LAND RESOURCES
LAND & WATER RESOURCESAbuse of the LandTragedy of the
CommonsDeforestationProvide fuel & building materials, space
for growing food, cash crops or cattleDesertificationNutrients
& moisture depletedWaterway & wetland alterationNo longer
provide ecological cleansing & biodiversityUrbanizationMove
away from self sufficiency into pools of pollutionSolid WasteHow do
we store the packaging of our purchases?
Land Restoration & ReuseMaximized
throughConservationPreservationRestorationRemediationReclamationMitigation
ConservationNot using & protecting resources that could be
expended with less responsible pattern of useDecreases useExampleIt
is less expensive to educate consumers about using less power than
it is to find new sourcesPreservationProviding an ample reserve of
resources so that they may be enjoyed by others in the
futureProtects resourcesExamplesPark Service Act of 1916 sought to
preserve natural features, unique populations and historical
objects for the enjoyment of future generations1964 Wilderness Act
established wilderness areas and wildlife refugesCurrently 1% of
the US is preserved as wildlife refuge1980 Alaska National Interest
Land Act increased acreageRestorationBringing a damaged ecosystem
back to its unspoiled, natural conditionExampleNature Conservancy
restoring 40,000 acres of prairie in Kansas (fires &
Bison)RemediationUsing chemical, biological or physical methods to
remove toxic or hazardous pollutantsChemical neutralizing acids or
oxidantsBiological bacterial digestion of oil or nutrients, using
plants to remove nutrients from wastewaterPhysical vaporization of
hydrocarbons from broken oil pipesCERCLA (1980,1984) Comprehensive
Environmental Response, Compensation and Liability Act SUPERFUND
cleanup of toxic waste dump sitesReclamationUsing large water
supply projects to bring water to un-arable landMovement of earth
to return massively scarred, denuded or devastated land to an
environmentally useful and socially or politically acceptable
conditionExamplesSurface Mining Control & Reclamation Act
(SMCRA,1977) requires escrowed funds to be used to reclaim land
after open-pit mining operations reburying mine tailings, refilling
open pits, returning surfaces to a more natural
topographyMitigationFinding a solution to a problemRefers to
establishing another ecosystem elsewhere of comparable health and
magnitude in exchange for damage done as a result of developing a
nearby areaExampleFish and Wildlife Conservation Act of
1980Managing Mineral Resources and MiningUS imports 50% of needed
mineral resources Common Metal Mineral ResourcesAluminum usually
mined as bauxite, requires large amounts of energy to process into
metalChromiumCopperGoldIronLeadManganeseNickelPlatinumSilverUranium
Managing Mineral Resources and MiningCommon Nonmetal Mineral
ResourcesSilicatesSandGravelLimestoneEvaporitesSulfurCoalOil
Managing Mineral Resources and MiningThe Mining OperationDue
DiligenceSite analysis evaluate site for potential of
cost-effective mineral extractionLeases, Licensing, Permits company
registers with state agency that implements SMCRA (Surface Mining
Control and Reclamation Act of 1977), if land is public, lease with
government negotiatedExtractionSurface Mining overburden removed
& storedSeam is mined or whole mountain displacedSub-surface
Mining underground used to extract deeper depositsRisky for miners
(explosions, lack of O2, gases, fires, collapses)Tailings must be
removed, may leach toxins to surface watersWells extraction of
fluidsManaging Mineral Resources and MiningThe Mining
OperationProcessingHeap-Leach Extraction for GoldPile of gold
sprayed with acidified cyanide to dissolve goldElectrolyte
reduction used to extract goldCyanide can be reusedWhen mining
operations complete toxic cyanide often left behindUranium
ProcessingEnvironmentally devastating at each step nuclear waste
produced100 tons of ore mined, 0.8 tons purified99.2 tons
high-level nuclear wasteAluminum Electrolytic Extraction energy
intensiveOre is crushed, melted, then put in large vats with
electrodesManaging Mineral Resources and MiningThe Mining
OperationReclamationSMCRA requires mining operations to put money
into an escrow account to reclaim mining sitesOverseen by
statesReturn of overburdenTopsoil put down & plants
grownHighwalls sculpted to appear naturalTailings removed &
placed where leaching and acid runoff prohibitedEnvironmental
Consequences of MiningLand deformed from digging or erosionMine
tailings exposed to rain become toxic spoiling soil, destroying
streams and rivers, or contaminates groundwaterParticulate air
pollution
Managing Agriculture and ForestryThe land must contain the
nutrients needed to grow the foodHuman nutritional needs2,000-2,500
calories otherwise undernourishedHumans need 22 different amino
acids to build proteins (body can synthesize all but 8 essential
amino acids)Contained in meat & cheese, legumes &
grainsFamines massive acute incidences of undernourishment
catalyzed by political or economic upheaval, or environmental
devastationOvernutrition Americans consume 1000-1500 more calories
than necessary1.1 billion people are overweightMalnourishment
inability to acquire adequate vitamins and nutrients can eventually
lead to disease
Managing Agriculture and ForestryLand degradationDesertification
the process of converting farmable grassland into nonarable
desertLand is overfarmed, nutrients and organic material
depletedErosion soil moved from its point of originWater and wind
can remove topsoilChemical nutrient depletion or salinization
(watering with brackish water)Physical compaction by machines or
cattleExcessive water (overirrigation, poor drainage or ocean
encroachment)Managing Agriculture and ForestryLand
degradationPesticide useToxicity to non target species
bioaccumulation & biomagnificationPest resistance and
resurgence a few hardy insects survive & bloom in a pest
resurgenceTypes of pesticidesInorganic pesticides arsenic, copper,
mercury, lead toxic & persistentChlorinated hydrocarbons DDT,
aldrin, lindane, toxaphene block nerve transmission bioaccumulate
& biomagnifyOrganophosphates parathion, malathion neurotoxin
& not persistentCarbamates carbofuron and aldicarb behave like
organophosphatesBotanical pesticides pyrethrum extracted from
botanicalsManaging Agriculture and ForestryLand
degradationPesticide useIntegrated Pest management (IPM)
non-chemical solutions to pestsCombination of strategiesNonchemical
use of natural predators, sex pheromones to attract, introduce
sterile breeding partners, crop rotationChemical Greater
deliberation & specific targetingPlanting trap crops that
mature earlier & attract pests, spraying & destroying trap
cropManaging Agriculture and ForestryLand degradationFertilizer
useOveruse can cause nutrient pollutionAlternate crop rotation of
nitrogen-demanding with nitrogen-producing (peas, alfalfa,
cloverEnergy useCurrent farming practices depend on fossil
fuelsManaging Agriculture and ForestrySustainable Agriculture vs
Industrial MonocultureSubsistence farming grow only what is needed
to support needs of growerMore than 65% of global
populationIndustrial monoculture planting large tracts of land with
a similar crop, same maintenance techniques appliedHigher
yieldsLarger accumulation of one type of pestSustainable farmingLow
or no-till farming & contour farmingUses crop rotation &
polycultureUses natural fertilizersMinimizes pesticide useMinimizes
use of fossil fuelsMinimizes use of irrigationManaging Agriculture
and ForestryFarming vs RanchingEcological aspects of Meat
ProductionTotal energy input more energy to produce meatFeedlot
pollutionGive antibiotics, growth hormonesRunoff contains
antibiotics & hormones & nutrientsOvergrazing Public
LandsUse of National Forests & BLM LandIn west 75% of land is
available for grazingPermits cost 3-5% of the true cost of grazing
land85% of government-owned rangeland is considered poor quality
landManaging Agriculture and ForestryAgricultural RevolutionsGreen
Revolution1950s scientists develop strains of crops the provide
higher yieldsFewer genetics strains of crops (where once there were
several)Single strains became vulnerable to diseases &
insectsGreater dependence on expensive seeds, chemical fertilizers
& pesticidesGMOs (Genetically Modified Organisms) or Transgenic
SpeciesMoving genes from one species to anotherHoped to produce
strains more resistant to pests & adverse environments, more
durable in shipping, yield better nutrients, grow at different
times of the yearRepresent 70% of food grown & sold in the
USManaging Agriculture and ForestryUse of forests30% of worlds land
areaAbsorbs precipitationControls climateProvides oxygenPurifies
airProduces usable resourcesCreates habitatManaging Agriculture and
ForestryCurrent Forest Harvesting PracticesClear-cutting cutting
every tree regardless of species or sizeLarge trees dragged to
access roadsSmaller trees wastedSoil exposed to erosionHabitat
disruptedSelective cutting harvesting a portion of mature
treesBetter growthMore stable habitatProtects from erosionManaging
Agriculture and ForestryCurrent Forest Harvesting PracticesSwidden
or milpa agriculture used by indigenous people of tropical
rainforestsFarmer clears small plot by cutting or burningAshes
provide nutrientsCrops are planted or harvested during natural
succession of forestSustainable as long as density of farmers does
not exceed forests ability to regenerateRainforest Deforestation to
grow hardwood and commercial food crops (sugar &
coffee)Rainforests contain 2/3 of global biomass & of global
biodiversityThreatens biodiversity, climate stabilization, flood
control & O2 productionManaging Agriculture and ForestryCurrent
Forest Harvesting PracticesForestry as AgricultureMonoculture
forestryDense single species standsIncreases yield & ease of
harvestingEncourages disease & pest infestationManaging
Agriculture and ForestryCurrent Forest Harvesting PracticesFire
ManagementPast practice was to eliminate all firesThis allowed
undergrowth to grow unabatedFires then became more
damagingEliminated benefits from fires (open seed cones, meadows
for wildlife)Current policy is let burn use fire-fighting resources
only when lives or property are threatenedBurned forests are
essential part of natural and healthy cycleThe National Forest
Management Act (1976)Mandated that plans for renewable resource
management had to be drawn up for every national forestGuidelines
included:Consideration of both economic and environmental
factorsProvision for species diversityEnsuring research and
monitoringPermitting only sustainable harvestsProtection of soils
and wetlandsAssessing all impacts before logging to protect
resourcesLivestock graze one-fourth of Earths landGrazing can be
sustainable if done carefully and at low intensityBureau of Land
Management (BLM) = owns and manages most U.S. rangelandNations
single largest landowner: 106 million ha (261 million acres) across
12 western statesRanchers can graze cattle on BLM lands for low
feesLow fees encourage overgrazingRanchers and environmentalists
have joined to preserve ranchland against development and urban
sprawlManagement of the American WestOverexploitation of resources
caused great damage to the American WestPoor farming practices,
overgrazing, farming arid landsJohn Wesley Powell in the late 1800s
called for agencies to base management on scienceFarming Western
lands had to account for arid conditionsHis ideas were ignored,
contributing to failures such as the Dust Bowl of the 1930s
Parks and reservesReasons for establishing parks and reserves
include:Monumentalism = preserving areas with enormous, beautiful
or unusual features, such as the Grand CanyonOffer recreational
value to tourists, hikers, fishers, hunters and othersProtect areas
with utilitarian benefits, such as clean drinking waterUse sites
that are otherwise economically not valuable and are therefore easy
to protectPreservation of biodiversityFederal parks and reserves
began in the U.S.National parks = public lands protected from
resource extraction and developmentOpen to nature appreciation and
recreationYellowstone National Park was established in 1872The
Antiquities Act of 1906 The president can declare selected public
lands as national monuments
The National Park Service (NPS)Created in 1916 to administer
parks and monuments388 sites totaling 32 million ha (72 million
acres)Includes national historic sites, national recreation areas,
national wild and scenic rivers273 million visitors in 2006National
Wildlife RefugesBegun in 1903 by President Theodore Roosevelt37
million ha (91 million acres) in 541 sitesU.S. Fish and Wildlife
Service administers refugesManagement ranges from preservation to
manipulationWildlife havensAllows hunting, fishing, wildlife
observation, photography, educationWilderness areasWilderness areas
= area is off-limits to development of any kindOpen to the public
for hiking, nature study, etc.Must have minimal impact on the
landNecessary to ensure that humans dont occupy and modify all
natural areasEstablished within federal landsOverseen by the
agencies that administer those areas
Habitat fragmentation threatens speciesContiguous habitat is
chopped into small piecesSpecies suffer
The SLOSS dilemmaWhich is better to protect species?A Single
Large Or Several Small reserves?Depends on the species: tigers vs.
insectsCorridors = protected land that allows animals to travel
between islands of protected habitatAnimals get more
resourcesEnables gene flow between populationsAquacultureWorld fish
populations are plummetingTechnology and increased
demandAquaculture = raising aquatic organisms for food in a
controlled environmentAquatic species are raised in open-water pens
or land-based ponds
Aquaculture is growing rapidlyThe fastest-growing type of food
productionProvides a third of the worlds fish for human
consumptionMost widespread in Asia
The benefits and drawbacks of aquacultureBenefits:A reliable
protein sourceSustainable Reduces fishing pressure on overharvested
wild fish stocksEnergy efficient
Drawbacks:Diseases can occur, requiring expensive
antibioticsReduces food securityLarge amounts of wasteFarmed fish
may escape and introduce disease into the wildSustainable
AgricultureIndustrial agriculture may seem necessary, but
less-intensive agricultural methods may be better in the long
runSustainable agriculture = does not deplete soil, pollute water,
or decrease genetic diversityLow-input agriculture = uses smaller
amounts of pesticide, fertilizers, growth hormones, water, and
fossil fuel energy than industrial agricultureOrganic agriculture =
Uses no synthetic fertilizers, insecticides, fungicides, or
herbicidesRelies on biological approaches (composting and
biocontrol)A standardized meaning for organicPeople debate the
meaning of the word organicOrganic Food Production Act (1990)
establishes national standards for organic productsThe USDA issued
criteria in 2000 by which food could be labeled organicSome states
pass even stricter guidelines for labeling
The market for organic food is increasingSales increased
20%/year in Canada and the U.S. from 1989-2005Expanded by a factor
of 40 in EuropeAmount of land for organic farming is
increasing10-35%/year in the U.S. and CanadaIn 2005 the U.S. had
1.7 million acres of organic cropland and 2.3 million acres of
organic pasturelandThe benefits of organic farmingFor farmers:Lower
input costs, enhanced income from higher-value products, reduced
chemical costs and pollutionObstacles include the risks and costs
of switching to new farming methods and less market
infrastructureFor consumers:Concern about pesticides health risksA
desire to improve environmental qualityObstacles include the added
expense and less aesthetically appealing appearance of the
productThe U.S. doesnt financially support organic farmersIn 1993,
the European Union adopted a policy to support farmers financially
during conversion to organic farmingThe U.S. offers no such
supportOrganic production lags in the U.S.Farmers cant switch,
because they cant afford the temporary loss of incomeIn the long
run, organic farming is more profitableOrganic agriculture succeeds
in citiesCommunity gardens = areas where residents can grow their
own foodIn Cuba, over 30,000 people work in Havanas gardens, which
cover 30% of the citys landRecord yields for 10 crops in
1996-1997
Locally supported agriculture is growingIn developed nations,
farmers and consumers are supporting local small-scale
agricultureFresh, local produce in season Community-supported
agriculture = consumers pay farmers in advance for a share of their
yieldConsumers get fresh foodFarmers get a guaranteed income
Managing Residential & Commercial Land Use Building
ConstructionCurrent Building PracticesHeavy dependence on toxic
compoundsHeavy dependence on energy to build the houseExampleWood
for framing (trees collect solar energy) one 3 bedroom house needs
1 acre of forest, transport, milling, shipped, power tools,
etcHeavy dependence on energy to operate a houseHeavy input into
waste streamExampleAverage 3 bedroom house produces 4-7 tons of
solid wasteManaging Residential & Commercial Land Use Building
ConstructionSustainable practicesUse nontoxic and recycled
materialsUse nontoxic finishes on wood surfacesChoose sites near
businesses and shoppingRecycle material from older buildingsUse
cellulose insulation rather than fiberglassUse ecologically
efficient carpeting (recycled)Use nontoxic cleaning fluidsPurchase
materials from local sourcesLandscape with drought resistant plants
plant deciduous trees on the sunny sideCompost wasteConsider a grey
water systemDesign for decreased energy use
Managing Residential & Commercial Land Use
UrbanizationTrends1800 6% lived in urban environments1990 75% live
in citiesPros of city livingLess land per personMass transit means
less energy useMore efficient recyclingBetter sanitationMore
educational and cultural opportunityCons of city livingDisconnected
with true costs of food consumedConsumerism rampantUnable to
naturally treat wastewater and solid wasteEnergy intensive (cooling
and heating buildings)
Managing Residential & Commercial Land Use
UrbanizationCauses of urban growthImmigration pull factors drawn to
citiesImproved sanitationImproved access and choice of foodImproved
medical careMore opportunity for employment and upward
mobilityHigher salariesRecreational and cultural eventsDiverse
lifestyles, more luxuryImmigration push factors leave rural
areasDecreased employment or economic downturnSubsistence farmers
unable to compete with industrial monocultureCultural conflict in
homogenous villagesIncreased need for medical careUnavailability of
landManaging Residential & Commercial Land Use
UrbanizationCurrent urban problemsTraffic and transportationAir
pollutionWater pollutionHousingCrimeMental illness or substance
abuseManaging Residential & Commercial Land Use
UrbanizationUrban renewalInvolve residents in the planning of
government-subsidized housingA sense of community grows when
residents take responsibility for upkeep and safety of
projectsManaging Residential & Commercial Land Use
UrbanizationCity planningCities have a typical evolution around
religious or intellectual centers, around railroad or road
junctions, wealthy live in suburbs, roads lead to malls, land
cheaper outside of city, city core becomes financial center &
wealthy live in city, perimeter village become urban
centersTransportation planning is vital to minimize traffic &
keep population movingMultiuse design & clustering decreases
transportation costs & fosters sense of communitySocial equity
in placement of subsidized housing least affluent not asked to pay
health costs of living in undesirable areasOpen space parks and
greenbelts reduce noise & air pollution, provide habitat
(greenspace on building tops reduces heat dome effect)
Managing WildlifeTraits of Endangered SpeciesK-selected
speciesSpecies requires large amount of land (solitary ore
migratory)Narrowly defined nicheLow genetic diversityGenetic
bottlenecks many individuals eliminated, remaining gene pool
limited by that of remaining breeding pairGenetic isolation small
number of individuals isolatedGenetic assimilation when crossbred
with related, hardier speciesCompetes with hardier, dominant
speciesLow tolerance for pollutionManaging WildlifeCauses of
ExtinctionLoss of habitatHuman development and pollutionCompetition
with dominant or exotic species for same habitatClimate change or
other abiotic factors make environment inhabitableHuntingLoss of
genetic diversityNormal fluctuation of population that result in
the total demise of the populationManaging WildlifeMitigating
ExtinctionMonitor markets for endangered speciesHunting and fishing
created market for habitat protectionLegislationConvention on
International Trade in Endangered Species of Wild Fauna and Flora
(CITES, 1973)Bans international transport of endangered species
body parts Endangered Species Act (ESA, 1973)Vulnerable species at
riskThreatened species likely to become endangeredEndangered
imminent danger of extinctionHabitat Conservation Plans use of
natural resources as long as species benefitIn Situ Management
protect in existing parks, wilderness areas & preservesEx Situ
Management zoos or captive breeding programsFlood ControlFlood
control and waterways policies affect availability of ecologically
important wetlandsImportance of wetlandsProvide essential
habitatProvide reservoir for flood waters prevents downstream
floodingProvide natural wastewater treatmentCoastal wetlands
provide buffer to saltwater intrusionProvide recreational
opportunitiesChannelization of rivers by Army Corps of Engineers
increases flow of water moving downstream impacting shore,
increasing siltation and drying out wetlandsManaging Solid Waste
DisposalWaste Stream the steady flow of matter from raw materials,
through manufacturing, product formation and marketing, and on to
its final resting place a solid waste dumpSome waste contains
valuable resources reduce, reuse, recycleAmericans produce 4.5
pounds of solid waste per day76% ends up in landfills
The U.S. municipal solid waste stream
Sanitary landfills are regulatedSanitary landfills = waste
buried in the ground or piled in large, engineered moundsMust meet
national standards set by the EPA under the Resource Conservation
and Recovery Act (RCRA) of 1976Waste is partially decomposed by
bacteria and compresses under its own weight to make more
spaceLayered with soil to reduce odor, speed decomposition, reduce
infestation by petsWhen a landfill is closed, it must be capped and
maintained A typical sanitary landfill
To protect against environmental contamination, landfills must
be located away from wetlands, earthquake-prone faults, and 20 ft
above water tableLandfills can be transformed after
closureThousands of landfills lie abandonedManagers closed smaller
landfills and made fewer larger landfillsIn 1988, the U.S. had
nearly 8,000 landfills Today there are fewer than 1,700Growing
cities converted closed landfills into public parksFlushing Meadows
in Queens, New York, was redeveloped for the 1939 Worlds Fair
Landfills have drawbacksExperts believe that leachate will
eventually escapeThe liner will become puncturedLeachate collection
systems eventually arent maintainedIt is hard to find places
suitable for landfillsThe Not-In-My-Backyard (NIMBY) syndromeThe
Garbage barge case In 1987, Islip, New Yorks landfills were full,
and a barge traveled to empty the waste in North Carolina, which
rejected the loadIt returned to Queens to incinerate the waste,
after a 9,700 km (6,000 mile) journeyIncinerating trash reduces
landfill pressureIncineration = a controlled process in which mixed
garbage is burned at very high temperaturesIncineration in
specially constructed faculties can be an improvement over open-air
burning of trashBut, the remaining ash must be disposed of in a
hazardous waste landfillHazardous chemicals are created and
released during burningScrubbers = chemically treat the gases
produced in combustion to remove hazardous components and
neutralize acidic gasesA typical solid waste incinerator
Many incinerators create energyIncineration is used to reduce
the volume of waste and generate electricity Waste-to-energy
facilities (WTE) = use the heat produced by waste combustion to
create electricityMore than 100 facilities are in use across the
U.S.They can process nearly 100,000 tons of waste per dayBut, they
take many years to become profitableCompanies contract with
communities to guarantee a minimum amount of garbageLong-term
commitments interfere with the communities later efforts to reduce
wasteHazardous wasteHazardous waste is defined as:Ignitable =
substances that easily catch fire (natural gas, alcohol)Corrosive =
substances that corrode metals in storage tanks or
equipmentReactive = substances that are chemically unstable and
readily react with other compounds, often explosively or by
producing noxious fumesToxic = substances that harm human health
when they are inhaled, are ingested, or contact human skinHazardous
wastes have diverse sourcesIndustry = produces the largest amount
of hazardous wasteBut waste generation and disposal is highly
regulatedMiningHouseholds = now the largest producer of hazardous
wastePaints, batteries, oils, solvents, cleaning agents,
pesticidesSmall businessesAgricultureUtilitiesBuilding
demolition
Organic compounds can be hazardousParticularly hazardous because
their toxicity persists over time Synthetic organic compounds =
resist decompositionKeep buildings from decaying, kill pests, and
keep stored goods intact Their resistance to decay causes them to
be persistent pollutantsThey are toxic because they are readily
absorbed through the skinThey can act as mutagens, carcinogens,
teratogens, and endocrine disruptorsHeavy metals can be
hazardousLead, chromium, mercury, arsenic, cadmium, tin, and copper
Used widely in industry for wiring, electronics, metal plating,
pigments, and dyesThey enter the environment when they are disposed
of improperlyHeavy metals that are fat soluble and break down
slowly can bioaccumulate and biomagnifyE-waste is a new and growing
problemElectronic waste (e-waste) = waste involving electronic
devices Computers, printers, VCRs, fax machines, cell phones
Disposed of in landfills, but should be treated as hazardous
wasteSome people and businesses are trying to use and reuse
electronics to reduce waste
Several steps precede disposal of hazardous wasteFor many years,
hazardous waste was discarded without special treatmentPublic did
not know it was harmful to human healthAssumed the substances would
disappear or be diluted in the environmentSince the 1980s, cities
designate sites or special collection days to gather household
hazardous waste
73Disposing of hazardous wasteResource Conservation and Recovery
Act (RCRA) = states are required to manage hazardous waste Large
generators of hazardous waste must obtain permits and must be
tracked from cradle to graveIntended to prevent illegal dumping
Illegal dumping of hazardous wasteSince hazardous waste disposal
is costly, it results in illegal and anonymous dumping by
companies, Creating health risks Industrial nations illegally dump
in developing nationsBasel Convention, an international treaty,
should prevent dumping but it still happensHigh costs of disposal
encourages companies to invest in reducing their hazardous
waste75Three disposal methods for hazardous wasteThese methods do
nothing to lessen the hazards of the substances But they help keep
the substance isolated from people, wildlife, and
ecosystemsLandfills = must have several impervious liners and
leachate removal systemsDesign and construction standards are
stricter than for ordinary sanitary landfillsMust be located far
from aquifers76
Surface impoundmentsSurface impoundments = store liquid
hazardous wasteShallow depressions are lined with plastic and
clayWater containing waste evaporates, the residue of solid
hazardous waste is then transported elsewhereThe underlying clay
layer can crack and leak waste, and rainstorms cause overflow,
contaminating nearby areasDeep-well injectionDeep-well injection =
a well is drilled deep beneath the water table and waste is
injected into itA long-term disposal methodThe well is intended to
be isolated from groundwater and human contactHowever, the wells
become corroded and leak waste into soil
Radioactive waste is especially hazardousRadioactive waste is
particularly dangerous and persistentYucca Mountain in Nevada is
now designated as the single-site repository for all U.S. nuclear
wasteThe Waste Isolation Pilot Plant (WIPP) is the worlds first
underground repository for transuranic waste from nuclear weapons
development Caverns holding the waste are 655 m (2,150 ft) below
ground in a huge salt formation thought to be geologically
stableWIPP became operational in 1999 and is receiving thousands of
shipments of waste79Contaminated sites are being slowly cleaned
upGlobally, thousands of former military and industrial sites are
contaminated with hazardous waste For most nations, dealing with
these messes is too difficult, time consuming and expensive
Comprehensive Environmental Response Compensation and Liability Act
(CERCLA) (1980) (Superfund)Established a federal program to clean
up U.S. sites polluted with hazardous waste Experts identify
polluted sites, take action to protect groundwater near these
sites, and clean up the pollution 80SuperfundLater laws charged the
EPA with cleaning up brownfields = lands whose reuse or development
are complicated by the presence of hazardous materialsTwo events
spurred creation of Superfund legislationIn Love Canal, Niagara
Falls, New York, families were evacuated after buried toxic
chemicals rose to the surface, contaminating homes and an
elementary schoolIn Times Beach, Missouri, the entire town was
evacuated after being contaminated with dioxin from waste oil
sprayed on roads
The Superfund processOnce a Superfund site is identified, EPA
scientists evaluate:How close the site is to human habitation
Whether wastes are currently confined or likely to spreadWhether
the site threatens drinking water supplies82Superfund: harmful
sitesHarmful sites are:Placed on the EPAs National Priority
ListRanked according to the level of risk to human health that they
pose Cleaned up on a site-by-site basis as funds are availableThe
EPA is required to hold public hearings and inform area residents
of tits findings and to receive feedback
Who pays for cleanup?CERCLA operates under the polluter pays
principle = polluting parties were to be charged for
cleanupHowever, the responsible parties often cant be foundA trust
fund was established by a federal tax on petroleum and chemical
industriesThe fund is bankrupt, and neither the Bush administration
nor Congress has moved to restore it, so taxpayers now pay all
costs of cleanupFewer cleanups are being completedAn average
cleanup costs $25 million and takes 12 - 15 yearsClimate change
will cause water shortagesClimate change will cause Altered
precipitation patternsMelting glaciersEarly season
runoffIntensified droughtsFloodingIncreasing probability that there
will be still less water for more people
How we use waterWe have achieved impressive engineering
accomplishments to harness freshwater sources60 % of the worlds
largest 227 rivers have been strongly or moderately affected Dams,
canals and diversionsConsumption of water in most of the world is
unsustainableWe are depleting many sources of surface water and
groundwaterWater is becoming non-renewable resource
Water supplies houses, agriculture, and industryProportions of
these three types of use vary dramatically among nationsArid
countries use water for agricultureDeveloped countries use water
for industry
Different types of water useConsumptive use = water is removed
from an aquifer or surface water body, and is not returned
Non-consumptive use = does not remove, or only temporarily removes,
water from an aquifer or surface waterElectricity generation at
hydroelectric damsWe have erected thousands of damsDam = any
obstruction placed in a river or stream to block the flow of water
so that water can be stored in a reservoirTo prevent floods,
provide drinking water, allow irrigation, and generate
electricity45,000 large dams have been erected in more than 140
nationsOnly a few major rivers remain undammedIn remote regions of
Canada, Alaska, and RussiaA typical dam
Chinas Three Gorges DamThe dam, on the Yangtze River, is the
largest in the world186 m (610 feet) high, 2 km (1.3 mi) wideIts
reservoir stretches for 616 km (385 mi)Provides flood control,
passage for boats, and electricity
Drawbacks of the Three Gorges DamCost $25 billion to buildIs
flooding 22 cities and the homes of 1.13 million peopleSubmerging
10,000-year-old archaeological sitesDrowning farmland and wildlife
habitatTidal marshes at the Yangtzes mouth are erodingPollutants
will be trapped China will spend $5 billion to build sewage
treatment plants
Benefits and drawbacks of damsBenefits:Power generationEmission
reductionCrop irrigationDrinking waterFlood controlShippingNew
recreational opportunities
Drawbacks:Habitat alterationFisheries declinesPopulation
displacementSediment captureDisruption of floodingRisk of
failureLost recreational opportunitiesSome dams are being
removedSome people feel that the cost of dams outweighs their
benefitsThey are pushing to dismantle damsRivers with dismantled
dams Have restored riparian ecosystemsReestablished
fisheriesRevived river recreation500 dams have been removed in the
U.S.Property owners who opposed the removal change their minds once
they see the healthy riverWe divert and deplete surface water
People have long diverted water to farm fields, homes, and
cities
The once mighty Colorado River has been extensively dammed and
divertedThe Colorado River is heavily divertedWhat water is left
after all the diversions comprises just a trickle into the Gulf of
CaliforniaOn some days, water does not reach the gulfDiversion has
drastically altered the rivers ecology
The Aral SeaOnce the fourth-largest lake on EarthIt has lost
more than 80% of its volume in just 45 years The two rivers leading
into the Aral Sea were diverted to irrigate cotton
fieldsConsequences of a shrinking sea60,000 fishing jobs are
gonePesticide-laden dust from the lake bed is blown into the airThe
cotton cannot bring back the regions economy
Can the Aral Sea be saved?People may have begun saving the
northern part of the Aral Sea
Areas where water use exceeds supply
We are depleting groundwaterGroundwater is easily depleted
Aquifers recharge slowly1/3 of world population relies on
groundwaterAs aquifers become depletedWater tables dropSalt water
intrudes in coastal areasSinkholes = areas where ground gives way
unexpectedlySome cities (Venice, Mexico City) are slowly
sinkingWetlands dry up
Will we see a future of water wars?Freshwater depletion leads to
shortages, which can lead to conflict261 major rivers cross
national bordersWater is a key element in hostilities among Israel,
Palestinians, and neighboring countriesMany nations have cooperated
with neighbors to resolve disputes
