SOLUTION 1-4  Well S23                              # define aquifer...
 Na 86.5; Mg 18.2; Ca 11.2
 Cl 160.0
EXCHANGE_SPECIES
 Mg+2 + 2X- = MgX2; -log_k 0.54; -gamma 5.5 0.2
 Ca+2 + 2X- = CaX2; -log_k 0.78; -gamma 5.0 0.165
EXCHANGE 1-4
 X 0.7500; -equilibrate 1
PRINT; -reset  false                                # ... note to reduce printout
END

SOLUTION 0                                          # define injected solution and xpt...
 Na 9.4; Mg 0.5; Ca 2.13
 Cl 14.66
END

TRANSPORT
 -cells     4
 -shifts  400
 -length 9.24  3.83  2.94  2.48
 -dispersivity 1.0
 -punch     3
USER_GRAPH
 -headings Injected Na Cl Mg Ca
 -axis_scale x_axis 100 100000 auto auto true       # use logarithmic axes
 -axis_scale y_axis 0.1 160 auto auto true
 -plot_concentration_vs time
 -axis_titles "m^3 injected" "mmol/L"
 -start
 10 V0 = 295                                        # m3 from injection well to S23
 20 graph_x V0 * (step_no + 0.5)/cell_no
 30 graph_y 1e3 * tot("Na"), 1e3 * tot("Cl"), 1e3 * tot("Mg"), 1e3 * tot("Ca")
 -end
END