• 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 ?

    Thanks for your help
  • 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 ,