WASHINGTON, D.C. – On Friday, the nation’s capital no longer allowed restaurants and other foodservice establishments to package food or beverages in polystyrene containers, the Washington Post reports. The city council approved of the Styrofoam ban in 2014 in a package of environmental proposals aimed at helping the Anacostia River recover its health. Nearby Montgomery County, Maryland, also enacted a limited foam container ban this year, with Prince George’s County, Maryland, to follow suit later in 2016.

In the District, the city’s Department of Energy and Environment doesn’t anticipate any hurdles in compliance with the ban. The department has been in contact with businesses to ensure all are aware of the change. “We’ve noticed that across the board a good portion of businesses are already foam-free,” said spokeswoman Julia Christian.

Some national chains, such as Dunkin’ Donuts, have switched from foam cups and containers to those made of other materials to make it easier for locations to comply with state or local ordinances.

Other localities with Styrofoam bans include Seattle, San Francisco and Minneapolis. In September, a judge overturned New York City’s ban on foam containers, disagreeing with the city’s assessment that the recycling polystyrene “was neither environmentally effective nor economically feasible.”