Chapter 22 Water Pollution

Types of Water Pollution Any physical or chemical change in water that adversely affects the health of humans and other organisms Eight categories ____________________ _____________________

1. Sewage Wastewater from drains or sewers Causes 2 serious environmental problems: 1. _____________________ Fertilization of water by high levels N and P 2. Increase in Biological Oxygen Demand (BOD) __________________________________________________________________________________ ____ _______________

Sewage

Sewage: Eutrophication Oligotrophic Unenriched, clear water that supports small populations of aquatic organisms

Sewage: Eutrophication Slow-flowing stream, lake or estuary enriched by inorganic plant and algal nutrients such as phosphorus

2. Disease-causing Agents Infectious organisms that cause diseases from wastes of infected individuals Examples: ____________________________________________________________________________ India

3. Sediment Pollution Excessive amounts of suspended soil particles. From: _____________________ Why Is This Bad? Limits light penetration Covers aquatic animals and plants Brings insoluble toxins into waterways

4. Inorganic Plant and Algal Nutrients N and P that stimulate the growth of plants and algae Harmful in large concentrations Sources: __________________________________________________________________________ Causes:

Inorganic Plant and Algal Nutrients: The Dead Zone

5. Organic Compounds Chemicals that contain carbon atoms Dangerous! Chemicals that contain carbon atoms Natural examples: sugars, amino acids, and oils Human-made examples: _____________________________________

Volatile Organic Compounds in Groundwater

6. Inorganic Chemicals Contaminants that contain elements other than carbon Do not degrade easily Examples: Lead- Mercury- Found in old paint, industrial pollutants, leaded gasoline bioaccumulates in the muscles of top predators of the open ocean

7. Radioactive Substances Unstable isotopes that emit radiation Sources: Mining Processing radioactive materials Nuclear power plants Natural sources

8. Thermal Pollution Factories release heated water into waterways Why is this bad? Organisms affected ________________________________________________________________________ ____________________________________

Two Types of Water Pollution 1. Point Source Pollution __________________________________________________________________________ 2. Non-point Source Pollution _______________________________________________________________________________________________________________ _____________________________________

Water Pollution from Agriculture Agriculture is ____________________ Animal wastes and plants residues have high BOD Chemical pesticides Almost all streams and rivers are polluted with agricultural pesticides Important**** There is NO regulation!!!!

Municipal Water Pollution

Industrial Wastes in Water Different industries generate different pollutants Food processing plants- high BOD Paper mills- High BOD and toxic compounds Many industries recover toxins before they go into the waste stream Green Chemistry

Groundwater Pollution

Water Pollution in Other Countries Lake Maracaibo, Venezuela Po River, Italy Ganges River, India Used for bathing and washing clothing Sewage and industrial waste discharged into river Ganga Action Plan initiated by government Construction of 29 sewage treatment plants

Purification of Drinking Water In US most municipal water supplies are treated

Purification of Drinking Water Treated water distributed to customers

Purification of Drinking Water Chlorine Dilemma Chlorine byproducts are linked to numerous cancers, miscarriages and birth defects Peru Fluoridation Prevents tooth decay Linked to cancer, kidney disease

Municipal Sewage Treatment

Laws Controlling Water Pollution Citizen Watchdogs to Monitor Pollution Safe Drinking Water Act (1974) Set uniform federal standards for drinking water including maximum contaminant level Clean Water Act (1972) EPA sets up and monitors National Emissions Limitations Effectively improved water quality from point sources