Your questions prompted me to do a little homework. It's been a while
since I studied chemistry.

Activated carbon removes impurities by adsorption, not by physical
screening. Organic molecules, including MTBE, tend to bind
preferentially to the carbon. The specific properties of activated
carbon depend on how it's made, so the question is what kind of carbon
to use, and how much. Last September, Calgon Corporation introduced a
carbon filter unit for residential use that is optimized for MTBE
removal. A little pour-through filter like the Brita probably would not
do much, especially because the contamination levels are often only a
few parts per million in the first place, and the recommended limit is
something like 20 parts per billion.

Reverse osmosis is not effective for molecules as small as MTBE
(C4H9OCH3, molecular weight 88). It will, however, remove inorganic
contaminants that carbon won't touch.

Bill Dooley


Michael Audette wrote:
>
>   Will it filter out MTBE? Can you find out from the company if it does?
> When MTBE binds with water, it can flow through the ground water, faster
> than anything. What's to stop it from going through a carbon filter?