U list - Listed Hazardous Waste: Toxic Hazardous Waste when Discarded, Off-Specification, or Spilled
UAC - User Advisory Committee
UAE - United Arab Emirates
UAM - Urban Airshed Model
UAO - Unilateral Administrative Order
UAPSP - Utility Acid Precipitation Study Program
UAQI - Uniform Air Quality Index
UARG - Utility Air Regulatory Group
UBC - Uniform Building Code
U/BK - Uptake/Biokinetic
UC - Unauthorized Commitment
UC - Unified Command
UCA - Undefinitized Contractural Action
UCC - Ultra Clean Coal
UCC - Uniform Code Council
UCC - Uniform Commercial Code
UCCI - Urea-Formaldehyde Foam Insulation
UCF - Upset Correction Factor
UCL - Upper Control Limit
UCL - Upper Confidence Limit
UCM - Unregulated Contaminant Monitoring
UCMR - Unregulated Contaminant Monitoring Regulation
UCNI - Unclassified Controlled Nuclear Information
UCR - Upper Confidence Range
UCS - Unconfined Compressive Strength
UDMH - Unsymmetrical Dimethyl Hydrazine
UDV - Unit Day Value
UEL - Upper Explosive Limit
UEM - Use Estimating Model
UF - Uncertainty Factor
UFA - Unsaturated Flow Apparatus
UFC - Uniform Fire Code
UFL - Upper Flammability Limit
UFO - Unfilled Order
UG&CMS - Texas Uniform Grant and Contract Management Act
UGLCCS - Upper Great Lakes Connecting Channels Study
UGST - Underground Storage Tank
UGT - Underground Tank
UGTA - Underground Test Area
µg - Microgram
µg/dl - Micrograms per Deciliter
µg/g - Micrograms per Gram (ppm)
µg/kg - Micrograms per Cubic Kilogram
µg/l - Micrograms per Liter
µg/m3 - Micrograms per Cubic Meter
UHC - Underlying Hazardous Constituent
UHF - Ultra High Frequency
UHIPP - Urban Heat Island Pilot Project
UIC - Underground Injection Control
UICTS - UIC Tracking System
UID - Unique Identifier
UL - Underwriters Laboratory
ULC - Underwriter’s Laboratory of Canada
ULEV - Ultra Low Emission Vehicles
ULF - Upper Flammability Limit
ULP - Unfair Labor Practice
ULPA - Ultra-Low Penetration Air
UM - Uniform Manifest
um - micrometer
U/M - Upset and Maintenance
UMCS - Utility Monitoring and Control System
µmoles - Micromoles
UMP - Upward Mobility Program
UMR - Underground Mining Regulations
UMRA - Unfunded Mandates Reform Act
UMRB - Utility Management review Board
UMRCC - Upper Mississippi River Conservation Committee
UMR-IWW - Upper Mississippi River Illinois Waterway
UMR-IWWSNS - Upper Mississippi River Illinois Waterway System Navigation
UMRS - Upper Mississippi River System
UMTA - Urban Mass Transportation Administration
UMTRA - Uranium Mill Tailings Remedial Action
UMTRCA - Uranium Mill Tailings Radiation Control Act
UN - United Nations
UNAMAP - User's Network for Applied Modeling of Air Pollution
UNCED - United Nations Conference on Environment and Development
UNCHE - United Nations Conference on the Human Environment
UNCHS - United Nations Center for Human Settlements
UNCLOS - United Nations Convention on the Law of the Sea
UNCSD - United Nations Commission on Sustainable Development
UNCTAD - United Nations Conference on Trade and Development
UNDAF - United Nations Development Assistance Framework
UNDESD - United Nations Department of Economic and Social Development
UNDP - United Nations Development Program
UNDPCSD - United Nations Department for Policy Coordination and Sustainable Development
UNECA - United Nations Economic Commission for Africa
UNECE - United Nations Economic Commission for Europe
UNECLAC - United Nations Economic Commission for Latin America and the Caribbean
UNEP - United Nations Environment Program
UNEP-DEIA - United Nations Environment Program Division of Environmental Information and Assessment
UNEP-EAP/AP - United Nations Environment Program Environment Assessment Program for Asia and the Pacific
UNESCAP - United Nations Educational, Scientific and Cultural Organization
UNESCO - United Nations Educational, Scientific, and Cultural Organization
UNESCWA - United Nations Economic and Social Commission for West Asia
UNESOB - United Nations Economic and Social Office in Beirut
UNFCCC - United Nations Framework Convention on Climate Change
UNFPA - United Nations Fund for Population Activities
UNICEF - United Nations Children’s Fund
UNIDO - United Nations Industrial Development Organization
UNISHIP - Unified Shippers Enforcement Data System
UNISIST - World Science Information System
UNITAR - United Nations Institute for Training and Research
UNIX - Operating System developed by AT&T
UNRWA - United Nations Relief and Works Agency for Palestine Refugees
UNSCEAR - United Nations Scientific Committee on the Effects of Atomic Radiation
UNSD - United Nations Statistical Division
UNSO - United Nations Sudano-Sahelian Office
UNU - United Nations University
UO - Utilization Officer
UOF - Used Oil Filter
UORA - Used Oil Recycling Act
UPC - Universal Product Code
UPCONE - Upconing of a Salt-Water/Fresh-Water Interface Below a Pumping Well
UPD - Up and Down Procedure
UPWP - Unified Planning Work Program for Regional Transportation
UPZ - Upper Perched Zone
UR - Uptake Rate
URF - Inhalation Unit Risk Factor
µR/hr - Micro Roentgen per Hour
URIS - Unregulated Contaminant Information System
URL - Uniform Resource Locator
URL - Upper Reporting Limit
URV - Unit Risk Value
US - United States of America
USA - United States of America
USA - United States Army
USA - United States Attorney
USACCE - United States Army Contracting Command, Europe
USACE - United States Army Corp of Engineers
USACOE - United States Army Corp of Engineers
USAEC - United Stated Army Environmental Center
USAEC - United Stated Army Environmental Command
USAED - US Army Engineer District
USAEHA - United States Army Environmental Hygiene Agency
USAF - United States Air Force
USAID - U.S. Agency for Economic Development
USAO - United States Attorney’s Office
USAPEHEA - United States Army Pacific Environmental Health Engineering Agency
USAREUR - United States Army, Europe
USAS - Uniform Statewide Accounting System
USATHAMA - U.S. Army Toxic and Hazardous Materials Agency
USBA - United States Bureau of Reclamation
USBM - United States Bureau of Mines
USBR - United States Bureau of Reclamation
USBS - United States Bureau of Standards
USC - Unified Soil Classification
USC - United States Code
USCA - United States Code Annotated
USCA - Unit- Specific Correlation Approach
USCG - United States Coast Guard
USCG-MSEP - United States Coast Guard Office of Marine Safety and Environmental Protection
USCIS - United States Citizenship and Immigration Services
USCP - United States Capitol Police
USCS - United Soil Classification System
USDA - United States Department of Agriculture
USDOD - United States Department of Defense
USDOE - United States Department of Energy
USDOI - United States Department of the Interior
USDOT - United States Department of Transportation
USDW - Underground Source(s) of Drinking Water
USE - Used Solvent Elimination
USEPA - United States Environmental Protection Agency
USFDA - United States Food and Drug Administration
USFS - Untied States Forest Service
USFW - United States Fish and Wildlife Service
USFWS - United States Fish and Wildlife Service
USGS - United States Geological Survey
USISTC - US-Israel Science and Technology Commission
USLADP - Urban Soil Lead Abatement Demonstration Project
USLE - Universal Soil Loss Equation
USM - United States Marshal
USMAB - US Man and the Biosphere Program
USMC - United States Marine Corps
USN - United States Navy
USNRC - United States Nuclear Regulatory Commission
USP - United States Pharmacopoeia
USPHS - United States Public Health Service
USPP - United States Park Police
USPS - United States Postal Service
US&R - Urban Search and Rescue
USSOCOM - US Special Operations Command
USSR - Union of Soviet Socialist Republics
USSS - United States Secret Service
UST - Underground Storage Tank
USTFP - Underground Storage Tank Facility Plan
US-VISIT - United States Visitor and Immigrant Status Indicator Technology
USWAG - Utility Solid Waste Activities Group
μS/cm - Microsiemens per Centimeter
UTL - Upper Tolerance Limit
UTM - Universal Transverse Mercator
UTP - Urban Transportation Planning
UTS - Universal Treatment Standards
UV - Ultraviolet
UVA - Ultraviolet Radiation Band A
UVB - Ultraviolet Radiation Band B
UVC - Ultraviolet Radiation Band C
UVCE - Unconfined Vapor Cloud Explosion
UV-Vis - Ultra Violet Visible Spectroscopy
UWAG - Urban Waterfront Action Group
UWL - Upper Warning Limit
UWMB - Urban Watershed Management Branch
UWR - Upland/Wetland Reuse
UXO - Unexploded Ordnance
UZM - Unsaturated Zone Monitoring