Sewer smell from whole house filter

[Randy]

A client just sent this problem, and I am not sure what the answer is.
I have just moved and installed a granular carbon filter into the drinking water line in the house. After 2 months, the water developed a sewer smell. This was traced back to the filter. I chlorinated and installed a new filter element. After about 2 months, the same thing happened.

I'm on municiple water and the city claims there are no contaminants... What is going on here and how can we protect the water we are drinking???

[Chris]

It sound like the filter is growing bacteria. The instructions for Omni Filters warn that this can happen; I don't know about other brands, but I remember that from the last one I installed.

I think the fix is just to change the cartridge more often. Even chlorinated water has some bacteria in it, and the carbon can act as a growth medium, is how I understand it. I think the sulfer level in the water might have something to do with it, too.

I'd recommend contacting the filter manufacturer and seeing what they have to suggest.

[Gary Slusser]

That's true and why whole house chlorine removal is a bad idea. All carbon/charcoal 'filters' have a warning against installing on water of unknown microbiological content. And yes, all waters have some bacteira in them.

The cure is to remove the carbon cartidge and use POU (point of use) filtration where you want the chlorine removed; such as the shower and kitchen sink. But then... you should worry more about DBPs (disinfection by-products) formed by chlorination than smell and taste problems caused by chlorine. The DBPs are a group called THMs (trihalomethanes) many of which are carcinogens.

Gary
Quality Water Associates

[Chris]

Gary:

Our city water has a bit of a sediment and suspended mineral problem, although the chlorination level is fairly low (according to the pamphlet they just sent me in the mail).

To the best of your knowledge, do string filters have the same bacterial problems as the carbon ones? I just want to keep the sediment out of my water heater, washing machine, toilet fill valve, etc., which seems to dictate a whole house filter.

I haven't had any problems, but hey, knowledge is power.

Thanks

[jadnashua]

The filter may be stopping some algai, too. These can build up and start to potentially rot. A sediment filter may let those pass, but take out the bigger particles, if that is all you are trying to keep out of your system. Most all carbon filters in the fine print tell you to run water for some period of time after they have been sitting unused for awhile to "flush" out bacteria, such as sitting overnight.

Filters are both good and bad things. FWIW, I've been happy with Seagull brand filters. I'm not a pro and don't have much experience with many brands.