• ### Method to simulate contamination transport

Hy,

I'm running a transient flow/transport model of  a chalk aquifer unconfined in one area, then becoming confined under a impermable formation.
The simulation starts from August 2007 to December 2012.
The contamination sources are represented by  5 points on the second slice (the model contains 16 slices) at which the concentration is 100 mg/l during one day (01/01/2008).
The concentration is observed in 13 bore hole (multilayer wells)

I have tested 2 method :

1.
First, I have applied an initial concentration equal to zero to all my model ("Mass concentration" parameter)
Then I have imported a time series like :
Concentration = 0 mg/L at 31/12/2007
Concentration = 100 mg/L at 01/01/2008
Concentration = 0 mg/L at 02/01/2008
And I have assigned this time serie to the parameter "Mass-concentration BC"

2.
The second method I have tried is to apply an initial concentration equal to zero to all my model ("Mass concentration" parameter) exept for 5 points (contamination sources) where concentration is set to 100 mg/L.
So, my time simulation runs from August 2007 to December 2012 with a contamination at the first step.

The results shows a big différence between this 2 method (factor 10).
So, Can somebody explain me the difference between this 2 method ?
What's the best way to simulate under FeFlow the pollution of aquifer ? Using the "Mass-concentration" parameter or the "Mass concentration-BC" ?

Any help will be appreciated.
Thanks ,
• ### Re: Evaluate quantity of contaminant injected

Thank you,

If I use Rate Budget, at the steptime of injection (injection : 100 mg/L - 1 day ), the Rate budget indicates :
Dirichlet BC'S = -68.804 [g/d]
Imbalance = -68.804 [g/d]

And when I export the period budget, it indicates at the steptime of injecition :
Dirichlet BC'S - Rate out = -68.804 [g/d]
Dirichlet BC'S - Out = -344 [g]

So, what can I deduce about the mass injected ? Have I injected 68 g or 344 g ?

• ### Evaluate quantity of contaminant injected

Hy,

I'm running a transient flow/transport model.  The quantity of contaminant is 100mg/L.
How can I evaluate the quantity of mass injected ? (Budget tool ?)

Any ideas would be great help

Thanks ,

Version 6.2
• ### High concnetration Transport model

Hy,

I'm running a transient flow/transport model.  The quantity of contaminant is 100mg/L. The concentration is observed in 13 bore hole.
The results  (Charts -> Average concentration) indicate a too high concentration for 2 bore hole.

Any ideas would be great help

Thanks ,