Salt

[Wild-Woman]

Does anyone know if the salt that's put down on the roads, during cold weather, does any environment damage? There must be an enormous amount of it washed off into adjacent land and into the water.

[Fourwings]

Originally Posted by Wild-Woman

Does anyone know if the salt that's put down on the roads, during cold weather, does any environment damage? There must be an enormous amount of it washed off into adjacent land and into the water.

That's a crackin' thought provoking question Jules, I have absolutely no idea what the enviromental impact of it would be but it's certainly has a very negative and highly corrosive impact on metal work, ie.. Cars, Trucks etc.....

Hopefully someone out there can enlighten us, I'd be really interested to hear if any studies have actually been done on this.

[Beryl]

I think it would kill an awful lot of slugs and snails. Salt desolve them

[svenrufus]

Originally Posted by Wild-Woman

Does anyone know if the salt that's put down on the roads, during cold weather, does any environment damage? There must be an enormous amount of it washed off into adjacent land and into the water.

Much of the salt will run off most roads into the foul drainage system which is isolated from the natural world at least through sewage treatment plants. Some spray and scattering of salt onto verges does occur and I have come across coastal plants quite far inland on road verges and roundabouts. I can only assume that this was the result of local environmental changes from salting.

I'm not too bothered about the salt issue though, the bigger concern is the other contaminants that come off roads. There are some nasty substances that come from motor traffic, such as residual polycyclic aromatic hydrocarbons - carcinogenic. Lots of heavy metals too, cadmium, mercury, other stuff, can't remember them all at the moment. Lots of research has been done on this, and it is a major issue. If it gets into the wider environment, it can contaminate river sediments for example and is very difficult to clear up. The possibility of this happening is a major tool in objecting to road developments passing environmentally sensitive areas. (I heard that Mohammed Al Fayed tried to sue the Highways Agency for killing his carp through run off after he bought a stately pile adjacent to the M25 is Surrey)

Salt, in the big scheme of things is the least of our worries when it comes to roads' impact on the environment - arguably, it could even increase biodiversity by creating areas with different conditions.

[Susie]

I am sure it has a negative environmental impact, which is why the Authority (in Wales I believe?) tried the sugar grit instead ... which got eaten by the sheep!

[Gill Catton]

Originally Posted by Wild-Woman

Does anyone know if the salt that's put down on the roads, during cold weather, does any environment damage? There must be an enormous amount of it washed off into adjacent land and into the water.

Chris Mead wrote an article once I think on the impact of road salt on small birds where it ends up getting mixed up with seed on the side of the road - where there's beech trees by the side of the road that sort of thing because they end up eating these seeds because of course they're not frozen - because of the salt and they end up then eating a lot of salt. Presumably this has a negative impact on the birds but whether this has an impact on national population levels I'm not sure......

[davewalker]

I do not know if this will help the discussion,but here goes. Although I can see a short-term effect on the enviroment,salt is probably only used on the roads for a very short period each year.
If you can imagine our roadside verges during the Spring, Summer and Autumn and the wide diversity of plant, insect and animal life that abounds in that enviroment,during this period,
it would seem to indicate that ,at present levels, no permanent damage is being done at the moment.
If, however,the verges ever cease to recover after winter, then we should have very real cause to worry about the long-term effect of keeping our roads safer.

This is a personal point of veiw, and not based on any solid evidence or facts, just my own observations

davew

[Gill Catton]

Originally Posted by davewalker

I do not know if this will help the discussion,but here goes. Although I can see a short-term effect on the enviroment,salt is probably only used on the roads for a very short period each year.
If you can imagine our roadside verges during the Spring, Summer and Autumn and the wide diversity of plant, insect and animal life that abounds in that enviroment,during this period,
it would seem to indicate that ,at present levels, no permanent damage is being done at the moment.
If, however,the verges ever cease to recover after winter, then we should have very real cause to worry about the long-term effect of keeping our roads safer.

This is a personal point of veiw, and not based on any solid evidence or facts, just my own observations

davew

Well as Sven pointed out there are many main roads now that have plants that are usually coastal growing on the edge of the tarmac - things like scurvygrass and sandworts this is a pretty permanant year round presence though I'm not certain it's negative - but it clearly illustrates that the properties of the immediately adjacent land have been altered.

[Wild-Woman]

This American article is quite interesting.

http://greendecade.org/download/rock_salt.pdf

[aeshna5]

Many halophytes- saltmarsh plants- have in recent decades increasingly colonised the central reservations , roadsides + roundabouts of our major highways. Danish Scurvygrass is possibly the most obvious as a white carpet appears from Feb-April in many places, but various grasses such as Puccinellia maritima + Parapholis strigosa have been found using this habitat as have some of the attractive Sea Spurrrey species.

These species have thrived due to their physiological adaptations to high salt levels. They are not strong competitive species, so do well when other species are physiologically stressed.

Certainly interesting for field botanists + ecologists studying this fairly recent phenomenon.