Mercury is a naturally-occurring element found in rock in the earth’s crust, including in deposits of coal. It exists in several forms. For example, pure mercury is a liquid metal that is traditionally used to make products like thermometers, switches, and some light bulbs.
Emissions from coal burning power plants are the biggest source of mercury in outdoor air. Airborne mercury eventually settles into water, or on land where it may be washed into lakes, streams and rivers. People are most likely to be exposed to mercury by eating fish and shellfish with high levels of methylmercury, a highly toxic form of mercury. Other sources include dental fillings and some jewelry. Mercury exposure at high levels can harm the brain, heart, kidneys, lungs, and immune system of people of all ages.
Mercury consumption is a health concern among Tribes whose traditional diets include large amounts of fish, waterfowl, medicinal plants, moose and other land animals. Such diets have not been adequately considered by the EPA in the process of addressing emissions standards for mercury. For example, in developing its recent rule for mercury emissions from power plants, EPA considered two segments of the population to be relevant to its analysis: recreational anglers, and “high level” consumers such as some Native American and other ethnic populations.
In calculating the risk to these groups, USEPA used maximum fish consumption levels of 25 g/day for anglers and 170 g/day for high consumers. However, even this “high level” number may be far from adequate for some Tribal populations. For example, a survey of Great Lakes area Tribes produced a range of 189.6 to 393.8 g/day, and the Minnesota Chippewa Tribe has adopted 227 g/day as its treaty protected subsistence quantity.
Many Tribes are in the midst of assessments of mercury levels in their water, fish, and wildlife. In general, however, there is marked absence of mercury deposition data in the western U.S., where the majority of the Tribal land base exists. Because dry deposition monitoring techniques are not as developed as wet deposition techniques, data is particularly lacking in the southwest, where dry deposition predominates. Acquiring more deposition and health effects data is a priority for Tribes in the years to come.
Like Mercury, power plant emissions of arsenic are regulated by the EPA under the MATS rule. EPA says power plants are responsible for 62% of arsenic air pollution in the US.
Arsenic occurs naturally in soil and minerals and it therefore may enter the air, water, and land from wind-blown dust and may get into water from runoff and leaching. Volcanic eruptions are another source of arsenic. Arsenic is associated with ores containing metals, such as copper and lead. Arsenic may enter the environment during the mining and smelting of these ores.
Breathing high levels of inorganic arsenic can give you a sore throat or irritated lungs or may cause a darkening of the skin and the appearance of small “corns” or “warts” on the palms, soles, and torso. Breathing inorganic arsenic can also increase the risk of lung cancer. The Department of Health and Human Services (DHHS) and the EPA have determined that inorganic arsenic is a known human carcinogen.
Benzene is a widely used chemical formed from both natural processes and human activities. Breathing benzene can cause drowsiness, dizziness, and unconsciousness; long-term benzene exposure causes effects on the bone marrow and can cause anemia and leukemia.
Industrial processes are the main sources of benzene in the environment. Benzene levels in the air can be elevated by emissions from burning coal and oil, benzene waste and storage operations, motor vehicle exhaust, and evaporation from gasoline service stations. Tobacco smoke is another source of benzene in air, particularly indoors.
Tribal New Source Review (NSR)
Title I of the Clean Air Act (CAA) requires that the New Source Review (NSR) program be established to protect public health and welfare, national parks, and wilderness areas as new sources of pollution are built or existing sources modified. The program is designed to ensure that new sources of pollution are constructed to be as clean as possible, recognizing that facility construction is typically the most economical time to incorporate state-of-the-art pollution prevention practices or air pollution control technologies.
In 2011, the EPA filled a regulatory gap with the development of the Tribal Minor New Source Review. The final rule outlines preconstruction permitting of air pollution control requirements for industrial facilities located in Indian Country.
The Tribal Minor NSR program provides three options for obtaining permits:
- Site-Specific Permits: includes case-by-case determinations of the source emission limits as well as any control technology requirements
- General Permits: permits that have been developed for a number of similar equipment types or facilities to simplify the permit issuance process for facilities; or
- Synthetic Minor Permits: applies to a facility that has the potential to emit pollutants in amounts that are at or above major source thresholds, but has voluntarily accepted emission limits so that its potential emissions are below those thresholds, allowing the facility to avoid more stringent major NSR requirements of the Clean Air Act.
In 1999, the EPA announced a major effort to improve air quality in national parks and wilderness areas. The Regional Haze Rule calls for state and federal agencies to work together to improve visibility in 156 national parks and wilderness areas such as the Grand Canyon, Yosemite, the Great Smokies and Shenandoah.
The rule requires the states, in coordination with the EPA, the National Park Service, U.S. Fish and Wildlife Service, the U.S. Forest Service, and other interested parties, to develop and implement air quality protection plans to reduce the pollution that causes visibility impairment. The first State plans for regional haze were due in December 2007. States, tribes, and five multi-jurisdictional regional planning organizations worked together to develop the technical basis for these plans. Comprehensive periodic revisions to these initial plans are currently due in 2021, 2028, and every 10 years thereafter.
NTAA submitted early comments in response to EPA’s request for comments for Tracking Visibility Progress in the Regional Haze Rule that focus on the Reasonable Progress Framework on Controllable Emissions that contribute to Regional Haze. In addition, comments were submitted by NTAA regarding the proposed delay of the current state implementation plan (SIP) submission deadlines, the timing and format of progress reports, limiting requirements for reasonably attributable visibility impairment (RAVI) while expanding the number of states that would be subject to Federal Land Management (FLM) RAVI certifications, and consultation with Indian Tribes concerning the RHR and associated activities. EPA will be drafting a guidance document in the coming months and issue that guidance document for further review in the new year.