Rotten egg smell is a common water quality issue in the New England region usually caused by Hydrogen sulfide (H2S).  Hydrogen sulfide is a colorless gas that can exist naturally in groundwater. (for removal techniques, see lower section on this page).  Sulfur-reducing bacteria present in groundwater use sulfur as an energy source to chemically change sulfates to hydrogen sulfide which releases a rotten egg smell in water. The bacteria use sulfur from decaying plants and other organic matter in oxygen-deficient environments. They can occur in deep or shallow wells and reside in plumbing systems. Hydrogen sulfide can reveal itself in other ways too.  Hot water heaters that have a magnesium rod used for corrosion control can chemically reduce sulfates to Hydrogen sulfide.

Hydrogen sulfide also can enter surface water through springs as well. It is most common in shale and sandstone. The occurrence of Hydrogen sulfide gas has been associated with groundwater with low pH and/or groundwater with high levels of iron and/or manganese (typical water quality issues in New England). Hydrogen sulfide has a pungent smell at low concentrations and most people can detect concentrations above 0.03 ppm. There is no Maximum Contaminant Level established by the United States EPA.

Effects of Hydrogen Sulfide

Other than releasing a rotten egg smell in water, Hydrogen sulfide may be corrosive and can leach metals from plumbing systems into the water. The result of this corrosion of metals by Hydrogen sulfide can be a black precipitate that can stain laundry and bathroom fixtures, darken silverware, and discolor copper and brass utensils. 

While there are several technologies available to remove the rotten egg smell in your water, it cannot be viewed in a vacuum. The pH level, iron & manganese levels, as well as other contaminants present in the water must be evaluated for an effective, comprehensive solution to this issue.  For more on this see https://h2ocare.com/treating-rotten-egg-smell-water/.

H2O Care is an established, full-service water filtration and testing organization originally formed in 1989 with offices in Middleton, Stow & Lakeville, MA. Also, see our published articles in Water Technology Magazines at http://h2ocare.com/publications.  Contact us at service@h2ocare.com or 833-828-5106.