Al Pierce of Consolidated Technologies Inc. spoke to the City Council Monday night about the issue.
The state tested well water a week ago, Pierce said.
The state has a mandate to check if surface water has gotten into the water system,” he said.
"Microscopic evidence has been proven that ground water has been getting in the well," Pierce said. "They would like us to look for some type of treatment facility."
Meanwhile, Chickamauga can still produce good drinking water, he said.
"We have 18 months to put in a new treatment facility," Pierce said. "It could be pressure filters, cartridge filters or membrane filters. We may have to put it in a separate building."
City Manager John Culpepper said the water is clear, and if the city had been in the old location the water would have been much worse, he said.
"Limestone formations are good for holding underground water, but there are fissures that can be a problem," Culpepper said. "Cartridge filters to fix the problem are approximately $70,000 for installation, engineering and purchase of equipment."
Any groundwater source will eventually be contaminated due to limestone, he said.
Pierce said the council will know on Wednesday what type of equipment can do the job.
"We are not talking about building whole treatment plants," Pierce said. "We have one offer to supply equipment for almost nothing. For the next few months this topic will be discussed at all Chickamauga Water Authority meetings."
"We have an excellent water supply, but we need to make adjustments to it,” Culpepper said