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Related: Editorials & Other Articles, Issue Forums, Alliance Forums, Region ForumsThe Environmental Cost of Salting Roads
I got to thinking about this. I found this article @ www.popsci.com/environment, the web site of Popular Science.
The Environmental Cost of Salting Roads
Why cost to the city's coffers outweighs cost to the Earth
By Matt Ransford
Municipalities are always weighing cost against environmental concerns and quite often, cost wins out at great expense to the environment. Residents of New York City will remember the summer of 2002 when the Bloomberg administration ceased recycling glass and plastic, citing budgetary concerns. It was cheaper for the city to dump tons of reusable refuse into landfills than to continue its recycling program. After a year of no plastic recycling and two years of no glass, the city determined the savings were negligible and resumed recycling both. Salting roads during the winter is another source of environmental concern weighed against cost. Now that Spring is finally rounding the corner, let's look at the consequences of spreading millions of tons of salt on our roads.
Keeping roads safe in the winter is a high priority for cities throughout the country. Salting the pavement is the cheapest way to do that. When a salt crystal dissolves, it releases its component ionssodium and chloridewhich both bond with water molecules, making it more difficult for them to join to each other and thereby freeze. The problem comes from all that chloride and salt run-off. The chloride gets into our water supply and poisons fish. The salt burns vegetation and contaminates soil, as well as corroding cars and bridges. But it's cheap. Ten times cheaper than effective alternatives. And when a city of 2.5 million people needs 135,000 tons of it, that's a significant cost difference.
Wilms
(26,795 posts)former9thward
(32,025 posts)Last edited Thu Feb 6, 2014, 12:27 PM - Edit history (1)
Look at a 10 year old car from the NE or Mid West and look at that same car in Arizona. The Arizona car looks brand new compared to cars from the snowbelt. That said there really is no alternative.
HereSince1628
(36,063 posts)My 16 year old escort wagon is somewhat remarkably free of body rust...
The body of my previous car...a Camry wagon...was well rusted thru (including a few places on the floor) at age 9.
snooper2
(30,151 posts)Fords especially......one of my favorite YouTube channels
Look at this truck...Crunch Crunch Crunch
liberal N proud
(60,336 posts)Orrex
(63,216 posts)I'm not a chemistry guy, but that sounds about 100% incorrect to me.
Here's a discussion of how to break NaCl into its constituent elements, and it has nothing to do with dumping it on a snowy road.
I'm happy to recant if I'm wrong, of course.
MineralMan
(146,317 posts)Instead, the salt goes into solution in the water. It remains NaCl. Saline solutions have a lower freezing point than pure water.
When salt is put onto roads, the points of contact with the salt and water melt, with the salt going into solution, which lowers the freezing point, producing more melting and more solution. But the NaCl remains NaCl.
To lower the freezing point even further, ice melting chemicals also include Magnesium chloride and Potassium chloride. Those two salts lower the freezing point of the solution even further.
The harm is done by having higher salinity of the water that flows into lakes and rivers. Saline solutions also can damage concrete and accelerate rust development on steel.
But the author of this thing wasn't paying attention in his Chemistry class.
GeorgeGist
(25,321 posts)NaCl dissociates into Na+ and Cl- ions when mixed with water.
MineralMan
(146,317 posts)Orrex
(63,216 posts)I'm guessing that the perpetual motion machine that you sold me doesn't work, either.
MineralMan
(146,317 posts)While most perpetual motion machines don't really work, mine does. Trust me. I only need another million or so dollars to go into production.
{DONATE NOW!}
Orrex
(63,216 posts)petronius
(26,602 posts)take up space in the mixture and reduce the rate of freezing onto the ice surface, disrupting the melt/freeze equilibrium and lowering the melting temperature of water. This link looks pretty good.
But they're correct that dissolving salt does break it into its constituent ions: Na+ and Cl-. Your link seems to relate to dividing salt into the (uncharged) basic elements, sodium (Na) and chlorine (Cl)...
(Note: I'm not a chemist either, so I'll echo your caveat.)
Blues Heron
(5,938 posts)When you dissolve salt in water the sodium chloride dissociates in Na+ ions and Cl- ions, which may be written as a chemical equation:
NaCl(s) ? Na+(aq) + Cl-(aq)
http://chemistry.about.com/b/2011/06/06/is-dissolving-salt-in-water-a-chemical-change-or-physical-change.htm
mathematic
(1,439 posts)NaCl is an ionic compound. It breaks up into Na+ and Cl- ion in water. It might help to think of water as a magnet with a positive and a negative end. The positive end attracts the Cl- and the negative end attracts the Na+. This "bond" is called an ion-dipole force.
The freezing point of a solution is lower than that of the freezing point of the pure solvent (water, in this case). To me, "making it more difficult to join together" is as acceptable a lay explanation as "the randomness of the molecules increase." Neither really does much to illuminate the specifics of what's going on and both give a correct sense of what's happening.
Orrex
(63,216 posts)It was my impression that dissolving NaCl into water is principally a physical reaction rather than chemical, in much the same way that making Kool-Aid is not chiefly a chemical reaction.
You seem to be suggesting that when I drink salt water I am drinking a mixture of NaOH and HCl.
No?
mathematic
(1,439 posts)The Na+ and the Cl- are floating around in the water, loosely attached to H2O molecules.
NaOH and HCl do not exist like that in solution. They are Na+, OH-, H3O+, and Cl-. Since we're dealing with equal molar amounts here, you just get a neutral solution of Na+, Cl- and H2O. In other words, if you put equal parts NaOH and HCl into water and drank it you would, in fact, just be drinking salt water.
Orrex
(63,216 posts)I'll take this as a useful lesson both in grade-school chemistry and a lesson in not being too sure of one's ideas.
DAMN YOU!
mathematic
(1,439 posts)Nye Bevan
(25,406 posts)notwithstanding the environmental impact.
LiberalEsto
(22,845 posts)From the Star-Ledger/ nj.com
Mike Frassinelli/The Star-Ledger
on February 05, 2014 at 12:00 PM, updated February 05, 2014 at 12:02 PM
"Mom always said beets were good for you.
Now neighboring Pennsylvania is experimenting with beet juice as a way to treat icy roads during extreme low temperatures.
With road salt in short supply this harsh winter, the Department of Transportation in that state is testing the juice on roads in Butler County, about 20 miles north of Pittsburgh, as part of a pilot program.
In a report on KDKA-TV, a CBS affiliate in Pittsburgh, PennDOT officials explained that chemicals in the juice help melt the ice during extreme low temperatures."
More:
http://www.nj.com/news/index.ssf/2014/02/beet_juice_on_roads_pennsylvania_looking_at_road_salt_alternative.html#inc
Vashta Nerada
(3,922 posts)Holly_Hobby
(3,033 posts)I spent 20 min. on the phone with our street dept. this morning asking them to please stop.
I live on a residential street 2 blocks long with a speed limit of 25mph. The salt truck has been back and forth spewing salt 7 times already today. It's 12 degrees - too cold for salt to work. Our city is nearly out of salt, time to conserve. We're way past the city budget for salt.
We don't have sidewalks, so I have to walk my dogs in the salted street if I want them to get their daily exercise. Salt and paws don't mix.
We have an extremely high water table of about 22". All that salt gets into our ground water.
I sold road salt to municipalities and private contractors for 6 years, I'm well aware of the environmental impacts.
We are used to not having our street salted. Plowed, yes. Salted, no. In 21 years on this street, there has never, ever been a car accident due to snow. We know how to drive in it, it's NW Ohio.
Children don't walk home from school on the road, their parents pick them up either at the school or at the bus stop. We don't have sidewalks.
I'm going to stop right there before I blow a gasket.
anasv
(225 posts)Holly_Hobby
(3,033 posts)as well as our city council rep.
I was told by a neighbor today that our new neighbor next door to us has a brother that works for the street dept. and he's the driver of the salt truck. Now it all makes sense.
I'm not going to stop complaining until it stops. I'm going to stop short of talking to the new neighbor about it, I don't want to get started out on the wrong foot, they just moved in Feb. 1st and I haven't met him yet.
SomethingFishy
(4,876 posts)Problem is once the snow melts and the weather clears the sand gets kicked up into the air and we end up with the "brown cloud" that hovers over Denver...
There has to be a better solution that salt or sand...
HappyMe
(20,277 posts)as often as they used to.
I would rather they salted instead of sand. Sand doesn't do a damn thing.