water pollution. types of pollutants microorganisms cryptosporidium giardia fecal coliform bacteria
TRANSCRIPT
Water Pollution
Types of Pollutants
Microorganisms• Cryptosporidium• Giardia• Fecal coliform bacteria
Types of Pollutants
Disinfectants• Chlorine• Bromate• Chlorite Inorganic chemicals• Arsenic, cadmium, lead mercury
Types of Pollutants
Organic chemicals• Benzene• Dioxin• Vinyl chloride Radionuclides • Uranium and radium
Sources of Pollutants
Human and animal waste (microorganisms)Naturally occurring in geologic deposits (As, U)Human activities– industry, mining, agriculture
deliver many inorganic and most organic pollution
Sediments from erosion and activities such as excavation & construction
Pollution Interaction with Water
Dissolved chemicals can be toxic or carcinogenic
Non-aqueous phased liquids (NAPLs) form a separate phase that does not mix with water
• Include gasoline, chlorinated hydrocarbons• Difficult to remove, slowly dissolve
Pollutant Interaction with Water
Soluble pollutants enter ground water , flow as plumes
• Concentrations fall as plumes spread, large area affected
• Some contaminants bind to soil (sorption)• Sorption may prevent migration of
contaminants; contaminants stick around even if contaminated plume is pumped out
Water Pollution Control
Easier to control if it comes from a point source
Approaches include:• Improving stormwater mgt systems• Regulating land use• Limiting broad app of pesticides, herbicides,
fertilizer• Restoring wetlands
Water Pollution Control
Coastal areas and estuaries are impacted by pollution and sedimentation
• Ocean pollution kills fish, wildlife• Damages ecosystems• Human illness• Economic damage
Water Pollution Control
2000 National Research Council cited nutrient pollution as one of the most important ocean pollution problems
• Stimulates plankton to increase photosynthesis (blooms)
• When excess plankton die and sink, O2 is used up
• Leads to hypoxic (dead) zones
Gulf of Mexico Dead Zone
Treatments for Human and Animal Wastewater
Septic systems- a large container that receives wastewater from the house.
Treatments for Human and Animal Wastewater
Sewage Treatment Plants- centralized plants in areas with large populations that receive wastewater via a network of underground pipes.
WATER-RELATED DISEASE
Some Statistics
More than 2 million people die each year (cholera, typhoid, dysentery)
1993 – cryptosporidium in Milwaukee killed 110, sickened 400,000
After the outbreak, federal regulators increased testing requirements for turbidity
Waterborne Diseases
• Includes cholera, typhoid, dysentery• Drinking water contains viruses/bacteria• Often from human or animal waste
Water-washed Diseases
• Includes skin and eye infections• Lack of clean water for washing
Water-based Diseases
• Such as schistosomiasis• Spread by organisms that develop in water
that become human parasites• Spread by water and insufficiently cooked
food
Water-related Insect Vectors
• Mosquitoes are the main meanies!• Diseases include dengue fever and malaria• Not directly related to water supply or
quality
Water-Related Diseases
• 1 billion people lack safe drinking water• The spectrum of disease is altering and the
incidence of many water-related microbial diseases is increasing
• Urbanization & dam construction can spread water related disease
• Global climate change is also a factor
MAJOR LAWS AND TREATIES
Clean Water Act of 1972
• Focuses on point sources• Sources obtain permits for discharges into
navigable waters• Federal aid to sewage treatment• Protection for wetlands has been an issue
(developers)
Safe Drinking Water Act
• Regulates contaminants in public water supplies
• Sets mandatory limits on 90 contaminants• Recommends voluntary standards for other
substances that alter water quality
United Nations Convention on the Law of the Sea (1982)
• Creates a comprehensive framework for nations’ use of oceans
• Outlines rights and responsibilities• Including pollution control, research
resource management