Mercury in
Municipal Solid Waste
Mass Balance Study on Waste Incinerators
to Improve Mercury Estimate
wq-iw4-02f3
Ian Babineau
Engineer
Environmental Analysis & Outcomes
Minnesota Pollution Control Agency
Background
3321
2843
2705
110
Background
• TMDL products sector is large and not
decreasing (~28% of total)
• Mercury emitted from municipal solid waste
during processing and handling is ~38% of
products sector
• We had “Very Low” confidence in our estimate
for mercury emitted from municipal solid waste
Goal
• Improve our estimate for mercury emitted from
municipal solid waste during processing and
handling regardless of fate
• Do this by more accurately estimating the
mercury content in municipal solid waste
• Perform a mass balance on waste incinerators in
MN to find mercury content of municipal solid
waste
Goal
• Improve our estimate for mercury emitted from
municipal solid waste during processing and
handling regardless of fate
• Do this by more accurately estimating the
mercury content in municipal solid waste
• Perform a mass balance on waste incinerators in
MN to find mercury content of municipal solid
waste
Goal
• Improve our estimate for mercury emitted from
municipal solid waste during processing and
handling regardless of fate
• Do this by more accurately estimating the
mercury content in municipal solid waste
• Perform a mass balance on waste incinerators in
MN to find mercury content of municipal solid
waste
Goal
• Improve our estimate for mercury emitted from
municipal solid waste during processing and
handling regardless of fate
• Do this by more accurately estimating the
mercury content in municipal solid waste
• Perform a mass balance on waste incinerators in
MN to find mercury content of municipal solid
waste
Why Waste Incinerators?
• Most available and extensive data for mercury
concentrations in municipal solid waste
• Data for mercury concentration in ash streams
were available
• Data for mercury concentration in stack gas
were available
• Incinerators are located across many regions of
the state
What Did We Find?
What Did We Find?
0.83 ppm in 2011[concentration of mercury in MSW]
244 pounds of mercury in 2011
Range:
0.22 – 1.16 ppm
65 – 340 pounds
What Did We Find?
0.83 ppm in 2011[concentration of mercury in MSW]
244 pounds of mercury in 2011
Range:
0.22 – 1.16 ppm
65 – 340 pounds
What Did We Find?
0.83 ppm in 2011[concentration of mercury in MSW]
244 pounds of mercury in 2011
Range:
0.22 – 1.16 ppm
65 – 340 pounds
Comparison to Historical Hg in
MSW Estimates
1990
1995
2000
2005
New Mass Balance Hg in
MSW Estimate
2011
MSW Composted [tons]
30,000
67,997
21,092
20,000
16,437
MSW Incinerated (Resource Recovery) [tons]
N/A
1,379,329
1,228,830
1,240,000
1,129,050
MSW Landfilled [tons]
800,000
1,145,067
1,909,152
2,120,000
1,789,612
TOTAL [tons]
2,200,000
2,592,393
3,159,074
3,380,000
2,935,099
Mercury Content [ppm]
3.66
0.97
0.62
0.50
0.83
Mercury Content [pounds]
16,104
5,029
3,917
3,380
4,872
Volatilization during handling and trasnport
[pounds] (5% of Hg content)
805
251
196
169
244
MSW (MN Totals and Fates)
Historical Hg in MSW Estimates (taken from TMDL)
How did we get there?
• Performed a mass balance on Olmsted, HERC,
Perham, and Polk from 2005 – 2013
• Performed a trend analysis on Hg content for
each facility from 2005 – 2013
• Selected an MSW content that best represents
the state as a whole
Mass Balance Process Flow
Stack Gas
𝐻𝑔𝐴𝑖𝑟
Carbon Injection
Lime Injection
Fly Ash
Lime
Carbon
Sorted MSW
𝐻𝑔𝑀𝑆𝑊
Incineration
Bottom Ash
Combined Ash
𝐻𝑔𝐴𝑠ℎ
Mass Balance Process Flow
Stack Gas
𝐻𝑔𝐴𝑖𝑟
Hg in stack gas was found
to be statistically irrelevant
when compared to Hg in
combined ash.
Carbon Injection
Lime Injection
Fly Ash
Lime
Carbon
Sorted MSW
𝐻𝑔𝑀𝑆𝑊
Incineration
Bottom Ash
Combined Ash
𝐻𝑔𝐴𝑠ℎ
Simplified Mass Balance
𝐻𝑔𝑀𝑆𝑊 ≈ 𝐻𝑔𝐴𝑠ℎ
Results
Range
Facility
Olmsted
HERC
Perham
Polk
Average Hg
content in MSW
[ppm]
0.61
0.83
1.16
0.22
• 0.22 – 1.16 ppm
• 65 – 340 pounds of Mercury emitted in
2011
HERC Facility
0.83 ppm
•
Processes wasted generated by
~2M residence in MN
•
Processes 32% of waste that is
incinerated in MN
•
Diverse range of activities in the
waste shed
•
No pre-sorter on the process
•
Further analysis of different waste
sheds without incinerators would
require more resources
Comparison to historical Hg in
MSW Estimates
Historical
TMDL
Historical
Hg in MSW
Estimates
1990
1995
2000
2005
New Mass Balance
2011
MSW Composted
30,000
67,997
21,092
20,000
16,437
MSW Incinerated (Resource Recovery)
N/A
1,379,329
1,228,830
1,240,000
1,129,050
MSW Landfilled
800,000
1,145,067
1,909,152
2,120,000
1,789,612
TOTAL
2,200,000
2,592,393
3,159,074
3,380,000
2,935,099
Mercury Content [ppm]
3.66
0.97
0.62
0.50
0.83
Mercury Content [pounds]
16,104
5,029
3,917
3,380
4,872
Volatilization during handling and trasnport
[pounds] (5% of Hg content)
805
251
196
169
244
Fate of MSW (MN Totals)
More To Think About
• All mercury disposal bans were in place by 1994
• Most product sale and use bans were put in
effect between 1997 and 2007
• CFL sales boomed between 2007-2009 with
disposal expected to be 3-7 years after
purchase
Summary
• We needed to improve our confidence in the mercury
emitted from municipal solid waste during processing
and handling
• We wanted a standard methodology to use for future
estimates
• We found no trend in the data indicating that mercury
levels in municipal solid waste are not changing
• We are using HERC as the state-wide representation
Questions?
THANK YOU!
Olmsted Facility
• Average Hg content over 2010, 2011, and 2012 = 0.61 ppm
HERC Facility
• Average Hg content over 2005 – 2013 = 0.83 ppm
Perham Facility
• Average Hg content over 2005 – 2013 = 1.16 ppm
Polk Facility
• Average Hg content over 2005 – 2013 = 0.22 ppm