ROTTEN EGG SMELL IN WATER?
The most prevalent cause of rotten egg smell in water in this region is hydrogen sulfide. Hydrogen sulfide is a colorless gas that can exist naturally in groundwater. 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.
DOES HYDROGEN SULFIDE POSE A HEALTH RISK OR IS THE ROTTEN EGG SMELL IN WATER ONLY AESTHETIC ?
Usually it is not a health risk at concentrations present in household water. However, hydrogen sulfide gas is flammable and poisonous at high concentrations. Buildup of hydrogen sulfide concentrations in confined areas has been known to cause adverse health effects.
Bacteria in groundwater are responsible for most of the sulfide smells detected while sampling water wells. These are not often associated with high enough concentrations to be a health issue. In rare cases, sulfide presence may be due to sewage pollution. If you experience a hydrogen sulfide odor suddenly, consult with a water filtration system professional.
ELIMINATING THE ROTTEN EGG SMELL IN WATER
While there are a number of 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. Some of the technologies and systems that may be used include:
- Ozone treatment creates a chemical reaction that precipitates sulfur. Ozone is effective for concentrations up to 10 ppm.
- Oxidizing filters will work for concentrations up to 6 ppm. The filter contains sand with a manganese dioxide coating that changes hydrogen sulfide gas to tiny particles of sulfur that are trapped inside the filter.
- Activated carbon filters can be effective when hydrogen sulfide is present in low levels (up to about 0.3 ppm). The hydrogen sulfide is absorbed onto the surface of the carbon particles. Filters require periodic replacement and can harbor sulfate-reducing bacteria
- Shock chlorination of your well may reduce the hydrogen sulfide-producing bacteria. It’s most effective in water with a pH between 5 and 7 and ineffective in alkaline (higher pH) water. An activated carbon filter may be necessary to remove residual chlorine or small amounts of remaining hydrogen sulfide.
- Oxidation removes hydrogen sulfide concentrations exceeding 6 ppm. It can be done by aeration, chlorination, and potassium permanganate.
- Water heater modification is necessary when hydrogen sulfide is causing an odor within the water heating system. Replacing the magnesium corrosion control rod with one made of aluminum or other metals usually improves the situation, however, you should check the manufacturer’s warranty on the water heater to make sure you aren’t voiding the warranty.
OTHER WHOLE HOUSE WATER FILTRATION SYSTEMS
Different types and sizes of whole house water filtration systems are available to address the various water quality issues experienced in Wenham. Not only is matching the right technology important, but also sizing the system to meet the water usage demands of your home is key. Additionally, a professionally plumbed system is critical as well as maintenance of the system throughout the years to optimize the useful life and proper functioning of your new equipment.
While symptoms of water quality issues such as bad odors & taste, staining of laundry, bathroom fixtures, etc. are indicators of problems, the preferred starting point is to get a water test to identify the minerals or contaminants in the water and at what quantity they exist. This will lead to an effective system recommendation and route to providing your home with excellent water quality. While certain minerals & contaminants can be tested on-site, health threat items like radon in water, arsenic in water, nitrates and others should be properly sampled and brought to a certified laboratory for testing that requires specialized equipment.
A water softener is a type of whole house water filtration system that is designed for removing hard water minerals (magnesium & calcium) as well as dissolved iron and manganese from the water. For water with high levels of iron or manganese (“the stainers”), a “down-flow” water softener is recommended to prevent mineral build-up in the bottom of the water softener. Also, high efficiency water softeners that are more efficient with both water and salt usage are preferred.
WHOLE HOUSE WATER FILTRATION FOR OTHER CONTAMINANTS
Other contaminants found in New England well water include Radon and Arsenic. A water softener will not remove these health threat contaminants. Radon in water is safely removed with an aeration system that agitates the incoming well water, releasing the gas from the water in a sealed chamber. This gas is then safely vented to the outside ambient air.
Arsenic in water can be removed at the point of entry into the home by installing tanks filled with arsenic specific resin that captures the arsenic before it can get into the home’s water supply. Point of use systems for drinking water can use reverse osmosis technology to effectively remove arsenic as well. Speak to a water treatment professional to decide which system is right for you.
In addition to the above systems described, there are many other types of systems to remove bad tastes & odors, sediment and many other objectionable minerals and contaminants in the water. Starting with a water test will dictate the right approach.
H2O Care, Inc. is an established full service water filtration and testing organization, originally formed in 1989, based in Middleton, MA on route 114 with over 9,000 systems installed & serviced. See our written and published articles in Water Technology Magazine by going to our website, http://h2ocare.wpengine.com and going to the publications tab at the top of the home page. Contact us by email at [email protected] or call us at 800-539-1100.