pollution chapter 13. water pollution types and sources of water pollution #1 problem - eroded...
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Pollution
Chapter 13
Water Pollution
Types and Sources of Water Pollution
#1 problem - Eroded soils
Organic wastes, disease-causing agents
Chemicals, nutrients
Radioactive stuff, heat
Point and Nonpoint SourcesNONPOINT SOURCES
Urban streets
Suburban development
Wastewater treatment plant
Rural homes
Cropland
Factory
Animal feedlot
POINT SOURCES
Major Problem: Drinking Water
Safe Drinking Water Act
EPA: Maximum contaminant levels (municipal, but not rural and private)
1/2 of world’s people drink polluted water
Pollution of Surface Water: Streams D.O., B.O.D., fecal coliform bacteria count
Pollution of Surface Water: LakesCultural eutrophication
Slow turnover
Accumulation of nutrients, excessive plant growth, algae blooms
Case Study: The Great Lakes
MississippiRiver Basin
MissouriRiver
OhioRiver
MississippiRiver
LOUISIANAMississippi
River
Depleted
Oxygen
Gulf of MexicoDead Zone
Suffocatedfish
Lowdissolvedoxygen
Decreased fishpopulation
Altered food web
Thermal Pollution
Groundwater Pollution: Sources Low flow rates Few bacteria
Cold temperatures
Coal strip mine runoff
Pumping well
Waste lagoon
Accidental spills
Groundwater flow
Confined aquifer
Discharge
Leakage from faulty casing
Hazardous waste injection well
Pesticides
Gasoline station
Buried gasoline and solvent tank
Sewer
Cesspool septic tank
De-icing road salt
Unconfined freshwater aquifer
Confined freshwater aquifer
Water pumping well Landfill
Groundwater Pollution Prevention
Monitoring aquifers - expensive
Leak detection systems
Strictly regulating hazardous waste disposal
Protecting recharge areas- aquifer classifications
Ocean Pollution: dumping and oil
Oil Spills Sources: offshore wells, tankers, pipelines and
storage tanks Effects: death of organisms, loss of animal
insulation and buoyancy, smothering
Significant economic impacts
Short-term cleanup problems - beaches, wildlife
Long-term cleanup problem - persistence (decades)
Case Study: Chesapeake Bay Largest US
estuary
Relatively shallow
Slow “flushing” action to Atlantic
Major problems with dissolved O2
Solutions: Preventing and Reducing Surface Water Pollution
Nonpoint Sources Point Sources
Reduce runoff
Buffer zone vegetation
Reduce soilerosion
Water PollutionControl Act (1972)
Clean Water Act(1977)- set effluent standards- secondary treatment
Technological Approach: Septic SystemsRequire suitable soils and maintenance
Technological Approach: Sewage Treatment
Mechanical and biological treatment
Technological Approach: Advanced Sewage Treatment
Removes specific pollutants
Technological Approach: Using Wetlands to Treat Sewage
Acid Deposition
Automobiles as a SourceNO from cars
Widespread Secondary Air Pollution: Acid DepositionWet deposition
Dry deposition
Acid Deposition in the U.S.
Acid Deposition, Plants, and Soil
Acid Deposition, Plants, and Soil Direct damage to
forest tree foliage Erodes protective
waxes from leaves, needles
Leaches nutrients from leaves
Acid Deposition, Plants, and Soil Lowers soil pH Affects mineral
solubility Leach out positively
charged ions (K, Mg, Ca) from clay particles
Easily flushed away
Acid Deposition, Plants, and Soil Increases concentration of
potentially toxic minerals E.g., aluminum Damages xylem - reduces
ability to take in water, nutrients - die from lack of moisture, nutrients
Acid Deposition, Plants, and Soil Has resulted in loss of
large stands of trees in many different regions around world
Canada, New England, Smoky Mountains
Acid Deposition, Plants, and Soil
Acid Deposition, Plants, and Soil Nearly 70% of forests
in Czech Republic have been destroyed
Trees in nearly half of Germany’s Black Forest have been impacted
Acid Deposition, Plants, and Soil Switzerland has lost
10% of its forests Increased chance of
avalanches
Acid Deposition, Plants, and Soil Large portions of
forests in Norway have been lost, especially in southern regions
Acid Deposition, Plants, and Soil Correlation between
dying forests and thriving ground layer of mosses
Acid Deposition, Plants, and Soil Mosses are acid-
loving Thick layer holds do
much moisture that surface soils become saturated
Feeder roots, tree die from lack of oxygen (drown)
Acid Deposition, Plants, and Soil Mosses also may kill
mycorrhizal fungi Reduce uptake of
nutrients
Acid Deposition, Plants, and Soil Dense layer of mosses
may further acidify water passing through them into soil
Dissolve more toxic trace metals, leach more soil nutrients
Acid Deposition, Plants, and Soil Even if trees
somehow manage to survive all these problems, their growth is reduced substantially
Acid Deposition, Plants, and Soil
Acid Deposition, Plants, and Soil Varying effects on
crop productivity, but wide distribution of problem areas
Acid Deposition, Plants, and Soil
Some evidence for direct damage
Potatoes in Canada - damage to foliage, potential uptake of toxins
Acid Deposition, Plants, and Soil Coffee plants have
shown damage to foliage in some areas
Acid Deposition, Plants, and Soil Although much
evidence points toward harmful effects from acid rain, some studies show the opposite
Acid Deposition, Plants, and Soil Helpful to crops where
soil nutrients may be very low - nitrogen-limited
Acidification may release nutrients, allow for greater uptake
Acid Deposition, Plants, and Soil Some evidence where
crops show now effect of acid deposition, either negative or positive
Balance each other out
Acid Deposition and Aquatic Systems Fish,Invertebratesdecline (<5.0)
Undesirable species
Acid Deposition and Aquatic Systems
Adirondacks - 25% of lakes too acidic for fish, 20% threatened
EPA: 15,000 U.S. lakes acidified or threatened
Acid Deposition and Aquatic Systems
1/3 of Florida lakes acidic enough to cause harm to aquatic life
Acid Deposition and Aquatic Systems
20,000 lakes in Sweden are too acidic for fish
Acid Deposition and Aquatic Systems
Salmon runs in most Norway rivers have been eliminated
No egg production
Acid Deposition and Aquatic Systems
20 famous salmon-fishing rivers in Nova Scotia have lost or are near to losing the fish
Acid Deposition and Aquatic Systems
Half of Quebec’s 48,000 lakes were acidified by year 2000, and more are becoming that way
Acid Deposition and Aquatic Systems
During most seasons, acids are not direct problem, but they mobilize toxic metals: aluminum, lead, mercury
Aluminum irritates gills of fish, causes mucus buildup, death from asphyxiation
Acid Deposition and Aquatic Systems
Major problem season: snowmelt
First 30% of meltwater contains virtually all the acid
pH 3.0-3.5 Toxic to eggs, fish
fry, adult fish
Global Carbon Cycle
Human effects: fossil fuel combustion,cutting and burning of trees
Global Carbon Cycle
Global Carbon Cycle Increasing
atmospheric CO2 has brought about a rise in global temperature
Greenhouse Effect CO2 acts like glass in
a global greenhouse Slows escape of
infrared radiation from earth’s surface
Greenhouse Effect Many other gases are far
more effective at trapping heat
Methane, CFCs, nitrous oxide (N2O)
20-270 X as effective CO2 responsible for 2/3 of
increase in greenhouse effect
Greenhouse Effect CO2 concentrations
increased 21.5% from 1870-1990
Increasing consumption of fossil fuels, deforestation
Doubling of CO2 concentrations may occur with continued fossil fuel use over 50-100 years
Greenhouse Effect CO2 doubling may
increase average global temperature by 2-5°C
Global temps have increased 0.8°C over last century, 0.6° of that in last 30 years
Major Climate Changes Worldwide change in
patterns of precipitation, storms, winds, ocean currents
Each 1°C increase pushes climatic zones 90 mi N in N. hemisphere
Major Climate Changes Variable effects
worldwide, but greatest changes between 40 and 70°N, in N. Amer. and Eurasia
Caused by both warmer temps and increased CO2 (greater forest productivity)
Major Climate Changes Polar ice sheets and
glaciers have been melting, and changes would escalate
Major Climate Changes Sea levels would rise due
to melting ice, expansion of warming water
4°C increase would cause 0.5-1.5 m rise worldwide
Flood coastal wetlands, low-lying cities, agricultural lands
Major Climate Changes Frequency, intensity of
weather extremes would increase
Heat waves, drought, hurricanes
Major Climate Changes Speed up decay of
organic matter Further increase CO2
concentrations in atmosphere
Major Climate Changes Warmer climates
spreading northward would bring insect-borne diseases, more pests into areas currently protected by cold temperatures
Major Climate Changes Growth rates of many
tree species would be lowered
Ranges would have to shift northward
At rate up to 10 X greater than they’ve ever done in the past
Birch, sugar maple
Major Climate Changes Stress from pests, disease
microorganisms would increase
Adapt faster than tress to changing environments
Major Climate Changes More frequent fires Forest and grassland Increased disturbance:
decreased diversity?
Major Climate Changes But are rising CO2
concentrations really a concern?
3-4 X higher 250 million years ago
Regular cycling over past 400,000 years
Major Climate Changes Rising global
temperatures? 30 years ago there were
signs that we were entering glacial cooling