Water PollutionWater Pollution

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 effectsMajor types of pollutants, sources and effects

Point and nonpoint sourcesPoint and nonpoint sources

Is the water safe to drink?Is the water safe to drink?

Major Categories of Water PollutantsMajor Categories of Water Pollutants

InfInfectious Agentsectious Agents• Bacteria, Viruses, Protozoa, Bacteria, Viruses, Protozoa,

Parasitic WormsParasitic Worms• Source: Human and animal wasteSource: Human and animal waste

Oxygen-Demanding WasteOxygen-Demanding Waste• Organic debris & waste + aerobic Organic debris & waste + aerobic

bacteriabacteria• Source: Sewage, feedlots, paper-Source: Sewage, feedlots, paper-

mills, food processingmills, food processing Inorganic ChemicalsInorganic Chemicals

• Acids, Metals, SaltsAcids, Metals, Salts• Sources: Surface runoff, Industrial Sources: Surface runoff, Industrial

effluent, household cleanserseffluent, household cleansers Radioactive MaterialsRadioactive Materials

• Iodine, radon, uranium, cesium, Iodine, radon, uranium, cesium, thoriumthorium

• Source: Coal & Nuclear Power plants, Source: Coal & Nuclear Power plants, mining, weapons production, naturalmining, weapons production, natural

Plant NutrientsPlant Nutrients• Nitrates, Phosphates, Nitrates, Phosphates, • Source: Sewage, manure, Source: Sewage, manure,

agricultural and landscaping runoffagricultural and landscaping runoff Organic ChemicalsOrganic Chemicals

• Oil, Gasoline, Plastics, Pesticides, Oil, Gasoline, Plastics, Pesticides, Solvents, detergentsSolvents, detergents

• Sources: Industrial effluent, Sources: Industrial effluent, Household cleansers, runoff from Household cleansers, runoff from farms and yardsfarms and yards

Eroded SedimentEroded Sediment• Soil, SiltSoil, Silt

Heat/Thermal PollutionHeat/Thermal Pollution• Source: Power plants, IndustrialSource: Power plants, Industrial

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

Pollution in StreamsPollution in Streams

Benefits of FloodplainsBenefits of Floodplains Highly productive wetlandsHighly productive wetlands

Provide natural flood and erosion controlProvide natural flood and erosion control

Maintain high water qualityMaintain high water quality

Recharge groundwaterRecharge groundwater

Fertile soilsFertile soils

Nearby rivers for use and recreationNearby rivers for use and recreation

Flatlands for urbanization and farmingFlatlands for urbanization and farming

Dangers of Floodplains and FloodsDangers of Floodplains and Floods

Deadly and destructiveDeadly and destructive

Human activities worsen floodsHuman activities worsen floods

Failing dams and water diversionFailing dams and water diversion

BangladeshBangladesh

Before and During a Flood in St. Before and During a Flood in St. Louis, MissouriLouis, Missouri

Oxygenreleased byvegetation

Diverseecological

habitatEvapotranspiration

Trees reduce soilerosion from heavyrain and wind

AgriculturallandSteady

river flowLeaf litterimprovessoil fertility

Tree roots stabilize soil and aid water flow

Vegetation releaseswater slowly andreduces flooding

Forested Hillside

Flooding After Deforestation of a Flooding After Deforestation of a HillsideHillside

Tree plantation

Evapotranspiration decreases

Ranching accelerates soil erosion by water and wind

Winds removefragile topsoil

Gullies andlandslides

Heavy rain leaches nutrients from soil and erodes topsoil

Rapid runoffcauses flooding

After Deforestation

Roadsdestabilizehillsides

Agriculture landis flooded andsilted up

Silt from erosion blocks rivers andreservoirs and causes flooding downstream

Flooding After Deforestation of a Flooding After Deforestation of a HillsideHillside

Reducing Flood RisksReducing Flood Risks

ChannelizationChannelization

Levees (floodwalls)Levees (floodwalls)

DamsDams

Protect and restore wetlandsProtect and restore wetlands

Identify and manage flood-prone areasIdentify and manage flood-prone areas

Precautionary approachPrecautionary approach

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

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

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)

SolutionsGroundwater Pollution

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

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.

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

Effects of Oil on Ocean LifeEffects of Oil on Ocean Life

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 oilRequire 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

SolutionsCoastal Water Pollution

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

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

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

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 Ecological Wastewater Wastewater TreatmentTreatment

Burlington, VTBurlington, VTUniversity of VermontUniversity of Vermont

Should the Clean Water Act be Should the Clean Water Act be Strengthened?Strengthened?

State and local officials want more discretionState and local officials want more discretion

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

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

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.