“My water smells like rotten eggs.” This is a very common complaint from many homeowners but one that may be easily explained. Hydrogen sulfide, a compound that is widely known for its distinct rotten egg or sulfur odor could be the culprit. This colorless, flammable gas occurs naturally in gases from swamps and stagnant pools of water, volcanoes, hot springs or crude petroleum. H2S is also a waste product of many industrial processes and from municpal sewers and sewage treatment plants. The production of H2S is due to a process called anaerobic digestion, a breakdown of organic matter in the absence of oxygen.  

In well water supplies, H2S is commonly formed by sulfate reducing bacteria. Well water naturally contains minerals of sulfate picked up from soil and rock formations. Sulfur reducing bacteria can change sulfates in the water to hydrogen sulfide gas. In other cases, hydrogen sulfide in well water can be caused simply by the decay of organic matter.

The human sense of smell can detect H2S in concentrations as low as 0.5 ppb (parts per billion). In addition to the odor, the taste of the water may also be affected. If left untreated, H2S can corrode steel, stainless steel and copper pipes. It can also tarnish silver and leave yellow or black stains on bathroom fixtures. While the amount of H2S typically found in most household water supplies is not high enough to pose serious health risks, slight nausea can occur due to the foul odor.

There are several options to treat H2S in a water supply. Trace amounts of the gas can be handled by activated carbon. If you have low to moderate amounts of H2S in your water, the gas can be converted to elemental sulfur and then filtered out by using an oxidizing filter. High amounts of H2S may require more advanced treatment.

It is important to note, if the rotten egg smell is only present in the hot water, not in the cold water, chances are the problem lies in the hot water heater. All hot water tanks have an anode rod, which is in place to prevent corrosion of the tank. However, if anaerobic bacteria are present in the water, they can use the electrons produced by the corrosion of the anode rod as an energy source to produce H2S. One simple fix is to switch out the anode rod in the tank. Check with a reputable dealer for replacement anode types to ensure you keep the warranty intact. Turning the temperature up on the hot water tank for a short period of time to kill the bacteria may help. But, remember to turn the temperature back down and drain the tank, otherwise scalding may occur. Shock chlorination of a private well is a temporary solution as well. Although these fixes can reduce the odor problem, they aren’t permanent.

If you suspect you have H2S in your water, it is best to contact a water professional for further on-site testing and precise treatment solutions.

Contact Cathy J.

A boil water alert (BWA) is issued when there is a threat of disease causing microorganisms such as Giardia lamblia and Cryptosporidium entering a water system. Contamination can be caused by several different factors, most commonly due to water main breaks or severe flooding which might allow the possibility of foreign substances to enter the water system.  In less common instances a BWA can be issued when there is a significant change in the turbidity reading. A BWA is issued after careful consideration among representatives from public health, regulatory agencies and municipal departments. 

When there is a BWA, it will be broadcast on the local news (radio, television, web) with instructions on what to do and how long it will last. 

The best way to make sure your water is safe for drinking, cooking or brushing your teeth is to boil your water.  To effectively kill the disease causing organisms, boil the water for at least one to five minutes.  Allow water to cool before use.  The water will taste “flat” but will be safe to use.  If you are unable to boil your water, you can use bleach or iodine.  Bleach will kill some, but not all, types of disease-causing organisms that may be in the water.  Add 1/8 teaspoon of regular, unscented, liquid household bleach for each gallon of water, stir it well and let it stand for 30 minutes before you use it. Store disinfected or boiled water in clean, air-tight containers with covers in the refrigerator. 

Hot (not boiled) soapy water will be sufficient for dishwashing and surface cleaning.  As a precaution, add one tablespoon of bleach per gallon. Unless specifically list in the BWA, laundry water and water for showering does not need to be treated.

Boil alerts are mostly for city and community water supplies.  If you have a well, you would want to boil your water after severe flooding or if your well pressure drops to almost non-existent (indicating a potential problem).  After correcting the problem or when the water recedes, it is recommended that you have your water tested by your local EPA certified laboratory to make sure it is safe to drink.

For a list of local certified laboratories or more information on safe drinking water, a very informative, reliable source is the EPA. 

Contact Cathy J.