- Slides: 55
Water Chapter 11
What is this line?
Chapter 5: WATER Much of the water we drink today has been around since water first formed on the earth billions of years ago Clean, fresh water is essential to life Water is a renewable resource that is endlessly circulated by the water cycle
8% 42% 50% WATER, WATER EVERYWHERE, BUT …… ~70% of the earth’s surface is water 97% of the water on the earth is saltwater 3% is freshwater (77% of which is frozen) This is the cryosphere.
The water we require for all our everyday needs comes from 2 sources: 1. SURFACE WATER Freshwater that’s above ground in lakes, ponds, rivers, and streams Most large cities depend on surface water for their water supplies Akron owns and manages approximately 19, 000 acres of land in the Upper Cuyahoga River watershed, including four reservoirs used to temporarily store runoff water.
2. Ground water Freshwater that is below ground in aquifers (underground lakes)
The Cuyahoga River in the Cuyahoga Valley National Park Rivers and lakes depend on precipitation
Tributaries of the Mississippi River
WATERSHED – the entire area of land that’s drained by a river http: //techalive. mtu. edu/meec/demo/Watershed. html The Cuyahoga River drainage basin The Mississippi river is the longest river in the U. S.
Muskingum River Watershed The Muskingum River Watershed is the largest wholly contained watershed in the state of Ohio, covering about 20 percent of the state.
Flow of our precipitation in Manchester: 1. Portage Lakes 2. Flows south to the Ohio River 3. Flows west to the Mississippi River 4. Flows south to the Gulf of Mexico
RIVERS OF CONTROVERSY River water is in such high demand that disputes arise over it The Colorado River has been fought over by Arizona and California for years It flows for 2, 335 km (1, 450 mi)
40% of the world’s people rely on water that originates in another country DAMS - a structure built across a river or stream that restricts the flow of water traveling downstream
The dam would be located right here The water in the reservoir is used for drinking, irrigation, and manufacturing reservoir Dams can also provide flood control and electricity the ecosystems both upstream and downstream of the dam changes
GROUNDWATER http: //www. kingcounty. gov/environment/waterandland/groundwater/education/animation. aspx Water that seeps or percolates underground through the soil
AQUIFER –usually consist of rocks, sand, and gravel with a lot of air spaces where the water can accumulate Occasionally, aquifers contain large areas of water without any rock in them Aquifers are continuously receiving water that percolates down from the surface
How can rocks hold water in them? Porosity – the amount of space between the particles of the rock. The more porous the rock, the more water it can hold.
Permeability is the ability of rock or soil to allow water to flow through it.
The wells may have to go as deep as 1, 000 m The aquifer may be so close to the surface that it bubbles out of the ground as a spring AQUIFERS ARE RUNNING LOW - the water levels of many aquifers are dropping rapidly
The Ogallala Aquifer, the vast underground reservoir that gives life to crop fields, is disappearing. In some places, the groundwater is already gone. Scientists say it will take natural processes 6, 000 years to refill the reservoir.
More than 90 percent of the water pumped is used to irrigate crops
Ogallala aquifer youtube video www. youtube. com/watch? v=XXFs. S 94 HF 08
This process is very slow – it may take millions of years for a large aquifer to form The area of land where the groundwater originates is called the recharge zone Some large cities, rural communities and individual farms and ranches depend on aquifers for their water needs The U. S. has several huge aquifers that supply millions of gallons of water for homes and agriculture The aquifer is tapped by drilling a well into the ground until the hole reaches the groundwater
Why are aquifers important? 1. Ground water is more reliable source of water than surface water. Resistant to droughts. 2. Aquifer water is filtered and purified as it travels underground.
There are 2 main methods of desalinization: 1. Distillation – heat is used to evaporate fresh water from salt water, leaving the salts behind 2. Reverse osmosis – pressure is used to push the water though a semipermeable membrane that won’t permit the salts to pass Both methods are very expensive
SOLUTIONS TO WATER SHORTAGES DESALTING THE SEA - removing the salt from salt water (DESALINIZATION) Click on BROADBAND button http: //www. oceanit. com/index. php? option=content&task=view&id=101 Nearly all the drinkable water in desert countries is produced by desalinization Some California cities built desalinization plants after they experienced severe droughts and had to pay a lot of money to have water shipped into them
TOWING WATER The possibility of towing icebergs by Saudi Arabia – this makes water more expensive than oil WATER CONSERVATION There are various ways to save water - shorter showers - collect rain water to water plants or wash car - when it is yellow leave it mellow, when it is brown flush it down - water lawn in the morning or evening to prevent too much evaporation - You come up with one for number 4.
5. 2: FRESHWATER POLLUTION In the past 20 years developed countries have made enormous strides in cleaning up water supplies Some of the water is still dangerously polluted in the U. S. and this causes lack of economic development They Cuyahoga River in the 1970’s
Cuyahoga River bursts into flames in 1969 In less-developed countries the water is often too polluted even for industry to use Water pollution isn’t always caused by industry: it’s sewage and agricultural runoff Water pollution – the introduction of chemical, physical, or biological agents into water that degrades the quality of the water and affect s the organisms that Catfish out of the Cuyahoga depend on it
Major kinds of water pollutants Pathogens – disease-causing organisms such as bacteria -Occurs when human sewage is untreated or enters water through storm sewers, and when animal feces wash off the land into the water Organic matter – biodegradable remains of animals and plants, including feces
Organic matter – pesticides, fertilizers, plastics, detergents, gasoline and oil, and other material made from fossil fuels such as petroleum Foam observed on the James River in Richmond Inorganic chemicals – acids, salts, toxic metals Toxic chemicals – chemicals poisonous to living things (lead, mercury, cadmium), many industrial chemicals, and some household chemicals
Physical agents – heat and suspended solids, such as soil Radioactive waste – from power plants or nuclear processing and defense facilities
With all this pollution, how do we get clean drinking water? drinking water treatment Potable water is clean enough to drink.
POINT POLLUTION Pollution that is discharged from a single source (a factory, a wastewater treatment plant, or an oil tanker) Easy to regulate and control because it’s easily identified and traced NONPOINT POLLUTION Pollution that comes from many sources rather than from a single specific site (storm sewers, streets, homes, lawns, farms, etc. )
The EPA has recently determined that 96% of the polluted bodies of water in the U. S. are contaminated by nonpoint sources WASTEWATER TREATMENT PLANTS
https: //vimeo. com/7707491 Video on water treatment and wastewater management Wally the water drop video
Separate sewers are when there are two pipes to collect water. One pipe collects water from the storm drains and takes it to a nearby lake or stream. The other pipe takes used water to the wastewater treatment plant.
Combined sewers mix both storm water from the streets collected in the storm drains and used water from a household. Both types of water are sent to the water treatment plant.
Sometimes the combined sewer can not hold all the water because of a storm, so an overflow valve is triggered in the pipe. This overflow ends up in the nearby river or lake. It is untreated water straight from the streets and a home.
Wastewater treatment plants may not remove all the harmful substances in water Sludge – the solid material that remains after treatment Often contains dangerous concentrations of toxic chemicals (it is hazardous waste) Pathogens – disease-causing organisms (bacteria, viruses, + parasitic worms) Cholera, hepatitis, + typhoid are among the diseases people can get by drinking polluted water
HOW WATER POLLUTION AFFECTS ECOSYSTEMS An entire ecosystem may suffer from the effects of water pollution toxins in soil enter bottom-dwelling organisms; hundreds of these are eaten by one fish; a hundred of these fish are eaten by a bigger fish; an eagle eats 10 big fish; each organism stores the toxins in its tissues, so at each step the amount of toxin passed on to the next “eater” increases The increase in concentration is called biological magnification
Water pollution can also cause immediate damage to an ecosystem Spills of toxic chemicals directly into rivers or streams kills nearly all living things for miles downstream ARTIFICIAL EUTROPHICATION Eutrophic – containing an abundance of nutrients http: //www. absorblearning. com/media/item. action? quick=v 3 Plants take root in the nutrient-rich sediment at the bottom and start to fill the shallow water – a swamp eventually forms Artificial eutrophication – when inorganic plant nutrients (phosphorus and nitrogen) get into the water from sewage and fertilizer runoff
Thermal pollution – when excessive amounts of heat are added to a body of water Occurs when power plants and other industries located along lakes or rivers use the water in their cooling systems http: //www. absorblearning. com/media/item. action? quick=v 4 Cool water is circulated around engines to absorb waste heat and then the warm water is returned to the lake or river, creating an unnatural warm area Massive fish kills occur and aquatic organisms are deprived of oxygen and suffocate (warm water can’t hold as much oxygen as cool water can)
CLEANING UP WATER POLLUTION 1972, Clean Water Act (CWA) – to “restore and maintain the chemical, physical, and biological integrity of the nation’s waters” The goal was to make all surface waters clean enough for fishing and swimming THE SPECIAL PROBLEM OF GROUNDWATER POLLUTION Pesticides, chemical fertilizers, and other agricultural chemicals are common pollutants that seep into groundwater
Leaky chemical storage tanks and industrial wastewater lagoons are also part of the problem http: //www. palmdalewater. org/YW/WS/Aquiferfinal. html The EPA has detected 200 hazardous chemicals that can seep through the soil and into groundwater
BOTTLED WATER Most bottled water is simply tap water that has been filtered and treated with various chemicals Bottled water is not tested for pollutants as often as the public water supply.
Ch. 5. 3: OCEAN POLLUTION HOW POLLUTANTS GET INTO OCEANS ~85% of ocean pollution, including most of the oil polluting the oceans, comes from activities on land
Most activities that pollute oceans occur near the coasts Sludge from wastewater treatment plants is dumped directly into the oceans
PREVENTING OCEAN POLLUTION It is very difficult to monitor every ship on the ocean to ensure that none are discharging oil, throwing garbage overboard, or abandoning plastic fishing lines and fishing nets WHO OWNS THE OCEANS? The laws of a coastal nation extend to 22 km from its coastline A nation has control over economic activity, environmental preservation, and research in this area – everything else is communal property