Four County Council members introduced a measure Tuesday that would scale back the Montgomery County bag tax so shoppers would have to pay 5 cents for bags only at grocery stores.

The bill would modify the tax to apply only to food stores, defined as any store where food consists of more than 2 percent of revenue. The tax still would apply to nongrocery items being bought in those stores.

The bag tax raised about $2.3 million last year for 57.6 million bags during its first year, with the money going toward cleaning up the county's streams.

But council members have questioned whether the tax is overreaching, since the tax is charged at every retail establishment in the county, from jewelry to hardware stores. Council members George Leventhal, at-large, Craig Rice, Upper County, Nancy Floreen, at-large, and Roger Berliner, Bethesda, all Democrats, introduced the legislation.

Bob Hoyt, director of the county's Department of Environmental Protection, called the program the best one he has seen in the county and said it's too soon to change it. Council staff agreed, recommending to keep the 5-cent charge intact while more analysis is done to see if it's working.

Hoyt cautioned the council that it might be moving too fast by changing the tax only a year after its inception. He said data on the tax's effectiveness are inconclusive, but anecdotal evidence shows the program is fulfilling its intended purpose.

"There's a lot of questions for us as to how this [new] bill would be implemented and who exactly it would cover and how that would be determined," he said. "It's been modeled after [a Boulder, Colo. law], so we're going to be talking to them and see how it's implemented there."

Berliner said the goal of the tax was to promote environmental consciousness and recognize how easy it is to use fewer bags, but he felt that charging shoppers a bag tax in clothing stores wasn't going to change behavior. He worried it was sending a message that the council wanted more money and not fewer bags.

He also said a less stringent law might make it easier for state lawmakers to gain support for passing a statewide bill.

"I think our law, as it stands, is the enemy of good," he said. "I think a good case can be made that if we focus on food retail establishments, as D.C. sought to do ... there is a greater likelihood that the state legislature could pass a statewide bill."