Removing these important but dangerous chemicals from your water is really quite simple. It is accomplished by passing the chemically treated water threw a bed of activated carbon.

What is Activated Carbon?
Activated carbon is a form of carbon processed to be riddled with small, low-volume pores that increase the surface area available or absorption or chemical reactions. The porosity within activated carbon imparts this characteristics of adsorption.
Activated carbon is made from hardwoods, coconut shells, fruit stones, coals, peat, petroleum coke, and synthetic macro-molecular systems
Contaminated water simply flows threw the activated carbon and the carbon's absorption extracts the dangerous chemicals from the water and holds it within itself.
It is Very Important to replace the activated carbon at regular intervals. This must be done regardless if the activated carbon looks clean. Remember... Dangerous chemical residue has been collecting in the activated carbon bed. You can not see this build up with your naked eye.
If you neglect to maintain your filter, the activated carbon will become full and eventually become a source of contamination.