Chemicals used to treat our drinking water could lead to health problems.
That's according to a report by the Environmental Working Group.
Researchers analyzed 2011 water quality tests from more than two hundred large US municipal water systems.
They found toxic chemicals known as Trihalomethanes in every system.
Trihalomethanes are reportedly a side effect of the process to clean tap water.
Chlorine and other chemicals are added to kill bacteria and other microorganisms.
Researchers say that process creates a family of byproducts they call "toxic trash."
The E-W-G says the chemicals can increase the risk of bladder cancer, birth defects and miscarriages.
The group recommends consumers find out which contaminates are found in their local water supply, so they can buy appropriate filters.