More than 2 million Americans live in residences without tap water or flushing toilets, says a new report—and Native Americans are the group most likely to be without them. 

The report, “Closing the Water Access Gap in the United States,” was conducted by the US Water Alliance and DigDeep, a nonprofit that has helped to build water systems for the Navajo Nation. It was released today (November 18) and concluded that race is the strongest predictor of water and sanitation access. Per NPR:

Fifty-eight out of every 1,000 Native American households lack plumbing, compared with three out of every 1,000 white people, according to the report. This disparity has implications for public health. They experience more deaths, poverty and higher unemployment rates.

The report was conducted after DigDeep founder George McGraw learned that there was no conclusive, national data on water access. “No one could tell us, from federal to state agencies to other nonprofits, just how many Americans still don’t have running water or a working toilet where they live,” he told NPR about why he commissioned water experts from across the country to pool their information to create the report.

On the Navajo Nation, the report found that some groundwater has been contaminated by the presence of 521 abandoned uranium mines. In addition, gastric cancer rates doubled in the 1990s in locations near the mining sites. According to the Indian Health Service, it would cost an estimated $200 million to provide basic water and sanitation access to the Navajo Nation.

“Our nations didn’t have access to funding for infrastructure in the same way that it’s federally allocated for cities and states overall,” Mahrinah von Schlegel, an anthropologist from New Mexico’s San Ildefonso Pueblo tribe, told NPR. “It’s been a struggle, one, to get the access to that infrastructure capital, and then, two, it’s really expensive to develop some of these remote areas.”

While an estimated 2 million people do not have water in their homes, over 44 million Americans get water from systems that were recently in violation of the Safe Drinking Water Act, reports NPR.

Read the entire report here