With another winter storm bearing down on central Maine Friday and Saturday, Auburn Public Works Director Bob Belz had his eyes on his salt shed Wednesday.

The city began the day with enough ice-melting road salt for two treatments – the first as the snow began falling just after midnight and a second Wednesday night, once the snow had let up.

That exhausts Auburn’s supply of road salt. They’ve used 4,000 tons of the stuff to treat roads this winter. They average 4,200 tons per winter.

“We need deliveries and we have them on order,” Belz said. “The word we’ve heard from our contractor is that they’ve hired more subcontractors and leased two more loaders to get shipments going faster.”

But it’s not coming fast enough, not for Auburn or every other city or town in Maine. The steady march of heavy snowstorms across the country this winter has boosted the demand for road salt to unprecedented levels and depleted stockpiles.

The result has been road salt rationing across the Northeast.

“We have a backlog of requests, and they send it to us when they can,” Belz said. “I think right now, we have about six loads on back order.”

One is due this week, he said. If it arrives, he’ll have enough for this weekend’s storm.

“But there’s plenty of winter left,” he said. “It’s only mid-February and we still have another six weeks to go.”

It’s a similar story across the Androscoggin. Public Works Director Paul Boudreau said Lewiston has room to keep a bigger stockpile of salt than most surrounding communities. The covered salt shed on River Road lets the city keep enough salt on hand to treat the roads for 12 storms per year, about average for a Lewiston winter.

But this hasn’t been an average year. The city so far has counted 19 plowable storms.

“We plan on an average of 73 inches of snow per season, and we’ve had 92 so far,” Boudreau said Tuesday night.

He said the city has loaned salt to Auburn, Lisbon and Greene several times in the past month.

“They’ve paid us back as soon as they can, but we might not have any left to loan if this keeps up,” Boudreau said.

Most cities in Maine get their salt from Morton Salt in New Hampshire, shipped via barge to Portland. From there, it’s trucked inland.

Lewiston received its most recent delivery Wednesday morning, enough to handle that day’s storm and any foul weather expected over the weekend.

Both cities say they are well-stocked with other road treatments: sand and liquid calcium chloride. Belz said Auburn has had no choice but to start using sand to bulk up its salt supply.

“We’ve been able to borrow salt twice this winter from Lewiston,” Belz said. “But Monday of this week, we couldn’t beg, borrow or steal enough salt to do the job. We had to revert back to using sand, and that’s why roads were icier on Monday.”

The science of traction

Road crews rely on three things – in addition to their plows – to help clear the snow. What they use depends on the conditions, from the type of snow to the temperature.

• Sand is great for giving roads traction, but it doesn’t melt ice. It’s only useful when the snow is falling and the temperatures are well above freezing.

• Salt is the main ingredient for clearing Maine roads. It melts ice well, helping to break the coating off slick roads. Mixed with sand, it helps clear the ice and gives cars extra traction, but it’s only effective when the temperature is at or above 20 degrees.

• Calcium chloride is of little use on its own, but it is a potent ice-melter when mixed with road salt. The combination can help break up ice in temperatures that are well below zero. Crews typically spray a coating on roads before a snowstorm begins to get an early lead on road-clearing.

– Source: Auburn and Lewiston public works departments