The addition of a gas bar and a parking lot expansion on the proposed Costco site caused close to 100 people to turn out to a Fredericton city council meeting on Tuesday night.

Eleven people spoke against the proposed expansion at the Costco site at the Corbett Centre on the city's south side. Many used the opportunity to voice their opposition to the entire project.

But Fredericton Mayor Brad Woodside made it clear that the Costco development was not up for debate.

"That was approved, went through the entire process we're going through now. So that part is behind us," Woodside said.

If the bylaw amendment is passed, a wetland will be filled in to make room for the parking lot expansion and a gas bar.

Claire Gibson was one of people who told the council that it's a bad idea to put a gas bar in that area.

"I'm not a scientist but it doesn't make common sense to put a gas bar near a wetland," Gibson said.

Rick Cunjak, a professor at the University of New Brunswick and the Canada research chair in river ecosystem science, also spoke against the motion on Tuesday night.

"The likelihood, my suggestion would be, that something could go wrong at a gas bar is there, is potentially high. Are we willing to take that risk? I would suggest not," he said.

Developer says safety precautions being taken

Scott Fash, a planner with the Terrain Group, the project developer said precautions are being taken to avoid any potential harmful environmental impacts.

"Not only the underground storage tanks but the above ground fuel pumps had to be outside the buffer of the existing wetland," he said.

Council has asked for a report on the possible effects the project could have on surface water and the city's drinking water supply. The amendment will go to third and final reading on April 27.