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WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER CONSERVATION MEASURES
WATER CONTAMINANT LEVELS
WATER FILTERS, HOME USE
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
Water odors & smells:
This article discusses how to identify, diagnose, and cure common odors that may be present in drinking water.
We also discuss which of these odors may warn of unsanitary conditions.
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Scott Bradley, Aquacheck Water Testing Laboratory
Although water as a pure compound, H2O, is colorless and odorless, contact with the earth's minerals and our distribution pipes may impart some flavor and odor characteristics.
The Threshold Odor Test Method
A subjective analysis called the Threshold Odor Test, number 2150b. in Standard Methods for the Examination of Water and Wastewater, 19th ed., can give us an idea of the strength of the odor as compared to controls of varying degree of odor concentration. But how do you interpret what the underlying problem is when your water has a peculiar odor?
Sulphur Odors in Water
Some odors are a little more insidious and require a bit of background knowledge to deal with them effectively. If your source water runs through an area where naturally occurring sulfur is present, some sulfur may dissolve into the water. We provide a diagnostic procedure to track down the source of sulphur smells in water just below.
Some of this dissolved sulfur turns to the gas, hydrogen sulfide, and this can give the water a rotten egg type smelly odor.
Sulphur odors can also be caused by a failing hot water heater component, or by certain bacteria in the building plumbing system, conditions we also discuss below.
Sulphur smells in water can also occur in rivers, lakes, streams, ponds, and can be caused by anoxia and algae which in turn may be caused by high nitrogen from agricultural runoff - a condition we discuss
Causes of other odors and smells in buildings (not just in building water) are discussed in a series of odor diagnosis articles which are listed at MORE READING found near the end of This article .
Since sulphur or "rotten egg" odors in drinking water are a very common complaint we'll look at this case next, continuing this article
We provide a detailed list of sewer and sulphur gas odor sources
Question: My client complains of a "certain smell" in her water but she can't identify it
I've got a client whose weekend home I inspected in 2005. They now have two young children and she's complaining about a "certain" smell in her water. She can't identify the smell.
Rotten eggs? No. Oily? No. Chemical? No.
But she smells it on herself and on her children after a bath or shower and says her skin fees dry after a shower.
Another twist. They've got two wells. They switch from one to the other when one gets dry. This home is in Ancramdale, NY 12503, Columbia County. Pretty rural. Lots of farming and sheep farming, I think.
The client wants me to test both wells. But I'm not confident that any generic water tests will do the job in this case.
I've looked at these two pages and I've got Smith Lab's price sheet in front of me and I think I'm in over my head.
I mean, this could cost them over $1,000 in lab fees alone for the two wells.
Any suggestions? - Arlene Puentes, ASHI
Reply: Starting Point for Chasing Down Unidentified Odors in the Water Supply
Who smells the odors?
Watch out: methane odors in a building water supply can be explosive (METHANE GAS SOURCES)
Continue reading at WATER ODOR DIAGNOSIS - SULPHUR or select a topic from the More Reading links shown below.
Suggested citation for this web page
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
Question: dead rodent smell in municipal water supply
I have been searching the internet and haven't had any luck finding an answer to a question I have, so I hope that you can help. My family and I just returned from a 2 week stay at my mothers and when I turned on the cold water tap to brush my teeth I noticed a strong dead mouse (or rodent) smell coming from the cold water only. We live in a suburban area with town water which is filtered with a kinetico whole house filtration system with water softener.
I checked the water system and it seems to be working fine and no dead animals are to be seen in the salt container. My question is: is there a way for animals to get into the water line and die? seems kinda impossible, but I can't seem to figure out why our water would be smelling this way otherwise. Plus it maybe dangerous for our health if it is in fact a dead animal in our water supply. thank you for your help and I hope you can get back to me soon. - S.S. 1/5/2014
Reply: steps in tracking down a dead animal smell in drinking water
As the building is served by a community water supply, the chances of an animal inside the water supply are rather low or obscure; chances of a dead animal in your piping are also unlikely as one would expect a mouse or larger to block water flow - typically building water piping is 1/2 or 3/4" inside diameter, and an opening that would let an animal of any size in would also be a huge leak out - one likely to be observed. More likely there is a piping, water treatment or water pressure tank issue (if the building uses a pressure booster tank) - such as bacterial growth in the plumbing system.
Often "dead animal" smells are a sulphur like odor or "rotten egg" odor -
WATER ODORS, CAUSE CURE should be helpful, as might
If you indicated the odor were in hot water supply only I'd suspect an anode failure or bacteria in the hot water tank.
Indeed when a building is served by a private well, it is possible, depending on well construction, for an animal to enter and die therein; to be sure the water is safe to drink in such cases the occupants should discuss their observations and concerns with a water testing company and then have the water tested for potability.
Question: Halo water purifier - now rotten egg smells
(July 14, 2014) firstname.lastname@example.org said:
Indeed any water treatment equipment can flip into an odor generator if it becomes contaminated - e.g.with bacteria. Start by cleaning and sanitizing the equipment that you suspect.
Also double check that there is not a sulphur odor in the incoming cold water or a sulphur odor coming from the water heater.
See SULPHUR & SEWER GAS SMELL SOURCES - live link just above
Question: new carpets, weird chemical smell, blamed on toilets
(July 20, 2014) M.Bradley said:
Several weeks have gone by and still get that smell when showers are on- occasinally when running washer machine, or by toilets- but just occasional.( smell inensfies some if you use bleach etc in washer or clean toilets. We replaced gas water heater based on plumbing company thinking it was water heater/annodes ec. put a new tankless in. They said it may take a while for lines to clean out. Been 2 weeks. They came by and took a water sample from hose bib- trying to wait for that. House is 11 years old and only owner. I have read off- gassing of new carpet in rare circumstances have been associated with this when humidity from shower/ gassing odors in air? ,
Can you have a methane smell with out the rotten egg smell? This started when they busted the tile flooring upstairs bathroom, layed new hardy layer, then tiled. They had their commercial crew doing work because they were busy- I did noticed it seemed like they guys was being very aggressive busting out tiles for house bathhoom.
We had a leak company come out to do a smoke test- he had his guy look around the house- thought the main guy would be more hands on- he just smelled the water from the showers and said to maybe get water tested. None of my neighbors have this issue.
Reply: tips for more successful track-down of source of smells in a building or in water or plumbing systems
Your note is a good (but frustrating) example of the difficulty of tracking down odors and smells - we've tossed so many possibilities into the pot that it's as confusing as heck. Let's try to sort some things out and figure how to proceed:
Carpet off-gassing may produce a chemical smell but would be strongest in the rooms where the carpet and padding were installed and would not particularly relate to toilets, open drains, or water odors.
Sewer gases may smell like rotten eggs or sulphur as do some other odor sources such as LP or natural gas leaks or sulphur in a water supply.
Using an odor log or diary may help you sort out the complaint.
Also see this checklist
Odors in a hot water supply that smell like sulphur may be from a bad water heater anode, bacteria in the water tank, or water contaminants.
Odors in a cold water supply that smell like sulphur most likely come from well water high in sulphur.
Methane could be present from a gas leak: if your home has natural gas or LP gas fueled appliances that's something to check using soap solution or a gas detector and a detailed inspection.
Taking note of when and where odors appear, relating them to operation of equipment or fixtures or other events & equipment can help track down the smell.
(July 21, 2014) Anonymous said:
Water conditions can change in the ground or in water equipment, even a water heater. Changes in the aquifer, a drop in the water table for example, can change well water chemistry by sending different water sources into a well. Nearby mining or fracking or even well drilling or blasting can also have this effect.
Sulphur odors in wells are sometimes seasonal as water table level crops in dry season.
You probably will need to install a sulphur odor water treatment system.
Question: acetone odor in water?
(Oct 17, 2014) KAREN VAN ESSA said:
There has been no construction in my rural neighbourhood, the nearest house is 500 feet away, and the only industrial site is a car wreckers/body shop about 1/2 a mile away whose owner is semi-retired.The land has not been farmed for at least 25 years. What could be the source of this volatile? Could it be natural? Is it dangerous? (this is a mainly wooded area with small streams and ponds) (PS Sorry, initially posted in wrong section)
try the diagnostic suggestions at WATER SMELLS or ODORS, OTHER as well as another water test
Question: rotten egg smell in very soft water
21 January 2015 Carol Gordey said:
We don't drink this water,use it for boiling on stove for cooking,has a h2s smell,like rotten egg,very soft water. We live on acreage,with well ,lots of gas wells and flare stacks, have 3 bathrooms,only one when flushed has that very bad smell.can this water and smell give problems with health issues
In the More Reading links just above see the article titled WATER ODOR DIAGNOSIS - SULPHUR for diagnostic and cure suggestions for the rotten egg smell you desribe.
Whether or not the rotten egg smell is also unhealthy depends on just what is causing the odor. Sulphur in water may be obnoxious but is not itself necessarily unhealthy, while in contrast, if odors are traced to sewage contamination that's obviously unhealthy.
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