CHEHALIS, Wash. -- The past weekend brought the season's first freeze, and Department of Transportation crews got a chance to try out a new anti-icing recipe that's touted as being more natural and less harmful to the environment.

The mix is made at the DOT's Chehalis maintenance facility. Most of the mix is salt, the main snow and ice-fighting ingredient.

But this year, crews also added another natural product from local cows -- cheesy whey, the salty water left behind after cheese is produced.

The whey, which comes from the Darigold Factory in Sunnyside, helps the DOT save as much as $40,000 on the cost of making its own salt water.

The whey is delivered to the DOT's Chehalis facility where it's stored in these huge tanks. Darigold can deliver up to 11,000 gallons a day.

"Instead of delivering back into sewers, we're able to work out a nice deal with the Department of Transportation," said Steve Rowe of Darigold. "When the pass is closed, our dairy farmers get stranded and the milk gets stranded, so it's a wonderful relationship."

The DOT also found that by adding molasses, the anti-icing mix sticks to the road up to four days longer. And the resulting color and smell are unmistakable.

"Our product is 77 percent less corrosive than salt," said Paul Simonsen of WSDOT.

And that means there will be less salt deposited into soil and groundwater

The DOT tested out the new anti-icing product last year on Highway 12 at White Pass. This year, the department is expanding its use to other state routes in Southwestern Washington.