Maximum Achievable Control Technology (MACT)

DOE-HDBK-XXXX-2005

06/30/2005

particular source for all exposure routes (e.g., inhalation, ingestion, direct exposure). [Derived

from NCRP 93]

110. MAXIMUM ACHIEVABLE CONTROL TECHNOLOGY (MACT). Technology for

achieving the maximum control of emissions from major sources of hazardous air pollutants,

using particularly stringent control devices, as prescribed in 40 CFR 63.41 for new sources and

in 40 CFR 63.51 for existing sources. [Derived from 40 CFR 63.41, 40 CFR 63.51]

111. MAXIMUM CONTAMINANT LEVEL (MCL). The designation for U.S. Environmental

Protection Agency standards for drinking water quality under the Safe Drinking Water Act.

The maximum contaminant level for a given substance is the maximum permissible

concentration of that substance in water delivered by a public water system. The primary

MCLs (40 CFR Part 141) are intended to protect public health and are federally enforceable.

They are based on health factors, but are also required by law to reflect the technological and

economic feasibility of removing the contaminant from the water supply. Secondary MCLs (40

CFR Part 143) are set by the U.S. Environmental Protection Agency to protect the public

welfare. The secondary drinking water regulations control substances in drinking water that

primarily affect aesthetic qualities (such as taste, odor, and color) relating to the public

acceptance of water. These regulations are not federally enforceable, but are intended as

guidelines for the states. [Derived from 40 CFR 141.2, 40 CFR 143.1, 40 CFR 143.2, EPA

OPPT]

Related term:

Maximum contaminant level goal (MCLG) means the maximum level of a contaminant in

drinking water at which no known or anticipated adverse effect on the health of persons would

occur, and which allows an adequate margin of safety. Maximum contaminant level goals are

non-enforceable health goals. [40 CFR 141.2]

112. METRIC TONS OF HEAVY METAL (MTHM). Quantities of unirradiated and spent nuclear

fuel and targets are traditionally expressed in terms of the initial weight in metric tons of

uranium, plutonium, and thorium (collectively called "heavy metal") in the unirradiated fuel.

Other fuel components, such as cladding, alloy materials, and structural materials, are not

included. A metric ton is 1,000 kilograms, which is equal to about 2,200 pounds. [Derived

from 40 CFR 191.12, OCRWM MP]

113. MILLIREM (MREM). One-thousandth of a rem (0.001 rem). (See rem.)

114. MINORITY POPULATION. Minority populations exist where either: (a) the minority

population of the affected area exceeds 50 percent or (b) the minority population percentage of

the affected area is meaningfully greater than in the general population or other appropriate

unit of geographic analysis (such as a governing body's jurisdiction, a neighborhood, census

tract, or other similar unit). "Minority" refers to individuals who are members of the following

population groups: American Indian or Alaskan Native; Asian or Pacific Islander; Black, not

of Hispanic origin; or Hispanic. "Minority populations" include either a single minority group

or the total of all minority persons in the affected area. They may consist of groups of

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