The notification also states that a factual record is warranted to examine
assertions that the EPA is failing to effectively ensure adoption in the
10 states of concern of total maximum daily loads (TMDLs) of mercury for
waterways that do not meet water quality standards for mercury. The submitters
assert that these permits and TMDLs must account for air emissions of
mercury from upwind coal-fired power plants.
"U.S. coal-fired power plants are the largest source of mercury emissions
in North America, spewing 48 tons each year,” said Dr. Elaine MacDonald
with Sierra Legal in Toronto.
“The CEC's investigation will highlight the connection between mercury
emissions from power plants and the thousands of mercury contaminated
water bodies and ensure that the EPA cannot continue to ignore the impact
of toxic air pollutants on water quality," MacDonald said.
The Secretariat did not recommend a factual record for the submitters'
assertion that the United States is failing to impose controls on air
emissions of coal-fired power plants through TMDLs or other Clean Water
The Secretariat noted that issues relating to control of mercury emissions
from coal-fired power plants are currently under review in litigation
challenging rules recently adopted in the United States under the Clean
Earlier this year, the EPA enacted a regulation that places restrictions
on power plant mercury emissions that environmental groups say are "minimal."
They allege that the cap and trade system established under that regulation
will allow coal-fired power plants to emit mercury for 10 years longer
than the current provisions of the Clean Air Act would allow at the expense
of public health.
Several environmental groups, including Waterkeeper Alliance, are currently
challenging the EPA mercury regulation in a U.S. federal court. They are
concerned about mercury emissions because the metal is a neurotoxin.
Exposure to high levels of metallic, inorganic, or organic mercury can
permanently damage the brain, kidneys, and developing fetus, according
to the Agency for Toxic Substances and Disease Registry (ATSDR), a U.S.
Metallic mercury and inorganic mercury compounds enter the air from mining
ore deposits, burning coal and waste, and from manufacturing plants, the
ATSDR explains. It enters the water or soil from natural deposits, disposal
of wastes, and volcanic activity.
Methylmercury may be formed in water and soil by the action of bacteria
on metallic and inorganic mercury. Methylmercury builds up in the tissues
of fish, and bioaccumulates up the food chain so that larger and older
fish tend to have the highest levels of mercury.
In the past 10 years, the number of U.S. states issuing warnings against
eating fish because of mercury poisoning has jumped from 27 to 45. One-third
of all U.S. lakes and hundreds of thousands of river miles are affected
by these advisories today, the submitters point out.
The CEC was established under the North American Agreement on Environmental
Cooperation to address environmental issues in North America from a continental
perspective, with a focus on those issues arising in the context of liberalized