1. Two main types of freshwater pollution 1. Point Source: Pollution that comes from a known and specific location EX) Factory pipes, tail pipe, leaking land fill, leaking storage tank 2. Non-Point: does not have a specific point of origin EX) Runoff - water that flows over the land rater than seeping into the ground. Eutrophication - Nutrients enter surface water & too many nutrients cause environmental problems -Large amounts of phosphates & nitrates promote runaway growth of algae and plants - Open water is choked with plant growth. - Plants die – increase in the # of decomposing bacteria - Oxygen in water decreases WATER POLLUTION Hypoxia_in_the_Delta.asf

2. Sources of Water Pollution 1. Agriculture Discussed in chapter 13 2. Municipal: Contains salts, asbestos, chlorides, copper, cyanides, grease, lead, zinc, hydrocarbons, motor oil, organic wastes, phosphates, sulfuric acid 3. Industrial - High BOD, toxic compounds, sludge - Some industries are cleaning water before they discharge it

3. Riparian buffers- the area on both sides of a creek or stream that acts as a habitat for immature organisms and helps catch & filter pollutants

4. RESOURCE DEGRADATION = pollution! Controlling Water Pollution - 1898 Rivers and Harbors Act - First legislation to address water pollution - Individual states were responsible for enforcing laws on water pollution - Studies not accurate - People not held accountable for pollution Rachel Carson- wrote the book Silent Spring - Brought water pollution problems to the common man in terms they could understand - Helped lead to water pollution control act

5. 1972 FEDERAL WATER POLLUTION CONTROL ACT - Set water-quality standards for all 50 states - Provides a vision of water quality standards and a means of measuring improvement - Does not set laws for enforcement Cuyahoga River notes later…. - Many states have improved their water quality, but there are still problems - Sewage treatment, soil erosion, removal of toxic chemicals, and heavy metals - Cancer causing agents identified in drinking water - Mississippi River is still dangerously polluted - by the time the water of the Mississippi reaches the ocean, it is estimated that the water has moved through 5 humans and 5 different treatment plants as well as many industrial sites "Clean Water Act"

6. 1969 Cuyahoga River Cleveland Ohio The Cuyahoga River was so polluted that the river actually caught fire and burned for several days. The incident was a major factor behind the passage of the Clean Water Act of '72 Other Countries don't have the same regulations we have:

7. TYPEEXAMPLESSOURCESEFFECTSINFORMATION Disease organisms Bacteria, viruses Waste from animals Typhoid, cholera, dysentery Chicago 1885- 90,000 deaths Direct dumping banned in US Sewage Animal/human manure and plant debris that bacteria decompose Sewage, animal feedlots, water treatment plants or the lack of them Great amounts of bacteria can remove oxygen from water killing fish. Also causes algal blooms and possible eutrophication -Industrialized societies have sewage treatment plants -Many unindustrialized societies dump waste directly into water sources. -encourages the growth of disease organisms Organic Chemicals Oil spills, plastics, pesticides, fertilizers Oil spills, leakage from ships, runoff from roads, improper disposal Deplete oxygen, animal contamination - largest Spill: Persian Gulf War ‘91 hundreds of thousands of metrics tons of oil spilled intentionally - Exxon Valdez – 42,000 metric tons of crude Inorganic chemicals Acids, toxic metals Industrial effluent, urban runoff, household cleaners Poisons fresh alter and sicken those who drink it -Lead & mercury levels in fresh water ecosystems enter human food web easily and cause brain, liver & kidney damage -Acid rain -Japan 1950- mercury poisoning- 8,000 people paralyzed or brain damaged

8. Plant Fertilizers Water soluble compounds with nitrate, phosphorous ions Sewage, manure, farm/garden runoff Spurs rapid growth of algae that decay and deplete water’s oxygen…fish die Largest source of runoff pollution SedimentSoilErosion Disrupts aquatic food webs, clogs lakes & reservoirs, reduces photosynthesis of aquatic plants - over time the water may fill with sediment causing fresh water ecosystems to fill with sediment and become a meadow over time Radioactive substances Radon, uranium Nuclear power plants, ore mining & processing Cancers, birth defects, genetic mutations 1973 & 1950 radioactive spills from sites- thousands exposed to high level radiation Thermal pollution Large increase in water temperature Power plants/industry Increase in fish metabolism requiring them to consume more oxygen- water holds less dissolved oxygen -Nuclear power plants pull in cold water and release water 10-15 degrees higher. - Industrial use

9. Groundwater Pollution

10. Municipal Sewage Treatment Waste water undergoes several treatments at a sewage treatment plant to prevent environmental and public health problems. The treated water is then discharged into rivers, lakes or the ocean.

11. Process: 1.Primary Treatment A.Removes suspended & floating particles B.Screening & gravitational settling 1.Solid material that settles out is known as primary sludge 2.Does not eliminate the inorganic & organic compounds remaining in the wastewater.

12. 2.Secondary Treatment A.Uses microorganisms to decompose the suspended organic material 1.Trickling filters: wastewater trickles through rock beds containing bacterial which degrade the organic material 2.Activated sludge process: Wastewater is aerated and circulated through bacteria rich particles. 3.Particles and microorganisms are allowed to settle out forming Secondary Sludge ** Water is clear and free of organic wastes such as sewage**

13. Primary and Secondary Treatment

14. Individual Septic Systems Many private residences use individual septic systems instead of municipal sewage treatment. –Household sewage is piped into the septic tank –Particles settle to the bottom –Grease and oils form a scummy layer where bacteria decomposes it –Waste water containing suspended organic and inorganic material flows into the drain field through a network of perforated pipes set in trenches of crushed stone Purified wastewater then percolates into the groundwater or evaporates from the soil

15. Do you see how there could be a contamination problem here?

16. Septic Systems The septic tank works much like primary treatment in municipal sewage treatment- sewage from the house is piped to the septic tank, where particles settle to the bottom Wastewater containing suspended organic and inorganic material flows into the drain field and gradually seeps into the soil