TheStar.com - = GTA - Cheap salt outweighs green concerns

Cheap salt outweighs green = concerns=20 TheStar.com -=20 GTA - Cheap salt outweighs green concerns

TARA=20 WALTON/TORONTO STAR

A = salt truck=20 fills up at a yard on Eastern Ave. in Toronto, Dec. 15, 2007.=20

How de-icing works

Generally, dry salt does nothing. But when it hits water it begins to = dissolve. This is why transportation departments "pre-wet" the salt = before=20 spreading it.

The salt breaks down into its component ions, the positively-charged = sodium=20 ion and the negatively-charged chloride ion.

As the temperature drops, water molecules would normally bond with = each other=20 in six-molecule rings making ice crystals. But the sodium and chloride = ions=20 attract the molecules instead.

This process depresses the temperature at which saltier water will = freeze.=20

Other chlorides

In the 1980s, towns and cities began also to use magnesium chloride = and=20 calcium chloride to tackle snow and ice. These have a much lower = freezing point=20 than sodium chloride and are often what's used in the liquid de-icing = that's so=20 prevalent on the West Coast.

Agriculturally-based products

What about sugar beet juice and corn syrup? These organically-based = compounds=20 don't have a charge like sodium or chloride. Instead, they get between = the bonds=20 of the water molecules, making the end result very soft. "It's like if = you add=20 corn syrup to ice cream. People think it's to make it sweet, but really = it makes=20 the ice crystals soft and mushy," says Steve Bytnar, a chemist and = director of=20 research at Colorado-based EnviroTech Services Inc., who has spent years = researching road salt alternatives. These products can also increase = salt's=20 effectiveness by making it useful in very cold weather. It also helps = the salt=20 stick to the road.

Acetates

Potassium acetate is an organic (carbon-based) chemical that has = acetic acid=20 (vinegar) as one of its forming parts. It's a very effective anti-icing = and=20 de-icing agent and has fewer effects on the environment than rock salt. = However,=20 it is as much as 10 times more expensive to buy. Since it's much less = corrosive=20 than salt, it's used on important bridges and tunnels, and at Toronto's = Pearson=20 International Airport.

=E2=80=93 Andrew Chung

March 02, 2008

Andrew Chung
staff=20 reporter

They spill out of the rumbling trucks, bouncing along the road like = tiny,=20 angular pearls. And they turn the water that runs off our highways in = wintertime=20 almost as salty as the sea.

Ontario alone spreads around two million tonnes of salt on our roads = each=20 winter. Toronto, Canada's biggest user of road salt, accounts for about = 135,000=20 tonnes of it. And as more roads are built, the more salt we are using. =

Our roads may stay snow-bare, but our heavy dependence on road salt = is toxic=20 to the environment.

The salt burns trees, chokes vegetation, and contaminates soil. It = depletes=20 water of oxygen, and is toxic to many fish. Salts also accelerate the = corrosion=20 of automobiles, roads, bridges and sidewalks.

So why do we keep using piles of the stuff?

It comes down to money. Salt is cheap. There are less harmful = alternatives =E2=80=93=20 some man-made, others naturally derived, from corn or sugar beets for = example =E2=80=93=20 and many jurisdictions in the United States, such as Colorado, New = Jersey and=20 Ohio, are beginning to put them into heavy use. But they are expensive. =

The fact that Toronto and the province have all but passed them over = in=20 favour of salt underscores a cold calculation: To the government, = reducing=20 environmental harm is apparently not worth the extra cost.

The rest of us seem to agree. "It's this odd situation where people = are=20 expecting to be able to drive 110 km/h on all-season radials, which are = not=20 suitable for the road conditions, because they assume enough salt has = been laid=20 down to make them safe," says Kevin Mercer, the founder of Toronto-based = watershed group Riversides who has studied road salt use in Ontario. =

"There's a tendency to use salt exclusively. It's ridiculous and it's = going=20 to have to change."

In a wintry place like Canada, keeping the roads clear is a serious = and=20 expensive business. The province budgets well over $160 million for = winter=20 maintenance of its roads and highways. Toronto: $67 million, of which = about $10=20 million is spent on salt.

Salt used to be relatively uncontrolled in its use. Salt truck = operators=20 would drop it all over the place with near abandon. Huge, salt mountains = would=20 sit uncovered in the portlands.

But with the new millennium came a stark realization on the part of = the=20 federal government. In 2001, Environment Canada recommended that road = salt be=20 placed on a schedule of toxic substances under the Canadian = Environmental=20 Protection Act, because of the harm it does to ecosystems.

That never happened. Mercer says it was due to heavy lobbying by the = salt and=20 transportation industries.

However, the federal department adopted a voluntary "code of = practice" to=20 reduce salt use. The province says that about 200 municipalities = representing 95=20 per cent of Ontario's population, have now "signed on" to the code. What = these=20 lower-tier governments are doing varies.

Toronto now has covered salt domes. It has fenced in snow dump sites = like the=20 one at Bayview Ave. and Bloor St., near the Don River, to capture silt = and=20 debris as the snow melts. It has retrofitted its spreaders with = computerized=20 calibration systems to more precisely sprinkle the salt.

And it's now "pre-wetting" the salt granules, which helps them start = to melt=20 the ice and snow more quickly. This process also keeps the crystals = adhered to=20 the road instead of bouncing into the ditch. The city typically uses a = brine,=20 salt in liquid form, to wet the salt.

Through the city's salt management plan, which began in 2004, salt = use is=20 down by 15 per cent, says Peter Noehammer, director of transportation = services=20 with the city.

However, Noehammer concedes the city uses salt for "close to 100 per = cent" of=20 its winter efforts. "It's our vital de-icing agent," he says.

Road salt use has elevated chloride levels in the waterways and wells = in and=20 around urban areas. Toronto is studying the effects salt reductions have = had on=20 its rivers and creeks, but refused to release the data to the = Star,=20 saying it's still in "raw" form. Noehammer said there are fewer winter = "peaks"=20 in salt concentrations, but sees no perceptible decrease yet in baseline = concentrations.

The Ministry of Environment also monitors rivers. Ministry official = Dave=20 McLaughlin says, "It's pretty evident that in urban areas, chloride = levels are=20 starting to creep up and it's pretty evident that it's due to salt = use."

Ontario's provincial roads are also fed a salt-only diet, with the = exception=20 of a few bridges and tunnels that are sprayed with various man-made = acetate=20 solutions, and the mixing of a small amount of a natural anti-corrosion = agent=20 with its brine.

Why? Non-saline alternatives are up to 10 times the price of salt. =

"For the quantities we use it would be cost prohibitive for = municipalities in=20 Ontario and Toronto to stop using salt and use a different product," = Noehammer=20 says.

"We do have to manage public funds and live within budgets," echoes=20 transportation ministry official Gary Todd, whose office sets standards = for=20 winter maintenance. "You have to consider cost with the impact on the=20 environment."

Salt, or sodium chloride, began its ascent to roadway dominance after = World=20 War II, and has vastly expanded along with the roadway network and = urbanization.=20

Despite this, salt is not a de-icing panacea. It's effectiveness is = limited=20 at temperatures colder than minus 15 degrees Celsius.

In the last few years, agriculture-based by-products of corn, sugar = beet and=20 alcohol processing have been mixed with salt. Manufacturers and now some = governments say this enhances salt's effectiveness by making it work in = colder=20 weather and reducing the amount of salt needed to cover the same ground. =

Toronto only uses a sugar-beet derivative called Fusion, made by = Milton-based=20 Eco Solutions, in severely cold weather.

The product is, "upfront, one of the most expensive products out = there," says=20 company manager Antonio Vaccari. "But once applied on the road we're one = of the=20 least expensive because they're able to reduce their application rates" = of salt.=20

Officials in Gray county, which includes the city of Owen Sound, back = up that=20 claim.

The county, northwest of Toronto, has been using agricultural salt=20 substitutes for a few years now. At first they tried a by-product of = beer=20 distillation. But they found it was attracting deer and wild turkey to = the=20 roads, where they'd lick it off. Roadkill rates were going up.

So they switched to the sugar beet concoction, which can be applied = before=20 the snow flies, and after, as a 50-50 solution of brine and Fusion added = to the=20 salt.

On a per-kilometre basis, they're using a lot less = salt. "It=20 has allowed us to bring our application rates down of sand and salts to = about=20 half what it was before," says Gary Shaw, the county's director of=20 transportation.

Shaw says the savings on salt and sand have more than recouped the = higher=20 cost of the sugar-beet product. It also means less corrosion on = equipment and=20 infrastructure.

Many states and cities in the U.S. are also heavily using these = liquid=20 substitutes.

They're in widespread use in Colorado. And the New Jersey Turnpike = Authority=20 told the Wall Street Journal recently that it also uses half = the salt=20 that it used to.

Still, salt's hold on Ontario and Toronto remains steadfast =E2=80=93 = and=20 controversial. Last December the province's environmental commissioner, = Gord=20 Miller, admonished the government for not forcing municipalities to = better=20 manage salt use.

His annual report also took on what environmental groups consider a = damaging=20 loophole in the province's Environmental Protection Act, dating back to = 1972,=20 which exempts from regulation the use of salt on roadways.

Riversides and the Sierra Legal Defence Fund, now called Ecojustice, = asked=20 for a review of this loophole but were turned down by the environment = ministry.=20 Miller criticized the denial and said the province needed a = comprehensive salt=20 strategy.

McLaughlin, assistant director of the ministry's monitoring and = reporting=20 branch, says there are no plans to rescind the loophole. He said = municipalities=20 like Toronto are participating in the federal government's "code of = practice,"=20 and Ontario would wait for a planned review of the program, scheduled = for 2009,=20 before taking any other action.

The environmental commissioner, in his report, however, commented = that in his=20 view "the road salts initiatives cited by MOE will not mitigate the = damage=20 caused by road salts."