District Judge Keith Ellison said the low security facility which only holds elderly and sick inmates should replace its water supply within 15 days.

But a spokesman for the Texas Department of Criminal Justice said they plan to appeal the ruling.

Prison officials have known for ten years that the prison water’s arsenic content registers between two and four-and-a-half times the amount permitted by the Environmental Protection Agency.

However, they say the levels aren’t lethal or likely to cause harm.

A prison engineer said they would rather continue with plans to install a new filtration system within a year or so.