(MERAF) for the Base Metals Smelting Sector - CCME

4.3. Best Available Techniques for Pollution Prevention and
Control
4.3.1. United States
As detailed above, in the United States 157 , there are different standards that have
been developed under the Clean Air Act (CAA) for some base metals smelters.
CAA standards are based on different technologies:
• Best Available Control Technology (BACT) is required on major new or
modified sources in clean areas (attainment areas). BACT means the
pollution control method that is recognized as the one removing the
greatest amount of air pollutants for a particular industry or process
taking into account costs;
• Lowest Achievable Emission Rate (LAER) is required on major new or
modified sources in non-attainment areas. LAER means the air
emission rate that is the lowest possible for a type of facility for a
specific pollutant; required of air pollution sources in air quality nonattainment
areas. LAER is the most stringent emission limitation
among control technologies;
• Maximum Achievable Control Technology (MACT) is required for a
published list of industrial sources referred to as "source categories"
which are emitting one or more of the 188 Hazardous Air Pollutants
(HAPs) listed under section 112 of the CAA. MACT means the
maximum degree of reduction in HAP determined achievable
considering the cost of achieving the reduction and any non-air-quality
health and environmental impacts and energy requirements.. For new
sources, MACT is the emission control achieved in practice by the best
controlled similar source. For existing sources, MACT is the average
emission limitation achieved by the best performing 12% of existing
sources if there are more than 30 sources or the best performing 5 if
there are less than 30 sources. Currently, there is a list of regulations
at different stage of development (completed, proposed, and
upcoming), which are also known as National Emission Standards for
Hazardous Air Pollutants (NESHAP). NESHAP are based on Maximum
Achievable Control Technology (MACT) standards.
• Reasonably Available Control Technology (RACT) is required on
existing sources in areas that are not meeting national ambient air
quality standards (non-attainment areas). RACT means the lowest
emission limit that a facility is capable of meeting by using control
technology that is reasonably available, considering technological and
economic feasibility;
157 US Environmental; Protection Agency. URL: http://www.epa.gov/ttn/atw/eparules.html
167