Water Quality & Water Quality & General Types of General Types of Water PollutionWater Pollution

Water covers 71% of earth’s surfaceWater covers 71% of earth’s surface Freshwater availability – 0.024%Freshwater availability – 0.024%

Groundwater, lakes, rivers, and streamsGroundwater, lakes, rivers, and streams Hydrologic cycle Hydrologic cycle

Movement of water in the seas, land, and airMovement of water in the seas, land, and air Driven by solar energy and gravityDriven by solar energy and gravity Distributed unevenlyDistributed unevenly

Humans can alter the hydrologic cycleHumans can alter the hydrologic cycle Withdrawing water, polluting, climate changeWithdrawing water, polluting, climate change

Most of the Earth’s Most of the Earth’s Freshwater Is Not Freshwater Is Not Available to UsAvailable to Us

Water UsageWater Usage Irrigation (70%)– watering cropsIrrigation (70%)– watering crops Industry (20%)– coolant (power Industry (20%)– coolant (power

plant)plant) Domestic and Municipal (10%)– Domestic and Municipal (10%)–

drinking, sewage, bathwater, drinking, sewage, bathwater, dishwater & laundrydishwater & laundry

Fig. 13-6, p. 322

Virtual waterVirtual water

Not consumed; Not consumed; used to used to produce food produce food and other and other productsproducts

Freshwater supplies are not evenly Freshwater supplies are not evenly distributed, and one of every six people on distributed, and one of every six people on the planet does not have adequate access the planet does not have adequate access to clean waterto clean water

We are using available freshwater We are using available freshwater unsustainably by wasting it, polluting it, unsustainably by wasting it, polluting it, and underpricing what is an irreplaceable and underpricing what is an irreplaceable natural resourcenatural resource

Effects our misuse are Floods, Drought, Effects our misuse are Floods, Drought, and Pollutionand Pollution

Case Study: Freshwater Case Study: Freshwater Resources in the United Resources in the United StatesStates

TOO MUCH WATERTOO MUCH WATER Problems include flooding, pollution of water Problems include flooding, pollution of water

supply, and sewage seeping into ground.supply, and sewage seeping into ground. Heavy rainfall, rapid snowmelt, removal of Heavy rainfall, rapid snowmelt, removal of

vegetation, and destruction of wetlands cause vegetation, and destruction of wetlands cause flooding.flooding.

Floodplains, which include wetlands, help provide Floodplains, which include wetlands, help provide natural flood and erosion control, maintain high natural flood and erosion control, maintain high water quality, and recharge groundwater.water quality, and recharge groundwater.

To minimize floods, rivers have been narrowed To minimize floods, rivers have been narrowed with levees and walls, and dammed to store with levees and walls, and dammed to store water.water.

Diverse ecological habitat

Evapotranspiration

Trees reduce soil erosion from heavy rain and wind

Tree roots stabilize soil

Vegetation releases water slowly and reduces flooding

Forested Hillside

Agricultural land

Stepped Art

Tree plantation

Roads destabilize hillsides

Overgrazing accelerates soil erosion by water and wind

Winds remove fragile topsoil

Agricultural land is flooded and silted upGullies and

landslides

Heavy rain erodes topsoil

Silt from erosion fills rivers and reservoirs

Rapid runoff causes flooding

After Deforestation

Evapotranspiration decreases

Fig. 13-29, p. 343

TOO MUCH WATER

Too Little WaterToo Little Water

Examples include drought and expanding deserts Examples include drought and expanding deserts (desertification).(desertification).

Most aquifers are renewableMost aquifers are renewable Unless water is contaminated or removedUnless water is contaminated or removed

Aquifers provide drinking water for half the Aquifers provide drinking water for half the worldworld

Water tables are falling in many parts of the Water tables are falling in many parts of the world, primarily from crop irrigationworld, primarily from crop irrigation

Groundwater used to supply cities and grow Groundwater used to supply cities and grow food is being pumped from aquifers in some food is being pumped from aquifers in some areas faster than it is renewed by areas faster than it is renewed by precipitationprecipitation

Groundwater / Aquifer Groundwater / Aquifer DepletionDepletion

Groundwater & Groundwater & AquifersAquifers

Groundwater or aquifers are water recharge areas that are located Groundwater or aquifers are water recharge areas that are located beneath the ground surface in soil pore spaces and fractures in the beneath the ground surface in soil pore spaces and fractures in the Earth’s formations. Natural discharge occurs from springs and Earth’s formations. Natural discharge occurs from springs and wetlands.wetlands.

The water table measures the level of Earth’s land crust to which the The water table measures the level of Earth’s land crust to which the aquifer is filled or the division between saturated and unsaturated rock.aquifer is filled or the division between saturated and unsaturated rock.Renewability rates of aquifers differ depending on the surrounding Renewability rates of aquifers differ depending on the surrounding conditions of the land and the water cycle. The circulation rate of most conditions of the land and the water cycle. The circulation rate of most aquifers is usually slow (300 to 4,600 years) compared to the rate they aquifers is usually slow (300 to 4,600 years) compared to the rate they are being depleted.are being depleted.

Ogallala Aquifer

Ground Water ProblemsGround Water Problems Ground water problems include Ground water problems include

pollution, increase in salinity, pollution, increase in salinity, and draining too much.and draining too much.

Sinkholes can form when the Sinkholes can form when the roof of an underground cavern roof of an underground cavern collapses from draining too collapses from draining too much water.much water.

Harms both humans and Harms both humans and endangers many species.endangers many species.

Ogallala aquifer – largest known aquiferOgallala aquifer – largest known aquifer Extends from South Dakota to TexasExtends from South Dakota to Texas Irrigates the Great PlainsIrrigates the Great Plains Very slow rechargeVery slow recharge Water table droppingWater table dropping

Water pumped 10-40 times faster than rechargeWater pumped 10-40 times faster than recharge Government subsidies to continue farming Government subsidies to continue farming

deplete the aquifer furtherdeplete the aquifer further Biodiversity threatened in some areasBiodiversity threatened in some areas Northern states will still have ample supplies, but Northern states will still have ample supplies, but

for the south it’s getting thinner.for the south it’s getting thinner.

Case Study: Overpumping the Case Study: Overpumping the OgallalaOgallala

Groundwater Depletion: Groundwater Depletion: A Growing ProblemA Growing Problem

The Ogallala, the world’s largest aquifer, The Ogallala, the world’s largest aquifer, is most of the red area in the center is most of the red area in the center (Midwest).(Midwest).

Areas of Areas of greatest greatest aquifer aquifer depletion depletion from from groundwater groundwater overdraft in overdraft in the the continental continental U.S.U.S.

Figure 13-5Figure 13-5

Population GrowthPopulation GrowthProblems include over-Problems include over-

drawing fresh water, drawing fresh water, pollution, and over-building pollution, and over-building so that water can’t seep so that water can’t seep into the ground.into the ground.

Sharing Water ResourcesSharing Water Resources There are water wars out west. There are water wars out west.

California bought the water from California bought the water from the Colorado River, but Arizona the Colorado River, but Arizona wants it. Who owns it? The same wants it. Who owns it? The same thing is happening in Texas. More thing is happening in Texas. More water rights are sold than the water rights are sold than the actual amount of water. How do actual amount of water. How do you share water? This is a you share water? This is a problem all over the world.problem all over the world.

Fig. 13-8, p. 323

Washington

OregonMontana

North Dakota

Idaho South DakotaWyoming

Nevada Nebraska

Utah Colorado Kansas

California Oklahoma

ArizonaNew Mexico

Texas

Highly likely conflict potentialSubstantial conflict potentialModerate conflict potentialUnmet rural water needs

U.S. Geological Survey projection, 2007: Water hotspots

By 2025, areas around world could face intense conflicts over scarce water

Overdrawing Surface WaterOverdrawing Surface WaterCase Study- Aral SeaCase Study- Aral Sea The The Aral SeaAral Sea has been greatly affected by water has been greatly affected by water

diversion projects for irrigation and this has caused diversion projects for irrigation and this has caused lake water levels to droplake water levels to drop. This has created a major . This has created a major ecological, economic, and health disaster.(read pg. ecological, economic, and health disaster.(read pg. 332)332)

Effects of the dropping sea level :Effects of the dropping sea level :Water has dropped 22 meters since 1961Water has dropped 22 meters since 1961The sea’s salinity has tripled The sea’s salinity has tripled 20 of the 24 native fish species have gone extinct.20 of the 24 native fish species have gone extinct.About 85% of wetlands have been eliminated and About 85% of wetlands have been eliminated and 50% of local bird and mammal species have 50% of local bird and mammal species have disappeared.disappeared.1989 2008 2012

Stable RunoffStable Runoff As water runs off from rain, it’s supposed As water runs off from rain, it’s supposed

to get into rivers, and finally off to the to get into rivers, and finally off to the sea. But when we dam rivers, less goes sea. But when we dam rivers, less goes to the ocean, meaning the brackish water to the ocean, meaning the brackish water (where the river hits the ocean) becomes (where the river hits the ocean) becomes more salty. This is the breeding ground more salty. This is the breeding ground for many fish and invertebrates. This for many fish and invertebrates. This harms the ecology of the area.harms the ecology of the area.

Salinization of Irrigated Salinization of Irrigated SoilSoilWater is poured onto soil and Water is poured onto soil and

evaporates. Over time, as this evaporates. Over time, as this is repeated, nothing will grow is repeated, nothing will grow there anymore.there anymore.

Impacts of Human Activities Impacts of Human Activities on Freshwater Systemson Freshwater Systems Dams, cities, farmlands, and filled-in wetlands Dams, cities, farmlands, and filled-in wetlands

alter and degrade freshwater habitats.alter and degrade freshwater habitats. Dams, diversions and canals have Dams, diversions and canals have

fragmented about 40% of the world’s 237 fragmented about 40% of the world’s 237 large rivers.large rivers.

Flood control levees and dikes alter and Flood control levees and dikes alter and destroy aquatic habitats.destroy aquatic habitats.

Cities and farmlands add pollutants and Cities and farmlands add pollutants and excess plant nutrients to streams and rivers.excess plant nutrients to streams and rivers.

Many inland wetlands have been drained or Many inland wetlands have been drained or filled for agriculture or (sub)urban filled for agriculture or (sub)urban development.development.

Water Management

Dams and ReservoirsDams and Reservoirs

•Description: A dammed stream that can capture & store water from rain & melted snow.

•Benefits: Hydroelectric power; provides water to towns; recreation; controls floods downstream

• Problems: Reduces downstream flow; prevents water from reaching the sea (Colorado River) devastates fish life; reduces biodiversity.

USING DAMS AND USING DAMS AND RESERVOIRS TO SUPPLY RESERVOIRS TO SUPPLY MORE WATERMORE WATER

Large dams and reservoirs can Large dams and reservoirs can produce cheap electricity, reduce produce cheap electricity, reduce downstream flooding, and provide downstream flooding, and provide year-round water for irrigating year-round water for irrigating cropland, but they also displace cropland, but they also displace people and disrupt aquatic systems.people and disrupt aquatic systems.

Provides water for year-round irrigation of cropland

Flooded land destroys forests or cropland and displaces people

Large losses of water through evaporation

Provides water for drinking Downstream

cropland and estuaries are deprived of nutrient-rich silt

Reservoir is useful for recreation and fishing

Risk of failure and devastating downstream flooding

Can produce cheap electricity (hydropower)

Downstream flooding is reduced

Migration and spawning of some fish are disrupted

Fig. 13-13a, p. 328

Powerlines

Reservoir

DamPowerhouse

Intake

Turbine

Fig. 13-13a, p. 328

The Colorado River has so The Colorado River has so many dams and withdrawals many dams and withdrawals that it often does not reach the that it often does not reach the ocean.ocean. Has 14 major dams , reservoirs, Has 14 major dams , reservoirs,

and canals.and canals. Flows through seven states and Flows through seven states and

two countries, with much of its two countries, with much of its course through desert. course through desert.

Large quantities of water removed Large quantities of water removed from it every year to reservoirs in from it every year to reservoirs in other parts of the country.other parts of the country.

Many endangered species live in Many endangered species live in or along the course of the river.or along the course of the river.

Case Study: Colorado River

Issues

Lake Powell, is the second largest reservoir in the U.S.

Advantages of a river’s use are:Advantages of a river’s use are:provides water for more than provides water for more than 24 million people24 million peopleirrigates 2 million acres of landirrigates 2 million acres of landprovides major tourist provides major tourist attractionsattractionsprovides 4,000 MW of provides 4,000 MW of electricityelectricity

Disadvantages of a river’s use are:Disadvantages of a river’s use are:lowered water qualitylowered water qualityriver delta affected by low water river delta affected by low water flowsflowsloss of habitat for many animalsloss of habitat for many animalsmajor construction and diversion major construction and diversion issuesissues

Colorado River Issues

Glen Canyon Dam

Aswan High Dam Aswan High Dam Two dams straddle the Nile River at Aswan, Egypt. Two dams straddle the Nile River at Aswan, Egypt.

Completed in 1970 and formed Lake Nasser which is 550 Completed in 1970 and formed Lake Nasser which is 550 km long and capable of holding two years of the Nile's km long and capable of holding two years of the Nile's annual flow.annual flow.

The main objectives of the project were:The main objectives of the project were:energy generation in a renewable form.energy generation in a renewable form.flood control in downstream locations.flood control in downstream locations.provision of water for agriculture and domestic use.provision of water for agriculture and domestic use.

A serious detrimental effect is the loss of the annual A serious detrimental effect is the loss of the annual floods downstream. These used to replenish the nutrients floods downstream. These used to replenish the nutrients of the flood plain and flush out accumulated salts. of the flood plain and flush out accumulated salts.

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‣Without flooding, fertilizers must be applied to the land and salts build up in the soils, causing crops to fail.

‣Without annual deposition of river sediments because of build-up behind the dam, the land is eroding, allowing the sea to encroach up the river delta.

‣Damming has also caused 64% of commercially fished species in the Nile to disappear.

‣Time will tell if better management will help to reverse the problems currently being experienced in the Nile Delta region.

Three Three Gorges DamGorges Dam Spans the Yangtze River at Spans the Yangtze River at

Sandouping, China, and is the Sandouping, China, and is the largest hydroelectric dam in largest hydroelectric dam in the world, capable of producing the world, capable of producing 22,500MW of electricity. (equal 22,500MW of electricity. (equal to 18 large coal burning plants to 18 large coal burning plants or nuclear power plants)or nuclear power plants)

Major construction began in Major construction began in 1994 and was completed by 1994 and was completed by 2012.2012.

Debate over whether Debate over whether advantages will out way advantages will out way disadvantages.disadvantages.

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Three Gorges Dam IssuesThree Gorges Dam Issues Advantages of construction:Advantages of construction:

reduction of coal use in coal fired reduction of coal use in coal fired power stationspower stationsflood control downstreamflood control downstreamdrought reliefdrought reliefbetter navigation of the river by better navigation of the river by shipsships

Disadvantages of construction:Disadvantages of construction:submergence of wetlands and submergence of wetlands and agricultural landsagricultural landsloss of endangered plant and animal loss of endangered plant and animal habitatshabitatsarchaeological sites flooded archaeological sites flooded upstreamupstreamtowns and cities flooded and 1.2 towns and cities flooded and 1.2 million people displacedmillion people displacedBuilt over seismatic fault and Built over seismatic fault and already has small cracks.already has small cracks.

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The critically endangered Siberian crane uses wetlands for winter feeding that will be

flooded by the Three Gorges Dam.

Dam RemovalDam Removal Some dams are being removed for ecological Some dams are being removed for ecological

reasons and because they have outlived their reasons and because they have outlived their usefulness.usefulness. In 1998 the U.S. Army Corps of Engineers In 1998 the U.S. Army Corps of Engineers

announced that it would no longer build large announced that it would no longer build large dams and diversion projects in the U.S.dams and diversion projects in the U.S.

The Federal Energy Regulatory Commission has The Federal Energy Regulatory Commission has approved the removal of nearly 500 dams.approved the removal of nearly 500 dams.

Removing dams can reestablish ecosystems, but Removing dams can reestablish ecosystems, but can also re-release toxicants into the environment.can also re-release toxicants into the environment.

Water DiversionWater Diversion

•Description: Damming a river to control where the water flows

•Benefits: Keeps water where we want it- cities!

•Problems: Drains wetlands, destroys land

DesalinizationDesalinization•Description: Removing salt from salt water

•Benefits: Freshwater

•Problems: Uses lots of energy; costs 3-5X’s more money; what do we do with the salt?

DESALTING SEAWATERDESALTING SEAWATER

Removing salt from seawater by current Removing salt from seawater by current methods is expensive and produces large methods is expensive and produces large amounts of salty wastewater that must be amounts of salty wastewater that must be disposed of safely.disposed of safely. DistillationDistillation: heating saltwater until it evaporates, : heating saltwater until it evaporates,

leaves behind water in solid form.leaves behind water in solid form. Reverse osmosisReverse osmosis: uses high pressure to force : uses high pressure to force

saltwater through a membrane filter.saltwater through a membrane filter.

SEEDING CLOUDS, AND SEEDING CLOUDS, AND TOWING ICEBERGS AND TOWING ICEBERGS AND GIANT BAGGIESGIANT BAGGIES

Seeding clouds with tiny Seeding clouds with tiny particles of chemicals to particles of chemicals to increase rainfall, towing increase rainfall, towing icebergs or huge bags filled icebergs or huge bags filled with freshwater to dry coastal with freshwater to dry coastal areas have all been proposed areas have all been proposed but are unlikely to provide but are unlikely to provide significant amounts of significant amounts of freshwater.freshwater.

Harvesting IcebergsHarvesting Icebergs

•Description: Towing massive icebergs to arid coastal areas (S. California; Saudi Arabia)

•Benefits: freshwater

•Problems: Technology not available; costs too high; raise temperatures around the earth.

INCREASING WATER SUPPLIES INCREASING WATER SUPPLIES BY WASTING LESS WATERBY WASTING LESS WATER Sixty percent of world’s irrigation water is currently Sixty percent of world’s irrigation water is currently

wasted, but improved irrigation techniques could wasted, but improved irrigation techniques could cut this waste to 5-20%.cut this waste to 5-20%.

Drip Method – delivers water directly to root. 90-Drip Method – delivers water directly to root. 90-95% efficient.95% efficient.

Center-pivot, low pressure sprinklers sprays water Center-pivot, low pressure sprinklers sprays water directly onto crop.directly onto crop. 80% of water reaches crop.80% of water reaches crop. Has reduced depletion of Ogallala aquifer in Texas High Has reduced depletion of Ogallala aquifer in Texas High

Plains by 30%.Plains by 30%.

Center pivot

Drip irrigation

Gravity flow(efficiency 60% and

80% with surge valves)

Above- or below-ground pipes or tubes deliver water to individual plant roots.

Water usually comes from an aqueduct system or a nearby river.

(efficiency 90–95%)

(efficiency 80%–95%)

Water usually pumped from underground and sprayed from mobile boom with sprinklers.

ConservationConservation

Using less water or saving the Using less water or saving the water we havewater we have

IndustryIndustry Recycle waterRecycle water

IrrigationIrrigation Surge flow (gravity) Surge flow (gravity) Drip irrigation $$Drip irrigation $$

Municipal usesMunicipal uses Incentives and regulations Incentives and regulations

limiting water uselimiting water use Gray waterGray water

Benefits: Saves Benefits: Saves money and money and wildlifewildlife

Problems: Problems: bothersome to bothersome to people; lack of people; lack of caring; lazinesscaring; laziness

PollutionPollution

WATER POLLUTION: WATER POLLUTION: SOURCES, TYPES, AND SOURCES, TYPES, AND EFFECTSEFFECTS

Water pollutionWater pollution is any chemical, biological, or is any chemical, biological, or physical change in water quality that has a physical change in water quality that has a harmful effect on living organisms or makes water harmful effect on living organisms or makes water unsuitable for desired uses.unsuitable for desired uses. Point sourcePoint source: specific location such as a factory or : specific location such as a factory or

sewage treatment plant (drain pipes, ditches, sewer sewage treatment plant (drain pipes, ditches, sewer lines).lines).

Nonpoint sourceNonpoint source: cannot be traced to a single site of : cannot be traced to a single site of discharge (atmospheric deposition, agricultural / discharge (atmospheric deposition, agricultural / industrial / residential runoff) industrial / residential runoff)

Point and Nonpoint Sources of Point and Nonpoint Sources of Pollution Pollution

Sources of PollutionSources of Pollution AgricultureAgriculture

Fertilizers, pesticides,animal wastes, sediment Fertilizers, pesticides,animal wastes, sediment eroded from the landeroded from the land

Municipal WasteMunicipal Waste Sewage, fertilizers, dumping into drainage Sewage, fertilizers, dumping into drainage

ditches, etc.ditches, etc. Industrial WasteIndustrial Waste

Chemicals left over from manufacturing, waste Chemicals left over from manufacturing, waste products, etc.products, etc.

MiningMining Erosion and toxic chemicalsErosion and toxic chemicals

Types of Water PollutantsTypes of Water Pollutants

Inorganic WastesInorganic Wastes Organic WastesOrganic Wastes SedimentsSediments Thermal Thermal RadioactiveRadioactive PathogensPathogens

In the Ganges River in India the people drink, wash clothes and use the restroom all in the same water.

Inorganic Inorganic CompoundsCompounds

Mineral, not biological, in Mineral, not biological, in origin.origin.

Contaminants that contain Contaminants that contain elements other than carbon.elements other than carbon. Ex. include acids, salts, and Ex. include acids, salts, and

heavy metals like mercury heavy metals like mercury and lead. and lead.

Many find their way into both Many find their way into both surface water and groundwater surface water and groundwater from sources such as from sources such as industries, mines, irrigation industries, mines, irrigation runoff, oil drilling and urban runoff, oil drilling and urban runoff from storm sewers.runoff from storm sewers.

Inorganic CompoundsInorganic CompoundsCausesCauses Nitrates and phosphates Nitrates and phosphates

come from sources such as come from sources such as human and animal wastes, human and animal wastes, plant residues, atmospheric plant residues, atmospheric deposition and residential deposition and residential land.land.

Environmental EffectsEnvironmental Effects Some of these inorganic Some of these inorganic

pollutants are toxic to pollutants are toxic to aquatic organisms.aquatic organisms. Bioaccumulation, Bioaccumulation,

biomagnificationbiomagnification

Health EffectsHealth Effects Lead and mercury are poisonous. Mercury Lead and mercury are poisonous. Mercury

exposure to developing fetuses in pregnant exposure to developing fetuses in pregnant women has been linked to a variety of women has been linked to a variety of conditions such as mental retardations, conditions such as mental retardations, cerebral palsy, and developing delays, cerebral palsy, and developing delays, causes kidney disorders and several causes kidney disorders and several damage the nervous and cardiovascular damage the nervous and cardiovascular systems.systems.

Low levels of mercury in the brain cause Low levels of mercury in the brain cause neurological problems such as headache, neurological problems such as headache, depression, and quarrelsome behavior.depression, and quarrelsome behavior.

Chemicals such as nitrogen and Chemicals such as nitrogen and phosphorus that stimulate the growth of phosphorus that stimulate the growth of plants and algae. Known as plants and algae. Known as eutrophication.eutrophication.

Plant and Algal Plant and Algal NutrientsNutrients

EutrophicationEutrophicationDefinitionDefinition The enrichment of a lake or pond by The enrichment of a lake or pond by

inorganic plant and algal nutrients inorganic plant and algal nutrients such as phosphorus.such as phosphorus.

Because this gets into our water Because this gets into our water supply from runoff, etc., and is supply from runoff, etc., and is something that is not normally in the something that is not normally in the water, it is considered pollution.water, it is considered pollution.

EutrophicationEutrophicationCause/EffectCause/Effect Fertilizers, erosion, sewage, etc. get into water Fertilizers, erosion, sewage, etc. get into water

and the effect is high photosynthetic productivity. and the effect is high photosynthetic productivity. Environmental EffectsEnvironmental Effects Excess nutrients encourage excessive growth of Excess nutrients encourage excessive growth of

algal and aquatic plants. This causes problems, algal and aquatic plants. This causes problems, including enrichment and bad odor. (Dead Zone including enrichment and bad odor. (Dead Zone or hypoxia)or hypoxia) water is cloudy and has layer of algae and water is cloudy and has layer of algae and

cyanobacteria.cyanobacteria.

Hypoxia Anoxia

Low oxygen conditions No oxygen conditions

Area of ocean/sea in which the oxygen has been depleted to the point that most animals and bacteria cannot survive.

Caused by runoff of chemicals and animal/human wastes

Natural Vs. Cultural Natural Vs. Cultural EutrophicationEutrophication

EutrophicationEutrophication natural aquatic succession of nutrient natural aquatic succession of nutrient

enrichment, mostly from runoff of plant enrichment, mostly from runoff of plant nutrients from the surrounding land.nutrients from the surrounding land.

occurs over several hundred yearsoccurs over several hundred years Cultural eutrophicationCultural eutrophication

drive by human activitiesdrive by human activities occurs rapidlyoccurs rapidly

85% of large lakes near major population 85% of large lakes near major population centers in the U.S. have some degree of cultural centers in the U.S. have some degree of cultural eutrophication.eutrophication.

DefinitionDefinition Chemicals that contain carbon. Most Chemicals that contain carbon. Most

found in water are synthetic chemicals.found in water are synthetic chemicals.CausesCauses Produced by human activities; these Produced by human activities; these

included pesticides, solvents, included pesticides, solvents, detergents, gas, industrial chemicals detergents, gas, industrial chemicals and plastics, and seepage from landfills.and plastics, and seepage from landfills.

Organic CompoundsOrganic Compounds

Organic CompoundsOrganic CompoundsHealth EffectsHealth Effects Hundreds of synthetic organic Hundreds of synthetic organic

compounds are toxic and some of compounds are toxic and some of these have been shown to cause these have been shown to cause cancer or birth defects.cancer or birth defects.

Environmental EffectsEnvironmental Effects Seeps into ground/surface waters Seeps into ground/surface waters

from land fillsfrom land fills Leaches into ground from runoffLeaches into ground from runoff

DefinitionDefinition Excessive amounts of suspended soil Excessive amounts of suspended soil

particles that eventually settle out and particles that eventually settle out and accumulate on the bottom of a body of accumulate on the bottom of a body of water. (Turbidity)water. (Turbidity)

CausesCauses Erosion of agricultural lands, forest soils Erosion of agricultural lands, forest soils

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

Sediment Sediment PollutionPollution

Environmental EffectsEnvironmental Effects Reduces light Reduces light

penetration, penetration, covering covering aquatic aquatic organisms, organisms, bringing bringing insoluble toxic insoluble toxic pollutants into pollutants into the water, and the water, and filling in filling in waterways. waterways.

Health EffectsHealth Effects Sediments adversely affect water Sediments adversely affect water

quality by carrying toxic chemicals. quality by carrying toxic chemicals. The sediment particles provide The sediment particles provide

surface area to which some surface area to which some insoluble, toxic compounds adhere; insoluble, toxic compounds adhere; when the sediments enter the water, when the sediments enter the water, so do toxic chemicals. so do toxic chemicals.

Disease-causing agents can also be Disease-causing agents can also be transported into water via transported into water via sediments.sediments.

Radioactive SubstancesRadioactive SubstancesContains atoms of unstable isotopes Contains atoms of unstable isotopes

that spontaneously emit radiation such that spontaneously emit radiation such as uranium, plutonium and thoriumas uranium, plutonium and thorium

Radioactive SubstancesRadioactive SubstancesCausesCauses Get into water from mining and processing of Get into water from mining and processing of

radioactive minerals, nuclear weapons radioactive minerals, nuclear weapons industry, or medical/scientific research.industry, or medical/scientific research.

Environmental EffectsEnvironmental Effects Pollutes air, water and soil.Pollutes air, water and soil.Health EffectsHealth Effects Mutations, birth defects, mental retardation, Mutations, birth defects, mental retardation,

genetic disease, leukemia, cancer (breast, genetic disease, leukemia, cancer (breast, bone, thyroid, skin, lung), burns, cataracts, bone, thyroid, skin, lung), burns, cataracts, male sterility.male sterility.

DefinitionDefinition Unnatural heating of water changing the Unnatural heating of water changing the

ambient temperatureambient temperatureCausesCauses When heated water produced during certain When heated water produced during certain

industrial processes is released into industrial processes is released into waterways.waterways.

Environmental EffectsEnvironmental Effects Decomposition of wastes occurs faster, Decomposition of wastes occurs faster,

depleting the water of oxygen; this affects depleting the water of oxygen; this affects aquatic life.aquatic life.

Thermal PollutionThermal Pollution

Thermal Pollution / Dissolved Thermal Pollution / Dissolved OxygenOxygen

Health EffectsHealth Effects Typically affects animals, not humans.Typically affects animals, not humans.

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 Only a few fish species can survive in water

less than 4ppm at 20°C.less than 4ppm at 20°C.

Pollution of Freshwater Pollution of Freshwater StreamsStreams

Flowing streams can recover from a Flowing streams can recover from a moderate level of degradable water moderate level of degradable water pollutants if they are not overloaded pollutants if they are not overloaded and their flows are not reduced.and their flows are not reduced. In a flowing stream, the breakdown of In a flowing stream, the breakdown of

degradable wastes by bacteria depletes degradable wastes by bacteria depletes DO and creates and DO and creates and oxygen sag curveoxygen sag curve..

This reduces or eliminates populations of This reduces or eliminates populations of organisms with high oxygen requirements.organisms with high oxygen requirements.

8 ppm

Biologicaloxygendemand

Dissolvedoxygen(ppm)

Types oforganisms

8 ppm

RecoveryZoneSeptic

ZoneDecomposition

ZoneClean Zone

Fish absent,fungi, sludgeworms,bacteria

(anaerobic)

Trash fish(carp, gar,leeches)Clean Normal clean

water organisms(Trout, perch, bass,

mayfly, stonefly)

Normal clean water organisms

(Trout, perch, bass,mayfly, stonefly)

Clean Zone

Trash fish(carp, gar,leeches)

Water Pollution Problems: Water Pollution Problems: StreamsStreams

Dilution and decay of degradable, Dilution and decay of degradable, oxygen-demanding wastes and heat in oxygen-demanding wastes and heat in a stream.a stream.

Pollution of Freshwater Pollution of Freshwater StreamsStreams

Most developed countries have Most developed countries have sharply reduced point-source sharply reduced point-source pollution but toxic chemicals and pollution but toxic chemicals and pollution from nonpoint sources are pollution from nonpoint sources are still a problem.still a problem.

Stream pollution from discharges of Stream pollution from discharges of untreated sewage and industrial untreated sewage and industrial wastes is a major problem in wastes is a major problem in developing countries.developing countries.

Pollution of Freshwater LakesPollution of Freshwater Lakes Dilution of pollutants in lakes is less Dilution of pollutants in lakes is less

effective than in most streams because effective than in most streams because most lake water is not mixed well and has most lake water is not mixed well and has little flow.little flow. Lakes and reservoirs are often stratified and Lakes and reservoirs are often stratified and

undergo little mixing.undergo little mixing. Low flow makes them susceptible to runoff.Low flow makes them susceptible to runoff.

Various human activities can overload Various human activities can overload lakes with plant nutrients, which decrease lakes with plant nutrients, which decrease DO and kill some aquatic species.DO and kill some aquatic species.

North Pacific Garbage PatchNorth Pacific Garbage Patch Two rotating gyresTwo rotating gyres On or just beneath the water surfaceOn or just beneath the water surface Tiny plastic pieces harmful to wildlifeTiny plastic pieces harmful to wildlife

Crude and refined petroleumCrude and refined petroleum Highly disruptive pollutantsHighly disruptive pollutants

Largest source of ocean oil pollutionLargest source of ocean oil pollution Urban and industrial runoff from landUrban and industrial runoff from land

Ocean PollutionOcean Pollution

Oil SpillsOil Spills When a tanker accident happens, it gets lots When a tanker accident happens, it gets lots

of publicity. EX. of publicity. EX. 1989 – Exxon Valdez, oil tanker1989 – Exxon Valdez, oil tanker But, more oil is released by normal But, more oil is released by normal

operation of offshore wells, washing tankers operation of offshore wells, washing tankers & from pipeline or storage tank leaks. EX. & from pipeline or storage tank leaks. EX. 2010 – BP Deepwater Horizon in the Gulf of Mexico2010 – BP Deepwater Horizon in the Gulf of Mexico

Estimated that oil companies spill, leak, or Estimated that oil companies spill, leak, or waste per year an amount of oil equal to waste per year an amount of oil equal to that shipped by 1000 huge Exxon Valdez that shipped by 1000 huge Exxon Valdez tankers.tankers.

Floating OilFloating Oil Oil coats the feathers of birds (especially Oil coats the feathers of birds (especially

diving birds) and the fur of marine diving birds) and the fur of marine animals, destroying the animals’ natural animals, destroying the animals’ natural insulation and buoyancyinsulation and buoyancy

Many drown or die of exposure from loss Many drown or die of exposure from loss of body heat.of body heat.

Heavy oil components sink Heavy oil components sink Affect the bottom dwellersAffect the bottom dwellers

Other InformationOther Information Oil is broken down by bacteria over time; Oil is broken down by bacteria over time;

slower in cold waters.slower in cold waters. Heavy oil components can smother Heavy oil components can smother

bottom-dwelling organisms such as crabs, bottom-dwelling organisms such as crabs, oysters, mussels, and clams, or make oysters, mussels, and clams, or make them unfit to eat.them unfit to eat.

Oil spills have killed coral reefs. A recent Oil spills have killed coral reefs. A recent study showed that diesel oil becomes study showed that diesel oil becomes more toxic to marine life with the more toxic to marine life with the passage of time.passage of time.

Methods of CleanMethods of CleanMechanical Mechanical

Floating booms contain the Floating booms contain the oil spill or keep it from oil spill or keep it from reaching sensitive areasreaching sensitive areas

Skimmer boats are used to Skimmer boats are used to vacuum up some of the oil vacuum up some of the oil into collection bargesinto collection barges

Absorbent pads or large Absorbent pads or large feather-filled pillows are feather-filled pillows are used to soak up oil on used to soak up oil on beaches or in waters that are beaches or in waters that are too shallow for skimmer too shallow for skimmer boatsboats

ChemicalChemical Coagulating agents cause Coagulating agents cause

floating oil to clump floating oil to clump together for easier pickup or together for easier pickup or sink to the bottom, where it sink to the bottom, where it usually does less harm.usually does less harm.

Dispersing agents break up Dispersing agents break up oil slicks. However, these oil slicks. However, these can also damage some can also damage some types of organisms.types of organisms.

Fire can also burn off Fire can also burn off floating oil, but crude oil is floating oil, but crude oil is hard to ignite.hard to ignite.

Spill from deep-sea oil drilling – 1 mile Spill from deep-sea oil drilling – 1 mile deepdeep Released 4.9 million barrels of crude oilReleased 4.9 million barrels of crude oil Contaminated vast areas of coastlineContaminated vast areas of coastline Caused by equipment failure and poor Caused by equipment failure and poor

decisionsdecisions Government developed new standards Government developed new standards

for offshore drilling proceduresfor offshore drilling procedures

Case Study: The BP Deepwater Case Study: The BP Deepwater Horizon Oil-Rig SpillHorizon Oil-Rig Spill

Drinking Water Drinking Water ProblemsProblems

SewageSewageCausesCauses Release of waste water from drains or Release of waste water from drains or

sewers (toilets, washing machines, and sewers (toilets, washing machines, and showers) and include human wastes, showers) and include human wastes, soaps and detergentssoaps and detergents

Environmental EffectsEnvironmental Effects Enrichment – the fertilization of a body of Enrichment – the fertilization of a body of

water, caused by the presence of high water, caused by the presence of high levels of plants and algal nutrients like levels of plants and algal nutrients like nitrogen and phosphorusnitrogen and phosphorus

SewageSewage

Health EffectsHealth Effects Oxygen – dissolved oxygen is Oxygen – dissolved oxygen is

needed by organisms, like fish, but needed by organisms, like fish, but when sewage enters an aquatic when sewage enters an aquatic ecosystem, the micro-organisms ecosystem, the micro-organisms bloom, leaving less oxygen for the bloom, leaving less oxygen for the fish, etc., and then they diefish, etc., and then they die

Sewage carries disease-Sewage carries disease-causing agents.causing agents.

Coliform BacteriaColiform Bacteria The W.H.O. recommends there be zero colonies The W.H.O. recommends there be zero colonies

of bacteria per 100ml of drinking water and of bacteria per 100ml of drinking water and 200 colonies per 100ml of swimming water. 200 colonies per 100ml of swimming water.

Average human excretes 2 billion organisms Average human excretes 2 billion organisms per day.per day.

These are organic wastes that can be These are organic wastes that can be decomposed by aerobic bacteria (causes lack decomposed by aerobic bacteria (causes lack of oxygen). Fish die as a result of a lack of of oxygen). Fish die as a result of a lack of oxygenoxygen

Disease-Causing Disease-Causing AgentsAgentsCausesCauses Comes from the wastes of infected Comes from the wastes of infected

individuals.individuals.Environmental EffectsEnvironmental Effects Municipal wastewater contains Municipal wastewater contains

bacteria, viruses, protozoa, parasitic bacteria, viruses, protozoa, parasitic worms, and other infectious agents worms, and other infectious agents that cause human or animal diseases.that cause human or animal diseases.

Health EffectsHealth Effects Typhoid, cholera, bacterial Typhoid, cholera, bacterial

dysentery, polio and infectious dysentery, polio and infectious hepatitis are some of the more hepatitis are some of the more common bacteria or viruses common bacteria or viruses that are transmitted through that are transmitted through contaminated food and water.contaminated food and water.

An estimated 1.6 million An estimated 1.6 million people die every year, mostly people die every year, mostly under the age of fiveunder the age of five

Table 21-2, p. 495

Global Outlook: Stream Global Outlook: Stream Pollution in Developing Pollution in Developing CountriesCountries

Half of the world’s 500 Half of the world’s 500 major rivers are polluted major rivers are polluted by untreated sewage or by untreated sewage or industrial waste.industrial waste.

Many China's rivers are Many China's rivers are greenish black from greenish black from uncontrolled pollution by uncontrolled pollution by thousands of factories.thousands of factories.

Case Study: India’s Ganges Case Study: India’s Ganges River: Religion, Poverty, and River: Religion, Poverty, and HealthHealth

Religious beliefs, cultural traditions, poverty, Religious beliefs, cultural traditions, poverty, and a large population interact to cause and a large population interact to cause severe pollution of the Ganges River in India.severe pollution of the Ganges River in India. Very little of the sewage is treated.Very little of the sewage is treated. Hindu believe in cremating the dead to free the Hindu believe in cremating the dead to free the

soul and throwing the ashes in the holy Ganges.soul and throwing the ashes in the holy Ganges. Some are too poor to afford the wood to fully cremate.Some are too poor to afford the wood to fully cremate. Decomposing bodies promote disease and depletes Decomposing bodies promote disease and depletes

DO.DO.

Case Study: India’s Ganges Case Study: India’s Ganges River: Religion, Poverty, and River: Religion, Poverty, and HealthHealth

Daily, more than Daily, more than 1 million Hindus 1 million Hindus in India bathe, in India bathe, drink from, or drink from, or carry out religious carry out religious ceremonies in the ceremonies in the highly polluted highly polluted Ganges River.Ganges River.

Figure 21-6Figure 21-6

Mississippi and Great Lakes polluted Mississippi and Great Lakes polluted Raw sewage and biological pollutionRaw sewage and biological pollution Nonpoint runoff of pesticides and fertilizersNonpoint runoff of pesticides and fertilizers Atmospheric deposition of pesticides and HgAtmospheric deposition of pesticides and Hg

1972 – Canada and the United States Great Lakes 1972 – Canada and the United States Great Lakes pollution control programpollution control program Decreased industrial wastes and banned phosphate containing Decreased industrial wastes and banned phosphate containing

household products.household products. Decreased algal bloomsDecreased algal blooms Increased dissolved oxygen and fishing catchesIncreased dissolved oxygen and fishing catches Better sewage treatment plantsBetter sewage treatment plants

Pollution in Great Lakes and Pollution in Great Lakes and MississippiMississippi

Reducing water pollution requires that Reducing water pollution requires that we:we: Prevent itPrevent it Work with nature to treat sewageWork with nature to treat sewage Use natural resources far more efficientlyUse natural resources far more efficiently

Reduce flow of pollution from landReduce flow of pollution from land Land-useLand-use Air pollutionAir pollution Linked to energy and climate policyLinked to energy and climate policy

How Can We Deal with How Can We Deal with Water Pollution? Water Pollution?

Controlling Sources of Controlling Sources of PollutionPollution

Point SourcesPoint Sources Ban phosphate detergentsBan phosphate detergents Sewage-treatment improvementsSewage-treatment improvements

Nonpoint SourcesNonpoint Sources Difficult to address runoff pollutantsDifficult to address runoff pollutants

UrbanUrban Agricultural fieldsAgricultural fields Deforested woodlandsDeforested woodlands Overgrazed pasturesOvergrazed pastures

Best Management Practices (BMP)Best Management Practices (BMP)

SEWAGE SEWAGE TREATMENTTREATMENT

Reducing Water Pollution Reducing Water Pollution through Sewage Treatmentthrough Sewage Treatment

Septic tanks and various levels of sewage Septic tanks and various levels of sewage treatment can reduce point-source water treatment can reduce point-source water pollution.pollution.

Figure 21-15Figure 21-15

Sewage TreatmentSewage TreatmentRaw sewage reaching a municipal sewageRaw sewage reaching a municipal sewagetreatment plant typically undergoes:treatment plant typically undergoes: Primary sewage treatmentPrimary sewage treatment: a : a physicalphysical

process that uses screens and a grit tank to process that uses screens and a grit tank to remove large floating objects and allows remove large floating objects and allows settling.settling.

Secondary sewage treatmentSecondary sewage treatment: a : a biologicalbiological process in which aerobic bacteria remove as process in which aerobic bacteria remove as much as 90% of dissolved and biodegradable, much as 90% of dissolved and biodegradable, oxygen demanding organic wastes.oxygen demanding organic wastes.

Tertiary sewage treatment: Tertiary sewage treatment: a a mixturemixture of of processes that includes chlorine disinfection processes that includes chlorine disinfection

Water TreatmentWater Treatment

PrimaryPrimary Removes suspended and floating Removes suspended and floating

particles, such as sand and silt, by particles, such as sand and silt, by mechanical processes such as mechanical processes such as screening and gravitational screening and gravitational settling. The solid material that is settling. The solid material that is settled out is called primary settled out is called primary sludge.sludge.Bar screens,

grit chambers, primary clarifiers, digesters and pre-aeration

SecondarySecondary Uses microorganisms to Uses microorganisms to

decompose the suspended organic decompose the suspended organic material in wastewater. Ex. material in wastewater. Ex. trickling filters – where wastewater trickling filters – where wastewater trickles through aerated rock beds trickles through aerated rock beds that contain bacteria and other that contain bacteria and other microorganisms, which degrade microorganisms, which degrade the organic material in the water. the organic material in the water.

Secondary (Cont.)Secondary (Cont.) Or activated sludge process – Or activated sludge process –

wastewater is aerated and circulated wastewater is aerated and circulated through bacteria-rich particles; the through bacteria-rich particles; the bacteria degrade suspended organic bacteria degrade suspended organic material. After several hours, the material. After several hours, the particles and microorganisms are particles and microorganisms are allowed to settle out, forming allowed to settle out, forming secondary sludge.secondary sludge.

Use aeration basins, settling tanks Use aeration basins, settling tanks and sand filtersand sand filters

Tertiary Water TreatmentTertiary Water Treatment This includes a variety of biological, chemical and This includes a variety of biological, chemical and

physical processes physical processes used to remove phosphorus and nitrogen, the used to remove phosphorus and nitrogen, the

nutrients most commonly associated with enrichment. nutrients most commonly associated with enrichment. Tertiary treatment can also be used to purify Tertiary treatment can also be used to purify

wastewater so that it can be reused in wastewater so that it can be reused in communities where water is scarce. communities where water is scarce.

Use chlorine as a disinfection and then chlorine is Use chlorine as a disinfection and then chlorine is removed by SOremoved by SO22 so it can be released into river. so it can be released into river.

Ozone (OOzone (O33) is also used but leaves no residual ) is also used but leaves no residual disinfectant. UV light does the same.disinfectant. UV light does the same.

Fig. 20-24, p. 566

Primary Secondary

Chlorine disinfection tankBar screen Grit chamber Settling tank Aeration tank Settling tank

To river, lake, or oceanRaw sewage

from sewers

SludgeActivated sludge (kills bacteria)

Air pump

Sludge digester

Disposed of in landfill or ocean or applied to cropland, pasture, or rangeland

Sludge drying bed

Reducing Water Pollution through Sewage Treatment

Reducing Water Pollution Reducing Water Pollution through Sewage Treatmentthrough Sewage Treatment Sewage sludge can be used as a soil Sewage sludge can be used as a soil

conditioner but this can cause health conditioner but this can cause health problems if it contains infectious bacteria problems if it contains infectious bacteria and toxic chemicals.and toxic chemicals.

Preventing toxic chemicals from reaching Preventing toxic chemicals from reaching sewage treatment plants would eliminate sewage treatment plants would eliminate such chemicals from the sludge and water such chemicals from the sludge and water discharged from such plants.discharged from such plants.

However, most sewage treatment plants are However, most sewage treatment plants are not designed to remove pharmaceuticalsnot designed to remove pharmaceuticals

Reducing Water Pollution Reducing Water Pollution through Sewage Treatmentthrough Sewage Treatment

Natural and artificial wetlands and Natural and artificial wetlands and other ecological systems can be used other ecological systems can be used to treat sewage.to treat sewage. California created a 65 hectare wetland California created a 65 hectare wetland

near Humboldt Bay that acts as a natural near Humboldt Bay that acts as a natural wastewater treatment plant for the town wastewater treatment plant for the town of 16,000 people.of 16,000 people.

The project cost less than half of the estimated The project cost less than half of the estimated price of a conventional treatment plant.price of a conventional treatment plant.

Core Case Study: Using Core Case Study: Using Nature to Purify SewageNature to Purify Sewage

Ecological wastewater Ecological wastewater purification by a purification by a living living machinemachine.. Uses the sun and a Uses the sun and a

series of tanks series of tanks containing plants, snails, containing plants, snails, zooplankton, crayfish, zooplankton, crayfish, and fish (that can be and fish (that can be eaten or sold for bait).eaten or sold for bait).

Pollution Pollution PreventionPrevention

Water monitoring Analytical technology Leak detection systems Contained storage systems Regulation Enforcement

Water Quality: Water Quality: United United StatesStates

Groundwater contamination still Groundwater contamination still occurs, especially due to non-point occurs, especially due to non-point source pollution, but laws like the source pollution, but laws like the Safe Drinking Water Act, Clean Safe Drinking Water Act, Clean Water Act, and Water Quality Act Water Act, and Water Quality Act have helped in the U.S.have helped in the U.S.

Water Quality: Global Water Quality: Global ProblemsProblems

According to the World Health According to the World Health Organization, an estimated 1.4 Organization, an estimated 1.4 billion people still do not have access billion people still do not have access to adequate sanitation systems. to adequate sanitation systems. Worldwide, at least 250 million cases Worldwide, at least 250 million cases of water-related illnesses occur each of water-related illnesses occur each year, with 5 million or more of these year, with 5 million or more of these resulting in death.resulting in death.

Dissolved OxygenDissolved Oxygen The amount of oxygen gas dissolved in a given The amount of oxygen gas dissolved in a given

volume of water at a particular temperature volume of water at a particular temperature and pressure.and pressure.

Carbon DioxideCarbon Dioxide Enters aquatic systems from the atmosphere Enters aquatic systems from the atmosphere

and from respiration by animals.and from respiration by animals. The concentration of COThe concentration of CO22 varies at different varies at different

depths because of light/photosynthesis.depths because of light/photosynthesis.

Specific Water Quality Specific Water Quality MeasuresMeasures

Water Quality MeasuresWater Quality MeasuresNitrateNitrate Contaminates shallow groundwater (100 feet or Contaminates shallow groundwater (100 feet or

less) and usually comes from fertilizers. A less) and usually comes from fertilizers. A concern in rural areas where 80-90% of the concern in rural areas where 80-90% of the residents use shallow groundwater for drinking. residents use shallow groundwater for drinking. Harms humans because it reduces the blood’s Harms humans because it reduces the blood’s ability to transport oxygen.ability to transport oxygen.

SulfateSulfate Problem because too much can kill fish. Gets in Problem because too much can kill fish. Gets in

water from industrial processes and mining.water from industrial processes and mining.

Water Quality MeasuresWater Quality MeasuresIronIron Causes problems because it separates out of the Causes problems because it separates out of the

water and forms particulates (sediment), it tastes water and forms particulates (sediment), it tastes bad if it gets in our water, and can coat fish’s bad if it gets in our water, and can coat fish’s gills. Groundwater problems in wells, from gills. Groundwater problems in wells, from natural minerals in rocks.natural minerals in rocks.

PhosphatePhosphate Plant nutrients that cause algae blooms. It Plant nutrients that cause algae blooms. It

comes from detergents, human wastes and comes from detergents, human wastes and fertilizers.fertilizers.

Water Quality MeasuresWater Quality MeasuresColiformColiform General group of bacteria from animal wastes. It General group of bacteria from animal wastes. It

uses up available oxygen. Also causes e-coli disease.uses up available oxygen. Also causes e-coli disease.GiardiaGiardia Organism (protozoa) that can cause diarrhea if you Organism (protozoa) that can cause diarrhea if you

drink unchlorinated water. It is a natural organism drink unchlorinated water. It is a natural organism that lives in the guts of animals.that lives in the guts of animals.

TurbidityTurbidity Cloudiness/muddiness; blocks the light; coats fish Cloudiness/muddiness; blocks the light; coats fish

gills.gills.

Water Quality MeasuresWater Quality MeasuresChlorideChloride Part of salts, but too many can cause Part of salts, but too many can cause

too much salt in the water. Too much is too much salt in the water. Too much is bad; a little is okay. It is naturally found bad; a little is okay. It is naturally found in water, but can come from pollution.in water, but can come from pollution.

pHpH Too high/too low can be bad; fish like Too high/too low can be bad; fish like

6.5-9.5; acid mine drainage can kill fish.6.5-9.5; acid mine drainage can kill fish.

Water Quality MeasuresWater Quality MeasuresHardnessHardness Calcium and magnesium dissolved in the Calcium and magnesium dissolved in the

water. A little is good (50-400 ppm for water. A little is good (50-400 ppm for fish is good), but very low or high is a fish is good), but very low or high is a problem. Low is more of a problem. problem. Low is more of a problem. Affects fish eggs, poor bone development.Affects fish eggs, poor bone development.

Can cause problems with cleaning Can cause problems with cleaning clothes. Soap doesn’t bubble as much.clothes. Soap doesn’t bubble as much.

Methods of Treating Methods of Treating WaterWaterIon ExchangeIon Exchange Substitute sodium for calcium and Substitute sodium for calcium and

magnesium. Water softeners usually magnesium. Water softeners usually do this.do this.

Reverse OsmosisReverse Osmosis Membrane system that allows water Membrane system that allows water

to go through but calcium and to go through but calcium and magnesium cannot. magnesium cannot.

Pollution of GroundwaterPollution of Groundwater Leaks from a number of sources have Leaks from a number of sources have

contaminated groundwater in parts of contaminated groundwater in parts of the world.the world. According the the EPA, one or more According the the EPA, one or more

organic chemicals contaminate about 45% organic chemicals contaminate about 45% of of municipalmunicipal groundwater supplies. groundwater supplies.

By 2003, the EPA had completed the By 2003, the EPA had completed the cleanup of 297,000 of 436,000 cleanup of 297,000 of 436,000 underground tanks leaking gasoline, diesel underground tanks leaking gasoline, diesel fuel, home heating oil, or toxic solvents.fuel, home heating oil, or toxic solvents.

Case Study: Arsenic in Case Study: Arsenic in GroundwaterGroundwater Toxic Arsenic (Toxic Arsenic (AsAs) can naturally occur at high ) can naturally occur at high

levels in soil and rocks.levels in soil and rocks. Drilling into aquifers can release Drilling into aquifers can release AsAs into drinking into drinking

water supplies.water supplies. According to WHO, more than 112 million people According to WHO, more than 112 million people

are drinking water with are drinking water with AsAs levels 5-100 times the levels 5-100 times the 10 ppb standard.10 ppb standard. Mostly in Bangladesh, China, and West Bengal, India.Mostly in Bangladesh, China, and West Bengal, India.

Water LegislationWater Legislation1974 Safe Drinking Water Act1974 Safe Drinking Water Act Required the EPA to determine the maximum Required the EPA to determine the maximum

contaminant level, the max permissible amount of contaminant level, the max permissible amount of any pollutant that might adversely affect human any pollutant that might adversely affect human health.health.

Health scientistsHealth scientists Strengthen lawStrengthen law

Water-polluting companiesWater-polluting companies Weaken lawWeaken law

Water LegislationWater Legislation Most developed countries use laws to set Most developed countries use laws to set

water pollution standards, but such laws water pollution standards, but such laws rarely exist in developing countries.rarely exist in developing countries. The U.S. Clean Water Act sets standards for The U.S. Clean Water Act sets standards for

allowed levels of key water pollutants and allowed levels of key water pollutants and requires polluters to get permits.requires polluters to get permits.

EPA is experimenting with a EPA is experimenting with a discharge discharge trading policytrading policy similar to that for air pollution similar to that for air pollution control.control.

Water LegislationWater Legislation1972 Clean Water Act1972 Clean Water Act Has two basic goals:Has two basic goals:

To eliminate the discharge of pollutants in To eliminate the discharge of pollutants in U.S. waterways especially in high U.S. waterways especially in high amountsamounts

To attain water quality levels that make To attain water quality levels that make these waterways safe for recreation like these waterways safe for recreation like fishing and swimming.fishing and swimming.

1987 Water Quality Act 1987 Water Quality Act (Amended Clean Water (Amended Clean Water Act)Act)

Controlling toxic pollutant dischargesControlling toxic pollutant discharges Control non-point sources of pollutionControl non-point sources of pollution Authorized $18 billion for wastewater Authorized $18 billion for wastewater

treatment treatment Address problems such as coastal Address problems such as coastal

estuaries, the Great Lakes, and the estuaries, the Great Lakes, and the Chesapeake BayChesapeake Bay

Using Laws: Protect Drinking Using Laws: Protect Drinking WaterWater The U.N. estimates that 5.6 million The U.N. estimates that 5.6 million

Americans drink water that does not Americans drink water that does not meet EPA standards.meet EPA standards.

1 in 5 Americans drinks water from a 1 in 5 Americans drinks water from a treatment plant that violated one or more treatment plant that violated one or more safety standard.safety standard.

Industry pressures to weaken the Safe Industry pressures to weaken the Safe Drinking Act:Drinking Act: Eliminate national tests and public Eliminate national tests and public

notification of violations. notification of violations. Allow rights to pollute if provider cannot Allow rights to pollute if provider cannot

afford to comply.afford to comply.

Is Bottled Water the Is Bottled Water the Answer?Answer?

Some bottled water is not as pure Some bottled water is not as pure as tap water and costs much more.as tap water and costs much more. 1.4 million metric tons of plastic 1.4 million metric tons of plastic

bottles are thrown away.bottles are thrown away. Fossil fuels are used to make plastic Fossil fuels are used to make plastic

bottles.bottles. The oil used to produce plastic bottles in The oil used to produce plastic bottles in

the U.S. each year would fuel 100,000 the U.S. each year would fuel 100,000 cars.cars.