LITTLE ROCK — The Arkansas Health Department has found that water at some state prisons doesn’t pose any immediate health risks after investigating complaints of brown and dirty water.

Water quality experts have deemed the water safe, saying the color is likely due to high levels of iron and manganese.

But one researcher who analyzed the state health agency’s prison inspections raised concerns that the reports are inconclusive because of the lack of samples taken from taps in prisoners’ barracks.

“We are unable to say anything about the quality of the water that is consumed by the prisoners since the data sheets do not indicate that any samples were collected at the taps accessed by prisoners,” said Wendy Heiger-Bernays, a Boston University researcher who reviewed the reports.

Families and former inmates expressed worry over prison conditions, such as dirty water, at a hearing with lawmakers in July.

Health Department inspection reports show concerns about iron levels in the raw well water at the East Arkansas Unit, and iron and manganese at the Tucker Unit. Two other prison water systems at Cummins and the North Central Unit showed no concerns.

The levels of iron and manganese acknowledged in the reports don’t pose an immediate sanitary risk for inmates, according to experts.

Iron levels at the Tucker Unit water treatment plant were measured at 2.25 and 1.44 milligrams per liter, which is well over the federally established maximum limit of 0.3 milligrams per liter. Measurements of manganese at the unit ranged from less than 0.02 to 0.04 milligrams per liter, above the 0.01 milligram federal limit. The samples were taken in May and June.

The limits set by the U.S. Environmental Protection Agency are part of “secondary maximum contaminant levels,” which are not enforceable by the agency. Violations of secondary standards may cause people to stop drinking the water due to smell or taste, “even though the water actually safe to drink,” according to the EPA’s website.

The Department of Correction has a $500,000 project underway to add filtration capacity at the Tucker Unit, said agency spokesman Solomon Graves.

“The current water supply at both the East Arkansas Regional and Tucker Units continues to pass safety tests by the Arkansas Department of Health,” he said in an email. “It remains safe for drinking, cooking, bathing, etc.”