Water Pollution Chapter 11-3

Water Pollution Water pollution – the introduction of chemical, physical or biological agents that degrade water quality

Water Pollution 2 main causes: Industrialization Rapid human population growth

Developing Countries The only water to drink is often polluted Spread waterborne diseases

Point Source Pollution Point Source Pollution – pollution discharged from a single source Factory Leaking oil tank

Nonpoint-Source Pollution Nonpoint-Source Pollution – comes from many sources Hard to identify Boats that leak fuel

Wastewater Wastewater – water that contains waste from home or industry Wastewater treatment Plant Filtered enough to return water back to a lake

Treating Wastewater Biodegradable wastes can be broken down by living organisms

Sewage Sludge Solid material that remains after treatment Incinerated Ash buried in landfills Fertilizers or bricks

Artificial Eutrophication Lakes and streams contain an abundance of nutrients Human caused Normally a natural process

Artificial Eutrophication Areas can become swampy Caused by: Fertilizer run-off Laundry soap

Algal Blooms Algal blooms – “Floating mats” Can suffocate fish Algae die and decompose Dissolved oxygen used in process

Thermal Pollution Thermal Pollution – temperature rise of a body of water Power plants discharge warm water back into lakes

Groundwater Pollution Enter by pollutants on surface Percolate into ground water Oil leaks Fertilizers Pesticides Septic Tank

Ocean Pollution 85% of ocean pollution comes from activities on land Rivers

Oil Spills 1989 Exxon Valdez Oil Spill Prince William Sound, Alaska Each year 37 million gallons spill

Oil Spills 2001 Galapagos Islands

Biomagnifications Pollution - DDT DDT – widely used pesticide Cheap Active for a long time Killed variety of insects Drained into rivers Can not eliminate from bodies Non-biodegradable Not broken down by plants or animals

Biological Magnification Stored in by algae Herbivores eat algae – concentration raises Carnivores eat – concentration raises Affects entire food web

Silent Spring 1962 – biologist Rachel Carson Osprey, Brown Pelican, Bald Eagle Threatened extinction Made eggs fragile 1970’s DDT banned

Cleaning Up 1969 – Cuyahoga River Cleveland Ohio Caught fire and burned for days Clean Water Act of 1972 Goal – To make all surface water clean enough for swimming and fishing by 1983

DDT VIDEO CLIP

Disaster in the Gulf – Video Clip