MINNEAPOLIS — The first major update of Minnesota's solid waste law in 25 years is aimed at improving a statewide recycling rate that has been stuck around 46 percent.

A state law passed by the Legislature this spring will make recycling mandatory for most Twin Cities businesses.

More than half of companies in the seven-county metro area send their garbage to the dump rather than pulling out valuable materials such as aluminum, cardboard, plastic and steel. That's based on a survey of 3,600 businesses by the company Waste Management.

"It was glaringly obvious that this needed to be done," said Julie Ketchum, government affairs director for Waste Management in Minnesota. "We want to increase recycling rates, and this is a huge opportunity for us to do that."

The law requires retailers, wholesalers, service companies and other industries in the metro area — with garbage bins of 4 cubic yards or more — to recycle at least three items.

Some industries, such as construction and manufacturing, are exempt because their waste needs special processing.

The law also requires recycling at all sports facilities. It sets a recycling target of 75 percent for the seven metro counties — up from 60 percent — and increases their funding from $14.25 million to $17.25 million, plus another $4 million in 2015.

"That's significant new money," said Rep. Frank Hornstein, DFL-Minneapolis, who sponsored the bill.

Supporters are counting on convincing businesses that recycling is a money-saver. One example: applicane retailer Warners' Stellian has figured out how to recycle Styrofoam that was making up about 70 percent of its waste volume.

The company got a foam "densifier" machine. Employees break up the foam and run it through the machine, and it's sold. The company saves $2,500 per month on its waste hauling costs.