Without consulting the public, or even its own policy board, the Oregon Department of Transportation has decided to change Oregon’s longtime practice of avoiding the use of rock salt to melt snow and ice on roads.

The Oregonian obtained a copy of an agency document that details a plan for a five-year pilot project to use salt in two locations: 11 miles of I-5 as it crosses the Siskiyou Pass near the California border and 120 miles of U.S. Highway 95 near Idaho and Nevada.

Those bordering states use salt, meaning drivers on clear roads cross into areas of packed snow when they drive into Oregon. If the experiment goes well, ODOT told The Oregonian, use could spread elsewhere in Oregon.

The benefits and hazards of salt on roads are well-understood and little disputed; it’s great for melting snow and ice, but it does nasty things to the environment and to vehicles. That’s why Oregon has long avoided it, despite having plenty of dangerous mountainous roads.

Although many people are aware that salt on roads can corrode their cars, they may be less aware of the effect on plants and water sources. A 2009 report from Purdue University says salt’s toxic effect on plants has been understood since it was used for biological warfare in ancient times. The salt prevents plants from absorbing essential nutrients, and it absorbs water otherwise available for the plants’ roots.

The salt also can wash into lakes and streams. Slate magazine reports 40 percent of the urban and suburban streams in the northern part of the U.S. where salt is commonly used have levels higher than recommended by the Environmental Protection Agency.

ODOT appears well aware of the problems, and is taking precautions to address them, the Oregonian reports, such as treating bridges with a glaze to lessen corrosion and not using salt in the Jordan Valley to protect its water supply. The department also got clearance for its pilot project from the state Department of Environmental Quality and the National Marine Fisheries Service.

We don’t necessarily disagree with the idea of the pilot project, which may show that carefully limited use of salt can make travel safer without significant environmental damage. We don’t, however, think such significant changes in policy should be made with no public comment.