The supermarket chain announced Wednesday that its 183 stores now donate or divert all unsold food. The chain claims to be the first large-scale supermarket in New England and New York to make that change.

The company has worked on the effort for the past decade as more states — including Connecticut, Massachusetts, Rhode Island and Vermont — have instituted mandates against throwing food and other organic wastes into dumpsters.

In the U.S., food waste is estimated at between 30% and 40% of the food supply, according to the U.S. Department of Agriculture.

“Eventually, it is sent off to landfills and generates harmful greenhouse gas,” said John Fifield, the chain’s director of retail operations.

Last year, Hannaford’s program kept 65 million pounds of food waste out of landfills, he said.

The chain follows the U.S. Environmental Protection Agency’s food recovery plan.

Surplus products are donated to local food banks, while the rest is donated to local farmers for animal feed or recycled into energy in partnership with Agri-Cycle, a food waste recycling company in Scarborough, Maine.

The sustainability effort starts with preventing food waste with efficient ordering, Provencher said during a tour of the store on Bicentennial Drive on the Hooksett-Manchester line.

All of the products are closely monitored. Dairy products are pulled from the shelves three days before the sell-by date. Some items, such as meat, get frozen before being donated.

Agri-Cycle, which launched in 2011, uses an anaerobic digester that transforms greenhouse gases into electricity that is sold back into the grid. The digester also produces fertilizer and bedding for dairy cows. The two companies have worked together since 2014.

“Hannaford had the vision to invest in food waste recycling long before states in the region began to mandate it through legislation,” said Dan Bell, president and co-founder of Agri-Cycle.

The company has recycled 50,000 tons — 100 million pounds — of food waste from Hannaford in the past five years.

The efforts created enough renewable energy to power about 500 homes a year.

Agri-Cycle also works with Trader Joe’s, Walmart, Whole Foods and other companies. Material in smaller trucks is transferred to larger vehicles to reduce emissions, Bell said.

Items that can be recycled include meat and bones, milk, cheese, fruits, vegetables, condiments, coffee grounds, seafood, fats, oils, soups, uncoated paper products and packaged foods.

“We needed a process that was very easy to implement at 183 stores,” said George Parmenter, health and sustainability lead at Hannaford. “We also needed a process that accepted all of the food waste.”

Food waste accounts for about 8% of global greenhouse gases that affects the climate, he said. Other impacts include the fertilizer and water used in growing crops and the transport of the products that are ultimately thrown out, he said.

Prep areas throughout the building remind Hannaford associates about what should be recycled.

The chain donated 25 million pounds of product to organizations like the New Hampshire Food Bank and Families in Transition-New Horizons.

jphelps@unionleader.com