Seattle preps roads for ice and snow

Brine, sodium chloride, salt, alkali, NaCl. Whatever the name, a new era has begun on the streets of Seattle.

In a reversal of last December's failed response to ice and snow, trucks are ready to sprinkle granular salt, at a rate of 200 pounds per mile, if a snow or ice storm arrives.

Already, city workers have been pouring salt solution on major streets in the subfreezing nights this month, to retard the formation of ice.

Last year, city trucks packed down snow-covered roads and dumped sand for traction after a storm that arrived Dec. 18, instead of spreading salt. Ice lingered on some streets an entire week, as Mayor Greg Nickels cited an environmental policy to prevent salt runoff into Puget Sound.

King County Metro Transit wound up cutting service in half, in part because of bad conditions within Seattle. Many electrically powered buses became stranded on hills between I-5 and Lake Washington, blocking buses behind them tethered to the same power lines.

Nickels changed his position by New Year's Eve, and the city this fall hired a new road-maintenance boss, Monty Sedlak, who is seasoned by Colorado blizzards.

The Transportation Department's new winter plan might be described as "salt first, ask questions later."

"We don't want tires hitting sand on ice. We want tires hitting a wet road," said Sedlak, who arrived here six weeks ago.

His former employer, suburban Arapahoe County south of Denver, switched to salt in 2001, he said. Ironically, that was for environmental reasons — flying sand created brown clouds over the valley.

As in Seattle, snowfall near Denver would often be melted by chinook winds, then refreeze overnight. But here, rainfall also will freeze some nights, he said.

Sedlak is hearing about Seattle landmarks such as the Nucor Steel mill, whose water vapor condenses then freezes on an elevated roadway near the West Seattle Bridge. And the Queen Anne counterbalance, where the SDOT will punt in favor of plowing 10th Avenue West, a detour route for King County Metro Transit buses.

The plan divides Seattle roads into three groups, with different goals for each:

• Level 1, where all lanes should be bare and wet within eight hours of a storm. These are north-south downtown streets, Stewart Street and Olive Way, 15th Avenue West, northern Greenwood Avenue North, Aurora Avenue North, Lake City Way Northeast, 23rd Avenue East, Rainier Avenue South, Fourth Avenue South, the Alaskan Way Viaduct, the West Seattle Bridge route and 35th Avenue Southwest.

• Level 2, where one lane each direction should be clear within eight hours. These arterials are often chosen to support bus detours. Examples are 15th Avenue Northeast, East Madison Street, Beacon Avenue South, California Avenue Southwest, and Northwest 85th Street.

• Level 3, where hills, curves, bridges and major intersections would be treated. These include Third Avenue Northwest, Lake Washington Boulevard South and 16th Avenue Southwest.

Crews will be assigned to certain areas of town, working 12-hour alternating shifts, so all Level 1 and Level 2 roads are continually being salted or plowed in a circuit. The city spent $400,000 this year preparing for ice. SDOT equipped its trucks to spread salt, sought expert help with planning and built a winter command center in Sodo with video screens, GPS feeds of de-icing vehicle locations, and desks for bus and police officials. About $650,000 in the 2010 budget covers "emergency response," which includes de-icing and landslides.

At an equipment yard behind the center, workers Thursday loaded salt granules into a spreader truck. Other trucks sport shiny "Snow Dogg" brand plows and "Ice Dogg" spreaders. SDOT is taking deliveries from the state highway system's salt stockpile, from a barge docked in the Duwamish Waterway, said city spokesman Rick Sheridan.

A standard de-icing brine, applied before snow or frost arrives, contains 75 percent saltwater, 20 percent fermented sugarcane, and 5 percent calcium chloride. The combination is supposed to enhance the salt, and melt ice at 25 degrees.

First treated are elevated structures such as the Aurora Bridge, followed by the ground-level boulevards.

Newly brined roads might spook drivers if they're unfamiliar. Glance at the car ahead. If water sprays back from the tires, the road is wet and safe. If the pavement "looks all glossy and glazy, and you don't see anything off the wheel," that means ice, Sedlak said. He urges motorists to keep their windshield-washer-fluid tanks full, to rinse away the salty spray.

SDOT trucks applied salt solution last week, just in time for a light frost Saturday morning. But they've been out this week, too, even in dry conditions. Asked if he's overreacting, Sedlak said frost did form on car windshields Thursday, a harbinger that pavement could freeze, too. The relatively low cost to spray brine is weighed against the enormous cost if the roads do ice, causing accidents and economic loss, he said.

Sedlak then argued for a second virtue: "You get a residual buildup of salt on the roads. It gives you a leg up on the next event."

Mike Lindblom: 206-515-5631 or mlindblom@seattletimes.com