STILLWATER (AP) — State health officials have said that the drinking water at a Minnesota prison is safe after inmate and advocate concerns over the water’s quality prompted a new round of tests.

The analysis “did not find indications of a health risk from the drinking water,” according to the report from the Minnesota Department of Health. But the report also noted that brown water at hot water taps, like where inmates shower, “can indicate degradation of water quality in the building.”

About 100 inmates at Minnesota Correctional Facility-Stillwater refused to return to their cells on Sept. 3 amid dangerously high temperatures in the region.

One former inmate called it an act of “self-preservation.”

Advocates have conveyed a long list of unsafe conditions, including what they said was brown-colored drinking water, excessive heat and limited access to showers and ice during on and off lockdowns over the past two months.

The lockdown on Sept. 3 was the result of staffing challenges, which the Department of Corrections and the union of corrections officers both acknowledged. But the department also said at the time that the claims “about a lack of clean water in the facility are patently false.” Additional tests were ordered about a week later.

The case in Minnesota is one of many across the country where concerns have been raised about water quality at prisons endangering the health of people who are incarcerated, along with persistent understaffing, curtailed family visitations and rehabilitation programs, and the spread of diseases, including COVID.

The department’s statement then and the health officials’ report Wednesday did little to alleviate the concerns in Minnesota.

“People have been saying it’s OK for a decade,” said David Boehnke of Twin Cities Incarcerated Workers Organizing Committee. “We really do need an independent testing of this water, and that’s what we’ve been asking for from the beginning.”