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Chapter 5 Water. 5.1 Our Water Resources. All is born of water; All is sustained by water. Clean, fresh water is Essential to life. People can live for a month or More without food but can Only live a few days without Clean water. One of the main reasons
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Chapter 5 Water
5.1 Our Water Resources All is born of water; All is sustained by water.
Clean, fresh water is Essential to life. People can live for a month or More without food but can Only live a few days without Clean water.
One of the main reasons People are living longer today Than they did 200 years ago Is because of clean water.
Water is a renewable resource Thanks to the water cycle. About 70% of the Earth is water, But only about 3% of that Is fresh water. And most of that is frozen In the polar icecaps, About 77% of all fresh water.
Most large cities depend on Surface water for their supplies. Surface water is fresh water That is aboveground in lakes, Ponds, rivers, and streams. All of the land that is drained By a river is called the Watershed.
Watersheds spread over Tons of area, in the case of The Mississippi, that is thousands Of square miles. The amount of water that falls To earth in any watershed Varies from year to year.
Rivers have very little water In them. So conflicts arise over them All the time. The US and Mexico fight over The Colorado river all the time. And inside the US; California, Arizona, and Nevada fight Over the river too.
In order to provide more stable Water for people, dams are Created to block water and Create lakes. A dam is a structure built Across a river or stream that Restricts the flow of water Downstream.
Dams are both good and bad. The dry land behind them gets Completely covered with water, While the land that was covered Is now dry. Both totally destroy ecosystems.
Not all of the water that falls To earth ends up into Rivers and streams. Some water soaks into the Soil and collects underground. This is called groundwater.
Large amounts of groundwater Are found in Underground formations Called aquifers. Aquifers usually consist of Rocks, sand, and gravel with A lot of air spaces between them In which water can accumulate.
The area of land from which The groundwater originates Is called a recharge zone. Aquifers are used by drilling Wells into the ground until They hit the water underneath, Sometimes up to 1000m.
The problem with aquifers is that They are being emptied faster Than they are able to refill. One aquifer that is being rapidly Used is the Ogallala Aquifer, It is the largest one in the United States.
So we are running out of water, What do we do now? Some communities are starting To use desalinization techniques. Desalinization is exactly how It sounds, it is the removal of Salt from water to make it Pure enough to drink.
There are some People That think it Is a good idea To tow icebergs To other Countries in Order to Provide fresh Water.
Alaska, which has 40% 0f the US’s fresh water, is Experimenting with Sending some of its water South in huge plastic bags And selling it. The idea is to float the bags Down the Pacific Coast to California, which is often Short of water.
But since water flows in a Cycle and only so much Lands on any certain place, The best thing to do is to Just conserve it.
Some ways to save water… Take shorter showers and Don’t let the water run Unnecessarily while you Brush your teeth. Store drinking water in the Fridge rather than letting The water run till it is cool.
Fix dripping faucets; if a Faucet is dripping, you can Waste 11,000 liters of Water per year. Avoid flushing the toilet Unnecessarily. Encourage family and friends To be part of the water Conscious community.
5.2 Freshwater Pollution In 1969, the Cuyahoga river Was so full of industrial Chemical runoff from steel Mills that it actually caught On FIRE!!
Water pollution is the Introduction of chemicals, Physical, or biological Agents into water that it Degrades the quality of The water supply. In Russia, the water is so Polluted that it isn’t even good Enough for industrial use, It could cost up to $2 billion to clean up!
Point pollution is the pollution That is discharged from a Single source, such as a Factory, or an oil tanker. Nonpoint pollution is pollution That comes from many Sources rather than from a Single specific site.
Where does water pollution Come from… It comes from many places; 23 million septic systems, about 2 million gasoline storage tanks, Storm water runoff from city Streets, 50 million tons of Fertilizer, 10 million tons of Salt applied to roads, etc.
Most of the water that goes Down the drain flows through Pipes to a wastewater Treatment plant where it is Treated before being returned To the environment.
Public water supplies are Often checked for the Presence of pathogens. Most of the time, water is checked By the fecal coliform test. This test checks for E. coli.
Entire ecosystems may suffer From the effects of Water pollution. What happens is that pollution Enters the water where the Fish absorb it, then another fish Eats that fish, then we eat That fish.
The concentration of the Pollution goes up each time Something eats another Something. This is called biological Magnification.
Lakes and slow moving streams Can become eutrophic, Which means that they Have an abundance of Nutrients. This usually occurs naturally Over many years.
But because of fertilizer Runoff, and sewage systems Emptying into water systems, We create artificial Eutrophication much faster. This creates imbalances in Dissolved oxygen for fish, Which then die because algae Suffocate them.
When excessive amounts of heat Are added to a body of water, Thermal pollution can result. Thermal pollution occurs when Power plants and other Industries located along lakes And rivers use the water in Their cooling systems.
In order to stop all of this Pollution, Congress passed The clean water act in 1972. The stated purpose of the act Was to “restore and maintain The chemical, physical, and Biological integrity of the Nation’s waters.”
The overall goal was to make All surface waters clean Enough for fishing And swimming. Since 1972, many states and Cities have passed their own, Even stricter water Quality standards.
Groundwater pollution is Likely to plague us for Centuries to come. The Environmental Protection Agency has detected over 200 hazardous chemicals That do everything from Just dirty the water to Cause cancer.
5.3 Ocean Pollution “there isn’t a clean spot in the Atlantic from Bermuda to The African Coast… A river Or polystyrene cups and Bits of plastic stretches Across the ocean”
Up to 85% of ocean pollution, Including most of the oil, Comes from activities on land. This pollution kills fish by Strangulation from six-pack Rings, kills turtles who eat Clear plastic bags that look Like jellyfish, and many Other animals from the Many oil spills in the open ocean.
