water pollution

1. Water Pollution –Water Pollution –
Sources, Types and EffectsSources, Types and Effects

2. Core Case Study: The Gulf ofCore Case Study: The Gulf of
Mexico’s Annual Dead ZoneMexico’s Annual Dead Zone
 Spring and summer – huge inputs ofSpring and summer – huge inputs of
nutrients from the Mississippi River basinnutrients from the Mississippi River basin
 Hypoxia – depletion of dissolved oxygen inHypoxia – depletion of dissolved oxygen in
the Gulf of Mexico’s bottom layer of waterthe Gulf of Mexico’s bottom layer of water

Contains little marine lifeContains little marine life

Disrupts nitrogen cycleDisrupts nitrogen cycle

3. Core CaseCore Case
Study: TheStudy: The
Gulf ofGulf of
Mexico’sMexico’s
Annual DeadAnnual Dead
ZoneZone

4. WATER POLLUTION: SOURCES,WATER POLLUTION: SOURCES,
TYPES, AND EFFECTSTYPES, AND EFFECTS
 Water pollutionWater pollution – any chemical, biological or– any chemical, biological or
physical change in water quality that has aphysical change in water quality that has a
harmful effect on living organisms or makesharmful effect on living organisms or makes
water unsuitable for desired useswater unsuitable for desired uses

Point sourcePoint source – from one spot (drain pipes,– from one spot (drain pipes,
ditches, sewer lines) – easier to monitor andditches, sewer lines) – easier to monitor and
regulateregulate

Nonpoint sourceNonpoint source – cannot be traced to a single– cannot be traced to a single
site of discharge – dispersed (atmosphericsite of discharge – dispersed (atmospheric
deposition, agricultural, industrial or residentialdeposition, agricultural, industrial or residential
runoff)runoff)

5. Atmospheric deposition

7. MAJOR SOURCES OF WATERMAJOR SOURCES OF WATER
POLLUTIONPOLLUTION
 AgricultureAgriculture – largest source – sediment,– largest source – sediment,
fertilizers, pesticides, bacteria, excess saltfertilizers, pesticides, bacteria, excess salt
 IndustryIndustry – organic and inorganic chemicals– organic and inorganic chemicals
 MiningMining – sediments, toxic chemicals– sediments, toxic chemicals
 As climate changes, precipitation will changeAs climate changes, precipitation will change

Downpours flush chemicals into waterDownpours flush chemicals into water

Drought reduces flow that dilutes waste, lessDrought reduces flow that dilutes waste, less
water for hygienewater for hygiene

8. Major Water PollutantsMajor Water Pollutants
and Their Effectsand Their Effects

9. Types of PathogensTypes of Pathogens
 Clean water for drinking and sanitation is a majorClean water for drinking and sanitation is a major
issueissue

10. Detecting PathogensDetecting Pathogens
 Scientists cannot test for all pathogensScientists cannot test for all pathogens
 Test forTest for indicator organismsindicator organisms which indicatewhich indicate
likely presence of other pathogenslikely presence of other pathogens

Ex: fecal coliform (Ex: fecal coliform (E. coliE. coli))
 If above standards, water is not drinkable,If above standards, water is not drinkable,
fishable or swimmablefishable or swimmable

Drinking = 0/100 mlDrinking = 0/100 ml

Swimming = 200/100 mlSwimming = 200/100 ml

Raw sewage = millions/100 mlRaw sewage = millions/100 ml

11. Indicators of PathogensIndicators of Pathogens
 Fecal coliformFecal coliform ((E. coliE. coli) – bacteria that live in) – bacteria that live in
intestines of humans and other warm bloodedintestines of humans and other warm blooded
animalsanimals
 EnterococciEnterococci sp. – bacteria – better indicatorsp. – bacteria – better indicator
than fecal coliformthan fecal coliform
 Coliphage – bacteriophage (virus) that infectsColiphage – bacteriophage (virus) that infects
E. coliE. coli – better indicator of viruses– better indicator of viruses
Figure 21-2Figure 21-2

12. Testing for Water PollutantsTesting for Water Pollutants
 Water quality and dissolved oxygen (DO)Water quality and dissolved oxygen (DO)
content in parts per million (ppm) at 20content in parts per million (ppm) at 20°C°C

Only a few fish species can survive in water lessOnly a few fish species can survive in water less
than 4ppm atthan 4ppm at 2020°C°C

13. Testing for Water PollutantsTesting for Water Pollutants
 Chemical analysisChemical analysis – determines presence– determines presence
and concentrations of chemicalsand concentrations of chemicals
 Indicator speciesIndicator species – help monitor water– help monitor water
pollutionpollution

Ex: cattails, musselsEx: cattails, mussels
 TurbidityTurbidity – cloudiness of water– cloudiness of water

Use secchi discUse secchi disc