While arguments centered on the clamor from off-loading barges, the larger debate played out over environmental-vs.-development considerations that could determine the fate of Dutra Materials' proposal.
Both sides were out in force.
Petaluma residents who said the plant will harm wildlife and air quality in addition to people's ears carried signs and wore stickers urging the commission to reject the proposal.
Heidi Rhymes, a member of the opposition group Moms for Clean Air, said the difference was huge between the county noise limit and what the plant will produce. She said the county shouldn't bend its rules for the plant.
"You can't fit a circle into a square," Rhymes said. "If it doesn't fit, it doesn't fit."
Asphalt plant backers, including developers and organized labor representatives from as far as San Francisco, wore their own stickers.
Cynthia Murray, president of the North Bay Leadership Council, said the county needs the jobs and inexpensive road material promised by the plant.
"This is something that will definitely improve the community," said Murray, a former Marin County supervisor who now lives in Petaluma.
After hearing from about 45 speakers -- both pro and con -- planning commissioners postponed a decison until May 21.
At that time, they will make a recommendation to the Board of Supervisors on whether to amend the county's noise limit.