Chapter 22Chapter 22Water PollutionWater Pollution

Overview of Chapter 22Overview of Chapter 22

o Types of Water PollutionTypes of Water Pollution• SewageSewage• Disease-causing agentsDisease-causing agents• Sediment pollutionSediment pollution• Inorganic plant and algal nutrientsInorganic plant and algal nutrients• Organic compoundsOrganic compounds• Inorganic chemicalsInorganic chemicals• Thermal pollutionThermal pollution

o Water Quality TodayWater Quality Todayo Improving Water QualityImproving Water Qualityo Laws Controlling Water PollutionLaws Controlling Water Pollution

Types of Water PollutionTypes of Water Pollution

o Water pollutionWater pollution• Any physical or chemical change in water Any physical or chemical change in water

that adversely affects the health of humans that adversely affects the health of humans and other organisms and other organisms

• Varies in magnitude by locationVaries in magnitude by locationo Major water pollution issue globallyMajor water pollution issue globally

• Lack of disease-free waterLack of disease-free watero Eight categoriesEight categories

• Sewage, disease-causing agents, sediment Sewage, disease-causing agents, sediment pollution, inorganic plant and algal pollution, inorganic plant and algal nutrients, organic compounds, inorganic nutrients, organic compounds, inorganic chemicals, radioactive substances, and chemicals, radioactive substances, and thermal pollution thermal pollution

1. Sewage1. Sewage

o The release of wastewater from drains or The release of wastewater from drains or sewers sewers • Includes human wastes, soaps, and detergents Includes human wastes, soaps, and detergents

o Causes 2 serious environmental problems:Causes 2 serious environmental problems:• EnrichmentEnrichment

• Fertilization of a body of water by high levels of plant Fertilization of a body of water by high levels of plant and algal nutrients (nitrogen and phosphorus)and algal nutrients (nitrogen and phosphorus)

• Increase in Biological Oxygen Demand (BOD)Increase in Biological Oxygen Demand (BOD)• Amount of oxygen needed by microorganisms to Amount of oxygen needed by microorganisms to

decompose biological wastesdecompose biological wastes• As BOD increases Dissolve Oxygen (DO) decreasesAs BOD increases Dissolve Oxygen (DO) decreases

SewageSewage

Sewage- EutrophicationSewage- Eutrophication

o OligotrophicOligotrophic• Unenriched, clear water that supports small Unenriched, clear water that supports small

populations of aquatic organisms populations of aquatic organisms

Sewage- EutrophicationSewage- Eutrophicationo Eutrophic-Eutrophic-

• Slow-flowing stream, lake or estuary enriched by Slow-flowing stream, lake or estuary enriched by inorganic plant and algal nutrients such as phosphorus inorganic plant and algal nutrients such as phosphorus

• Often due to fertilizer or sewage runoffOften due to fertilizer or sewage runoff

2. Disease-causing Agents2. Disease-causing Agents

o Infectious organisms Infectious organisms that cause diseasesthat cause diseases• Originate in the Originate in the

wastes of infected wastes of infected individuals individuals

o Common bacterial or Common bacterial or viral diseases:viral diseases:• Typhoid, cholera, Typhoid, cholera,

bacterial dysentery, bacterial dysentery, polio, and infectious polio, and infectious hepatitishepatitis

Disease-causing AgentsDisease-causing Agentso Monitored by testing for presence of E. coli Monitored by testing for presence of E. coli

in the water via a in the water via a fecal coliform testfecal coliform test• Indicates the presence of pathogenic organismsIndicates the presence of pathogenic organisms

Types of Water PollutionTypes of Water Pollutiono Monitoring for Sewage (Fecal Coliform Test) Monitoring for Sewage (Fecal Coliform Test)

– – small sample of water passed through filter to trap bacteria, small sample of water passed through filter to trap bacteria, transferred to a petri dish with nutrients; incubated until transferred to a petri dish with nutrients; incubated until greenish colonies form, which can be counted to indicate the greenish colonies form, which can be counted to indicate the number of E. coli in the original samplenumber of E. coli in the original sample

Fecal Coliform Test - ResultsFecal Coliform Test - Resultso Safe drinking water = no more than 1 Safe drinking water = no more than 1

coliform bacterium per 100 mL of drinking coliform bacterium per 100 mL of drinking water (1/2 cup)water (1/2 cup)

o Safe swimming water = no more than 200 Safe swimming water = no more than 200 bacteria per 100 mL of waterbacteria per 100 mL of water

o Safe recreational boating = no more than Safe recreational boating = no more than 2,000 per 100 mL of water2,000 per 100 mL of water

o Raw Sewage = usually several million Raw Sewage = usually several million coliform bacteria per 100 mL of water!coliform bacteria per 100 mL of water!

3. Sediment Pollution3. Sediment Pollutiono Excessive amounts of suspended soil Excessive amounts of suspended soil

particlesparticles• Originates from Originates from erosionerosion of agricultural lands, of agricultural lands,

forest soils exposed by logging, degraded stream forest soils exposed by logging, degraded stream banks, overgrazed rangelands, strip mines, and banks, overgrazed rangelands, strip mines, and construction construction

o ProblemsProblems• Limits light penetration thereby decreasing Limits light penetration thereby decreasing

photosynthetic activityphotosynthetic activity• Covers aquatic animals and plants, providing Covers aquatic animals and plants, providing

less shelter for aquatic organismsless shelter for aquatic organisms• Brings insoluble toxins into waterwaysBrings insoluble toxins into waterways

4. Inorganic Plant and Algal 4. Inorganic Plant and Algal NutrientsNutrients

o Chemicals such as nitrogen and phosphorus Chemicals such as nitrogen and phosphorus that stimulate the growth of plants and that stimulate the growth of plants and algaealgae• Harmful in large concentrationsHarmful in large concentrations

o Sources:Sources:• Human and animal wastes, plant residues, Human and animal wastes, plant residues,

atmospheric deposition, and fertilizer runoffatmospheric deposition, and fertilizer runoff

o Causes:Causes:• Enrichment, bad odors, and a high BOD Enrichment, bad odors, and a high BOD

Inorganic Plant and Algal Nutrient- Inorganic Plant and Algal Nutrient- The Dead ZoneThe Dead Zone

5. Organic Compounds5. Organic Compoundso Chemicals that contain carbon atomsChemicals that contain carbon atoms

• Natural examples: sugars, amino acids, and oils Natural examples: sugars, amino acids, and oils • Human-made examples: pesticides, solvents, Human-made examples: pesticides, solvents,

industrial chemicals, and plastics industrial chemicals, and plastics

Organic Compounds2002 U.S. Geological Survey of 139 streams in

the United States found trace amounts of:

antibiotics, ibuprofen, acetaminophen, insect repellents, fragrances, caffeine, steroids (like hormones from birth control pills)

What is the effect of trace amounts of these in our water supply?????

6. Inorganic Chemicals6. Inorganic Chemicalso Contaminants that contain elements other Contaminants that contain elements other

than carbonthan carbon• Examples: acids, salts, and heavy metals Examples: acids, salts, and heavy metals

o Do not degrade easilyDo not degrade easilyo LeadLead

• Found in old paint, industrial pollutants, leaded Found in old paint, industrial pollutants, leaded gasolinegasoline

o MercuryMercury• Mercury bioaccumulates in the muscles & fat of Mercury bioaccumulates in the muscles & fat of

top predators of the open ocean top predators of the open ocean

Inorganic ChemicalsMercury:

Vaporizes even at room temperature (so can be inhaled!)

Coal-fired power plants mostly to blame for mercury exposure

Under the current Clean Air Act, mercury emissions are NOT mandated for power plants (unlike sulfur emissions)

Municipal waste incinerators, smelting of metals, industrial chemicals also expose us to mercury

7. Radioactive Substances7. Radioactive Substanceso Contain atoms of unstable isotopes that Contain atoms of unstable isotopes that

spontaneously emit radiation spontaneously emit radiation o SourcesSources

• MiningMining• Processing radioactive materialsProcessing radioactive materials• Nuclear power plantsNuclear power plants• Natural sourcesNatural sources

8. Thermal Pollution8. Thermal Pollution

o Occurs when heated Occurs when heated water produced water produced during industrial during industrial processes is released processes is released into waterways into waterways

o Organisms affectedOrganisms affected• Temperature affects Temperature affects

reproductive cycles, reproductive cycles, digestion rates, and digestion rates, and respiration rates respiration rates

• Warm water holds less Warm water holds less DO than cold waterDO than cold water

Water Quality TodayWater Quality Today

o Two Types of Water PollutionTwo Types of Water Pollutiono -Point Source Pollution-Point Source Pollution

• water pollution that can be traced to a water pollution that can be traced to a specific origin specific origin

• Discharge via pipes, sewage, and ditchesDischarge via pipes, sewage, and ditcheso -Non-point Source Pollution-Non-point Source Pollution

• Pollutants that enter bodies of water over Pollutants that enter bodies of water over large areas rather than being concentrated large areas rather than being concentrated at a single point of entry at a single point of entry

• Diffuse, but its cumulative effect is very Diffuse, but its cumulative effect is very largelarge

• Ex: runoff from agricultural fields or parking Ex: runoff from agricultural fields or parking lotslots

Water Pollution from AgricultureWater Pollution from Agricultureo Agriculture is leading source of water Agriculture is leading source of water

pollution in US (72% of the pollution)pollution in US (72% of the pollution)• Animal wastes and plants residues have high Animal wastes and plants residues have high

BODBOD• Chemical pesticides can leach into groundwaterChemical pesticides can leach into groundwater

o Almost all streams and rivers are polluted Almost all streams and rivers are polluted with agricultural pesticideswith agricultural pesticides

Municipal Water PollutionMunicipal Water Pollution

Industrial Wastes in WaterIndustrial Wastes in Watero Different industries generate different Different industries generate different

pollutantspollutants• Food processing plants- high BODFood processing plants- high BOD• Paper mills- High BOD and toxic compoundsPaper mills- High BOD and toxic compounds

o Many industries recover toxins before they Many industries recover toxins before they go into the waste streamgo into the waste stream

Case-In-Point Green ChemistryCase-In-Point Green Chemistry

Examples of Green ChemistryExamples of Green Chemistryo Researchers at Carnegie-Mellon U. are using Researchers at Carnegie-Mellon U. are using

TAML’s (tetra-amido-macro-cyclic ligands) TAML’s (tetra-amido-macro-cyclic ligands) for helping break down synthetic substances for helping break down synthetic substances before dumping into riversbefore dumping into rivers

o Changing chemical processes to use fewer Changing chemical processes to use fewer synthetic chemicals in industrysynthetic chemicals in industry• Plastic bottles can now be made from sugars, Plastic bottles can now be made from sugars,

with no use of harmful chemicals, and also break with no use of harmful chemicals, and also break down in the environment after usedown in the environment after use

o Dry cleaners in California can no longer use Dry cleaners in California can no longer use perchloroethylene (perc), and have found perchloroethylene (perc), and have found less harmful alternativesless harmful alternatives

Groundwater Pollution Groundwater Pollution (1/2 the people in (1/2 the people in the U.S. get their drinking water from the U.S. get their drinking water from

groundwater!)groundwater!)

Water Pollution in Other CountriesWater Pollution in Other Countrieso Lake Maracaibo, VenezuelaLake Maracaibo, Venezuela

• 10,000 oil wells tap lake bottom10,000 oil wells tap lake bottom• drilling platforms throughout the lake…pipelines running to drilling platforms throughout the lake…pipelines running to

refineries on land…10,000 oil wells have been drilled…much refineries on land…10,000 oil wells have been drilled…much oil spilled!oil spilled!

• Agricultural Agricultural wastes from wastes from local fieldslocal fields

• Unit recently Unit recently raw human raw human waste polluted waste polluted the lakethe lake

Water Pollution in Other CountriesWater Pollution in Other Countrieso Po River, ItalyPo River, Italy

• Similar to Mississippi River• Pollutants: Sewage, industrial wastes, sediment• >16 million Italians depend on the river for

drinking water• Pollution is high

• Swimming and fishing prohibited• Cleanup will require a national management plan

and may take decades

Water Pollution in Other CountriesWater Pollution in Other Countries

o Ganges River, IndiaGanges River, India• Used for bathing and Used for bathing and

washing clothingwashing clothing• Sewage and industrial Sewage and industrial

waste discharged into waste discharged into riverriver

• Ganga Action Plan Ganga Action Plan initiated by governmentinitiated by government

• Construction of 29 Construction of 29 sewage treatment plantssewage treatment plants

Improving Water Quality-Improving Water Quality-Purification of Drinking WaterPurification of Drinking Water

o In US most In US most municipal water municipal water supplies are supplies are treated, typically treated, typically with chlorine!with chlorine!

o First step…water is First step…water is collected from collected from water or reservoir water or reservoir (dam may be (dam may be involved, or involved, or groundwater wells groundwater wells and water towers and water towers used)used)

o Treated water Treated water distributed to distributed to customerscustomers

o Sewer lines bring Sewer lines bring sewage to sewage to treatment planttreatment plant

o Sewage treated at Sewage treated at sewage treatment sewage treatment plantplant

Improving Water Quality-Improving Water Quality-Purification of Drinking WaterPurification of Drinking Water

Purification of Drinking WaterPurification of Drinking Water

o Chlorine DilemmaChlorine Dilemmao Chlorine kills disease causing organisms!Chlorine kills disease causing organisms!

• BUT - Chlorine byproducts are linked to numerous BUT - Chlorine byproducts are linked to numerous cancers, miscarriages and birth defectscancers, miscarriages and birth defects

• Peru stopped using chlorinePeru stopped using chlorine• 1991- huge cholera epidemic that infected 300,000 1991- huge cholera epidemic that infected 300,000

peoplepeople

o FluoridationFluoridation• Prevents tooth decayPrevents tooth decay• Linked to cancer, kidney diseaseLinked to cancer, kidney disease

o With both of these…the risk must be With both of these…the risk must be compared to the benefits!compared to the benefits!

Municipal Sewage TreatmentMunicipal Sewage Treatmento Primary treatmentPrimary treatment

• Removing suspended and floating particles by Removing suspended and floating particles by mechanical processes (usually screens)mechanical processes (usually screens)

o Secondary treatmentSecondary treatment• Treating wastewater biologically to decompose Treating wastewater biologically to decompose

suspended organic material; reduces BOD suspended organic material; reduces BOD

Municipal Sewage TreatmentMunicipal Sewage Treatmento Sewage SludgeSewage Sludge

• Solids remaining after primary and secondary Solids remaining after primary and secondary sewage treatment has been completed sewage treatment has been completed

• This material is either landfilled or used as This material is either landfilled or used as composting for farms (may contain mercury and composting for farms (may contain mercury and other harmful toxins)other harmful toxins)

o Tertiary treatmentTertiary treatment• Advanced wastewater treatment methods that Advanced wastewater treatment methods that

are sometimes employed after primary and are sometimes employed after primary and secondary treatments (usually an additional secondary treatments (usually an additional bacterial treatment)bacterial treatment)

• Reduce phosphorus and nitrogenReduce phosphorus and nitrogen

Municipal Sewage TreatmentMunicipal Sewage Treatment

Individual Septic System-Individual Septic System-Septic TankSeptic Tank

Individual Septic System-Individual Septic System-Drain FieldDrain Field

Laws Controlling Water PollutionLaws Controlling Water Pollution

o Citizen Watchdogs to Monitor PollutionCitizen Watchdogs to Monitor Pollutiono Safe Drinking Water Act (1974)Safe Drinking Water Act (1974)

• Set uniform federal standards for drinking waterSet uniform federal standards for drinking water• Maximum contaminant levels and MCL goals were Maximum contaminant levels and MCL goals were

established for many common water pollutants!established for many common water pollutants!

o Clean Water Act (1972)Clean Water Act (1972)• EPA sets up and monitors National Emissions EPA sets up and monitors National Emissions

LimitationsLimitations• Effectively improved water quality from point Effectively improved water quality from point

sourcessources• Still largely ineffective at controlling NONPOINT Still largely ineffective at controlling NONPOINT

sources!sources!

Laws that Protect GroundwaterLaws that Protect Groundwatero Safe Drinking Water Act (1974)Safe Drinking Water Act (1974)o Resource, Conservation and Recovery Act Resource, Conservation and Recovery Act

(1976)(1976)o Comprehensive Environmental Response, Comprehensive Environmental Response,

Compensation, and Liability Act (Superfund – Compensation, and Liability Act (Superfund – 1980)1980)