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Chapter 20: Water Pollution

20.1 What Are the Causes and Effects of Water Pollution?

Water Pollution

  • Water pollution: Change in water quality that can harm organisms or make water unfit for human uses

    • Contamination with chemicals

    • Excessive heat

  • Nonpoint sources: Broad, diffuse areas. they are hard to identify and control as well as expensive to clean

    • Runoff

  • Point sources: Located at specific places. Easy to identify, monitor, and regulate

    • Sewage

Leading Causes of Water Pollution

  • Agriculture activities

    • Sediment eroded from the lands

    • Fertilizers and pesticides

    • Bacteria from livestock and food processing wastes

  • Industrial facilities

    • Release inorganic & organic chemicals

    • EX→ Coal ash (waste from burning coal) – stored in ponds (leak) & dumped into lakes & rivers

  • Mining

    • Surface mining disturbs the land-- creates soil erosion & runoff of toxic chemicals

Major Water Pollutants Have Harmful Effects

  • Infectious disease organisms: contaminated drinking water

  • The World Health Organization (WHO)

    • 1.6 million people die every year, mostly under the age of 5

Major Water Pollutants and Their Sources

  • Infectious agents (pathogens)

    • Effects→causes diseases

    • Examples→ bacteria, viruses, protozoa, parasites

    • Sources→ include human and animal wastes

  • Oxygen demanding wastes

    • Effects→ deplete dissolved oxygen needed by aquatic species

    • Examples→ biodegradable animal wastes and plant debris

    • Sources→ sewage, animal feedlots, food processing facilities, paper mills

  • Plant nutrients

    • Effects→ cause excessive growth of algae and other species

    • Examples→ Nitrates and phosphates

    • Sources→ sewage, animal wastes, inorganic fertilizers

  • Organic chemicals

    • Effects→ Add toxins to aquatic systems

    • Examples→ oil, gasoline, plastics, pesticides, fertilizers, cleaning solvents

    • Sources→ Industry, farms, households, mining sites, runoff from streets and parking lots

  • Inorganic chemicals

    • Effects→ Add toxins to aquatic systems

    • Examples→ acids, bases, salts, metal compounds

    • Sources→ Industry, households, mining sites, runoff from streets, and parking lots

  • Sediments

    • Effects→ disrupt photosynthesis, food webs, and other process

    • Examples→ soil, silt

    • Sources→ Land erosion from farms and construction and mining sites

  • Heavy metals

    • Effects→ cause cancer, disrupt immune and endocrine systems

    • Examples→ lead, mercury, arsenic

    • Sources→ unlined landfills, household chemicals, mining refuse, industrial discharge

  • Thermal

    • Effects→ make some species vulnerable to disease

    • Examples→ heat

    • Sources→ Electric power and industrial plants

Common Diseases Transmitted to Humans through Contaminated Drinking Water

  • Bacteria

    • Typhoid fever: diarrhea, severe vomiting, enlarged spleen, inflamed intestine; often fatal if untreated

    • Chlorea: diarrhea, severe vomiting, dehydration; often fatal if untreated

    • Bacterial dysentery: diarrhea, bleeding; rarely fatal except in infants without proper treatment

    • Enteritis: severe stomach pain, nausea, vomiting; rarely fatal

  • Viruses

    • Infectious hepatitis (type B): Fever, severe headache, loss of appetite, abdominal pain, jaundice, enlarged liver; rarely fatal but may cause permanent liver damage

    • Poliomyelitis: Fever diarrhea, backache, sore throat, aches in limbs; can infect the spinal cord and cause paralysis and muscle weakness

  • Parasitic protozoa

    • Amoebic dysentery: Severe diarrhea, headache, abdominal pain, chills, fever; if not treated can cause a liver abscess, bowel perforation, and death

    • Giardiasis: Diarrhea, abdominal cramps, flatulence, belching, fatigue

    • Cryptosporidium: Severe diarrhea, cramps for up to 3 weeks, and possible death for people with weakened immune systems

  • Parasitic worms

    • Schistosomiasis: Abdominal pain, skin rash, anemia, chronic fatigue, and chronic general ill health

    • Ancylostomiasis: Severe anemia and possible symptoms of bronchial infection

20.2 What Are the Major Water Pollution Problems in Streams and Lakes?

Stream Pollution in More Developed Countries

  • The 1970s→ Water pollution control laws

  • Successful water clean-up stories

    • Ohio Cuyahoga River, U.S.

    • Thames River, Great Britain

  • Contamination of toxic inorganic and organic chemicals by industries and mines

Too Little Mixing and Low Water Flow Makes Lakes Vulnerable to Water Pollution

  • Less effective at diluting pollutants than streams

    • Stratified layers: Little vertical mixing

    • Little to no water flow

    • Can take up to 100 years to change the water in a lake

    • Biological magnification of pollutants

Eutrophication

  • Eutrophication: Natural enrichment of a shallow lake, estuary, or slow-moving stream. Caused by runoff into the lake that contains nitrates and phosphates

  • Oligotrophic lake: Low nutrients, clear water

  • Cultural eutrophication: Nitrates and phosphates from human sources. Farms, feedlots, streets, parking lots. Fertilized lawns, mining sites, sewage plants

Revisiting Lake Washington and Puget Sound

  • Severe water pollution can be reversed

  • Citizen action combined with scientific research

  • Good solutions may not work forever

    • Wastewater treatment plant effluents sent into Puget Sound

20.3 Pollution Problems Affecting Groundwater, Other Water Sources

Ground Water Cannot Cleanse Itself Very Well

  • Common pollutants

    • Fertilizers and pesticides

    • Gasoline

    • Organic solvents

  • Pollutants dispersed in a widening plume

  • Slower chemical reactions in groundwater due to

    • Slow flow

      • contaminants not diluted

    • Less dissolved oxygen

    • Fewer decomposing bacteria

    • Low temperatures

Groundwater Pollution Is a Serious Hidden Threat in Some Areas

  • China→ 90% of urban aquifers are contaminated or overexploited

  • U.S.→ FDA reports of toxins found in many aquifers •

  • Threats

    • Gasoline, oil

    • Nitrate ions

    • Arsenic

  • Prevent contamination of groundwater

  • Cleanup can be very expensive and time-consuming

    • PUR: chlorine and iron sulfate powder

Using Laws to Protect Drinking Water Quality

  • 1974 U.S. Safe Drinking Water Act: Sets maximum contaminant levels for any pollutants that affect human health

  • Health scientists: strengthen the law

  • Water-polluting companies: weaken the law

20.4 What Are the Major Water Pollution Problems Affecting Oceans?

Ocean Pollution Is a Growing and Poorly Understood Problem

  • 2006→ State of the Marine Environment

    • 80% of marine pollution originates on land

    • Sewage

    • Coastal areas most affected

  • Deeper ocean waters

    • Dilution

    • Dispersion

    • Degradation

  • U.S. coastal waters

    • Raw sewage

    • Sewage and agricultural runoff: NO3 and PO4 3-

    • Harmful algal blooms

    • Oxygen-depleted zones

  • The huge mass of plastic in the North Pacific Ocean

Ocean Pollution from Oil

  • Crude and refined petroleum: Highly disruptive pollutants

  • The largest source of ocean oil pollution: Urban and industrial runoff from land

  • 1989: Exxon Valdez, oil tanker

  • 2010: BP explosion in the Gulf of Mexico

  • Volatile organic hydrocarbons: Kill many aquatic organisms

  • Tar-like globs on the ocean’s surface

    • Coat animals

  • Heavy oil components sink

    • Affect the bottom dwellers

20.5 How Can We Best Deal with Water Pollution?

Reducing Surface Water Pollution from Nonpoint Sources

  • Agriculture

    • Reduce erosion

    • Reduce the number of fertilizers

    • Plant buffer zones of vegetation

    • Use organic farming techniques

    • Use pesticides prudently

    • Control runoff

    • Tougher pollution regulations for livestock operations

    • Deal better with animal waste

Sewage Treatment Reduces Water Pollution

  • Wastewater or sewage treatment plants

    • Primary sewage treatment: Physical process

    • Secondary sewage treatment: Biological process with bacteria

    • Tertiary or advanced sewage treatment: Special filtering processes and bleaching, chlorination

We Can Improve Conventional Sewage Treatment

  • Peter Montague: environmental scientist

    • Remove toxic wastes before the water goes to the municipal sewage treatment plants

    • Reduce or eliminate the use and waste of toxic chemicals

    • Use composting toilet systems

    • Wetland-based sewage treatment systems

There Are Sustainable Ways to Reduce and Prevent Water Pollution

  • Developed countries: Bottom-up political pressure to pass laws

  • Developing countries: Little has been done to reduce water pollution

Solutions: Methods for Preventing and Reducing Water Pollution

  • Prevent groundwater contamination

  • Reduce nonpoint runoff

  • Reuse treated wastewater for drinking and irrigation

  • Find substitutes for toxic pollutants

  • Work with nature to treat sewage

  • Practice the three R’s of resource use

  • Reduce air pollution

  • Reduce poverty

  • Slow population growth

Reducing Water Pollution

  • Fertilize garden and yard plants with manure or compost instead of commercial inorganic fertilizer

  • Minimize your use of pesticides, especially near bodies of water

  • Prevent yard wastes from entering storm drains

  • Do not use water fresheners in the toilet

  • Do not flush unwanted medicines down the toilet

  • Do not pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground

Chapter 20: Water Pollution

20.1 What Are the Causes and Effects of Water Pollution?

Water Pollution

  • Water pollution: Change in water quality that can harm organisms or make water unfit for human uses

    • Contamination with chemicals

    • Excessive heat

  • Nonpoint sources: Broad, diffuse areas. they are hard to identify and control as well as expensive to clean

    • Runoff

  • Point sources: Located at specific places. Easy to identify, monitor, and regulate

    • Sewage

Leading Causes of Water Pollution

  • Agriculture activities

    • Sediment eroded from the lands

    • Fertilizers and pesticides

    • Bacteria from livestock and food processing wastes

  • Industrial facilities

    • Release inorganic & organic chemicals

    • EX→ Coal ash (waste from burning coal) – stored in ponds (leak) & dumped into lakes & rivers

  • Mining

    • Surface mining disturbs the land-- creates soil erosion & runoff of toxic chemicals

Major Water Pollutants Have Harmful Effects

  • Infectious disease organisms: contaminated drinking water

  • The World Health Organization (WHO)

    • 1.6 million people die every year, mostly under the age of 5

Major Water Pollutants and Their Sources

  • Infectious agents (pathogens)

    • Effects→causes diseases

    • Examples→ bacteria, viruses, protozoa, parasites

    • Sources→ include human and animal wastes

  • Oxygen demanding wastes

    • Effects→ deplete dissolved oxygen needed by aquatic species

    • Examples→ biodegradable animal wastes and plant debris

    • Sources→ sewage, animal feedlots, food processing facilities, paper mills

  • Plant nutrients

    • Effects→ cause excessive growth of algae and other species

    • Examples→ Nitrates and phosphates

    • Sources→ sewage, animal wastes, inorganic fertilizers

  • Organic chemicals

    • Effects→ Add toxins to aquatic systems

    • Examples→ oil, gasoline, plastics, pesticides, fertilizers, cleaning solvents

    • Sources→ Industry, farms, households, mining sites, runoff from streets and parking lots

  • Inorganic chemicals

    • Effects→ Add toxins to aquatic systems

    • Examples→ acids, bases, salts, metal compounds

    • Sources→ Industry, households, mining sites, runoff from streets, and parking lots

  • Sediments

    • Effects→ disrupt photosynthesis, food webs, and other process

    • Examples→ soil, silt

    • Sources→ Land erosion from farms and construction and mining sites

  • Heavy metals

    • Effects→ cause cancer, disrupt immune and endocrine systems

    • Examples→ lead, mercury, arsenic

    • Sources→ unlined landfills, household chemicals, mining refuse, industrial discharge

  • Thermal

    • Effects→ make some species vulnerable to disease

    • Examples→ heat

    • Sources→ Electric power and industrial plants

Common Diseases Transmitted to Humans through Contaminated Drinking Water

  • Bacteria

    • Typhoid fever: diarrhea, severe vomiting, enlarged spleen, inflamed intestine; often fatal if untreated

    • Chlorea: diarrhea, severe vomiting, dehydration; often fatal if untreated

    • Bacterial dysentery: diarrhea, bleeding; rarely fatal except in infants without proper treatment

    • Enteritis: severe stomach pain, nausea, vomiting; rarely fatal

  • Viruses

    • Infectious hepatitis (type B): Fever, severe headache, loss of appetite, abdominal pain, jaundice, enlarged liver; rarely fatal but may cause permanent liver damage

    • Poliomyelitis: Fever diarrhea, backache, sore throat, aches in limbs; can infect the spinal cord and cause paralysis and muscle weakness

  • Parasitic protozoa

    • Amoebic dysentery: Severe diarrhea, headache, abdominal pain, chills, fever; if not treated can cause a liver abscess, bowel perforation, and death

    • Giardiasis: Diarrhea, abdominal cramps, flatulence, belching, fatigue

    • Cryptosporidium: Severe diarrhea, cramps for up to 3 weeks, and possible death for people with weakened immune systems

  • Parasitic worms

    • Schistosomiasis: Abdominal pain, skin rash, anemia, chronic fatigue, and chronic general ill health

    • Ancylostomiasis: Severe anemia and possible symptoms of bronchial infection

20.2 What Are the Major Water Pollution Problems in Streams and Lakes?

Stream Pollution in More Developed Countries

  • The 1970s→ Water pollution control laws

  • Successful water clean-up stories

    • Ohio Cuyahoga River, U.S.

    • Thames River, Great Britain

  • Contamination of toxic inorganic and organic chemicals by industries and mines

Too Little Mixing and Low Water Flow Makes Lakes Vulnerable to Water Pollution

  • Less effective at diluting pollutants than streams

    • Stratified layers: Little vertical mixing

    • Little to no water flow

    • Can take up to 100 years to change the water in a lake

    • Biological magnification of pollutants

Eutrophication

  • Eutrophication: Natural enrichment of a shallow lake, estuary, or slow-moving stream. Caused by runoff into the lake that contains nitrates and phosphates

  • Oligotrophic lake: Low nutrients, clear water

  • Cultural eutrophication: Nitrates and phosphates from human sources. Farms, feedlots, streets, parking lots. Fertilized lawns, mining sites, sewage plants

Revisiting Lake Washington and Puget Sound

  • Severe water pollution can be reversed

  • Citizen action combined with scientific research

  • Good solutions may not work forever

    • Wastewater treatment plant effluents sent into Puget Sound

20.3 Pollution Problems Affecting Groundwater, Other Water Sources

Ground Water Cannot Cleanse Itself Very Well

  • Common pollutants

    • Fertilizers and pesticides

    • Gasoline

    • Organic solvents

  • Pollutants dispersed in a widening plume

  • Slower chemical reactions in groundwater due to

    • Slow flow

      • contaminants not diluted

    • Less dissolved oxygen

    • Fewer decomposing bacteria

    • Low temperatures

Groundwater Pollution Is a Serious Hidden Threat in Some Areas

  • China→ 90% of urban aquifers are contaminated or overexploited

  • U.S.→ FDA reports of toxins found in many aquifers •

  • Threats

    • Gasoline, oil

    • Nitrate ions

    • Arsenic

  • Prevent contamination of groundwater

  • Cleanup can be very expensive and time-consuming

    • PUR: chlorine and iron sulfate powder

Using Laws to Protect Drinking Water Quality

  • 1974 U.S. Safe Drinking Water Act: Sets maximum contaminant levels for any pollutants that affect human health

  • Health scientists: strengthen the law

  • Water-polluting companies: weaken the law

20.4 What Are the Major Water Pollution Problems Affecting Oceans?

Ocean Pollution Is a Growing and Poorly Understood Problem

  • 2006→ State of the Marine Environment

    • 80% of marine pollution originates on land

    • Sewage

    • Coastal areas most affected

  • Deeper ocean waters

    • Dilution

    • Dispersion

    • Degradation

  • U.S. coastal waters

    • Raw sewage

    • Sewage and agricultural runoff: NO3 and PO4 3-

    • Harmful algal blooms

    • Oxygen-depleted zones

  • The huge mass of plastic in the North Pacific Ocean

Ocean Pollution from Oil

  • Crude and refined petroleum: Highly disruptive pollutants

  • The largest source of ocean oil pollution: Urban and industrial runoff from land

  • 1989: Exxon Valdez, oil tanker

  • 2010: BP explosion in the Gulf of Mexico

  • Volatile organic hydrocarbons: Kill many aquatic organisms

  • Tar-like globs on the ocean’s surface

    • Coat animals

  • Heavy oil components sink

    • Affect the bottom dwellers

20.5 How Can We Best Deal with Water Pollution?

Reducing Surface Water Pollution from Nonpoint Sources

  • Agriculture

    • Reduce erosion

    • Reduce the number of fertilizers

    • Plant buffer zones of vegetation

    • Use organic farming techniques

    • Use pesticides prudently

    • Control runoff

    • Tougher pollution regulations for livestock operations

    • Deal better with animal waste

Sewage Treatment Reduces Water Pollution

  • Wastewater or sewage treatment plants

    • Primary sewage treatment: Physical process

    • Secondary sewage treatment: Biological process with bacteria

    • Tertiary or advanced sewage treatment: Special filtering processes and bleaching, chlorination

We Can Improve Conventional Sewage Treatment

  • Peter Montague: environmental scientist

    • Remove toxic wastes before the water goes to the municipal sewage treatment plants

    • Reduce or eliminate the use and waste of toxic chemicals

    • Use composting toilet systems

    • Wetland-based sewage treatment systems

There Are Sustainable Ways to Reduce and Prevent Water Pollution

  • Developed countries: Bottom-up political pressure to pass laws

  • Developing countries: Little has been done to reduce water pollution

Solutions: Methods for Preventing and Reducing Water Pollution

  • Prevent groundwater contamination

  • Reduce nonpoint runoff

  • Reuse treated wastewater for drinking and irrigation

  • Find substitutes for toxic pollutants

  • Work with nature to treat sewage

  • Practice the three R’s of resource use

  • Reduce air pollution

  • Reduce poverty

  • Slow population growth

Reducing Water Pollution

  • Fertilize garden and yard plants with manure or compost instead of commercial inorganic fertilizer

  • Minimize your use of pesticides, especially near bodies of water

  • Prevent yard wastes from entering storm drains

  • Do not use water fresheners in the toilet

  • Do not flush unwanted medicines down the toilet

  • Do not pour pesticides, paints, solvents, oil, antifreeze, or other products containing harmful chemicals down the drain or onto the ground