A legislative change in the amount of liquid salt used on Montana roads will have to wait another two years.

Senate Bill 262 — which would have imposed limits on the amount of liquid de-icer such as sodium chloride (table salt) and magnesium chloride used by the Montana Department of Transportation — failed in the Senate Thursday.

The bill’s sponsor, Sen. Dee Brown, R-Hungry Horse, said the state has been using more liquid de-icers each year, which could carry serious implications for the environment.

“There are trees dead along our roads,” she said. “We have the largest freshwater lake west of the Mississippi in my county, and I am very concerned that the continuing runoff of chlorine-based products is not good for us.”

Sen. Dick Barrett, D-Missoula, objected to Brown’s claim that application of salts has increased six-fold over the last seven years. He said the department is actually using less overall salt by using the liquid chemicals, and that historic use of salt-sand mixtures was not as effective, requiring more salt overall.

Sen. Bob Keenan, R-Bigfork, voted for the bill, saying that mechanics in his district told him the corrosion associated with the chemicals was so bad they couldn’t remove car tires to change them. He referred to a Colorado highway nicknamed the “trail of rust,” after corrosion associated with heavy liquid de-icer applications.

He also said studies indicated that pine beetles were living longer after consuming magnesium chloride, thus posing more threats to forests in Western Montana.

Under the proposed law, the use of chloride-containing chemicals on state roads would have been limited to Dec. 1 through March 31 each year, with an exception for sand mixed with one-tenth rock salt. It would have phased down the allowable quantities of chloride-containing chemicals until they reached the average amount used between Dec. 1, 2007, and March 31, 2010.

Brown noted during a committee hearing Wednesday that she introduced a bill during the 2013 session that would have completely banned the use of the liquid de-icers, but the $29 million price tag for the highway department was too prohibitive.

The fiscal note this time estimated an annual cost between $8 million and $10 million.

The bill failed on its second reading by a 34-16 vote.

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.