Saint John Mayor Mel Norton said the city wants to explore the idea of turning to well water instead of using lake water. (CBC)

The owner of a drilling company says Saint John will have a hard time finding enough water to serve its population if it wants to switch to a system of wells.

Saint John Mayor Mel Norton announced this summer the city wants to look into converting the drinking water system to wells.

Norton said it could be less expensive to find water underground than continuing with the current system of using lake water.

Well water is cleaner and less expensive to treat, the mayor said.

But, one drilling expert is already raising concerns about the mayor’s proposal.

"Water's getting harder and harder to find,” said Carmen Doherty, who has more than 30 years of experience drilling wells in the greater Saint John area.

Doherty said locating water under Saint John will be a real challenge because of the deep shale rock formations beneath the city.

“The way the rock formation is formed, there's no huge fractures in the bedrock that produce big, big flows of water,” he said.

Doherty said many of the wells now in the city provide just enough water to service individual homes.

He said finding larger volumes will be a challenge.

If there is water to be found, Doherty said, it will most likely be on the west side in an area between South Bay and the Bay of Fundy.