Supporting Information for
Reactive Transport Modeling of Geochemical Controls on Secondary Water Quality Impacts at a
Crude Oil Spill Site near Bemidji, MN
Authors: Gene-Hua Crystal Ng*,a (gcng@umn.edu), Barbara A. Bekinsb (babekins@usgs.gov), Isabelle
M. Cozzarellic (icozzare@usgs.gov), Mary Jo Baedeckerc (mjbaedec@usgs.gov), Philip C. Bennettd
(pbennett@jsg.utexas.edu), Richard T. Amose (richard.amos@carleton.ca), and William N. Herkelrathb
(wnherkel@usgs.gov)
*
Corresponding author
Affiliations:
a
University of Minnesota, Dept. of Earth Sciences, 310 Pillsbury Dr SE, Minneapolis, MN 554550231, 612-624-9243
b
U.S. Geological Survey, 345 Middlefield Rd, Menlo Park, CA 94025, United States
c
U.S. Geological Survey, 12201 Sunrise Valley Dr, Reston, VA 20192, United States
d
University of Texas at Austin, Dept. of Geological Sciences, 1 University Station C1100, Austin,
TX 78712, United States
e
Carleton University, Dept. of Earth Sciences, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6,
Canada
Contents of this file:
Table (SI1), Figures (SI1)-(SI6)
Introduction:
Table (SI1) includes the initial condition geochemical values used in the simulation
Figures (SI1)-(SI4) show observations and simulations at well locations, which are used to calculate
residuals in Figures in main text.
Figure (SI5) shows full plume simulation results.
Figure (SI6) shows residuals, calculated from observations and simulations in Figures in main text.
Table (SI1): Initial condition and background concentrations [M] of inorganic aqueous species, with
oxidation states specified in parentheses. The second column shows concentrations from an
uncontaminated background well, 310e, located upgradient; the third column shows PHREEQC-2
batch simulation results after equilibrating with calcite, Fe(OH)3(a), and MnO2 and establishing charge
balance.
Total carbonates
CH4
Ca
Cl
Fe2+
Mg
Na
O2
Mn2+
N2
pH
pe
Well 310e
3.69x10-3
6.23x10-7
1.28x10-3
1.35x10-5
0.00
5.95x10-4
7.70x10-5
9.88x10-4
0.00
4.49x10-4
7.72
14.472
Equilibrated
3.65x10-03
0.00
1.25x10-3
3.10x10-4
5.06x10-24
5.95x10-4
7.70x10-5
9.88x10-4
8.54x10-16
4.49x10-4
7.629
14.297
Figure (SI1): Observations of the six major redox species shown in Figure (3) (in the main text) at the
three observational periods. Plots include well data from the available year closest to the target year
and are adapted to our model resolution. Left-hand stripes indicate the background and initial
concentrations, determined from up-gradient well observations. The boxes correspond to the oil body
reference rectangle. The polygons outline the plume extent for the corresponding component, which
are delineated around wells with measurements significantly different than background. Adapted from
Figures (5) and (6) from Ng et al. [2014].
Figure (SI2): Model simulation results for the six major redox species shown in Figure 4 (in main text),
at observation locations corresponding to Figure (SI1), at the three times corresponding to the
observational time periods. Left-hand stripes indicate the background and initial concentrations. The
boxes correspond to the oil body reference rectangle. The polygons outline the observed plume extent
for the corresponding component (same as in Figure (SI1)), and not the simulated results.
Figure (SI3): Observations of the three aqueous phase components in Figure (5) (in the main text), at
the three observational periods. Plots include well data from the available year closest to the target
year and are adapted to our model resolution. Left-hand stripes indicate the background and initial
concentrations, determined from up-gradient well observations. The boxes correspond to the oil body
reference rectangle. The polygons outline the plume extent for the corresponding component, which
are delineated around wells with measurements significantly different than background. Adapted from
Figures (5) and (6) from Ng et al. [2014].
Figure (SI4): Model simulation results for the three aqueous phase components in Figure (5) (in the
main text), at observation locations corresponding to Figure (SI3), at the three times corresponding to
the observational time periods. Left-hand stripes indicate the background and initial concentrations.
The boxes correspond to the oil body reference rectangle. The polygons outline the observed plume
extent for the corresponding component, and not the simulated results.
Figure (SI5): Full plume model simulation results corresponding to Figure (5) (in the main text). The
boxes correspond to the oil body reference rectangle.
Figure (SI6): Normalized model residuals (equation (11) in main text) corresponding to simulated
results and observations in Figure (9) (in the main text). Simulated Fe(III) corresponds to Fe(OH)3,
and simulated Fe(II) corresponds to the combined amounts of FeX2 (sorbed Fe(II)) and siderite
(precipitated Fe(II)). The boxes correspond to the oil body reference rectangle. The polygons outline
the observed plume extent for the corresponding component, and not the simulated results.