Water that Smells

My Water Stinks! What Can I Do?

First, you must learn a little about your nose: Once you smell some things, your sense of smell is dulled for a short while, and you can't make accurate judgments of smell. For instance, if I blindfold you, let you smell gasoline, hand you a piece of onion to eat and tell you it is an apple, you can't tell it's not because your nose isn't working properly!! (Your sense of taste isn't working either -- smell and taste are closely related and affect each other!)

So, to correctly analyze your problem, you need to become a detective. The best time to locate the smell is after you have been away from home for a few hours -- this allows your nose to become sensitive to "that smell" again. With your 'sensitized' nose, go to an outside spigot -- one that the raw, untreated water flows from. Turn it on, let it run a few minutes, then smell it. If it smells -- we found it. If not, we must look further. (Many, many smells are not in the raw water at all, they are introduced into the water inside the house.) Go to a cold, treated water spigot inside the house, turn it on and let it run a minute; then smell. If this water smells, and the outside, untreated water didn't -- you must have a device (cartridge filter, water softener, etc.) in the water line that needs to be cleaned and sanitized.

If it is a cartridge, or 'string' filter, replace the element and sanitize the housing. If you have a water conditioner call the Company where you bought the unit for advise on how to sanitize the unit. If you rent the unit, just call! You can sanitize the unit by pouring Hydrogen Peroxide or Chlorine Bleach in the brine well of the salt tank, and placing the unit into regeneration. Check with the seller, or, if they are no longer in business, any Professional Water Conditioning Dealer for how much to put in your particular unit.

If the cold, treated water inside didn't smell, turn on the hot water and let it run a few minutes -- does it smell? If it does, chances are you have a sacrificial anode inside your hot water heater that is "coming apart at the seams" and throwing off a "rotten egg" odor. This obnoxious smell will drive you right out of your shower! The only solution is to remove the anode from the heater, voiding your warranty, or replace it with a new one made with aluminum alloy. This anode is placed in a (glass lined) hot water heater to seal up any cracks in the glass lining and prevent corrosion of the heater tank. You will find the anode on the top of the heater; remove the tin cover and insulation -- look for what looks like a pipe plug -- about 3/4 inch in size with a 1 1/16"fitting. Turn off the heat source and the water; have someone hold the tank to prevent it from turning, and unscrew the "plug". You will find that the 'plug' has a 30 - 40 " long pipe (or what's left of one) attached to it. Hopefully, most of the rod is still attached -- just corroded. If so, replace the plug with a real pipe plug and throw the anode away. If part of the rod has corroded off, and fallen into the heater, you may have to try to fish it out. Either way, before you plug the hole, pour about 2 pints of chlorine bleach into the heater first. This will kill the smell left in the heater. If, after a week or so, the smell returns, you must fish out the rod that is in the bottom of the tank. Good Luck!

OK, It's my Raw Water That Smells -- Now What?

First, you must determine what is causing the smell, and how strong it is.

Minor, musty smell

If it is a minor, or low-level smell, you MIGHT be able to solve it with a small, point-of-use carbon filter. You can place these types of filters on the water line going to the cold water where you draw you drinking water. Or, you might solve it with a whole-house filter on your incoming water line to filter all of the water inside your home.

Because carbon removes smells by ADsorbtion, ie, the smell "sticks" or "adheres" to the carbon particles, you must be careful not to exceed the manufactures recommended flow -- some filters even have a flow restriction built in them. If you run water through them too fast, you will not remove the smells. Whenever you place a carbon filter in your water line, you must be sure to replace the element and sanitize the housing on a regular basis. Carbon filters remove organics from water, and the bacteria found in water like to eat organics -- the carbon filter is a nice, dark place, just full of food for them to grow and reproduce in. Regular and routine replacement will help prevent any buildup of bacteria in the cartridge.

Strong, rotten-egg smell

Strong, rotten-egg odors in the raw water is usually the result of the decomposition of decaying underground organic deposits. As water is drawn to the surface, hydrogen sulfide gas can be released to the atmosphere. In strong concentrations, this gas is flammable and poisonous. It rapidly tarnishes silver, turning it black. It is toxic to aquarium fish in sufficient quantities. As little as 0.5 ppm hydrogen sulfide can be tasted in your drinking water.

Strong, musty smell

If you are unlucky enough to have this problem, you should look for a company that has local experience in dealing with this problem. There are three basic ways to solve this problem for homeowners.


Installation of a whole house filter loaded with a media that is specific for hydrogen sulfide removal is successful many times. These types of filters must be recharged with chlorine or potassium permanganate. The removal capacities of these types of filters are usually fairly low, and must be sized to contain enough media to prevent premature exhaustion, and subsequent passage of the smell to service. It is also typical that the amount of hydrogen sulfide can fluctuate rapidly, causing great difficulty in sizing the unit. In addition, potassium permanganate is extremely "messy", and will leave stains that are very difficult to remove.


Feeder systems consist of a small pump that injects small amounts of chlorine (usually) into the incoming water. The water must then be held for a short period of time to allow the hydrogen sulfide to precipitate out of the water. This tank should be designed in such a manner that the water that enters it will mix thoroughly with the water in the tank, to assure complete reaction. The water then should pass through a filter to remove both the precipitated matter and the chlorine remaining in the water. You should be aware, however, that whenever you mix chlorine with organic materials (remember where hydrogen sulfide come from!), the chances are very high that trihalomethanes (possible cancer causing carginigns) will be formed. Also, feeder maintenance is high, you should be prepared to "play" with the unit frequently.


Aeration consists of breaking the incoming water into small droplets (spray) into the air, drawing fresh air through that spray, collecting the water into a storage tank, repressurize the water, passing it through a particulate filter to catch any particles that might be carried out of the storage tank. The air drawn though the spray must be vented outside the house -- remember, it is toxic and explosive. Although this system necessitates another pump to repressurize your supply, you are not adding any chemicals to your water, which makes it attractive. This system is low maintenance and no chemicals to purchase. Initial cost may be higher, however, and space requirements may be greater.