Chapter 11 Water  The Water Cycle – we have already discussed this Evaporation Evaporation Condensation Condensation Precipitation Precipitation Run-off Run-off From the surfaceFrom the surface Transpiration Transpiration EvaporationEvaporation from plants from plants In book

Global Water Distribution  97% of the earth’s water is salt water  3% is fresh – 77% of which is locked in glaciers or ice caps, 22% is found in ground water and the remaining 1% is found in lakes, ponds, and streams

 Surface Water – found in rivers, lakes, streams and wetlands River Systems – network of water – determine where many cities are built River Systems – network of water – determine where many cities are built Watersheds – area of land drained by a river Watersheds – area of land drained by a river Chesapeake Bay Watershed Chesapeake Bay Watershed encompasses 6 states – Virginia, Maryland, Pennsylvania, West Virginia, New York, and Delaware encompasses 6 states – Virginia, Maryland, Pennsylvania, West Virginia, New York, and Delaware

 Groundwater – water which is stored beneath the earth’s surface in sediment and rock formation Aquifers – underground formations Aquifers – underground formations includes the water table which is the upper boundary of an aquiferincludes the water table which is the upper boundary of an aquifer droughts lower aquifers sometimes to the point of depletion – once completely depleted, it is almost impossible to replenishdroughts lower aquifers sometimes to the point of depletion – once completely depleted, it is almost impossible to replenish

 Porosity and Permeability – depends upon the type of soil and rock in the area Gravels = permeable Gravels = permeable Clay and granite impede = impermeable Clay and granite impede = impermeable The most productive aquifers contain sandstone, limestone, sand and gravel The most productive aquifers contain sandstone, limestone, sand and gravel

 Recharge Zone = area of Earth’s surface where water seeps through to aquifers Very sensitive to chemical pollutants Very sensitive to chemical pollutants Size dependent upon porosity and permeability Size dependent upon porosity and permeability  Wells = holes that are dug or drilled into the ground to reach groundwater

2 - Water Use and Management  Global Water Use Most used for irrigation of crops Most used for irrigation of crops 80% in Asia, 38% in Europe80% in Asia, 38% in Europe Industry the next highest amount used Industry the next highest amount used Highest amount used in Europe and North AmericaHighest amount used in Europe and North America Only 8% of freshwater is used for household drinking and washing Only 8% of freshwater is used for household drinking and washing

Water Treatment  Removes pathogens (bacteria or any other disease causing organism) or elements such as mercury, or metals to make water potable or drinkable See Figure 2.1 page 276 – 277 (you must know this!) See Figure 2.1 page 276 – 277 (you must know this!)

Water Management Projects  Began with the Romans  Diversion projects – canals, Colorado River  Dams and Reservoirs – interrupts the flow of the river – can be good or bad  Conservation – (know types) drip irrigation, recycling cooling water, low-flow toilets, xeriscaping, desalination

3 - Water Pollution  The introduction of chemical, physical or biological agents into the water that degrades the quality of the water and adversely affects the organisms within it  Underlying causes a. industrialization b. rapid human population growth  2 types of water pollution –point sources –nonpoint sources

Point-Source Pollution  Identified or traced backed to a single source  Examples include: a factory, a leaking septic system or sewage pipe, unlined landfills, etc.  (see Table 3 – page 284)

Non-Point Sources  Comes from many different sources  Often difficult to identify, regulate, and control  96% of polluted waters in U.S. are from nonpoint sources  Examples include: runoff, pesticides, oil, etc.  (See Table 4 – Page 285)

 Principal Water Pollutants (Know Table Page 286)  Wastewater water that contains wastes from homes or industry water that contains wastes from homes or industry Treating wastewater Treating wastewater contains biodegradable materialcontains biodegradable material broken down by bacteria some contains toxic material that cannot be broken downbroken down by bacteria some contains toxic material that cannot be broken down Sewage Sludge Sewage Sludge the solid material that remains after treatmentthe solid material that remains after treatment can be treated and sterilized and used as fertilizer or combined with clay to make brickscan be treated and sterilized and used as fertilizer or combined with clay to make bricks

 Artificial Eutrophication the increase of nutrients and phosphates from fertilizers and detergents into streams and lakes the increase of nutrients and phosphates from fertilizers and detergents into streams and lakes causes an increase in algae which decreases the amount of oxygen and suffocates the other organisms in the water causes an increase in algae which decreases the amount of oxygen and suffocates the other organisms in the water  Thermal Pollution the increase in the temperature of water the increase in the temperature of water usually from power plants usually from power plants can cause fish kills because it lowers the amount of oxygen in the water can cause fish kills because it lowers the amount of oxygen in the water  Groundwater Pollution pollutants enter the groundwater when they percolate through from the surface pollutants enter the groundwater when they percolate through from the surface storage tanks are a major problem storage tanks are a major problem examples include: pesticides, oil, fertilizers, gas, paints, etc. examples include: pesticides, oil, fertilizers, gas, paints, etc.

 Ocean Pollution pollutants are often dumped directly into oceans legally pollutants are often dumped directly into oceans legally 85% comes from activities on land 85% comes from activities on land Oil Spills Oil Spills only responsible for 5% of oil pollutiononly responsible for 5% of oil pollution road runoff for 1 city could fill a tankerroad runoff for 1 city could fill a tanker  Water Pollution and Ecosystems can have immediate and fatal impact for miles or can have a gradual, long-lasting impact can have immediate and fatal impact for miles or can have a gradual, long-lasting impact biomagnification = accumulation of pollutants at successive levels of the food chain with alarming consequences biomagnification = accumulation of pollutants at successive levels of the food chain with alarming consequences

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