Editor's Note: This article has been revised to include details on the the Environmental Working Group's methodology.

SCARSDALE, NY — 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.

According to the Environmental Working Group, which produced the study, "The vast majority of the nation's drinking water supplies get a passing grade from federal and state regulatory agencies. However, many of the 250-plus contaminants detected through water sampling and testing are at levels that are perfectly legal under the Safe Drinking Water Act or state regulations, but well above levels authoritative scientific studies have found to pose health risks. What's more, the Environmental Protection Agency has not added a new contaminant to the list of regulated drinking water pollutants in more than 20 years.

"For the levels this database endorses as safe, we relied on the best available science, going far beyond regulations that are too often driven by political compromise with polluters rather than protecting public health," the researchers said. In the communities served by Westchester County Water District #1, nine contaminants aboveEnvironmental Working Group's standards were detected across the district's water supply, according to data from the Environmental Working Group that was released on Wednesday.

EWG notes, however, that tap water provided by this water utility was in compliance with federal health-based drinking water standards in the latest quarter address by the Environmental Protection Agency, which was from January to March 2017. From 2010 to 2015, EWG collected results of tests conducted by the water utility, which was provided to them by the New York Department of Health-Bureau of Public Water Supply Protection, as well as information from the U.S. EPA Enforcement and Compliance History database.

The following contaminants were detected above Environmental Working Group's standards in communities served by Westchester County Water District #1:

Bromodichloromethane

Chloroform

Dichloroacetic acid

Radiological contaminants

Trichloroacetic acid Long Island Water Conference Legislative Committee Co-Chair Paul Granger did not agree with this study. "This report is nothing more than a fear mongering scare tactic for the sole purpose of selling unnecessary water filters," he said.

Read Granger's full statement below: "The premise of this report is patently false and the information portrayed is extremely misleading. This report is nothing more than a fear mongering scare tactic for the sole purpose of selling unnecessary water filters. The water being delivered to our customers is meticulously regulated by federal, state and local authorities on a weekly basis. Under no circumstances would water containing harmful levels of these chemicals, or any other chemical for that matter, come out of our treatment plants and be sent to the public. In fact, water providers publicly release information about their water quality on an annual basis. The authors of this report should be ashamed of themselves for purposely broadcasting misinformation about the safety of drinking water to the public for the sake of selling water filters." "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 EWG.