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Want to know what hazards might be lurking in your local water supply? An updated online database launched today by the Environmental Working Group, a research and advocacy organization, provides some answers.

The online resource is known as the EWG’s Tap Water Database. It lists contaminants as well as their levels and likely sources, and any federal drinking water violations by local water utilities. Consumers, after typing in their zip code, get a detailed analysis based on testing from 2010 through 2015.

That information surpasses what is available in the federally mandated Consumer Confidence Reports issued by water utilities annually. Those reports, for example, are required to identify only regulated contaminants found in drinking water.

The EWG database, in contrast, identifies more than 160 unregulated contaminants —- including solvents such as acetone and chloroform -— routinely found in drinking water but not subject to federal standards.

The aim is to make a complicated array of information “easy and more personal for people to look at, and for them to understand what it all means,” said Sonya Lunder, a senior analyst with EWG who helped put the database together.

“So many people rely on smell and color and taste as an indicator of water quality,” Lunger said. The database “is a necessary reminder that there are a lot of contaminants that are invisible, and don’t have a taste or an odor.”

The EWG database also goes beyond the federally mandated annual reports by comparing contamination levels not only to national and state averages, but also to government health guidelines. Lunder explained that national and state averages often exceed advisory health guidelines and that even legally permissible levels of contamination can be unsafe.

EWG took two years to build the website, pulling data from 28 million records from nearly 49,000 local utilities, along with state environmental agencies, the U.S. Environmental Protection Agency and the agency’s Enforcement and Compliance History Online database. Each utility had the opportunity to review its data. Authorities tested for 500 contaminants in all, and detected 267 in one or more cases.

The database highlights environmental health disparities between the nation’s wealthiest and poorest communities. The California Water Service Company serves 115,000 people in the East Los Angeles area, whose median household income was more than 20 percent below the national average according to the latest available numbers. During 2015 in the service area, 14 pollutants tested above advisory health guidelines.

Compare that to the New York American Water system serving the Long Island, N.Y., hamlet of Merrick, where the median household income was nearly three times the national average. Only one contaminant was detected above health guidelines in 2015.

California Water Service representative Yvonne Kingman said the East LA water system isn’t in violation of any mandatory federal or state water quality standards. “Protecting our customers’ health and safety is our highest priority, and we will work tirelessly to ensure their water continues to be safe to use and drink,” she wrote in an email to FairWarning.

The database also provides information on home filtration systems, which are more effective when they are designed for the specific contamination hazard threatening a community. For example, carbon-activated filters can get rid of contaminants such as asbestos, lead, and mercury, but reverse osmosis technologies should be used when the problems are inorganic compounds like arsenic and nitrate.

Philip Landrigan, a professor of environmental health at the Icahn School of Medicine at Mount Sinai in New York, called the database another “step forward.” He lauded it for putting “information relevant to public health into the hands of consumers” and for providing “comprehensive information that’s easily accessible 24/7.”

Simon Fraser University professor Bruce Lanphear, an expert in childhood exposure to environmental neurotoxins, agreed that the database is a crucial tool. “Few things are more essential than clean water,” he wrote in an email. “The EWG database throws a bright light on the failure of the EPA and water authorities to provide Americans with safe drinking water.”

But Diane VanDe Hei, chief executive of the Association of Metropolitan Water Agencies, said the database doesn’t address the problem of contaminated waterways that provide drinking water. “Data collected from streams and rivers that serve as sources of drinking water would provide a much better indicator of pollution levels and the need for source water protection,” she said in a written statement.

An EPA spokesperson said in an email that U.S. drinking water remains “among the safest” in the world and added, “We take our commitment to protecting public health seriously and when issues arise, we work closely with states, local governments, and water suppliers to review and address, as appropriate.”

The EWG project received funding from four foundations with a history of supporting water programs: the Park Foundation, founded by the late media mogul Roy H. Park; the McKnight Foundation, a Minnesota-based family foundation; the Walton Family Foundation, which was established by the family that founded Walmart; and the Pisces Foundation, which focuses on environmental education.

This is the second time EWG has put together such a database. The first one provided data from 2004 through 2009.

About FairWarning

This story was reported by FairWarning (, a nonprofit news organization based in Pasadena, Calif., that focuses on public health, safety and environmental issues.