Filtration of Water in the Recharge Zone  Water travels through soil, sand/clay to the aquifer.  What if any contaminates are removed by these layers before they reach the ground water system?

Lab

Chapter 11 Water use and Management Section 2

Fresh water  To understand factors that affect the world’s fresh water supply, we need to first look at how water is used.

Global Water Use  In the world, 69% of the water used is for Agriculture.  23% of the water used is for Industry.  8% of the fresh water used is for domestic use.

Residential water use  Domestic water use depends on environment and culture.  The average person in the US uses 300L or 80 gal of water a day.  The average person in India uses only 41 L per day.

Water Treatment  Most water is treated to make it POTABLE.  Potable means safe to drink.

Water treatment continued  Water treatment also removes pathogens which are small organisms that can cause disease.  Examples include bacteria, viruses, protozoa and parasites.

Drinking Water Treatment  1. First Filtration Water is filtered through screens that remove fish, leaves, and trash.  2. Coagulation Alum is added to form sticky flocs. Mud, bacteria and other particles stick to the flocs. The water then passes into settling basins, where the flocs sink.

Drinking Water Treatment  3. Second Filtration The water trickles through sand or gravel, which filters out algae, bacteria, and some chemicals.  4. Chlorination Chlorine is added to kill any remaining organisms

Drinking Water Treatment  5. Aeration Forcing air through the water releases gases, reducing unpleasant odors and taste.  6. Additional Treatment Sodium or lime may be used to soften hard water. Some communities add fluoride, which helps prevent tooth decay.

Filtration of Water in the Recharge Zone  Today’s lab is on Ground water filtration.  Water travels through soil, sand/clay to the aquifer.  What if any contaminates are removed by these layers before they reach the ground water system?

1. First Filtration 3. Second filtration 4. Chlorination 5. Aeration Additional Treatment

Industrial Water Use  Industry accounts for 19% of water use. Manufacturing goods Manufacturing goods Waste disposal Waste disposal Power generation Power generation *Most water in industry is used to cool power plants.

Cooling Power Plants 1. Water is pumped from river or lake. 2. Water runs through pipes in cooling tower. 3. Water is pumped back into lake or river. *Water is warmer than before, but usually clean.

Agricultural Water Use  Accounts for 67% of water use in world.  80 % of water used in agriculture evaporates and never reaches plant roots.  Irrigation: providing plants with water from sources other than direct precipitation. Shallow water-filled ditches. High-pressure, over-head sprinklers.

Water Management Projects  Goals: bringing water in to make a dry area habitable, creating a reservoir for recreation or drinking water, or generating electric power.

Water Diversion Projects  Rivers diverted into canals that carry water to dry regions. Colorado river is diverted for irrigation and drinking water in Arizona, Utah, and California. Colorado river is diverted for irrigation and drinking water in Arizona, Utah, and California.

Dams and Reservoirs  Dam: structure built across a river to control its flow. Used to generate electrical energy. 20% of world’s energy is generated by hydroelectric dams. Used to generate electrical energy. 20% of world’s energy is generated by hydroelectric dams.  Reservoir: formed behind a dam. Water can be used for flood control, drinking water, irrigation, recreation and industry. Water can be used for flood control, drinking water, irrigation, recreation and industry.

Dangers of Dams  Harm river ecosystems: cause nutrients to be trapped on one side of the dam.  Displace ecosystems  Fail (may burst and flooding can occur)

Water Conservations  As water sources become depleted, water becomes more expensive. Water Conservation in Agriculture: water is lost through evaporation, seepage, and run-off. Solution: Drip Irrigation- water is delivered directly to plant roots.

Water Conservation in Industry: Water Conservation in Industry: Recycling of cooling water and wastewater.Recycling of cooling water and wastewater. Cities bring in small business to institute water conservation projects.Cities bring in small business to institute water conservation projects.

Water Conservation at Home: low-flow toilets and shower heads. Water Conservation at Home: low-flow toilets and shower heads. Xeriscaping: designing landscapes that require minimal water loss.Xeriscaping: designing landscapes that require minimal water loss.

Solutions for the Future  Desalination: removing salt from salt water.  Transporting Water: water transported from other regions. Water transported in huge plastic bags to dry places. Water transported in huge plastic bags to dry places.