Although domestic oil refining has been tagged as a bottleneck in U.S. oil production that contributes to rising gas prices, environmental groups and concerned citizens voiced their opposition to expansion plans at Chevron's 3,000-acre waterfront property, the San Francisco Chronicle reported Wednesday.

"We're driving to the hospital while Chevron goes to the bank," said Rev. Kenneth Davis, a Richmond resident.

Opposition groups said Chevron's project would add mercury, selenium and sulfur to the environment.

Chevron disputes the claims, saying the project, which includes a new power plant, would reduce overall pollution, the Chronicle reported.

"This project has no significant environmental impacts. That's a remarkable achievement for a project of this magnitude," Chevron environmentalist Bob Chamberlin said.

"In fact, this project makes things even better," he said.