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