CHATSWORTH, GA (WRCB) – Hundreds of people in one north Georgia town are not allowed to drink their water.

The water treatment plant in Ramhurst is temporarily shut down after someone broke in and changed the chemical settings.

It’s affecting about 400 Murray County residents. Local, state and federal officials are investigating who’s to blame. Officials with Chatsworth Water Works say the source of the problems is at the Carter’s Lake Water Treatment Plant in the Ramhurst area.

Saturday workers noticed someone had changed some chemical settings. First, officials issued a “boil advisory” but the Environmental Protection Department bumped it up to a total “do not drink” order and shut down the plant until they’re certain it’s safe for the public to consume. It could be a few more days.

“First thing I thought of was somebody’s trying to kill us, trying to poison our water,” resident Chirstine Forrest said.

And that’s the thought investigators say they have to operate under too.

“When you’re dealing with the public water supply, it’s more than just a prank,” Chatsworth Water Works General Manager Steve Smith said.

Officials say someone tampered with the chlorine and fluoride settings at the Carter’s Lake Water Treatment Plant.

“That could be considered a terroristic act,” Smith said.

The Georgia Bureau of Investigation and the FBI are investigating.

Crews are digging around the well so the Environmental Protection Department can gather samples to test. Until it’s given the all clear, around 400 residents are under a “do not drink” order. Around a dozen don’t have water at all.

“We use water for pretty much everything from cooking to drinking and now we’re not going to be able to,” resident Steven Forrest said.

“They didn’t want us to boil it or anything. I’m paying for this water but I can’t use it. I’m very upset,” Christine said.

Bottles of water are flying off shelves at stores in Ramhurst. At the Dollar General they’re sold out of gallons. The manager says when their supplier came to restock, he was out too.

“Pretty much going to every store from here to Ellijay trying to find water,” Steven said.

Chatsworth Water Works officials say it’s just a precaution and that they’re confident the affected water didn’t get out to customers because initial tests came back negative and a valve was closed.

“If we hadn’t found it, the worst thing that would’ve happened is we’d have burn up some pumps,” Smith said.

Whoever did it got past the barbed wire and no windows or doors are broken. Smith says their employee trucks have trackers on them, and none were near the plant when it happened.

“Former employees might still have keys or access that we don’t know about,” Smith said.

They’ve already changed the locks.

Water officials say the earliest the “do not drink” order will be lifted is Tuesday. For the dozen without water, it will take a few more days to return service, because they’ll have to flush out the system before re-opening the plant.

They say it is OK to bath or wash dishes with the water.