CARPINTERIA, CALIF. (March 14, 3:15 p.m. ET) -- The number of bans on single-use plastic bags in California continues to increase at a rapidly accelerating pace.

The city of Carpinteria has enacted the state’s first --and the nation’s second -- bag ban that applies to both single-use plastic bags and to paper bags.

Austin, Texas, also has a double bag ban, approved earlier this month.

The Carpinteria plastic bag ban, scheduled to go into effect July 11 for large retailers, was approved March 12.

However, it still faces a legal challenge before it can go into effect. The Save the Plastic Bag Coalition has said it will file a lawsuit because the ban does not include an exemption for restaurants — a provision that the coalition contends is both a violation of the California Retail Code and also a safety hazard.

Some 20 miles east, the city of Ojai is poised to become the first city in Ventura County with a single-use plastic bag ban after another vote March 27. The final vote in Ojai had been scheduled for March 13, but the bill was amended at that session, necessitating one more vote.

Retailers with less than $5 million in annual sales will be exempt from the paper bag portion of the Carpinteria ban. They will also not have to comply with the plastic bag ban until April 11, 2013.

The two additional bans would bring the total number of communities in California with bans to 44 and raise the total number of plastic bag bans in the United States to 69.

In addition, Montgomery County, Md., and Washington, D.C., have a 5-cent fee on plastic bags handed out at retail, and Basalt, Colo., has a 20-cent fee on plastic bags.