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Groundwater Pollution

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Title: Water Pollutants and their Sources Author: Thomas C. Voice Last modified by. Created Date: 10/13/2003 1:21:17 AM Document presentation format – PowerPoint PPT presentation

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Title: Groundwater Pollution


1
Groundwater Pollution
  • 0331 Types of Pollution

2
  • http//techalive.mtu.edu/meec/module04/title.htm

3
  • Contaminants are separated into four main
    categories
  • Physical
  • Biological
  • Inorganic chemicals
  • Organic chemicals

4
  • These categories may overlap sometimes. eg a
    biological organism might make organic chemicals
    and the organisms have a physical effect on the
    water.

5
  • Contaminants can have effects at very small
    concentrations.
  • Measure amounts of contaminants in terms of
    concentration.
  • ppm and ppb and ppt, which are parts per million
    and parts per billion and parts per trillion.
  • PPM is the amount of contaminant units in
    1,000,000 (1 million) units of groundwater.
  • PPB is lthe amount of contaminant units in
    1,000,000,000 (1 billion) units of groundwater.
  • PPT is the amount of contaminant units in
    1,000,000,000,000 (1 trillion) units of
    groundwater.

6
  • http//techalive.mtu.edu/meec/module04/GWContamina
    tionBasics1.htm

7
  • Very small concentrations of some groundwater
    contaminants could have serious health effects.
  • Different kinds of contaminants have different
    concentration limits.
  • It is necessary to find out both the specific
    type of contaminant and the concentration of the
    contaminant.

8
  • http//techalive.mtu.edu/meec/module04/GWContamina
    tionBasics3.htm

9
Contamination Movement
  • As contamination moves it disperses.
  • The concentration decreases as it moves farther
    away from the source of the pollution.
  • So there are different concentrations of
    contaminants at different points in the aquifer.

10
  • The representation of these different
    concentrations is called a contamination plume.
  • http//techalive.mtu.edu/meec/module04/Contaminati
    onMovement.htm

11
Area of Contamination
  • A contaminant may be released into the
    groundwater for only a short time and in a very
    small area, but as it disperses the contaminant
    can affect a very large area and number of
    people.
  • http//techalive.mtu.edu/meec/module04/AreaofConta
    mination.htm

12
Plumes can be very irregular
13
http//techalive.mtu.edu/meec/module04/PlumeExampl
e.htm
  • Watch and say
  • Where is the source of the contamination?
  • Is the source continuous or a one-time event?
  • Based on the direction of the plume, which way is
    the groundwater moving?
  • How far does the contamination travel in 16
    years?
  • What important areas of the city are affected by
    the contamination?

14
Finding Contaminants
  • Look at the history of the site.
  • See if a nearby river is contaminated or what
    possible above-surface sources exists.
  • To find the contaminant plume drill test wells or
    use other technology to find concentrations at
    different points underground.
  • http//techalive.mtu.edu/meec/module04/PlumeSource
    Game.htm

15
  • Some specific contaminants.

16
(No Transcript)
17
  • Sites to search for contaminants
  • http//www.clu-in.org/contaminantfocus/default.foc
    us/sec/General_Contaminant_Information/cat/Overvie
    w/
  • http//www.clu-in.org/contaminantfocus/default.foc
    us/sec/General_Contaminant_Information/cat/Overvie
    w/
  • has a large list of sites, including
  • http//www.nature.nps.gov/hazardssafety/toxic/entr
    y.cfm

18
Suspended Solids
  • Organic and inorganic particles in water are
    termed suspended solids
  • May be distinguished from colloids, particles
    that do not settle readily
  • Measured by filtering a water sample, drying and
    weighing the filter

19
Suspended Solids
  • Problems
  • sedimentation
  • may exert oxygen demand
  • primary transport mechanism for many metals,
    organics and pathogens
  • aesthetic
  • complicates drinking water treatment
  • Sources
  • storm water
  • wastes
  • erosion

20
Pathogenic Organisms
  • Many organims that cause human or animal diseases
    colonize the instinal tract but can live for a
    period of time outside the body
  • Carriers (who may or may not exhibit disease
    symptoms) excrete these intestinal tract organims
    in very large numbers
  • When water is contaminated by excretia, the
    organisms can be transmitted to those who contact
    the water

21
Pathogenic Organisms
22
Pathogenic Organisms
23
Toxic and Hazardous Substances
  • Volatile organic compounds
  • Hydrophobic organic compounds
  • Endocrine disruptors
  • Surfactants
  • Petroleum Additives
  • Pesticides
  • Heavy metals
  • Other inorganic elements
  • Acids/bases
  • Oxidants/reductants
  • Chlorination by-products
  • Combustion by-products

24
Volatile Organic Compounds
  • Petroleum constituents
  • benzene and substituted benzenes
  • prevalent in gasoline, diesel fuel, heating oil
  • most easily transported, slow degradation, toxic

25
Volatile Organic Compounds
  • Oxygentated gasoline additives
  • added to gasoline to improve air quality
  • very soluble, resistant to degradation, toxic
  • attempt to solve one problem caused another
    (spills)

Methyl tertiary butyl ether (MTBE)
26
Volatile Organic Compounds
  • Chlorinated solvents
  • C1 and C2 aliphatics
  • widely used in degreasing, dry cleaning,
    extraction
  • somewhat soluble, volatile, difficult to degrade

27
Hydrophobic Organic Compounds
  • Polycyclic aromatic hydrocarbons (PAHs)
  • potent carcinogens, tend to associate with
    particles
  • also combustion by-products

28
Hydrophobic Organics/ Chlorinated Aromatics
  • Chlorinated Pesticides
  • Polychlorinated dibenzodioxins (PCDDs)
  • Polychlorinated biphenyls (PCBs)

29
Some Other Categories
  • Trihalomethanes
  • Explosives and Propellants
  • Phenolics
  • Aldehydes
  • Organometallics
  • Asbestos

30
Arsenic
  • Occurs naturally in rock and soil
  • Released to groundwater under some conditions
  • Health effects include cardiovascular diseases,
    skin cancer, nervous system effects, and kidney
    disease
  • Major problem in Bangladesh
  • Drinking water standard being lowered in U.S.
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