£
\
%
^,eDst%
Q
o
s?
Toxics Release Inventory
2007 Mercury Report
U.S. EPA Region 9: California, Arizona, Nevada, Hawaii, the Pacific Islands, and Tribal Nations
The 2007 Data for Mercury
Mercury1 is a persistent, bioaccumulative and toxic
(PBT) chemical. As such, it has a significantly lower
Toxic Release Inventory (TRI) reporting threshold
(10 pounds) than do non-PBT chemicals (10 thou-
sand or 25 thousand pounds). Metal mining is the
largest source of mercury releases reported in Re-
gion 9. Other main sources of mercury releases in
the Region are hazardous waste treatment and dis-
posal, cement manufacturing and fossil fuel electric
power generation facilities.
Nevada ranks #1 in the United States for reported
mercury releases, with 88% of all releases. Arizona
ranks #7; California #8; and Hawaii #49.
2007 Mercury Releases: Ranking by State
#7 Arizona #8 California
1%	1%
#9 Texas
0.4%
All Other
3%
Mercury Releases in Region 9
Within the region, Arizona had the largest percent
increase (440%) of mercury releases from 2006,
from 8.8 to 47 thousand pounds. The industry with
the top mercury releases varies by state: Gold Min-
ing (Nevada), Copper Mining (Arizona); Hazardous
Waste Treatment and Disposal (California); Petro-
leum Refineries (Hawaii).
State
2007 Mercury
Releases
Largest
Releases
Nevada
6,094,786
Gold Mining
Arizona
47,550
CopperMining
California
43,893
HazardousWaste
Hawaii
201
Petroleum Refineries
One hundred forty-six facilities in Region 9 reported
6.2 million pounds of mercury releases, up 1.8
million pounds from 2006. Nevada miningfacilities
account for 98% of the Region's mercury releases.
Facilities with Largest Mercury Releases
(Region 9)
Facility
Name
State
2006
2007
Percent
Change
Barrick Goldstrike
Mines Inc
NV
2,149,211
2,220,174
3%
Newmont Mining Corp
Twin Creeks Mine
NV
1,500,697
1,980,659
32%
Newmont Mining Corp -
Carlin North Area Mine
NV
87,020
780,166
797%
Ruby Hill Mine
NV
14,229
409,607
2,779%
Newmont Mining Corp -
Carlin South Area Mine
NV
90,470
295,554
227%
Cortez Gold Mines
NV
148,949
152,234
2%
Marigold Mining Co
NV
69,001
75,573
10%
Bald Mountain Mine
NV
26,626
62,228
134%
Newmont Mining Corp
Lone Tree Mine
NV
109,631
59,630
-46%
Freeport-Mcmoran
Morenci Inc
AZ
No report
42,017
—
Chemical Waste
Management Inc
CA
28,073
30,965
10%
US Ecology
Nevada Inc.
NV
26,112
25,857
-1%
1 Includes the mercury present in mercury compounds.

-------
Releases to the Environment
Total (on- & off-site) mercury releases increased
41.3% (1.8 million pounds) from 2006 to 2007.
Releases to land are the largest category of releas-
es, followed by air.
Release
Desination
Reporting Year
Percent
Change
2006
2007
Air
8,563
7,081
-17%
Land
4,355,860
6,177,091
+42%
Water
6
6
-1%
Underground Injection
3
4
+24%
Off-site
13,990=
2,414
-83%
Total Releases
4,378,422
6,186,595
+41%
Releases to Land
Mercury releases to land increased 42% since
2006, and 72% since 2005. Largest Increase:
Gold mines Newmont Mining Corporation
(Newmont)-Carlin North Area Mine (693 thousand
pounds), Newmont-Twin Creeks Mine, (480 thou-
sand pounds), Ruby Hill Mine (395 thousand
pounds) and Newmont-Carlin South Area Mine
(205 thousand pounds). Largest Decrease:
Newmont-Lone Tree (gold) Mine (50 thousand
pounds).
Releases to Air
Reported mercury releases to air decreased 17%
(1,483 pounds). Largest Decrease: Marigold
(gold) Mining Co. (903 pounds), Lehigh Southwest
Cement (442 pounds), Kennecott Rawhide Mining
Co (290 pounds), Hanson Permanente Cement
(258 pounds), and Bald Mountain (gold) Mine (147
pounds). Largest Increase: The Salt River Project
Navajo Generation Station (326 pounds), Newmont
Mining-Carlin South Area Mine (196 pounds),
Newmont Mining Corp-Carlin North Area Mine
(146 pounds), Barrick Goldstrike (gold) Mines, Inc.
(115 pounds) and Cortez Gold Mines (103 pounds).
Off-site Transfer and Disposal
Reported off-site releases decreased 83% from
2006 to 2007. Largest Decrease: Clean Harbors
San Jose LLC (hazardous waste facility) - 11
thousand pounds, 99% reduction. Largest In-
crease: US Ecology Nevada Inc. (hazardous waste
facility) - 469 pounds, a 100% increase.
2007 Mercury Releases (in pounds) by State
State
Air
Land
Underground
Injection
Water
Off-site
Total
Releases
AZ
1,966
45,355
0
0
112
47,433
CA
1,677
40,960
1
2
1,193
43,832
HI
55
0
3
4
141
203
NV
3,383
6,090,776
0
0
968
6,095,127
Total
7,081
6,177,091
4
6
2,414
6,186,595
Nevada's Elko, Humboldt and Eureka Counties re-
leased the largest amounts of mercury in 2007. The
counties with the largest releases of mercury in
Arizona and California are Greenlee County and
Kings County, respectively.
10 Counties with Largest Mercury Releases (Region 9)
County
State
2007
ELKO
NV
2,220,562
HUMBOLDT
NV
2,119,216
EUREKA
NV
1,485,327
LANDER
NV
169,238
WHITE PINE
NV
62,228
GREENLEE
AZ
42,017
NYE
NV
33,154
KINGS
CA
30,965
IMPERIAL
CA
9,940
PERSHING
NV
4,704
Industry Sectors
The gold mining industry accounts for 98% of
reported mercury releases in Region 9. Among the
remaining two percent, hazardous waste treatment
and disposal, non-gold metal mining, and fossil fuel
electric power generation are the top contributors.
2 FreeportMcMoran (formerly Phelps Dodge) Miami revised its 2006 off-site releases
from 39 thousand to 21 pounds.

-------
Mercury Releases (in pounds) by Industry Sector
Industry Sector
2007 Releases (lbs.)
Gold Ore Mining
6,073,999
Hazardous Waste Treatment and Disposal
57,401
Copper Ore & Nickel Ore Mining
44,210
Silver Ore Mining
4,381
Fossil Fuel Electric Power Generation
3,335
Cement Manufacturing
1,137
Petroleum Refineries
1,002
Other
1,129
Total
6,186,595
Gold Mining
Mercury can be processed as a trace constituent
in metal ores or recovered as a by-product from
gold ores. Many mines extract, move, store, process,
and dispose of large amounts of waste rock and
ore materials containing low concentrations of
naturally-occurring metals.
The vast majority of this material is placed in sur-
face impoundments or on land, and the metals are
reported as on-site releases to land. This material
is subject to leaching by rain, snow, and acid mine
drainage, and must be carefully managed and moni-
tored to prevent surface or ground water contam-
ination. Gold ore processing and metal refining
operations also release mercury to the air.
In the Pacific Southwest Region, 16 gold mines
reported 6.1 million pounds of total mercury
releases, most of which were released on-site to
land. These gold mines reported a total of 3,236
pounds of mercury releases to the air.
Copper Mining
Five copper mines in Region 9, all located in
Arizona, reported 44 thousand pounds of mercury
releases. The majority of these mercury releases
were to land.
Hazardous Waste Disposal
Hazardous waste facilities reported 57 thousand
pounds of mercury released to land. These facilities
also reported 1,063 pounds of off-site releases.
Silver Mining
One silver mining facility, Coeur Rochester (NV),
reported mercury releases of 4,365 pounds to land
and 16 pounds to air.
Electricity Generation
Only facilities that burn coal or oil to generate elec-
tricity commercially are required to report to TRI.
Mercury compounds may be formed during the
combustion process. Eighteen fossil fuel electricity
generation facilities reported 3,335 pounds of
mercury releases, with 62% to air and 38% to land.
Cement Manufacturing
Mercury may be processed or otherwise used as a
trace element in raw materials and fuels in the
manufacture of hydraulic cement. Eleven facilities
reported 1,137 pounds of mercury releases, 99%
of which were releases to air.
Petroleum Refineries
Mercury may be processed or otherwise used as
trace components in crude oil. In 2007, 21 petro-
leum refineries reported 1,002 pounds of mercury
releases, with 73% transferred off-site, and 26%
released to the air.
National Security Facilities
The U.S Navy Naval Air Weapons Station China Lake
is the onlyfederal national security facility in Region
9 to report mercury releases in 2007. Of the 454
pounds in total releases, 429 pounds were trans-
ferred off-site and 25 pounds were released to the
air.

-------