1. Water Pollution

2. Water Pollution
The introduction of chemical, physical or biological agents into water that degrade water quality and adversely affect the organisms that depend on the water.
Developing countries – mostly polluted by sewage and agricultural runoff – waterborne diseases
Water pollution comes from two types of sources- point and non-point solutions

3. Point-source pollution
Comes from a single source like a factory, wastewater treatment plant or a leaking oil tanker
Septic-tank leaking
Leaking storage lagoons
Unlined landfills
Leaking underground storage tanks for fuel or chemicals
Abandoned and active mines
Discharge from industries
Public and Industrial water treatment plants

4. Nonpoint-source pollution
From many different sources – often difficult to identify
Runoff from any of the land surface in a watershed polluted by
Chemicals or other debris on road surfaces – salt, oil, gas, animal feces, litter
Pesticides, herbicides and fertilizers
Precipitation containing air pollutants – acid rain
Soil runoff from farms or construction sites
Oil and gasoline from personal watercraft

5. Wastewater Typically carried to treatment plants through pipes
Sewage Sludge – product of waste water – the solid material that remains after treatment
May contain highly concentrated levels of toxic chemicals so it has to be disposed of as hazardous material
Incinerated and ash buried in a secure landfill
Expensive to dispose of and running out of places - communities are looking for new uses for the toxic sludge
Water that contains waste from homes or industry

6. Eutrophication
Nutrients in an ecosystem can be good in the right amount, but destructive in high or low amounts
Natural process when organic matter builds up and decomposes in a body of water
Decomposition process uses oxygen, with oxygen used more in the water the type of organisms that live there is changed
Organic matter continues to build up in water
Plants root in water in organic matter and more organic matter build up until it becomes a swamp or marsh

7. Artificial Eutrophication
Eutrophication caused by humans
Can be caused by runoff from farms, lawns and gardens
Runoff that has an excess of nutrients – phosphorus and nitrogen
Causes excess plant and algae growth

8. Thermal Pollution Temperature of a lake or stream increases
Can be caused by industries that release cooling water that is now warmer into the lake or stream
Rapid- can cause a fish kill
Slowly – can slowly suffocate organisms and change the ecosystem

9. Groundwater Pollution
When polluted surface water percolates down
Pesticides, herbicides, fertilizers, petroleum products, and underground tanks are common sources
Clean up is very difficult