Chapter 11-3 Water Pollution 1/08

Water Pollution Introduction of chemical, physical or biological agents that adversely affect the organisms that depend upon that water

Point-source versus Nonpoint-source pollution Point-source can be traced to a source Nonpoint –source comes from many different sources that are often hard to identify

                                                                                  

Pathogens Parasites, bacteria and viruses that cause illness in living things Many spend part of their life cycle in water Pathogens carried by water cause more human deaths than any other environmental problem

Cholera Acute diarrhea Caused by bacteria Infected food water, shellfish Heat kills cholera bacteria

Dysentery Several bacteria and protozoa responsible Vomiting, severe diarrhea Cause water contamination Heat kills most of these

Typhoid Fever Salmonella Thyphi Only people carry the bacteria Shed in feces Vaccination available Boil it , cook it, peel it or forget it

Schistosomiasis Caused by microscopic worms Enters through the skin of people who walk in infected water Attacks liver, urinary bladder, and intestines

Schistosomiasis Africa, Middle East, Egypt 100 million people affected 1 million deaths annually Aswan Dam

WAPI 158 degrees F

Malaria Protozoan Transmitted by mosquito The mosquitoes breed in standing water 800 million affected 1 million deaths annually

Organic Matter Animal and plant remains, feces etc.

Organic Chemicals Pesticides, fertilizer, gasoline, oil etc..

Runoff from farmlands Organic pesticides, herbicides and fertilizers

Inorganic chemicals Acids, bases, salts, etc..

Heavy Metals Dangerous heavy metals include: Mercury, lead, cadmium, nickel, chromium and Slipknot.

Physical Agents Heat and suspended solids

Wastewater Contains waste from homes or industry

Treatment Primary – filtration and settling. Gets the big stuff out

Secondary Aeration Second settling tank Chlorination to kill pathogens

Artificial eutrophication Caused by fertilizer run-off or other organic wastes

Thermal Pollution Heat can be a type of water pollution Power Plants Reservoirs

Groundwater Pollution Any polluted surface water can become polluted groundwater Very hard to clean up

Ocean Pollution Oil spills – Exxon Valdez 1989 Plastics

Cleaning up water pollution Clean Water Act of 1972 Safe Drinking water act of 1996