7/8/2013 1 The Long‐Term Impact of Metal Smelting Operations on Arsenic Availability in Urban Lakes of the South‐Central Puget Sound Region Jim Gawel, Ph.D. University of Washington Tacoma Environmental Science and Studies Research Team • UWT Undergraduates: Lindsay Tuttle, Sarah Burdick, Michelle Miller, Jessica Asplund, Shawna Peterson, Kara Ziegler and Alexandra Ehle • Bellarmine High School: Amanda Tollefson and Brian Rurik • UW Seattle Faculty: Becca Neumann Importance of Urban Lakes • Human population concentrated in urban areas; already 50% or greater worldwide • Urban poor rely on local, inexpensive recreational water resources • Some rely on water sources for cultural ties and diet augmentation • Urban waters serve as critical habitat for multiple species Urbanization & Arsenic Pollution • Lake sediments act as As reservoirs after external source removal • If remobilized periodically As may migrate to surface sediments • Cultural eutrophication can exacerbate As release from sediments • Other anthropogenic inputs may affect As mobility (e.g. road salt, nitrate and phosphate) Major Sources of Arsenic in Lakes • Herbicide applications in lakes • Fruit orchard insecticides [Paris Green ‐ 3Cu(AsO 2 ) 2 .Cu(C 2 H 3 O 2 ) 2 ] • Chemical manufacture • Timber treatment [CCA] • Mine tailings and drainage • Smelting – Air emissions – Slag disposal ASARCO • 1890 Lead smelting begins • 1905 Conversion to copper smelter • 1912 Arsenic recovery begun in Tacoma • 1917 Tall stack constructed (700 ft asl) + electrostatic precipitators • 1970 Meteorological Curtailment Program • 1986 All smelting operations cease
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7/8/2013
1
The Long‐Term Impact ofMetal Smelting Operations on
Arsenic Availability in Urban Lakes of the South‐Central Puget Sound Region
Jim Gawel, Ph.D.
University of Washington Tacoma
Environmental Science and Studies
Research Team
• UWT Undergraduates: Lindsay Tuttle, Sarah Burdick, Michelle Miller, Jessica Asplund, Shawna Peterson, Kara Ziegler and Alexandra Ehle
• Bellarmine High School: Amanda Tollefson and Brian Rurik
• UW Seattle Faculty: Becca Neumann
Importance of Urban Lakes
• Human population concentrated in urban areas; already 50% or greater worldwide
• Urban poor rely on local, inexpensive recreational water resources
• Some rely on water sources for cultural ties and diet augmentation
• Urban waters serve as critical habitat for multiple species
Urbanization & Arsenic Pollution
• Lake sediments act as As reservoirs after external source removal
• If remobilized periodically As may migrate to surface sediments
• Cultural eutrophication can exacerbate As release from sediments
• Other anthropogenic inputs may affect As mobility (e.g. road salt, nitrate and phosphate)
Major Sources of Arsenic in Lakes
• Herbicide applications in lakes• Fruit orchard insecticides
[Paris Green ‐ 3Cu(AsO2)2.Cu(C2H3O2)2]
• Chemical manufacture• Timber treatment [CCA]• Mine tailings and drainage• Smelting
WA Dept. of Ecology. 2002. King County mainland soil study.
Angle Lake
Steel Lake
Lake Meridian
Lake Killarney
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3
Lakes within predicted deposition zone significantly higher in As and Pb
As vs. Pb in Surface Sediments
0
20
40
60
80
100
120
140
160
0 100 200 300 400 500 600
average Pb conc (ppm)
ave
rag
e A
s c
on
c (p
pm
)
Crescent
Killarney
Fenwick
Meridian
Fivemile
Long (Kitsap)
Spanaway
Geneva
Horseshoe
Bay
Angle
Wye
Wicks
Surprise
Steel
Snake
Steilacoom
Two Different Sources?
R2 = 0.8932
R2 = 0.69780
20
40
60
80
100
120
140
0 100 200 300 400 500 600
Average Concentrations of Pb in ppm
Av
era
ge
Co
nc
en
tra
tio
n o
f A
s in
pp
m
•1:1 As:Pb ratio may be fingerprint of ASARCO slag/emissions (Mariner et al. 1997)
As in Sediment Cores
•Significant correlation between As and Pb in all cores except Brook and Spanaway
0
5
10
15
20
25
30
35
40
45
50
0 20 40 60 80 100
As (mg/kg dry sediment)D
ep
th in
co
re (
cm)
Fivemile Lake
Lake Geneva
Steel Lake
Spanaw ay Lake
Bonney Lake
0
10
20
30
40
50
60
70
0 50 100 150 200 250
As (mg/kg dry sediment)
De
pth
in c
ore
(cm
)
Angle Lake
North Lake
Lake Meridian
Lake Killarney
Killarney AmericanAngle
WaughopBonnie Dolloff
Sediment Summary
• Surface sediments in 10 of 12 lakes in deposition zone exceed probable effects concentration of 33 ppm As and 128 ppm Pb– PEC = “above which harmful effects are likely to be observed” (MacDonald et al. 2000)
• Lake Killarney and Angle Lake show highest sediment concentrations at sediment surface– Ongoing inputs?
– Vertical migration?
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4
Sediment/Water Transfer
p < 0.01
•Similar ratio seen in Lake Washington by Peterson and Carpenter (1986)•Similar ratio in suite of lakes in Massachusetts by Lattanzi et al. (2007)
Basic Red/Ox Chemistry
AsO43- [As(+V)]
(arsenate)
AsO33- [As(+III)]
(arsenite)
Fe(OH)3(s) [Fe(+III)]
Fe2+ [Fe(+II)]
SO42- [S(+VI)]
HS- [S(-II)]
Effect of Eh and pH on As/Fe/S
• Primary inorganic forms:
– arsenate [As(V):H2AsO4‐]
– arsenite [As(III): H3AsO4]
• As(V) binds readily to Fe(III)‐oxides and may precipitate
• As(III) is more soluble and toxic
• As(III) may bind to S(‐II) and Fe(II) and precipitate
•Generally dissolved As, Fe, and S increase proportionately under reducing conditions•Killarney does not match that pattern, why?
DO vs PO4 in Select Lakes
•PO4 still elevated in Killarney in the presence of high DO•Highest PO4 when near bottom water goes anoxic (calm, warm weather)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 2 4 6 8 10 12
Dissolved PO4(µM)
Dissolved Oxygen (mg/L)
Meridian, Angle, North
Killarney
Filtered vs. Unfiltered
Dissolved Arsenic Speciation
0
2
4
6
8
10
12
14
0% 20% 40% 60% 80% 100%
% of total (IC-ICP-MS)
De
pth
(m
)
As(III)
As(V)
Other
Angle Lake
0
2
4
6
8
10
12
14
0% 20% 40% 60% 80% 100%
% of total (IC-ICP-MS)
De
pth
(m
)
As(III)
As(V)
Other
Steel Lake
0
2
4
6
8
10
12
14
0% 20% 40% 60% 80% 100%
% of total (IC-ICP-MS)
De
pth
(m
)
As(III)
As(V)
Other
North Lake
0
2
4
6
8
10
12
14
0% 20% 40% 60% 80% 100%
% of total (IC-ICP-MS)
De
pth
(m
)
As(III)
As(V)
Other
Lake Killarney
•Analysis by Applied Speciation Inc.•Highly mobile As(V) in these lakes in general, with only North Lake having As(III)
Proposed Model for As Mobilityin Presence of Oxygen
Current hypothesis:(1) Microbially available orgC for reductive dissolution of arsenic‐bearing sediments(2) NOM and/or phosphate to keep arsenic from sorbing to settling particles(3) Shallow water column that resists stratification
7/8/2013
6
Wa
pa
to L
ake
Dep
th (
me
ters
)
Lak
e D
ollo
ff
Dep
th (
met
ers
)
Temperature ºC Dissolved OxygenArsenic in Water (ppb)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
10 12 14 16 18 20 22 24
06/21/07
08/16/07
Secchi depth
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 2 4 6 8 10 12 14
06/21/07
08/16/07
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
0 2 4 6 8 10 12 14 16
As Filtered06/21/07As Unfiltered06/21/07As Filtered08/16/07As Unfiltered08/16/07
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
10 12 14 16 18 20 22 24
07/05/07
08/30/07
Secchi depth
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10 12 14
07/05/07
08/30/07
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0 2 4 6 8 10 12 14 16
As Filtered07/05/07As Unfiltered07/05/07As Filtered08/30/07As Unfiltered08/30/07 Total As (unfiltere d) nM
0 50 100 1 50 200 250
0
2
4
6
8
10
6/22/98
7/6/98
7/30/988/17/98
9/17/98
10 /6/98 10 /27/98
To tal As (unfilte red) nM
0 2 0 40 60 80 100
4/14 /99
5/3/99
5 /19 /996/2/99
6 /25 /99
Not Just in Washington
North Basin – Spy Pond, MA (Senn et al. 2007)
Questions to Address in Research
• What is the mix of water quality parameters to measure to predict As mobility in urban lakes?
• Does the presence of high levels of dissolved As in surface waters increase biotic uptake by phytoplankton, zooplankton, and fish?
• Would fish bioaccumulation become an issue under these conditions?
• How might this be important to freshwater sediment criteria development?
0.0E+00
2.0E‐10
4.0E‐10
6.0E‐10
8.0E‐10
1.0E‐09
1.2E‐09
Angle Killarney North Steel Wapato
mol PC(n=2)/ug chl‐a
(n=1)
ND
Bioindicators of Metal Toxicity
Acknowledgements
• Funded by:
– UWT Environmental Sciences Program
– UWT Founders Endowment
– UWT Chancellor’s Fund for Research
• As speciation provided by Applied Speciation, Inc., Tukwila, WA, at major discount
• Environmental Sciences and Studies at University of Washington Tacoma:http://www.tacoma.uw.edu/interdisciplinary‐arts‐sciences/courses/environmental‐studies
• University of Washington Superfund Research Program:http://depts.washington.edu/sfund/
• US EPA Region 10:http://www.epa.gov/aboutepa/region10.html
• Dr. Bruce Duncan, Regional Science Liaison, US EPA Region 10([email protected])
• Superfund Research Program‐ National Institute of Environmental Health Sciences(NIEHS)http://www.niehs.nih.gov/research/supported/srp/