Water%20Pollution%20

1

• Water Pollution Sources and Effects
• Sources
• Other factors
• Factors besides chemical pollutants can degrade
  water quality
• Removal of adjacent vegetation
• Destabilization of shoreline
• Removal of shade ? destabilizes temperatures
• Siltation
• Increased turbidity ? vision, photosynthesis
• Burial of organisms, filling of water body
• Alteration of drainage patterns
• Damming, dredging, channelization
• Changes in vegetation cover in watershed
• Changes flow patterns, predictability, chemistry,
  sediment load
• Leaching of chemicals from natural sources
  (geogenic, biogenic)
• Salts, metals (Ex As), nutrients (Ex P), acids
  (Ex tannins)
• Warm weather
• Raises temperatures, reduces oxygen solubility,
  may dry up

2

• Water Pollution Components
• Oxygen-Depleting Substances
• Pollutants may lower O2 concentrations directly
  or indirectly
• Usually biodegradable (organic wastes)
• Reduced O2 levels can influence species
  composition in a water body
• Ex Salmon and trout sensitive to O2 levels
• Low O2 levels also favor survival of anaerobic
  bacteria, many of which produce noxious gases
  (H2S, CH4)
• Examples
• Sewage (including animal and plant materials)
• Agricultural waste (leaves, plant debris, manure)
• Food processing wastes
• Toxic wastes can kill aquatic organisms, leading
  to O2 depletion by decomposing bacteria
• Warm temperatures exacerbate O2 depletion
• Reduce solubility of oxygen
• Accelerate bacterial decomposition rates

3

• Water Pollution Components
• Infectious Agents
• Pathogenic bacteria
• Common components of animal wastes
• Can produce outbreaks of typhoid, cholera,
  salmonellosis, infectious hepatitis, dysentery
  (affect billions of people)
• Examples
• Giardia causes swimmers itch by irritating skin
  but can cause intestinal problems internally
• Cryptosporidium contaminated Milwaukee water
  supply in 1993
• More than 400,000 people with symptoms and 100
  deaths
• Cysts passed through filtration in water
  treatment system and went undetected
• Very difficult to scan water bodies for all
  potential pathogens (problem lag time b/w test
  results)
• Use of indicator organisms (coliform bacteria,
  enterococci)
• Possible sources (source identification
  challenging)
• Municipal sewage Inadequately treated or
  spilled
• Stormwater drains
• Septic systems
• Runoff from livestock pens
• Sewage from recreational vehicles (boats, campers)

4

• Water Pollution Components
• Toxic Organic Chemicals (TOCs)
• Usually synthetic chemicals
• Persistent organic pollutants (POPs)
• Polychlorinated biphenyls (PCBs)
• Polycyclic aromatic hydrocarbons (PAHs)
• Dioxins
• Herbicides, pesticides (Ex chlordane, DDT)
• Characteristics
• Bioavailable readily assimilated
• Lipid soluble incorporated into lipid deposits
• Bioaccumulate concentrations increase with time
  and exposure
• Biomagnify concentrations increase through food
  web
• Tend to be resistant to degradation
• Facilitates wide dispersal
• Long residence times (persistence)
• Ex DDT near White Point
• Effects Poorly understood for most compounds

5
Time Magazine - 1947
6
Beach on Long Island, NY - 1945
7

• Water Pollution Components
• Toxic Organic Chemicals (TOCs)
• Usually synthetic chemicals
• Persistent organic pollutants (POPs)
• Polychlorinated biphenyls (PCBs)
• Polycyclic aromatic hydrocarbons (PAHs)
• Dioxins
• Herbicides, pesticides (Ex chlordane, DDT)
• Characteristics
• Bioavailable readily assimilated
• Lipid soluble incorporated into lipid deposits
• Bioaccumulate concentrations increase with time
  and exposure
• Biomagnify concentrations increase through food
  web
• Tend to be resistant to degradation
• Facilitates wide dispersal
• Long residence times (persistence)
• Ex DDT near White Point
• Effects Poorly understood for most compounds

8
(No Transcript)
9

• Water Pollution Components
• Toxic Organic Chemicals (TOCs)
• Usually synthetic chemicals
• Persistent organic pollutants (POPs)
• Polychlorinated biphenyls (PCBs)
• Polycyclic aromatic hydrocarbons (PAHs)
• Dioxins
• Herbicides, pesticides (Ex chlordane, DDT)
• Characteristics
• Bioavailable readily assimilated
• Lipid soluble incorporated into lipid deposits
• Bioaccumulate concentrations increase with time
  and exposure
• Biomagnify concentrations increase through food
  web
• Tend to be resistant to degradation
• Facilitates wide dispersal
• Long residence times (persistence)
• Ex DDT near White Point
• Effects Poorly understood for most compounds

10
http//www.epa.gov/region9/superfund/pvshelf/image
s/ddtconcbig.gif
11
(No Transcript)
12

• Water Pollution Components
• Toxic Organic Chemicals (TOCs)
• Usually synthetic chemicals
• Persistent organic pollutants (POPs)
• Polychlorinated biphenyls (PCBs)
• Polycyclic aromatic hydrocarbons (PAHs)
• Dioxins
• Herbicides, pesticides (Ex chlordane, DDT)
• Characteristics
• Bioavailable readily assimilated
• Lipid soluble incorporated into lipid deposits
• Bioaccumulate concentrations increase with time
  and exposure
• Biomagnify concentrations increase through food
  web
• Tend to be resistant to degradation
• Facilitates wide dispersal
• Long residence times (persistence)
• Ex DDT near White Point
• Effects Poorly understood for most compounds