Ask A Scientist Chemistry Archive

name         Lavonne
status       other
grade        other
location     AR

Question -   My husband and I own a ranch property in the Ouachita
Mountains of Arkansas.  We recently had a new well dug and are having
serious problems with the sulphur smell.  The cold water does not seem to
smell as bad, and it tastes okay, but the hot water smells horrible.  My
father-in-law says it is the copper heating element in the water heater
and we need to get a glass-lined water heater.  Is it possible this could
help?  Any other ideas would be greatly appreciated!
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    The web sites below will provide you with an understanding of your
"sulfur water". The fact that the hot water is more highly affected
suggests hydrogen sulfide producing bacterial infestation in your water
heater -- this is mentioned in the documents below. I doubt that the
copper heating element is the cause, because copper reacts readily with
hydrogen sulfide to form insoluble CuS. Also if the origin of the
odor/taste in the hot water is bacterial, a glass-lined water heater 
will not offer any long term solution.
     Now possible solutions: One reference suggests periodically increasing
the temperature of the water heater to sterilize the water heater.
Personally, I would be reluctant to do that on my own. You are talking about
creating 50-100 gal of water at about 170-190 F. Should a pressure valve
release you could have a potential for scalding. In my opinion that should
be left to a professional. Chlorination of the water will oxidize the H2S to
sulfate; however, you may introduce a "chlorine" odor in the process. In
addition, chlorination will oxidize ferrous iron (+2) to ferric iron (+3).
The latter is insoluble in water and that introduces iron oxide (rust) into
the water that can cause staining of clothes etc. I think the best solution,
albeit a bit more expensive, is a commercial water treatment unit in the
water line. This has several advantages: 1. It will remove the sulfur odor.
2. It will remove other possibly noxious dissolved substances. 3. It will
assure that the water system is biologically clean.
     I do not have a particular "brand" that I would recommend, but a 
 place to
start is with your county extension service, or the head engineer of a local
municipal water works. http://www.newton.dep.anl.gov/teachers/coop.htm
They have to face this problem frequently. There is
also the American Water Works Association (AWWA). They may have some
literature and recommendations. In any case:  Beware of "magical" cures like
magnets.
     Your sulfur problem is curable, you just have to find the best solution
for your particular water source.
http://www.pureintake.com/hydrogen_sulfide_gas.asp
http://www.newton.dep.anl.gov/askasci/chem00/chem00580.htm
http://www.ext.vt.edu/pubs/housing/356-488/356-488.html

Vince Calder
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