A bill sponsored by Senate District 2 legislator Dee Brown, R-Coram that would require the state to reduce its use of liquid chloride de-icers was tabled by the Senate finance committee recently. A tabled bill typically dies in the state legislature.

Brown’s bill looked to reduce the amount of chloride “from the current level of use by 10 percent each year over the 10 years following [the effective date of this act] or until the use of chloride-based liquid de-icers reverts to the mean average use over the period from Dec. 15 2007, through March 31, 2010, whichever occurs first.”

Brown has long argued that the chloride de-icers are harmful not only to vehicles, but to the environment.

“It’s time for (the Montana Department of Transportation) to look for a solution,” she said.

MDT uses about 9.1 million gallons of chloride de-icer a year. To comply with the law as written, it would have to reduce that amount by about 2.8 million gallons, an MDT analysis found.

MDT financial officer Larry Flynn told the committee that the fiscal note — the amount the law would end up costing the state — was $14 million by 2023, when the state would come into full compliance with the law.

He said $14 million is a significant chunk of the state’s highways budget.

“That’s a pretty serious hit,” he said. He said the could maintain about 2,800 miles of road for $14 million. To make up for that expense, it would require about a 2.5 cent hike in the gas tax, he added.

The state based its fiscal note on the use of another de-icer, potassium acetate as an alternative to the chlorides. Potassium acetate is incompatible with the chlorides and would require separate storage tanks and the rinsing of vehicles in mid-season. Potassium acetate is less corrosive to metals and concrete, but can be harmful to aquatic organisms in high quantities. But for most streams, it dilutes quickly and is less toxic than other chloride brines, a study for the Colorado Department of Transportation found.

The Colorado study, done in 2001, ranked sodium chloride brine the most toxic for streams.

Brown argued at the hearing that a hike in the gas tax would be supported by voters in her district if it meant less use of chlorides.

“I actually think (constituents) would vote for it,” she said.

At the very least, Brown suggested the interim committee on transportation take a closer look at the impact of de-icers after the session is over.