For years, the water at one of Massachusetts' largest prisons — MCI-Norfolk — has been described by prisoners as smelly and looking like black tea.

Massachusetts Department of Correction officials say the water meets state standards for potability. But they acknowledge there's a problem in at least some of the samples collected from the prison's well: elevated levels of the mineral manganese, which can cause health problems including a Parkinson's disease-like neurological disorder.

DOC is constructing a $5 million water treatment system at the prison, which is slated to go online in May. The state Department of Environmental Protection ordered DOC to install the system and later said it would fine DOC because of delays.

A DOC spokesman, Christopher Fallon, says delays in constructing the treatment system were due to funding issues and the project bidding process, and no fines were assessed.

In the meantime, a coalition of prisoner advocates, called Deeper Than Water, has formed. It's been raising money for MCI-Norfolk prisoners to buy cases of bottled water from the prison commissary and distribute it.

"People in the community shouldn't have to be put in a position to raise funds to provide water for people incarcerated in our state prison system," says Greg Diatchenko, who served almost 30 years at MCI-Norfolk for murder and was paroled in 2014. "You're in the care and custody of the Department [of Correction], they're supposed to provide health care, dental, nutritional food. Anywhere, people will tell you that you need clean drinking water to survive."

"The folks inside are human, you know? And so they deserve the basic human rights that we all have out here, too," adds Christine Mitchell, a Harvard doctoral student in public health and member of Deeper Than Water. "We know [DOC has] the money and the resources to provide clean water, and they haven't done it."

Coalition members say their efforts to distribute bottled water hit a snag because a prisoner who was handing out the water, Wayland Coleman, was put in solitary confinement last week for doing so.

Fallon, the DOC spokesman, says state law prohibits him from discussing whether any inmate was placed in solitary confinement, but adds, "I can tell you generally that no one would ever be placed into segregation for hoarding water." He says there would have to be more extenuating circumstances, such as refusing orders to vacate an area or attempting to incite other prisoners.

According to Fallon, many outside groups work with the prison administration to distribute items such as socks, toiletries and holiday care packages to prisoners. He says advocates should have worked with prison officials to do the same thing with bottled water.

"We can't allow an inmate to have power over other inmates and say, 'I'm going to be the one' " to distribute an item, Fallon says.

Mitchell says she and other members of the advocacy coalition wouldn't have trusted prison administrators to distribute bottled water, because they haven't taken care of the water problem for years.

Coleman's family tells WBUR he was released from solitary confinement Friday.

You can listen to our All Things Considered conversation with Diatchenko and Mitchell via the audio button atop this post.