Local volunteers with Water Missions International are providing drinking water to troubled Haiti, which was met with another crisis last week as Hurricane Tomas battered and flooded tent cities — fragile communities built in the wake of January’s earthquake that are now struggling with a cholera outbreak. Based in Charleston, Water Missions is a Christian nonprofit that distributes mobile water-filtration systems to disaster victims and developing countries.

“We have to remember that hundreds of thousands of Haitians are living under pieces of plastic, and even small winds could be devastating,” says Water Missions founder and CEO George Greene III. “The potential for a significant cholera outbreak in these conditions multiplies.”

The group already had 115 systems in Haiti. In advance of Tomas’ landfall Friday, Water Missions sent 20 more water treatment systems to the small country. Each is expected to provide 5,000 Haitians with drinking water.