EMC Washoff in SWMM5

There are four steps to using EMC concentrations in your network:

1. Define your pollutant by adding a pollutant using the Data=>Quality=>Pollutant command:

2. Define the Land Use by using the Data=>Land Uses command or the Land Use Editor:

3. Define Buildup to be None by clicking on the None Tab:

4. Define the EMC Washoff concentration by clicking on the Washoff Tab:

This is where you would add a GW concentration
Zemanta Pixie

More: http://www.swmm2000.com/


Shams said…
Dear Dr Dickinson,

For example, I want to see N discharge in a water body through both surface and subsurface runoff. So, I intend to incorporate GW concentration also, how do I do that?

For example, I have data for total N.

GW conc=1 mg/L

EMC for Runoff= 2.5 mg/L

1. What should I use for rainfall concentration?

2. What should I use for washoff (EMC) ?

3. How is the rainfall conc used along with the EMC conc provided also?
Hi Shamns,

See the image i added to the blog to seen where the various concentrations are added.
Shams said…
Dr Dickinson,

Thank you for such a quick response!

As you mentioned in the images, the rainfall concentration(step 1)and EMC concentration (step 4) are both 5 mg/l

Are this concentrations depend on each other?

I am actually trying to learn how this concentrations are used. Let me summarize it this way

1. GW concentration will be used along with GW flow to generate subsurface pollutant contribution.

2. EMC concentration will be used along with runoff volume to generate surface runoff pollutant contribution.

3. How is rainfall concentration used ?

Thank you once again for helping me.
If you use the Rainfall concentration then all runoff will have the rainfall concentration + the EMC, it would be better if you just use the EMC as the EMC is a combination of the wet deposition and washoff from the dry deposition. You might be double counting if you use both rainfall and EMC.

Your GW concentration ideas seems correct to me.
Shams said…
Thank you Dr. Dickinson. I appreciate your help.

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