Lots of eyes rolled two years ago when San Francisco banned plastic grocery bags, but milllions of saved bags later, the experiment has swept across America, into many foreign countries and may soon take root in the nation’s capital.

A Washington, D.C. councilmember has proposed legislation aimed at reducing the amount of trash that falls into the city’s Anacostia River, where an estimated 40 percent of trash pulled out of the river is plastic bags. The San Francisco bag-ban has translated to 5 million fewer bags a month. The bags are now outlawed in South Africa and Bangladesh. Ireland imposed a tax on plastic bags in 2003, leading the public to almost entirely use cloth totes.