Why are they melting snow?

I noticed, during all the coverage of the recent snowstorm, that a number of locations are now going through the trouble of dumping snow into heaters so that the snow melts and they can then empty the water into a sewer. I saw this at O’hare and some city locations, as well. Assuming they have room for the piles, and I would think they do out at O’hare, why would they spend all the money and energy to melt it?

One tv station mentioned that municipalities can no longer dump snow into lakes and rivers because of some EPA rules. Perhaps that is true and, if so, no doubt is designed to keep contaminants like road salt out of the rivers. But changing the snow to water doesn’t get rid of the salt, and it looks to me like the water is being dumped into storm sewers, not sanitary sewers. So the salt would still get to the river, no?

I seem to remember years ago when Chicago would dump snow into empty IC RR cars and ship them to New Orleans. Letting nature take its toll, I guess.

The EPA problem involved dumping plowed snow in the lake. That’s bad because it contains oil, salt, plastic wrappers, etc.
Dumping melt water in sewers is better generally as sewer water is treated before being released.
I’ve seen giant machines in Europe where the snow is melted and water dumped in the sewer. Their streets may be somewhat cleaner too.

I bolded what may very well be another reason. I’ve heard lots of Northerners bitching about the snowplows shoveling snow back into the parking spots they’ve shoveled out, and that they’re running out of room to put the stuff they’re shoveling. Snow takes up a lotta space.

The assumption that there is enough room for the snow is presumptuous. In my neighborhood (a burb of Chicago), we have 8+ foot high piles on many street corners which prevent seeing before turning. It’s blind-ass luck that I and many others haven’t been t-boned while making one of these turns.

And in an airport situation, visibility is even more important.

I understand the desire to get rid of the big piles at street corners but I do not agree that airports have a bigger problem. Commercial jets sit way up in the air, they have no problem seeing around a mound of snow. And anyway, airports have huge amounts of empty space between runways so I would think finding a spot for snow wouldn’t be a problem.

To make those kind of piles you’d need some way of picking the snow up and putting it on top of other snow. Just using a plow wouldn’t be enough. Could it be that the melters are cheaper than the pilers?

Interesting that the opposite question came up just a few days ago.

Why Don’t We Melt Snow?

Piles of snow like that can blow around in the wind, seriously reducing visibility. It’s called ‘white-out’ conditions. As a child in western Minnesota, we sometimes got out of school when there was no snow falling, because the wind was blowing the existing snow around enough to make driving unsafe.

And Chicago is known to have a certain amount of wind, right?

Just as freezing water is easier if you vaporise it(like snow machines do), reflaking the snow would cause individual bits to melt(and boil off) more quickly. You could save a lot of energy while you are wasting even more.

There’s not just the runways to plow off at airports, but all those parking lots as well. That’s a lot of snow to stack up between runways. Also, if a plane veers off a runway, I’d rather have it run a bit on pavement or grass than smack into a high, frozen pile of snow and ice and whatever else.

Plus I suspect high piles of snow would reduce visibility on runways for cross-traffic/ground lighting.

I remember Toronto experimenting with snow-melting equipment over 30 years ago, IIRC. The logic explained at the time was that given the distance the snow would have to be trucked to a legal dump site, etc. it was more fuel-efficient to melt it than to truck it 20 or 30 miles - and the dump-truck would have to do a round trip, and how many dump-trucks do you have, so how fast can you haul the stuff away if each is doing 30 miles a load, etc.

That’s not actually true, generally. Sanitary sewers (what your toilet, sink, and everything else in your house dump to) are treated. Storm sewers (what street drains dump to) are almost never treated (beyond maybe some coarse sediment traps). That’s why you see the stencils above a lot of street drains “Don’t Dump: Drains to River”.

It’s actually a pretty good point that dumping snow in a river often isn’t going to be much worse than letting the melted snow run into a storm drain. I think it’s something that EPA and state agencies are just trying to get a handle on.

The cockpit may be high but the engines aren’t. The snow has to be away from the runways. Wherever the plows move the snow there has to be a road for them to operate on. The snow blowers used at airports can’t be used while other runways are active because they cause visibility problems.

As far as melting the snow into drainage sewers, that’s were it’s going when it melts any.

And before anyone asks, they don’t use salt at airports because it would get into the engines.

Typically, the run-off at airports (and other establishments w/ large paved/roofed area) will go down specific drains and into a nearby holding pond. Our airport, and even some of our newly-constructed Wal-marts, have this feature.

and the holding ponds go into the drain sewers. Their purpose is to slow down runoff to help mitigate flooding. And yes, some of it absorbs into the ground.

Airports have different runoff systems for deice areas but otherwise are no different than any other location.