Environmental Dictionary U-Z - Environmental Links - 1/1/2015 - Health Asbestos Asbestosis Mesothelioma Lung Cancer

Environmental Dictionary U-Z

UAC

User Advisory Committee.

UAM

Urban Airshed Model.

UAPSP

Utility Acid Precipitation Study Program.

UAQI

Uniform Air Quality Index.

UARG

Utility Air Regulatory Group.

ubiquitous background levels

concentrations of chemicals that are present in the environment due to anthropogenic sources (e.g., industry, automobiles).

UCC

Ultra Clean Coal.

UDMH

Unsymmetrical Dimethyl Hydrazine.

UEL

See Upper Explosive Limit, Upper Flammable Limit.

UFL

See Upper Explosive Limit, Upper Flammable Limit.

ULF

Upper Flammability Limit.

ultra clean coal (UCC)

coal that has been washed, ground into fine particles, then chemically treated to remove sulfur, ash, silicone, and other substances; usually briquette and coated with a sealant made from coal.

ultraviolet rays

radiation from the sun that can be useful or potentially harmful. UV rays from one part of the spectrum enhance plant life and are useful in some medical and dental procedures; UV rays from other parts of the spectrum to which humans are exposed (e.g., while getting a sun tan) can cause skin cancer or other tissue damage. The ozone layer in the atmosphere provides a protective shield that limits the amount of ultraviolet rays that reach the Earth's surface.

UMTRCA

Uranium Mill Tailings Radiation Control Act.

UNAMAP

Users' Network for Applied Modeling of Air Pollution.

underbedding

see Support Media.

underground area

means an underground room, such as a basement, cellar, shaft or vault, providing enough space for physical inspection of the exterior of the tank situated on or above the surface of the floor.

underground release

means any belowground release.

underground storage tank (or "UST")

means any one or combination of tanks (including underground pipes connected thereto) that is used to contain an accumulation of regulated substances, and the volume of which (including the volume of underground pipes connected thereto) is 10 percent or more beneath the surface of the ground. This term does not include any: (a) Farm or residential tank of 1,100 gallons or less capacity used for storing motor fuel for noncommercial purposes; (b) Tank used for storing heating oil for consumptive use on the premises where stored; (c) Septic tank; (d) Pipeline facility (including gathering lines) regulated under:(1) The Natural Gas Pipeline Safety Act of 1968 (49 U.S.C. App. 1671, et seq.), or(2) The Hazardous Liquid Pipeline Safety Act of 1979 (49 U.S.C. App. 2001, et seq.), or(3) Which is an intrastate pipeline facility regulated under state laws comparable to the provisions of the law referred to in paragraph (d)(1) or (d)(2) of this definition; (e) Surface impoundment, pit, pond, or lagoon; (f) Storm-water or wastewater collection system; (g) Flow-through process tank; (h) Liquid trap or associated gathering lines directly related to oil or gas production and gathering operations; or (i) Storage tank situated in an underground area (such as a basement, cellar, mineworking, drift, shaft, or tunnel) if the storage tank is situated upon or above the surface of the floor. term "underground storage tank (or "UST") does not include any pipes connected to any tank which is described in paragraphs (a) through (i) of this definition.

underground sources of drinking water

as defined in the UIC program, this term refers to aquifers that are currently being used as a source of drinking water, and those that are capable of supplying a public water system. They have a total dissolved solids content of 10,000 milligrams per liter or less, and are not "exempted aquifers". (See: exempted aquifer).

unit operation

a single, discrete process as part of an overall sequence, e.g., precipitation, settling or filtration.

UN Number

See DOT Identification Numbers; PIN.

United States

when used in relation to section 311(a)(5) of the CWA, means the states, the District of Columbia, the Commonwealth of Puerto Rico, the Northern Mariana Islands, Guam, American Samoa, the United States Virgin Islands, and the Pacific Island Governments. United States, when used in relation to section 101(27) of CERCLA, includes the several states of the United States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa, the United States Virgin Islands, the Commonwealth of the Northern Marianas, and any other territory or possession over which the United States has jurisdiction.

unsaturated zone

the area above the water table where the soil pores are not fully saturated, although some water may be present.

unstable

tending toward decomposition or other unwanted chemical change during normal handling or storage. An unstable chemical in its pure state, or as commonly produced or transported, polymerizes vigorously, decomposes, condenses, or becomes self-reactive under conditions of shock, pressure, or temperature. See Stability. See Stability, Reactive.

upgrade

means the addition or retrofit of some systems such as cathodic protection, lining, or spill and overfill controls to improve the ability of an underground storage tank system to prevent the release of product.

Upper Explosive Limit, Upper Flammable Limit

UEL, UFL. The highest concentration of a material in air that produces an explosion in fire or ignites when it contacts an ignition source (high heat, electric arc, spark, or flame). A higher concentration of the material in a smaller percentage of concentration of air may be too rich to be ignited. See Flammable Limits.

uranium

a radioactive heavy metal element used in nuclear reactors and the production of nuclear weapons. Term refers usually to U 238, the most abundant radium isotope, although a small percentage of naturally occurring uranium is U 235.

urban runoff

storm water from city streets, usually carrying litter and organic wastes.

urticaria

nettle rash; hives; elevated, itching, white patches.

USA

United States Army.

USAF

United States Air Force.

USAO

United States Attorney's Office.

USATHAMA

United States Army Toxic and Hazardous Materials Agency.

USBM

United States Bureau of Mines.

USBS

United States Bureau of Standards.

USC

United States Code.

USCA

United States Code Annotated.

USCG

United States Coast Guard.

USCS

United Soil Classification System.

USDA

United States Department of Agriculture.

USDOI

United States Department of the Interior.

USDW

Underground Sources of Drinking Water.

USEPA

United States Environmental Protection Agency.

USFS

United States Forest Service.

USGS

United States Geological Survey, Department of the Interior.

USMC

United States Marine Corps.

USN

United States Navy.

USNRC

United States Nuclear Regulatory Commission.

USPHS

United States Public Health Service.

USPS

United States Postal Service.

UST

underground storage tank; regulated by RCRA; tank with 10 or more percent of its volume underground with connected piping; used to store petroleum products or CERCLA regulated hazardous chemicals.

UST system or "Tank system"

means an underground storage tank, connected underground piping, underground ancillary equipment, and containment system, if any.

UV

ultraviolet (light)

USWAG

Utility Solid Waste Activities Group.

UTM

Universal Transverse Mercator.

UV

Ultraviolet.

UZM

Unsaturated Zone Monitoring.

vaccine

dead or partial or modified antigen used to induce immunity to certain infectious diseases.

vacuum degasifier

a tower to which a vacuum is applied and through which water droplets descend to remove dissolved gases.

valence

is measured by the number of atoms or ions of hydrogen it takes to combine with or be replaced by an element or radical. In short, the number of positive or negative charges of an ion.

vapor

the gaseous phase of substances that are liquid or solid at atmospheric temperature and pressure -- such as steam.

vapor capture system

any combination of hoods and ventilation system that captures or contains organic vapors in order that they may be directed to an abatement or recovery device.

vapor density

the weight of a vapor or gas compared to the weight of an equal volume of air; an expression of the density of the vapor or gas calculated as the ratio of the molecular weight of the gas to the average molecular weight of air, which is 29. The mw of gas/29 = vapor density. Materials lighter than air have vapor densities of less than 1.0. Materials heavier than air have vapor densities greater than 1.0. All vapors and gases mix with air, but the lighter materials tend to rise and dissipate (unless confined). Heavier vapors and gases are likely to concentrate in low or enclosed places (along or under floors; in sumps, sewers, manholes, trenches, and ditches) creating fire, explosion, or health hazards. A factor in still, enclosed air.

vapor dispersion

the movement of vapor clouds in air due to wind, gravity spreading, and mixing.

vapor plumes

flue gases that are visible because they contain water droplets.

vapor pressure

the pressure exerted by a saturated vapor above its own liquid in a closed container. Vapor pressures reported on MSDSs are in millimeters of mercury (mm Hg) at 68 degrees F (20 degrees C), unless stated otherwise. Three facts are important to remember: (1) vapor pressure of a substance at 100 degrees F (38 degrees C) is always higher than the vapor pressure of the substance at 68 degrees F (20 degrees C). (2) Vapor pressures reported on MSDSs in mm Hg are usually very low pressures; 760 mm Hg is equivalent to 14.7 pounds per square inch. (3) the lower the boiling point of a substance, the higher its vapor pressure. Vapor pressures are useful (with evaporation rates) in learning how quickly a material becomes airborne within the workplace and thus how quickly a worker is exposed to it.

vaporization

the change of a substance from a liquid to a gas.

variance

Government permission for a delay or exception in the application of a given law, ordinance, or regulation.

VE

Visual Emissions.

vector

a carrier, usually an insect, which is capable of transmitting disease from one organism to another.

ventilation/suction

the act of admitting fresh air into a space in order to replace stale or contaminated air; achieved by blowing air into the space. Similarly, suction represents the admission of fresh air into an interior space by lowering the pressure outside of the space, thereby drawing the contaminated air outward.

venturi

a device for measuring fluid flow, including a short converging cone succeeded on the same axis by a long diverging cone. This device is also used in gas scrubbing.

VEO

Visible Emissions Observation.

vertigo

a feeling of revolving in space; dizziness, giddiness.

VES

Vertical Electric Sounding.

vessel

as defined by section 101(28) of CERCLA, means every description of watercraft or other artificial contrivance used, or capable of being used, as a means of transportation on water; and, as defined by section 311(a)(3) of the CWA, means every description of watercraft or other artificial contrivance used, or capable of being used, as a means of transportation on water other than a public vessel.

VHS

Vertical and Horizontal Spread Model.

VHT

Vehicle-Hours of Travel.

vinyl chloride

a chemical compound used in producing some plastics. Excessive exposure to this substance may cause cancer.

virus

the smallest form of microorganisms capable of causing disease.

viscosity

Measurement of the flow properties of a material expressed as its resistance to flow. Unit of measurement and temperature are included.

VMT

Vehicle Miles Traveled.

VOC

volatile organic compound; family of highly evaporative organic materials used in a variety of industrial applications, such as paints and solvents; VOC emissions are a component in the formation of ground-level ozone (smog).

void volume

the space between particles of ion exchange resins in a settled bed; also called interstitial volume.

volatile

any substance that evaporates at a low temperature.

volatility

measure of a material's tendency to vaporize or evaporate at ambient routine conditions.

volatile organic compound (VOC)

any organic compound which participates in atmospheric photochemical reactions except for those designated by the EPA Administrator as having negligible photochemical reactivity.

volatile substances

material that is readily vaporizable at a relatively low temperature.

volatile synthetic organic chemicals

chemicals that tend to volatilize or evaporate from water.

volume solids

solids content based on volume.

volunteer

means any individual accepted to perform services by the lead agency which has authority to accept volunteer services (examples: See 16 U.S.C. 742f(c)). A volunteer is subject to the provisions of the authorizing statute and the NCP.The Act, CERCLA, or Superfund means the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (Pub. L. 96-510);

VOS

Vehicle Operating Survey.

VP

See Vapor Pressure

VSI

Visual Site Inspection.

VSS

Volatile Suspended Solids.

vulnerability analysis

assessment of elements in the community that are susceptible to damage should a release of hazardous materials occur.

vulnerable zone

an area over which the airborne concentration of a chemical involved in an accidental release could reach the level of concern.

WAP

Waste Analysis Plan.

waste

unwanted materials left over from manufacturing processes, refuse from places of human or animal habitation.

waste load allocation

the maximum load of pollutants each discharger of waste is allowed to release into a particular wasteway. Discharge limits are usually required for each specific water quality criterion being, or expected to be, violated.

waste treatment plant

a facility containing a series of tanks, screens, filters and other processes by which pollutants are removed from water.

waste treatment stream

the continuous movement of waste from generator to treater and disposer.

wastewater

any water that has been released from the purpose for which it was intended to be used.

wastewater operations and maintenance

actions taken after construction to assure that facilities constructed to treat wastewater will be properly operated, maintained, and managed to achieve efficiency levels and prescribed effluent levels in an optimum manner.

wastewater constituents

those materials which are carried by or dissolved in a water stream for disposal.

wastewater treatment tank

means a tank that is designed to receive and treat an influent wastewater through physical, chemical, or biological methods.

waterborne disease outbreak

means the significant occurrence of acute infectious illness, epidemiologically associated with the ingestion of water from a public water system which is deficient in treatment, as determined by the appropriate local or State agency.

waterflooding

a process of displacing oil from underground formations with water and returning it to the surface for recovery.

water hammer

instantaneous surges of water pressure caused by sudden interruptions in water flow in pipe or tank systems.

water pollution

the addition of enough harmful or objectionable material to damage water quality.

water purification

any process that involves removing or reducing the level of suspended or dissolved contaminants from a water supply.

water quality criteria

the levels of pollutants that affect use of water for drinking, swimming, raising fish, farming or industrial use.

water quality standard

a management plan that considers, 1) what water will be used for 2) setting levels to protect those uses 3) implementing and enforcing the water treatment plans and 4) protecting existing high quality waters.

water reactive

describes a material that reacts with water to release a flammable gas or to present a health hazard.

water recirculation or recycling

volume of water already used for some purpose in the plant which is returned with or without treatment to be used again in the same or another process.

watershed

the land area that drains into a stream.

water softening

to exchange sodium for the harness in water by ion exchange. The removal of calcium and magnesium, the ions which are the principle cause of hardness, from water.

water solubility

the maximum concentration of a chemical compound which can result when it is dissolved in water. If a substance is water soluble it can very readily disperse through the environment.

water supplier

a person who owns or operates a public water system.

water supply system

the collection, treatment, storage and distribution of potable water from source to consumer.

water table

the level of ground water.

watershed

the land area that drains into a stream.

water use

total volume of water applied to various uses in the plant. It is the sum of water recirculation and water withdrawal.

WBA

(abbr.) weakly basic anion resin.

WDR

Waste Discharge Report.

WDROP

Distribution Register of Organic Pollutants in Water.

weak electrolyte

the equivalent of weakly acidic or weakly basic resins not capable of splitting neutral salts.

WEEL

Workplace Environmental Exposure Level Guides are established by the AIHA (American Industrial Hygiene Association) WEEL Committee for substances which do not have exposure guidelines established by other organizations [see TLVs]. All WEELs are expressed as time-weighted average (TWA) concentrations; however, different time periods are specified depending on the properties of the material.

weight of evidence

an EPA classification system for characterizing the extent to which the available data indicate that an agent is a human carcinogen.

weight solids

solids content based on weight.

weir

a spillover device used to measure or control water flow.

well

a bored, drilled, or driven shaft, or a dug hole, whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil, or to store or bury fluids below ground.

well injection

the subsurface emplacement of fluids in a well.

well plug

a watertight and gastight seal installed in a bore hole or well to prevent movement of fluids.

WENDB

Water Enforcement National Data Base.

WERL

Water Engineering Research Laboratory.

WES

Waterways Experiment Station.

WET

Waste Extraction Test.

wetlands

an area that is regularly saturated by surface or ground water and subsequently is characterized by a prevalence of vegetation that is adapted for life in saturated soil conditions. Examples include: swamps, bogs, fens, marshes, and estuaries.

white liquor

cooking liquor from the kraft pulping process produced by recausticizing green liquor with lime.

white water

the filtrate from a paper-or board-forming machine, usually recycled for density control.

WHMIS

Workplace Hazardous Materials Information System. A Canadian nationwide system to provide information to workers on hazardous materials used in the workplace through the use of MSDSs.It is the Canadian counterpart of the OSHA Hazard Communication Standard, but has different provisions and interpretations.

wildlife refuge

an area designated for the protection of wild animals, within which hunting and fishing are either prohibited or strictly controlled.

WICEM

World Industry Conference on Environmental Management.

WINC

Woman with Infant Children.

WLA/TMDL

Waste Load Allocation/Total Maximum Daily Load.

WMMA

Waste Materials Management Act.

wood-burning stove pollution

air pollution caused by emissions of particulate matter, carbon monoxide, total suspended particulates, and polycyclic organic matter from wood- burning stoves.

working level (WL)

a unit of measure for documenting exposure to radon decay products. One working level is equal to approximately 200 picocuries per liter.

working level month (WLM)

a unit of measure used to determine cumulative exposure to radon.

WPCF

Water Pollution Control Federation.

WQA

Water Quality Act of 1987.

WQMP

Water Quality Management Plan.

WRC

Water Resources Council.

WRDA

Water Resources Development Act.

WSF

Water Soluble Fraction.

WSRA

Wild and Scenic Rivers Act.

WYSWYG

What You See is What You Get.

xenobiotic

term for non-naturally occurring man-made substances found in the environment (i.e., synthetic material solvents, plastics).

YTD

Year to Date.

zeta potential

the difference in voltage between the surface of the diffuse layer surrounding a colloidal particle and the bulk liquid beyond.

ZHE

Zero Headspace Extractor.

zinc, fume fever, ZFF

caused by inhalation of zinc oxide fumes and characterized by fluelike symptoms; a metallic taste in the mouth, coughing, weakness, fatigue, muscular pain, and nausea, followed by fever and chills. Symptoms occur 4 to 12 hours after exposure.

ZINC OUT

Zinc Treatment-Powder Precipitant - Chelate Breaker - Heavy Metal (ETUS).

Z-List

OSHA's Toxic and Hazardous Substances Tables Z-1, Z-2, and Z-3 of air contaminants, found in 29 CFR 1910.1000. These tables record PELs, TWAs, and ceiling concentrations for the materials listed. Any material found on these tables is considered hazardous.

ZOI

Zone of Incorporation.

zooplankton

tiny aquatic animals that fish feed on.

Restoration Environmental Contractors (Environmental cleanups, pcb ...

--   Biological and hazardous materials information and toxic mold conference in Toronto, January 31, 2002....

Access Eggan Environmental emergency response for oil spills ...

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Welcome to the Department of Environmental Protection Website

--   Headlines, publications and information.

Illinois Environmental Protection Agency

--   Information about permit application forms, vehicle emissions testing station locations, annual reports...

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Hamilton County Department of Environmental Services

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Environmental Enterprises, Inc.

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Maryland Department of the Environment

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Villa Environmental Home Page

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Gray Environmental, Inc.

--   Provides full industrial hygiene services. XRF, leadinspection, monitoring, and risk assessment, mold...

Great Lakes Environmental Directory: extensive information ...

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CNN.com - School chief: We will test environment - May 20, 2002

--   [CNN]

environmental assessment California

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