WASHINGTON — Residents of the US capital may have to dig a little deeper into their pockets when they go grocery shopping once the city slaps a five-cent levy on each plastic bag issued at the checkout line.

The measure, which takes effect on January 1, 2010 and is the first such initiative in the United States, seeks to make consumers bear the brunt of clean up costs for the bags which currently are dispensed for free with a customer's purchases.

Plastic bags, while popular with shoppers, often end up clinging to tree branches, tangled in power lines, polluting rivers and clogging up storm drains.

"I signed this law in July to cut down on the disposable bags that foul our waterways," said Mayor Adrian Fenty in a statement last month, saying that one particularly urban waterway, the city's Anacostia River, has been particularly befouled by the plastic shopping bags.

"Our research shows that plastic bags are a major component of the trash in the Anacostia River," said Maureen McGowan, interim director of the city's environment department.

"By taking disposable bags out of production and out of the waste stream, everyone who goes to the store can help keep the waters clean," McGowan said.

And Fenty noted that part of the money collected will be spent toward cleanup of the Anacostia.

"We want everyone to know that you can save the river, and five cents, if you bring your own reusable bag to the store instead," the mayor said.

Under the new law, city businesses that sell food or alcohol must charge customers five cents for every disposable paper or plastic carryout bag. The law also requires that these bags be recyclable and carry a message encouraging recycling."

To prepare for the change, the city government has distributed some 122,000 reusable shopping bags to elderly and low-income residents who complain that their limited spending power will be further hampered by the levy.

The measure is opposed by the American Chemistry Council, which says standard issue plastic bags already are reusable and work just fine.

"Most major grocery and retail chains currently offer programs that allow shoppers to bring back plastic bags and all sorts of product wraps for recycling," the group said in a statement earlier this year in which it called the new levy "misguided and unnecessary."