New York City is cracking down on food waste.

Starting Tuesday, big businesses that generate a lot of food waste ― including hotels, stadiums, food manufacturers and wholesalers ― will have to separate out their organic waste for composting or other approved processing, according to new city rules.

Companies can compost the waste themselves or hire carting services to collect any leftover food, food-soiled paper or yard waste, and transport it to a facility.

“The message has gone out that New York City is going to treat its food scraps sustainably,” Eric Goldstein of the Natural Resources Defense Council told Mic.com. “[This will] get them out of landfills and into composting.”

Sharon Dominick via Getty Images

Food waste is a major problem in the United States. Up to 40 percent of food in the U.S. goes uneaten, according to the Natural Resources Defense Council. Some of the food is composted, but most of it winds up in landfills.

In New York City, organic waste alone makes up around one-third of all waste generated by businesses, according to the city.

The new rules mean that large businesses’ leftover food will no longer be destined for landfills, where they contribute to harmful greenhouse gas emissions. Now the waste will have to be composted into fertilizer, according to Christian Science Monitor, or converted by machines into sewage water.

Digital Light Source via Getty Images Fresh Kill Land fill in Staten Island, New York.

New York City will join other U.S. cities, like San Francisco and Seattle, in implementing organic waste recycling, according to Mic.com.

This is a significant step toward Mayor Bill de Blasio’s goal of zero waste by 2030.

Earlier this year, de Blasio launched the Zero-Waste challenge, asking businesses to halve their food waste by June. The 31 participating businesses, including Whole Foods and Anheuser-Busch, exceeded the mayor’s goal, diverting on average 56 percent of food waste away from landfills over five months.

Now 350 large businesses will be doing the same under the new organic waste rules, according to Mic.com, making the city that much more environmentally-friendly.