Mercury in the West Land and Water Fund of the Rockies and Rocky Mountain Office of Environmental Defense

Hg is present in the earth’s atmosphere in the form of elemental vapor, reactive (i.e., oxidized) gaseous Hg, and particulate Hg
Hg that gets into aquatic ecosystems through atmospheric deposition or soil runoff can be transformed into an extremely toxic organic methylmercury which bioaccumulates up the food chain as humans and animals consume contaminated organisms such as fish.
Total Hg emissions are higher in the East than in the West, as expected, since utility emissions are much higher in the East
In fact, New Mexico had the highest average atmospheric Hg concentration in U.S. for 2000
The EPA Information Collection Request analysis indicates that subbituminous coals emit relatively more elemental Hg than bituminous coals
Both elemental and reactive gaseous Hg can be absorbed onto porous solids such as fly ash, powdered activated carbon or calcium-based acid gas sorbents for subsequent collection in a PM control device such as a fabric filter

1. Mercury in the West*
Land and Water Fund of the Rockies
and
Rocky Mountain Office of
Environmental Defense
January 2003
*The information in this presentation is largely drawn from the white paper “A Closer Look at Mercury in the
West” prepared by Paulette Middleton for the Land and Water Fund of the Rockies and Environmental Defense
(http://panoramapathways.net/mercuryinthewest.pdf)

2. Mercury Overview
Hg is present in the earth’s atmosphere in
the form of elemental vapor, reactive (i.e.,
oxidized) gaseous Hg, and particulate Hg
Hg that gets into aquatic ecosystems
through atmospheric deposition or soil
runoff can be transformed into an extremely
toxic organic methylmercury which
bioaccumulates up the food chain as humans
and animals consume contaminated
organisms such as fish

3. Mercury Overview - II
Children and fetuses, because they are in rapid
developmental stages, are particularly susceptible
to the harmful neurological effects of
methylmercury
In a 2000 report, the National Academy of Sciences’
National Research Council estimated that each
year about 60,000 children may be born in the U.S.
with neurological problems that could lead to poor
school performance because of exposure to
methylmercury in utero

4. Mercury Fate and Transport
Because of differences in the forms of
Hg and its transport behavior,
populations can be placed at risk from
Hg that may have come from local
sources, a different state, or a different
part of the world
In the US, both the West and East are
source regions of mercury as well as
affected areas

5. Mercury Fate and Transport - II
The more reactive gaseous forms of
Hg can be deposited on land and
water much closer to the sources
Elemental Hg can persist in the
atmosphere and be transported
longer distances, but is a substantial
contributor to Hg concentrations in
land and water especially in remote
areas where atmospheric transport is
the main mechanism of contamination
All airborne Hg also can undergo
chemical reactions that lead to Hg
compounds that are more readily
deposited

6. Mercury Fate and Transport – III
Long-range vs. Short-range
Quantification of transport is a matter of on-going investigation
Grumet (former NESCAUM) estimates that 47% of Hg deposited in the
Northeast comes from within that region, 30% from other US sources
and 23% from global sources
(http://www.eerc.und.nodak.edu/catm/graphics/v7i1part2.pdf)
Levin suggests that Hg deposition is concentrated in areas close to
sources, that Asian emissions account for 10-20% of deposition on the
West Coast, and that non-anthropogenic sources contribute 4-7% in the
East and 10-12% in the West (same cite)
Based on modeling, Bullock (NOAA) estimates that 25-30% of the
deposition in the US comes from global background, the rest from US
sources (http://pubs.acs.org/hotartcl/est/98/apr/mer.html)
Comparing lake sediment core samples from MN and coastal AK, Swain
(MN Pollution Control Agency) estimates that 40% of Hg is due to
regional anthropogenic sources (same cite)
Modeling analysis by Seigneur (AER, Inc.) suggests that global
background accounts for about 70% of Hg deposition in the US

7. Sources of U.S. Anthropogenic Hg
Source: EPA Mercury Report to Congress (1997)
About 158 total tons of Hg are
emitted in the US each year
4 source categories are responsible
for about 80% of total
anthropogenic Hg:
–Coal-fired utilities are largest
source at 33%
–Municipal waste combustors (19%)
–Commercial/industrial boilers (18%)
–Medical waste incinerators (10%)
Coal-fired power plants are largest
uncontrolled anthropogenic source
of Hg

8. Coal-fired Power Plant
Hg Emissions
US Coal-fired units emitted 48 tons of Hg in 1999
Speciation: about 3% particulate, 43% reactive
gaseous, and 54% elemental
Breakdown varies from plant-to-plant depending
on type of coal being burned and emission
controls in place
Total Hg emissions are higher in the East than in
the West, as expected, since utility emissions are
much higher in the East
NM is highest in West and ranks 15
th
nationally
Source: EPA 1999 Information Collection Request

9. Western Coal-fired Power Plant
Hg Emissions
Source: EPA 1999 Information Collection Request
0
0.2
0.4
0.6
0.8
1
1.2
NMWYAZMTWACONVUTORCA
Hg from Power
Plants (tons/yr)

10. The West Has High Levels of
Mercury Contamination
Although there are limited monitoring sites in
the West, recent observations of Hg
concentration and deposition indicate that Hg
levels in the West are similar to those in the
East
In fact, New Mexico had the highest average
atmospheric Hg concentration in U.S. for
2000
Colorado had a high total wet deposition level
in 2000, comparable to eastern monitoring
sites
SOURCE: National Atmospheric Deposition Program, Mercury Deposition Network

11. Annual Average Mercury
Atmospheric Concentrations, 2000
National Atmospheric Deposition Program, Mercury Deposition Network

12. Total Annual Mercury Wet
Deposition, 2000
National Atmospheric Deposition Program, Mercury Deposition Network

13. Hg Monitoring in the West
The western NADP sites indicated on the
preceding maps are:
–Buffalo Pass, Routt County, Colorado
–Caballo, Sierra County, New Mexico
–Seattle, King County, Washington
–San Jose, Santa Clara County, California
–Covelo, Mendocino County, California

14. Fish and Wildlife Advisories
If high concentrations of Hg or
other chemicals are found in
local fish and wildlife, states
or tribes may issue a
consumption advisory
Virtually every western state
(except Wyoming) had active
fish consumption advisories
for specific water bodies in
2000

15. Fish Consumption Advisories
by State for 2000
Total Number of Fish Consumption Advisories —2000
(Change from 1999)
Note: The numbers depicted here do not necessarily reflect the geographic extent of the
chemical contamination in each state or the extent of the state’s monitoring effort.Source: NLFWA, December 2000

16. Current advisories issued for:
Mercury
PCBs
Chlordane
Dioxins
34 other chemicals.
Advisories are in effect in:
63,288 lakes, representing
23% of our Nation’s lake
acres
9.3% of our Nation’s rivers
miles
100% of the Great Lakes
71% of coastline of
contiguous 48 states.
Number of advisories in the US in
2000 represents a 7% increase over
1999; 124% increase since 1993.
48 states, the District of Columbia,
and 1 US territory and 8 Canadian
provinces and 1 Canadian territory
have fish advisories.
48 states and 1 US territory and 7
Canadian provinces and 1
Canadian territory have
waterbody-specific advisories
14 states and the District of
Columbia have statewide
advisories and 2 Canadian
provinces have provincewide
advisories for lakes and/or rivers
15 states have all of their marine
coastal waters under advisory.
NOTE: This map depicts waterbodieswhere fish consumption advisories were in effect in 2000 based on information
provided to the USEPA by the states in December 2000 and Canadian provinces in December 1997. Because only
selected waterbodiesare monitored, this map may not reflect the full extent of chemical contamination of fish tissues
in each state or province. EPA US Fish and Wildlife Contamination Progrram
LEGEND
Source : NLFWA, December 2000
LEGEND
Location of Waterbodies under Consumption
Advisories, by Pollutant – 2000

17. Western Mercury Advisories
The table in word
format accompanying
this presentation lists
mercury advisories for
waterbodies in western
states
Advisories are in effect
for waterbodies across
the West

18. Mercury Control Options for
Western Power Plants
The EPA Information Collection Request
analysis indicates that subbituminous coals
emit relatively more elemental Hg than
bituminous coals
Both elemental and reactive gaseous Hg can
be absorbed onto porous solids such as fly
ash, powdered activated carbon or calcium-
based acid gas sorbents for subsequent
collection in a PM control device such as a
fabric filter

19. Mercury Control Options – II
Western Power Plants
Powdered activated carbon (PAC)
injection has been successfully
demonstrated for about 10 years on med
waste incinerators, mun waste
combustors and haz waste combustors
The activated carbon is injected before
the fabric filter and, if necessary, a water
mist used to cool the flue gas
In cases where a spray dryer fabric filter
system is used, the gas cooling occurs in
the spray dryer and no mist is necessary

20. Mercury Control Options – III
Western Power Plants
The EPA Information Collection
Request data also indicate that
chemistry associated with the
selective catalytic reduction (SCR)
systems may be enhancing the
oxidation of Hg and, as a result,
increasing capture efficiency
How it Works: SCR processes
designed to reduce NOx by
converting NOx to N2 can enhance
the oxidation of Hg to forms that
are more readily captured