Odoriferous Water

Q: For years we drew water from the lake without any problems. Recently, during a rebuild, we had a new well sunk. The water is clear, cool and great tasting, but we find that frequently, from the two bathroom sinks (one main floor, one in the basement) there is a distinct sulfur smell from the water when the tap is turned on. Can you help?
– Les Hauck, Harrison, Maine  

A: There are many things in drinking water besides just hydrogen and oxygen. Some of the extras are beneficial, some benign – and a few are harmful. Assessing the quality of your well water can be daunting for those of us who aren’t Ph.Ds in chemistry. But take heart, Les; that unpleasant smell coming from your taps is most likely an aesthetic problem and there are ways to take care of it.

According to Max Burns in his book “Cottage Water Systems,” there are two main ways water develops that rotten egg smell. The first is through the presence of iron bacteria or manganese bacteria, two nonharmful  microorganisms. The bacteria occur in water that contains iron or manganese that is oxidizing which can turn the water a reddish brown and stain the sink and toilet bowl.

If there is no staining, perhaps the source of the smell is hydrogen-sulphide gas released from vegetable matter that is composting in the water. To throw another variable into the mix, it would also be possible to have composting vegetable matter that contains tannic acid (likely to appear in wells near swampy areas or coniferous trees), which could color the water and stain fixtures.

So what should you do? One approach Burns recommends for bad smelling water is activated-carbon filtration. An expensive tank filter could take care of the problem systematically, but so could the inexpensive kind that you usually see as a dedicated drinking line running next to the tap. (Skip the ultra cheap kind that simply clip or screw onto the end of your tap.)

If you do begin to notice the kind of discoloration that results from iron bacteria and/or manganese bacteria or tannic acid, your options are distillation, chlorination – an effective bacterial eradicator that has numerous environmental downsides – or a manganese greens and filtration system.

If you want to know for sure what’s coming out of your taps, have your water professionally tested.