The water crisis in Flint, Michigan, reminded the nation that dangerously contaminated water is a very real problem today—especially when it comes to poor communities of color.

But which communities are in danger of becoming the next Flint? A new report from WIRED argues that no one really knows.

Published today (June 23), it sheds light on the lack of available data on lead levels in water and in the blood of children around the country. If a parent wants to find out if their town’s water is contaminated with lead, there is no system in place to collect that information. And given President Donald Trump’s severe budget cuts to the EPA, the agency in charge of regulating and detecting such incidents, finding out may become harder.

Reports like this one from CNN in 2016 offer tips and guidance on how a resident can contact the local water supplier about their home’s water, but the manslaughter charges levied against officials in Michigan show that correct information doesn’t always make it to the people who need it.

And in some places, the WIRED report argues, the data doesn’t even exist. “The data gaps are so huge. It is abominable. We have a huge number of people in this country living completely in the dark,” Eric Feigl-Deng, an epidemiologist at Harvard University and founder of the public health site ToxinAlert.org, told WIRED.

For example, a system that serves 90,000 people may use a sample of just 60 taps to determine lead levels. “Would you really rely on a sample of 100 people in New York or Boston?” Feigl-Deng says. “In no universe is that going to give you a statistically significant result. That’s just ludicrous.”

One expert suggests that a system that integrates GPS might allow people to monitor their own home’s water. But current regulations puts regulation authority in the hands of the states. Only about 30 states consistently provide the Centers for Disease Control and Prevention with children’s blood lead levels.

Read the WIRED story in full here.