Water Pollution

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

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

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

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

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

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

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

Groundwater Pollution When polluted surface water percolates down Pesticides, herbicides, fertilizers, petroleum products, and underground tanks are common sources Clean up is very difficult http://www.pbs.org/wgbh/pages/frontline/poisonedwaters/view/