areas (such as well pits and basements) or enclosed places (such as thriving houses).
Only well specialists should enter a healthy pit or other confined place containing hydrogen sulfide gas.
How to detect
- Bacterial slime If coupled with iron bacteria (signs of sulfur bacteria), it may be white, grey, black, or reddish brown.
- Black stains on silverware and plumbing fittings (hydrogen sulfide gas indications).
- Corrosion on water distribution system pipes and metal components (evidence of hydrogen sulfide gas).
- Have your water tested at a laboratory.
Consider testing your water
In most circumstances, the rotten egg smell has nothing to do with the water’s hygienic condition. In rare cases, the gas may be caused by sewage or other contaminants. Test your healthy water for coliform bacteria and nitrates to be safe.
What you can do
The first step is to determine the root of the problem; this will inform you of the best treatment approach.
How to Find the Source
After you have been away from your home for a few hours, smell the water from the hot and cold faucets. Determine which faucets have the “rotten egg” odor.
If the Problem is in the Water Heater
Unless you are highly experienced with water heater operation and maintenance, get the repair done by a plumber or water system specialist.
- Replace or remove the magnesium anodeMany water heaters include a magnesium anode connected to a plug on the water heater. Please turn off the water, release the pressure from the water heater, then unscrew the plug to remove it. Make careful to close the hole. However, removing the anode may dramatically reduce the water heater’s life. You should check with a water heater dealer to see whether an alternative material, such as aluminum, may be used as a new anode. A replacement anode may defend against corrosion while not contributing to the formation of hydrogen sulfide gas.
- Using a chlorine bleach solution, disinfect and cleanse the water heater. Sulfur bacteria may be killed by chlorine. If not all germs are killed by chlorination, the issue may reoccur within a few weeks.
- Raise the temperature of the water heater to 160 degrees Fahrenheit. (71 degrees Celsius) for several hours This will kill the sulfur bacteria. After treatment, flushing to remove the dead bacteria should manage the odor.
CAUTION IIncreasing the temperature of the water heater might be hazardous. Contact the manufacturer or dealer to get a functional pressure relief valve and other advice. To minimize harm from scorching hot water and expensive energy expenses, decrease the thermostat setting and ensure the water temperature is adjusted after treatment.
How Hydrogen Sulfide Gas is Produced in a Water Heater
A water heater may offer an optimal atmosphere for sulfate to hydrogen sulfide gas conversion. The water heater may generate hydrogen sulfide gas in two ways: by providing a warm environment for sulfur bacteria to thrive and by maintaining a reaction between sulfate in the water and the water heater anode.
A water heater often includes a metal rod known as an “anode,” which is placed to prevent water heater tank corrosion. The anode often comprises magnesium metal, which may provide electrons to help convert sulfate to hydrogen sulfide gas. The anode has a diameter of 1/2 to 3/4 inches and a length of 30 to 40 inches.
If the Problem is in the Well, Plumbing System, or Water Softener
Use a robust chlorine solution to disinfect the well and plumbing system. You may either employ a professional well contractor or follow the guidelines on the Well Disinfection website.
Sulfur bacteria can be difficult to remove once established in a well. Pre-work (such as scrubbing the well casing, using special treatment chemicals, and agitating the water before disinfection) may be necessary—especially if there are also iron bacteria. Contact a licensed well contractor to do this pre-work.
If the germs are in the water softener or other treatment equipment, get disinfection instructions from the installation, manufacturer, or Minnesota Department of Health.
If the Problem is in Groundwater
Both installing home water filtration systems and digging a new well in a different formation are choices. The kinds of home water treatment listed below successfully reduce hydrogen sulfide gas. Visit the Home Water Treatment website to learn more.
- Activated carbon filters are effective for less than 1 milligram of hydrogen sulfide levels per liter (mg/L). The gas is trapped by the carbon until the filter is saturated. Since the carbon filter can remove substances in addition to hydrogen sulfide gas, it is difficult to predict its service life. Some large carbon filters have been known to last for years, while some small ones may last only weeks or even days.
- The methods listed below are effective for levels both below and above 1 mg/L.
- Oxidizing media filtration (such as a manganese greensand filter) can handle hydrogen sulfide levels as high as 6 mg/L. This form of treatment is often used to address iron issues in water. The device is made up of manganese greensand medium, which is sand that has been coated with manganese dioxide. As the water travels through the filter, the hydrogen sulfide gas is converted to microscopic sulfur particles. Before the capacity of the greensand is depleted, the filter must be regularly renewed using potassium permanganate.
- Aeration and filtration .
- Continuous chlorination and filtration .
- Ozonation and filtration .
Should I test my well water for anything besides Hydrogen Sulfide?
Yes. Both natural and human activities may pollute well water and have short- and long-term health consequences. Most toxins in Minnesota groundwater can only be detected by testing your healthy water; you cannot taste, see, or smell most contaminants. The Minnesota Department of Health suggests testing for:
- Coliform bacteria every year and if the water’s flavor, odor, or appearance changes. Coliform bacteria may signal the presence of disease-causing germs in your water.
See Bacterial Safety of Well Water.
- Nitrate every other year Bottle-fed babies under six months of age are most vulnerable to nitrate levels in drinking water more than 10 milligrams per liter.
See Nitrate in Well Water.
- Arsenic at least once . Arsenic is found in the water of around 40% of Minnesota wells. Drinking arsenic-contaminated water for an extended period of time may lead to lower intellect in children as well as higher risks of cancer, diabetes, heart disease, and skin disorders.
See Arsenic in Well Water.
- Lead at least once The well and water system may include lead-containing components, which may leach into the drinking water. Lead has the potential to harm the brain, kidneys, and neurological system. Lead may also impede growth and create difficulties in learning, behavior, and hearing.
See Lead in Well Water Systems.
- Manganese before a baby drinks the water High amounts of manganese may impair memory, attention, and motor abilities. In addition, it might cause developmental and behavioral issues in newborns and children.
See Manganese in Drinking Water.
Other pollutants may be found in private water systems, however they occur less often than the chemicals mentioned above. Consider testing for the following:
- Volatile organic chemicals If the well is close to gasoline tanks or a commercial or industrial zone.
- Agricultural chemicals commonly used in the area if the well is shallow and near planted fields or agricultural chemical processing zones, or if it is in a geology sensitive location (such as cracked limestone).
- Fluoride if children or teenagers drink the water.