Plastic shopping bags could be largely prohibited countywide following Tuesday decisions by the city councils of Santa Rosa and Rohnert Park to back a law that institutes the ban but allows cities to opt out -#8212; which Santa Rosa did on a split vote.

In Rohnert Park, the decision was unanimous to endorse the plan and let the Sonoma County Waste Management Agency enforce the ban in the county's third-largest city.

"The more I think about it, it seems inevitable," said Rohnert Park Councilwoman Pam Stafford, who was among city officials who had previously resisted a countywide approach.

"There is great value in regional consistency in matters like this," said Councilman Jake Mackenzie.

But Santa Rosa, while it did not torpedo the proposed bag ban by voting against it, chose on a 4-3 vote to pass its own ban that would be identical to the county's but controlled and enforced locally.

As it stands, then, the county would enforce a ban in its unincorporated areas and eight of its nine cities, while Santa Rosa's own version would be in force within its borders.

Mayor Scott Bartley, who supported the majority's approach, called the debate over the two identical approaches "splitting hairs."

But he argued that retaining the city's independence might actually better position it to expand its laws in the future, for example, to cover Styrofoam or to extend it to restaurants, which are now exempted.

The ordinance, pushed by a regional coalition of environmentalists and the waste agency, is designed to reduce trash sent to landfills and reliance on petroleum-based products.

Third District Supervisor Shirlee Zane, the county's representative on the waste agency board, expressed relief at Tuesday's developments, but made clear which city's action she preferred.

"Huge kudos to Rohnert Park and I wish Santa Rosa had made that choice, too. Whenever your largest city opts out of a major policy and program such as banning plastic bags, that does defeat the purpose of a joint powers agreement," Zane said, referring to the waste agency.

"Nevertheless, the point is that this is long overdue and we can still move forward," she said.

A waste agency public hearing today at 9 a.m. could lead to the law's final approval. At the Rohnert Park hearing, waste agency program manager Patrick Carter said the agency hopes to implement the ban by September if all goes well.

The plan, already officially backed by the county's seven other cities, needed both Santa Rosa's and Rohnert Park's support to move forward.

Santa Rosa officials' reluctance to turn over some regulatory powers to the county had previously threatened to scuttle the proposal, now under discussion for three years.

But the opt-out provision written into the ordinance turned the tide -#8212; although there still was council argument about it.

"We're solving a problem that doesn't exist right now," Councilman Gary Wysocky said of creating a ban unique to the city but mirroring the county's.

Retailers don't want multiple regulations and for the city to write its own ordinance would add a redundant layer of government, and create more work for city staff, he said.

Councilwoman Erin Carlstrom noted that by passing its own ordinance, the city might have to pay to defend it, a liability the county was willing to assume if the city had joined the larger program.

"That just bolsters my opinion that we would be better served by joining the county ordinance," Carlstrom said.

The ban would affect a range of retail outlets, including grocery, clothing, electronics, hardware and drug stores, as well as convenience and liquor stores. It would not apply to bags that hold meat or produce, or to restaurants, stand-alone delis or charities.

Retailers would have to provide paper bags of at least 40 percent recycled content, charging customers who want them 10cents per bag. Fines could be levied against businesses that don't comply, though few expect that to be necessary.

Asked what the ban would mean to his family's businesses, Teejay Lowe, CEO of G-G Markets, said: "How the consumer responds to the ban will be the determining factor on the implications to our business."

Staff Writer Matt Brown contributed to this report. You can reach Staff Writer Jeremy Hay at 521-5212 or jeremy.hay@pressdemocrat.comand Staff Writer Kevin McCallum at 521-5207 or kevin.mccallum@pressdemocrat.com.