Do some research for yourself:

Fluoride Action Network
The Fluoride Deception

Then consider contacting the city regarding your water supply. The city of Monroe, according to their 2007 water quality report, adds fluoride to the water supply.

Chlorine is then added for disinfection
(we carefully monitor the amount of chlorine, adding
the lowest quantity necessary to protect the safety of
your water without compromising taste). At this point,
the water is filtered through layers of fine coal and
silicate sand. As smaller, suspended particles are removed,
turbidity (an optical quality of the water) disappears
and clear water emerges. Finally, fluoride (used to fight
tooth decay) and a corrosion inhibitor (used to protect
distribution system pipes) are added before the water
is pumped to sanitized, underground reservoirs, water
towers, and into your home or business.