Wanted: Practical advice on silt traps

[ecosven]

Hello everyone,

I'm working on a large development in Scotland where floating roads are being constructed over blanket peat bog. The stone being used for the roads is soft sandstone, and watercourses on the site are under threat from silty slurry from the roads (the result of heavy traffic and wet weather).

Mitigation measures such as silt traps are specified, but I need advice on size, shape, design, flow rate etc. They need to be a)Effective, and b) COST-effective!

Does anyone have any practical advice on them, or ideas on where I might look?

Any contributions gratefully accepted.

Ecosven

 

[dicksewerrat]

Wrap the entire road in a geotextile. Then construct a new wear course out of real rock.

 

[ecosven]

Thanks Dicksewerrat,

If only using "real rock" was an option. Unfortunately the rock is quarried on site, and the cost, and environmental benefits of this were judged to outweigh the negatives.

Any ideas for silt traps...

Thanks again for the reply.
Ecosven

 

[DRC1]

The Connecticut Department of Transportation has its drainage manual online at

http://www.ct.gov/dot/cwp/view.asp?a=1385&Q=260116&dotPNavCtr=|#40139

Hope it helps

 

[layfieldman]

You can look at information from either the International Erosion Control Association (IECA) or the Erosion Control Control Technology Council (ECTC). One of the most traditional methods is for a sedimentation pond but if you have a peat bog that's probably not feasible. I think that you are looking too much for a quick fix instead of the real problem which is the road itself. I suggest building the road by containing the materials in a geocell with a geotextile under it.

 

[dicksewerrat]

Can the water be drained to one area? So you can run it throught a filter? I recall a product called 'Stormceptor that takes a lot of suspended solids out. Look for thier wbsite.

 

[pba]

Are we talking about an unsurfaced road? If we are I don't see any sensible method of catching the run-off.

If we are talking about a surfaced road, camber or crossfall to channel drain and gullys and then pipe to a shallow tank (or imperviously lined pit) with several sucessive filters before discharge to watercourse. Although this is Scottish peat bog, check the 'Sustainable Urban Drainage' guides from Environment Agency and CIRIA.

With peat bog I assume very high surface water level. It may be necessary to elevate the roadway to enable falls to be provided on the drainage system.

 

[ecosven]

Thanks everyone for their posts so far.

I completely agree that this is a "quick fix", and that better planning initially would have reduced the problems. It's too long a story to explain here.

Your help is greatly appreciated and has, I hope, assisted progress towards a solution.

I hope I'm able to contribute in the near future.

Ecosven

 

[KRSServices]

Can you elaborate on the origins of the silty runoff water? I am under the assumption that the surface of the road is anACP or similar structure. Or is it a gravel road? We use a number of different options for elimination of the silty water, but they depend on what your final objective is as well.

Can you provide more information?

KRS Services

http://www.krs-services.com