Sulfur – What’s That Rotten Egg Smell?

The most important question is, will drinking water with a rotten egg smell, which indicates the presence of sulfates, harm my health? The short answer is typically no. But it can still be a problem.

The EPA standards for water fall into two categories: Primary and Secondary standards.

Primary are based on health considerations and secondary are based on taste, color, odor, corrosively, foaming and staining properties. Sulfate is classified under the secondary standards.

Hydrogen sulfide, a product of sulfur bacteria in groundwater using iron and sulfur as energy to chemically change sulfates to gas, is flammable and poisonous. But it is not usually a health risk at typical house water concentrations, unless extremely high.

Sources for sulfates include decay, organic matter, or chemical reactions with sulfur-containing minerals in soil and rock.

Naturally Occurring – Sulfates are a result of naturally-occurring elements of sulfur and oxygen in some soil and rock formations that contain ground water.

Nearby Industries – Oil & Gas, Fracking, Mining – Hydrogen sulfide can be in wells drilled in shale or sandstone, or near coal and peat deposits, or oil fields.

Community Hazards – Nearby landfills, leaky fuel tanks or pipelines, old septic systems, chemical labs.

Electric Water Heater – The magnesium corrosion control rod can chemically reduce naturallyoccurring sulfates to hydrogen sulfide. See more below.

Aside from the smell and taste being an issue, water containing an excess in sulfur can cause issues with a number of household items and infrastructure:

Your first order of business is to find the source — in your drain, or in your water. Take a glass of water from your drain area the smell is originating from, and take a glass of water from another faucet in your home.

If both glasses of water contain a rotten egg smell, the problem is your water, which could come from a number of other issues – water heater, well or municipal. If only one glass has the unpleasant odor, it is most likely that specific drain.

Find the specific drain and pour ½ cup of bleach down the drain to disinfect it. If you are weary of pouring bleach into your drain system, or do not have bleach on hand, dump ½ cup of baking soda and 1 cup of vinegar in your drain. This should be sufficient to disinfect that specific drainpipe.

Hot Water Heater Troubleshooting – If the issue is from hot water only, the likely culprit is the anode rod in your electric water heater chemically reacting with the natural sulfate ions. This rod is typically made of magnesium. Replace this with an aluminum rod.

You can operate your water heater without the rod, though you risk corrosion of your steel water tank after you remove one. Culligan can add FDA-approved corrosion inhibitors to help correct this potential problem, and can also remove the sulfate by using a de-alkalizer.

Sulfur-reducing bacteria could be lurking in your water tank without the rod. One way to test for this is to set your water temperature over 140° Fahrenheit for 48 hours to kill the bacteria. If the odor goes away, this was likely the problem. If it does not, it is likely a rod issue.

If the contamination is located at the actual source of your drinking water, get a water analysis. This test should include a pH analysis, iron, manganese, hardness and TDS (Total Dissolved Solids).

A Culligan Softener-Cleer Plus, Sulfur-Cleer Plus, or Iron-Cleer filter, chlorine or hydrogen oxide chemical feed and carbon filtration are all options, depending on the results of testing.