Water PollutionWater Pollution
Chapter 11Chapter 11
11.5 - 11.911.5 - 11.9
Question of the DayQuestion of the Day
The Leading cause of water pollution is?The Leading cause of water pollution is?
Answer of the DayAnswer of the Day
Agricultural activitiesAgricultural activities which cause which cause sediment erosion from agricultural sediment erosion from agricultural lands and overgrazed rangeland, lands and overgrazed rangeland, followed by fertilizers and pesticides, followed by fertilizers and pesticides, and bacteria form livestock and food and bacteria form livestock and food processing wastes, also excess salt processing wastes, also excess salt form soils of irrigated cropland.form soils of irrigated cropland.
Water Pollution: Types, Effects, Water Pollution: Types, Effects, and Sourcesand Sources
What is water pollution?What is water pollution?
Major types of pollutants, sources and effects (Table 11-1, p. 254)Major types of pollutants, sources and effects (Table 11-1, p. 254)
Point and nonpoint sourcesPoint and nonpoint sources
Is the water safe to drink?Is the water safe to drink?
Table 11-1, p. 254
Polluted StreamsPolluted Streams Factors influencing stream recovery from pollutionFactors influencing stream recovery from pollution
Oxygen sag curveOxygen sag curve
Importance of wastewater treatment plants Importance of wastewater treatment plants
Improvements in quality of US streamsImprovements in quality of US streams
Cuyahoga River of OhioCuyahoga River of Ohio
Effect of regulations in USEffect of regulations in US
Pressures from US citizen groupsPressures from US citizen groups
Problems with nonpoint, accidental and illegal releasesProblems with nonpoint, accidental and illegal releases
Problems in developing countriesProblems in developing countries
Clean ZoneDecomposition
Zone
Septic ZoneRecovery
Zone
Clean Zone
Normal clean water organisms(trout, perch, bass,
mayfly, stonefly)
Trash fish(carp, gar,leeches)
Fish absent, fungi,sludge worms,bacteria
(anaerobic)
Trash fish(carp, gar,leeches)
Normal clean water organisms(trout, perch, bass,
mayfly, stonefly)
8 ppmDissolved oxygen (ppm)
Biological oxygendemand
8 ppmTypes of
organisms
Fig. 11-24, p. 256
Pollution in StreamsPollution in Streams
Lake PollutionLake Pollution Dilution less effective than with streamsDilution less effective than with streams
Stratification in lakes and relatively little flow hinder rapid dilution of Stratification in lakes and relatively little flow hinder rapid dilution of pollutantspollutants
Lakes more vulnerable to pollutants than streamsLakes more vulnerable to pollutants than streams
How pollutants enter lakesHow pollutants enter lakes
Eutrophication: causes and effectsEutrophication: causes and effects
Oligotrophic and eutrophic lakesOligotrophic and eutrophic lakes
Cultural eutrophicationCultural eutrophication
Preventing or removing eutrophicationPreventing or removing eutrophication
Oligotrophic and Eutrophic Oligotrophic and Eutrophic LakesLakes
Fig. 11-25, p. 257
Groundwater Pollution: Causes Groundwater Pollution: Causes and Persistenceand Persistence
Sources of groundwater pollutionSources of groundwater pollution
Slow flowing: slow dilution and dispersionSlow flowing: slow dilution and dispersion
Consequences of lower dissolved oxygenConsequences of lower dissolved oxygen
Fewer bacteria to decompose wastesFewer bacteria to decompose wastes
Cooler temperatures: slow down chemical reactionsCooler temperatures: slow down chemical reactions
““Degradable” and nondegradable wastes in groundwaterDegradable” and nondegradable wastes in groundwater
Coal strip mine runoff
Pumping well
Waste lagoon
Accidental spills
Groundwater flow
Confined aquifer
Discharge
Leakage from faulty casing
Hazardous waste injection wellPesticides
and fertilizers
Gasoline station
Buried gasoline and solvent tank
SewerCesspool septic tank
De-icing road salt
Unconfined freshwater aquifer
Confined freshwater aquifer
Water pumping well
Landfill
Polluted air
Fig. 11-26, p. 258
Groundwater PollutionGroundwater Pollution
Extent of Groundwater PollutionExtent of Groundwater Pollution
Not much is known about groundwater pollutionNot much is known about groundwater pollution
Organic contaminants, including fuel leaksOrganic contaminants, including fuel leaks
ArsenicArsenic
Protecting groundwater: Prevention is bestProtecting groundwater: Prevention is best
Pump nanoparticles of inorganic compounds to remove pollutants (may be the cheapest, easiest, and most effective method but is still being developed)
Find substitutes for toxic chemicalsKeep toxic chemicals out of the environment
Install monitoring wells nearlandfills and underground tanks
Require leak detectors on underground tanks
Ban hazardous waste disposalin landfills and injection wells
Inject microorganisms to clean up contamination (less expensive but still costly)
Store harmful liquids in aboveground tanks with leak detection and collection systems
Prevention Cleanup
Pump to surface, clean, and return to aquifer (very expensive)
Solutions
Groundwater Pollution
Fig. 11-27, p. 259
Preventing and Cleaning Up Preventing and Cleaning Up Pollution in GroundwaterPollution in Groundwater
Ocean PollutionOcean Pollution
How much pollution can oceans tolerate?How much pollution can oceans tolerate?
Some pollutants degrade and dilute in oceansSome pollutants degrade and dilute in oceans
Ocean dumping controversiesOcean dumping controversies
Fig. 11-28, p. 260
IndustryNitrogen oxides from autos and smokestacks; toxicchemicals, and heavymetals in effluents flow into bays and estuaries.
CitiesToxic metals andoil from streets andparking lots pollutewaters; sewageadds nitrogen andphosphorus.
Urban sprawlBacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilization from lawns adds nitrogen and phosphorus.
Construction sitesSediments are washed into waterways,choking fish and plants, cloudingwaters, and blocking sunlight.
FarmsRun off of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus.
Red tidesExcess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals.
Healthy zoneClear, oxygen-rich waterspromote growth of planktonand sea grasses, and support fish.
Toxic sedimentsChemicals and toxic metalscontaminate shellfish beds,kill spawning fish, andaccumulate in the tissuesof bottom feeders.
Closed shellfish beds
Closedbeach Oxygen-depleted
zone
Coastal Water PollutionCoastal Water Pollution
Oxygen-depleted zoneSedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat.
Fig. 11-29, p. 261
MississippiRiver Basin
MissouriRiver
OhioRiver
MississippiRiver
LOUISIANAMississippi
River
Depleted Oxygen
Gulf of Mexico
Oxygen-depleted Water in Oxygen-depleted Water in the Gulf of Mexicothe Gulf of Mexico
Chesapeake BayChesapeake Bay
Largest US estuaryLargest US estuary
Pollution “sink”Pollution “sink”
Oxygen depletionOxygen depletion
Chesapeake Bay Chesapeake Bay ProgramProgram
Fig. 11-30, p. 261
Effects of Oil on Ocean LifeEffects of Oil on Ocean Life Crude and refined petroleumCrude and refined petroleum
Tanker accidents and blowoutsTanker accidents and blowouts
Exxon ValdezExxon Valdez
Volatile hydrocarbons kill larvaeVolatile hydrocarbons kill larvae
Tar-like globs coat birds and marine mammalsTar-like globs coat birds and marine mammals
Oil destroys insulation and buoyancyOil destroys insulation and buoyancy
Heavy oil sinks and kills bottom organismsHeavy oil sinks and kills bottom organisms
Coral reefs dieCoral reefs die
Slow recoverySlow recovery
Oil slicks ruin beachesOil slicks ruin beaches
Limited effectiveness of clean up methodsLimited effectiveness of clean up methods
Prevention Cleanup
Ban dumping of wastes and sewage by maritime and cruise ships in coastal waters
Reduce input of toxic pollutants
Separate sewage and storm lines
Regulate coastal development
Recycle used oil
Require double hulls for oil tankers
Require at least secondary treatment of coastal sewage
Use wetlands, solar-aquatic, orother methods to treat sewage
Sprinkle nanoparticles over an oil or sewage spill to dissolve the oil or sewage without creating harmful byproducts(still under development)
Protect sensitive areas from development, oil drilling, and oil shipping
Ban ocean dumping of sludge and hazardous dredged material
Improve oil-spill cleanup capabilities
Solutions
Coastal Water Pollution
Fig. 11-31, p. 263
Preventing and Cleaning Up Preventing and Cleaning Up Pollution in Coastal WatersPollution in Coastal Waters
Preventing Nonpoint Source Preventing Nonpoint Source PollutionPollution
Mostly agricultural wastesMostly agricultural wastes
Use vegetation to reduce soil erosionUse vegetation to reduce soil erosion
Reduce fertilizer useReduce fertilizer use
Use plant buffer zones around fieldsUse plant buffer zones around fields
Integrated pest management: Only use pesticides when necessaryIntegrated pest management: Only use pesticides when necessary
Use plant buffers around animal feedlotsUse plant buffers around animal feedlots
Keep feedlots away from slopes, surface water and flood zonesKeep feedlots away from slopes, surface water and flood zones
Laws for Reducing Point Source Laws for Reducing Point Source PollutionPollution
Clean Water ActClean Water Act
Water Quality ActWater Quality Act
Discharge trading controversiesDischarge trading controversies
Question of the DayQuestion of the Day
Wastewater sewage treatment plants Wastewater sewage treatment plants can be broken into two levels of can be broken into two levels of treatment, Primary and Secondary. treatment, Primary and Secondary. (Note: There is Tertiary also which we (Note: There is Tertiary also which we will discuss)will discuss)
Make a list of the processes which Make a list of the processes which occur in each level and identify which occur in each level and identify which is physical and which is a biological is physical and which is a biological process.process.
Question of the Day Question of the Day
PrimaryPrimary SecondarySecondary
StepsSteps
In ProcessIn Process
Which is Which is
Bio. Or Phys.Bio. Or Phys.
Answer of the DayAnswer of the Day
PrimaryPrimary SecondarySecondary
Steps Screens AerationSteps Screens Aeration
In Process Grit Tank Settling TankIn Process Grit Tank Settling Tank
Settling Tank DisinfectionSettling Tank Disinfection
Which is Which is
Bio. Or Phys. Physical BiologicalBio. Or Phys. Physical Biological
Sewage Treatment SystemsSewage Treatment Systems Sewage treatment in rural and suburban areasSewage treatment in rural and suburban areas
Septic tanksSeptic tanks
Primary (physical) sewage treatmentPrimary (physical) sewage treatment
Secondary (biological) sewage treatmentSecondary (biological) sewage treatment
Urban sewage treatment (Clean Water Act)Urban sewage treatment (Clean Water Act)
Sewage treatment facilities in many cities fail to meet federal Sewage treatment facilities in many cities fail to meet federal standardsstandards
Bleaching and disinfectionBleaching and disinfection
Disinfectants: chlorine, ozone, and ultraviolet radiationDisinfectants: chlorine, ozone, and ultraviolet radiation
Fig. 11-32, p. 264
Typical Septic Tank SystemTypical Septic Tank System
Householdwastewater
Perforated pipe
Distribution box (optional)
Septic tank with manhole (for cleanout)
Drainfield
Vent pipe
Nonperforated pipe
Gravel orcrushedstone
Primary and Secondary Sewage Primary and Secondary Sewage TreatmentTreatment
Fig. 11-33, p. 265
Raw sewagefrom sewers
Bar screen Grit chamber Settling tank Aeration tank Settling tankChlorinedisinfection tank
Sludge
Sludge digester
Activated sludge
Air pump
(kills bacteria)
To river, lake,
or ocean
Sludge drying bed
Disposed of in landfill or ocean or applied to cropland, pasture, or rangeland
Primary Secondary
Improving Sewage TreatmentImproving Sewage Treatment
Systems that exclude hazardous wastesSystems that exclude hazardous wastes
Non-hazardous substitutesNon-hazardous substitutes
Composting toilet systemsComposting toilet systems
Working with nature to treat sewageWorking with nature to treat sewage
Using wetlands to treat sewageUsing wetlands to treat sewage
Ecological Wastewater TreatmentEcological Wastewater Treatment
Fig. 11-34, p. 265
Reducing Water Pollution from Reducing Water Pollution from Point Sources in the USPoint Sources in the US
ImprovementsImprovements
Bad newsBad news
Should the Clean Water Act be Should the Clean Water Act be Strengthened?Strengthened?
Yes: environmentalistsYes: environmentalists
No: farmers, libertarians, manufacturers, No: farmers, libertarians, manufacturers, and developersand developers
State and local officials want more State and local officials want more discretiondiscretion
How Would You Vote How Would You Vote exerciseexercise
Drinking Water QualityDrinking Water Quality
Purification of urban drinking waterPurification of urban drinking water
Purification of drinking water in Purification of drinking water in developing countriesdeveloping countries
Bottled waterBottled water
Fig. 11-35, p. 267
Solutions
Water Pollution
• Prevent groundwater contamination
• Greatly reduce nonpoint runoff
• Reuse treated wastewater for irrigation
• Find substitutes for toxic pollutants
• Work with nature to treat sewage
• Practice four R's of resource use (refuse,
reduce, recycle, reuse)
• Reduce resource waste
• Reduce air pollution
• Reduce poverty
• Reduce birth rates
Reducing Water PollutionReducing Water Pollution
Fig. 11-36, p. 268
What Can You Do?
Water Pollution
• Fertilize your garden and yard plants with
manure or compost instead of commercial
inorganic fertilizer.• Minimize your use of pesticides.• Never apply fertilizer or pesticides near a body
of water.• Grow or buy organic foods.• Compost your food wastes.• Do not use water fresheners in toilets.• Do not flush unwanted medicines down the
toilet.• Do not pour pesticides, paints, solvents, oil,
antifreeze, or other products containing harmful
chemicals down the drain or onto the ground.
What Can We Do?What Can We Do?