SIMULATION
  SIMULATION_TYPE SUBSURFACE
  PROCESS_MODELS
    SUBSURFACE_TRANSPORT transport
      MODE GIRT
    /
  /
END

SUBSURFACE

CHEMISTRY
  PRIMARY_SPECIES
    tracer
  /
  #LOG_FORMULATION
  OUTPUT
    TOTAL
    ALL
  /
END

NUMERICAL_METHODS TRANSPORT
  LINEAR_SOLVER
    SOLVER DIRECT
  /
END

GRID
  TYPE structured
  NXYZ 575 1 1
  DXYZ
   0.034782608695652174d0
   1.0d0
   1.0d0
  END
END

REGION all
  COORDINATES
    0.0d0 0.0d0 0.0d0
    20.0d0 1.0d0 1.0d0
  /
END

REGION first_cell
  COORDINATES
    0.d0 0.d0 0.d0
    0.d0 1.d0 1.d0
  /
END

REGION middle_cell
  COORDINATES
    9.982608695652173d0 0.0d0 0.0d0
    10.017391304347827d0 1.0d0 1.0d0
  /
END


MATERIAL_PROPERTY soil1
  ID 1
  POROSITY 1.d0
  TORTUOSITY 1.d0
END

FLUID_PROPERTY
  DIFFUSION_COEFFICIENT 1.d-9
END

STRATA
  REGION all
  MATERIAL soil1
END

TIME
  FINAL_TIME 80.d0 y
  INITIAL_TIMESTEP_SIZE 1.d0 h
  MAXIMUM_TIMESTEP_SIZE 1.d-1 yr
END

OUTPUT
  SNAPSHOT_FILE
    TIMES y 10. 20. 40. 80.
    FORMAT HDF5
  /
END

TRANSPORT_CONDITION initial
  TYPE DIRICHLET
  CONSTRAINT_LIST
    0.d0 initial
  /
END

TRANSPORT_CONDITION initial_conc
  TYPE DIRICHLET
  CONSTRAINT_LIST
    0.d0 initial_conc
  /
END

INITIAL_CONDITION initial
  REGION all
  TRANSPORT_CONDITION initial
END

INITIAL_CONDITION intial_conc
  REGION middle_cell
  TRANSPORT_CONDITION initial_conc
END


CONSTRAINT initial_conc
  CONCENTRATIONS 
    tracer 20.d0      T
  /
END

CONSTRAINT initial
  CONCENTRATIONS
    tracer 1.d-20     T
  /
END

END_SUBSURFACE