When water flows out of the faucet and into a glass, it usually appears clean and healthy. A report released Wednesday, though, found hundreds of harmful contaminants across the American water supply that can cause cancer, developmental issues in children, problems in pregnancy and other serious health conditions.

In Maryland, 10 contaminants in drinking water were found to be above health guidelines, while five are above legal limits. "There are chemicals that have been linked to cancer, for example, that are found above health-based limits, or health guidelines, in the water of more than 250 million Americans," said Nneka Leiba, director of Healthy Living Science at the Environmental Working Group (EWG), an independent nonprofit organization that released a detailed account of the contaminants.

In conjunction with outside scientists, EWG assessed health-based guidelines for hundreds of chemicals found in our water across the country and compared them to the legal limits. (SIGN UP: Get Patch's daily newsletter and real-time news alerts, or like us on Facebook. Or, if you have an iPhone, download the free Patch app.

These contaminants are above health guidelines in Maryland, according to the report:

Chromium (hexavalent), which is linked to cancer, liver damage and productive system damages

Total trihalomethanes (TTHMs), which are linked to bladder cancer, skin cancer and fetal development issues

Radium-228, which is linked to cancer

Bromodichloromethane, which is linked to harm to child and fetuses, as well as reproductive difficulties

Chloroform, which is linked to cancer and fetal development issues

Dibromochloromethane, which is linked to cancer and harm to fetuses

Radium-226, which is linked to cancer

Chlorate, which impairs thyroid function

Perfluorooctanoic acid (PFOA), which has been linked to cancer, endocrine disruption, accelerated puberty, liver and immune system damage and thyroid changes

Arsenic, which has been linked to cancer These contaminants were detected above legal guidelines: Total trihalomethanes (TTHMs), which are linked to bladder cancer, skin cancer and fetal development issues

Arsenic, which has been linked to cancer; brain damage; central nervous system damage; skin damage, heart and blood vessel changes; and increased risk of stroke, heart disease and diabetes

Radium-226 and Radium-228, which have been linked to cancer

Nitrate, which can cause oxygen deprivation in infants and increase the risk of bladder cancer

"There are more than 250 contaminants across our nation's drinking water," Leiba said. "About 160 of those are unregulated. And that's a big concern, because if a chemical is unregulated, that means it can be present in our water at any level — and be legal." Most of the water in the United States comes from local utilities that measure contaminants in their water supply, but this data can be difficult to obtain.



Contaminants in your water: EWG has released a public database cataloging contaminants in water systems in every state in the country — the first comprehensive database of its kind that took two years to build. First select the state where you live, and you'll see state-level data. For more local information, enter your zip code.

After you enter your zip code, you'll be directed to a page showing the water utilities in your county. Select your town to see which contaminants put your families at risk. What You Can Do