Short on salt

Connecticut’s dire shortage of salt? Not your grandfather’s crisis. Like everything else related to modern infrastructure, the current salt emergency has a history illustrating technological innovation and good intentions toward the environment — but blind, unfortunately, to a 500 pound gorilla.

When the public got traveling after World War II, state and local road maintenance was limited: Motorists battled snow themselves by strapping on chains.

With the expansion of roads and federal maintenance funding in the 50s, the Connecticut Department of Transportation (CDOT) and local municipalities were charged with managing snow. At first they just used sand. As spreaders and plows advanced, sand and salt were mixed, sand dominant at 7:2.

But sand has environmental problems. It absorbs everything spilled on the roads, principally pollutants like oil. Snow with all that in it isn’t good to put in the Sound when trucks have nowhere else to dump. In areas without catch basins, sand runs off and clogs waterbodies; in areas with catch basins sand clogs the basins and accumulates.

In either case, come spring, tons of sand must be dug out or swept up and disposed of with special precautions.

Besides, while sand is good for traction it isn’t a de-icer. Pure salt (sodium chloride) prevents ice from forming down to 20 degrees; other salt recipes bring the melt-point down to single digits. Research has demonstrated eight times fewer accidents after salt application, rates of injury down similarly, the severity of injury further reduced, and the average cost of an accident 10% less. A 1992 study concluded: “[De-icing] pays for itself within 25 minutes of spreading.”

Salt has environmental problems too, however. It pollutes watersheds, kills vegetation, sickens mammals, birds, fish and other aquatic creatures, corrodes metals, and degrades soils. Although many of these environmental dangers are familiar by now, some are surprises: Salt facilitates invasive species — notably, phragmites — and weakens the root systems of roadside trees, perhaps being as much at fault for toppling trees onto power lines as canopy-level snow and ice.

Highway maintenance engineers are hunting for new de-icers that are less toxic and more efficient, principally brines for spraying. A relatively harmless one is calcium magnesium acetate; sometimes it’s mixed with vegetable bi-products (beet juice is popular) to help the de-icer stick to the pavement.

CDOT now sprays a custom brine on major state highways; Milford uses the old 7:2 sand-to-salt spread.

Milford, apparently, isn’t seeking state salt aid in the current shortage. But the proverbial gorilla no one has mentioned is the growing number of square miles taken up by roads and parking lots that create the demand for de-icing. What we have isn’t so much a salt emergency as a sprawl emergency.

Still, if we must ignore the real cause of the crisis and worry only about the cost of utilizing gourmet de-icers or of importing salt from far-flung latitudes like Chile and the Bahamas, let’s console ourselves with this thought: At least we don’t use coal-ash.