m
Meter
m3
Cubic meter (Stere)
M
Metric Tons (1000kg)
M
Molarity
MAAC
Maximum Acceptable Ambient Concentration (units ppm or mg/m3)
MACT
Maximum Achievable Control Technology (CAA): Applied to air toxic pollutants; used in cleanest 12% of a source category. (40 CFR Part 61)
Major Source
(1) any source that emits or has the potential to emit, in the aggregate, 10 tons per year or more of any HAP or 25 tons per year or more of any combination of HAP, or (2) a source that emits over 100 tons of a NAAQS
MCL
Maximum Contaminant Level (SDWA: Primary Standards): Maximum permissible level of a drinking water source.
MCLG
Maximum Contaminant Level Guidelines
MD/NJ
Maryland - New Jersey list for TRI reporting
MEK
Methyl Ethyl Ketone
Melting Point
The temperature at which a solid substance becomes a liquid, or at which a liquid substance solidifies.
MeV
Million Electron Volts
MFL
Millions of fibers (of asbestos) per liter (fibers > 10 microns in length). SDWA
mg
Milligram (1/1000 gram)
Mg
Megagram (1E + 6 grams = 1,000,000 grams = 1 metric ton)
MGD or mgd
Million Gallons Per Day
mg/kg
Milligram Per Kilogram
mg/L
Milligram Per Liter (Parts Per Million for DI (deionized) water)
mg/m 3
Milligrams Per Cubic Meter (concentrations in air)
MHE
Material Handling Equipment
MIBK
Methyl Isobutyl Ketone
Microorganism
A living organism not discretely visible to the unaided eye. These organisms obtain nutrients from and discharge waste products (largely CO2 or O2) into the fluid in which they exist, thus serving to lower the nutrient level.
Mixed Wastes
Any matrix containing a RCRA hazardous waste and radioactive waste subject to the Atomic Energy Act.
mL
Milliliter, a metric unit of volume, equal in volume to one cubic centimeter (cc). There are 1,000 milliliters in one liter (L).
MHE
Material Handling Equipment
MIBK
Methyl Isobutyl Ketone
MSHA
Mine Safety & Health Administration
MSWL
Municipal Solid Waste Leachate
MTB
Materials Transportation Bureau
MTG
Manual Tank Gauging
Municipal landfill
A landfill that receives household waste, and that is not a land application unit, surface impoundment, injection well or waste pile. Such a landfill may be publicly or privately owned. Also known as a “Subpart D Landfill”.
MUST
Management of Underground Storage Tanks
Mutagen
A substance capable of causing genetic damage.
MWPP
Municipal Water Pollution Prevention
MWTA
Medical Waste Tracking Act
m/a
Mass-to-Charge ratio