For more information about how the situation in Darfur, as well as many other countries, violates the human right to water, see the Human Rights fact sheet.
Ground water has several other purposes, besides providing drinking water. Geothermal energy uses ground water to produce energy-efficient heating and cooling systems. A swimming pool and recreational facility in Moose Jaw, Saskatchewan, a health centre complex in Sussex, New Brunswick, and Carleton University in Ottawa, Ontario are examples of large facilities that are using ground water to heat and cool buildings.
However, there are a few concerns about ground water. As population and pollution increase, there becomes more pressure on ground water. While ground water sources are more plentiful than surface water sources, aquifers take longer to recharge because of the length of time that it takes for rainwater to reach the aquifer.
For this reason, aquifers can run dry. Surface water can also be depleted, but when ground water sources are depleted, the overlying ground can compact and subside, causing damage to buildings on the surface. As well, when the ground water level decreases in coastal regions and on small islands, saline water can enter the water supply.
Canada has a lot of surface water, but even more ground water. Approximately eight million Canadians rely on ground water, two-thirds of whom are people in rural areas. Ground water in Canada is also used for agricultural including irrigation and livestock watering and industrial operations.
Half of the United States population relies on ground water sources to provide drinking water. The map below shows the distribution of aquifers across Canada.
There are several large aquifers and many more small ones. While, individually, small aquifers may not seem significant, they total a very large and important source of water.
The Canadian Shield regions do not have as many aquifers, because the rocks that make up the Canadian Shield do not store water well. Alberta, Saskatchewan and Manitoba use ground water mainly for livestock watering. British Columbia, Quebec and the Northwest Territories use ground water mainly for industrial purposes, and Newfoundland and Nova Scotia use ground water to provide drinking water for people living in rural areas. The map to the right shows the proportion of the population in each province and territory that is reliant on ground water for domestic use.
While only 26 percent of the Canadian population relies on ground water, more than half of the population in the Yukon, New Brunswick, Nova Scotia and Prince Edward Island use ground water for domestic purposes. Nearly half of Saskatchewan residents are also reliant upon ground water. Ground water can become contaminated, by many of the same pollutants that contaminate surface water. For more information about water contamination, including the sources of pollution, see the fact sheet about Water Pollution.
Pollution of ground water occurs when contaminants are discharged to, deposited on, or leached from the land surface above the ground water. Even if there are no industrial and domestic pollution sources in the area, it is important to realize that the water may not be free from contaminants, and should be tested before human consumption.
Arsenic, for example, is found in high concentrations in different parts of the country, and other contaminants, such as dissolved organic material, iron, manganese, ammonium and high salt levels are prominent in ground water sources, especially on the Canadian prairies.
Pollution can come from two types of sources; point and non-point. Point sources are identifiable and localized sources of pollution. Point sources that can contaminate ground water include landfills, buried gasoline or oil storage tanks, septic systems, industrial sources and accidental spills. Non-point sources tend to be in the form of pesticides and nutrients that enter the soil as a result of intense agricultural operations or the widespread use of road salts and chemicals.
The diagram below illustrates some of the many ways in which ground water can become contaminated. Landfills can contaminate ground water when harmful chemical leach downwards. Landfills should have protective bottom layers to prevent leaching, but there are some landfills that do not have this protective layer, or it is old and cracked, and this allows chemicals to leak through. In the United States, there is estimated to be more than ten million buried storage tanks, holding fluids such as gasoline, oil and chemicals.
In the s and s, there were a large number of underground steel storage tanks that were installed in Canada. Without adequate protection, up to half of steel tanks will corrode and develop cracks by the time they are 15 years old. Much of the water is used for irrigation of crops in the Bread Basket of the central plains. Currently there is great concern about the longterm health of this vast aquifer because it is being tapped into and used at a greater rate than being replenished by natural processes.
This could have huge implications in regards to food production in the country if this critical water source is depleted. At current rates of use, 70 percent of the aquifer could be gone by Click here to learn more. Overuse and lowering of the water tables of aquifers could have other impacts as well. Lowering the water table may cause the ground surface to sink. Subsidence may occur beneath houses and other structures.
When coastal aquifers are overused, salt water from the ocean may enter the aquifer, contaminating the aquifer and making it less useful for drinking and irrigation. Salt water incursion is a problem in developed coastal regions, such as on Hawaii.
Groundwater meets the surface in a stream, as shown below, or a spring. A spring may be constant, or may only flow at certain times of year. Towns in many locations depend on water from springs. Springs can be an extremely important source of water in locations where surface water is scarce. A well is created by digging or drilling to reach groundwater. When the water table is close to the surface, wells are a convenient method for extracting water. When the water table is far below the surface, specialized equipment must be used to dig a well.
By , about 30 percent of the Ogallala Aquifer's groundwater had been tapped, according to a study from Kansas State University. Some parts of the Ogallala Aquifer are now dry, and the water table has declined more than feet in other areas. More than two-thirds of this Ogalalla aquifer groundwater could be drained in the next several decades, the study found.
We're taking out old water that isn't being replenished. The same problem is increasingly found throughout the world, especially in areas where a rapidly growing population is placing greater demand on limited aquifer resources — pumping can, in these places, exceed the aquifer's ability to recharge its groundwater supplies.
When pumping of groundwater results in a lowering of the water table, then the water table can drop so low that it's below the depth of a well. In those cases, the well "runs dry" and no water can be removed until the groundwater is recharged — which, in some cases, can take hundreds or thousands of years.
When the ground sinks because of groundwater pumping, it is called subsidence. In California's southern San Joaquin Valley, where farmers rely on wells for irrigation, the land surface settled 28 feet 8.
In addition to groundwater levels, the quality of water in an aquifer can be threatened by saltwater intrusion a particular problem in coastal areas , biological contaminants such as manure or septic tank discharge, and industrial chemicals such as pesticides or petroleum products. Groundwater is invaluable for many uses, from irrigation to drinking-water supply. But, you can't see groundwater, so how do water scientists know where it is in order to be able to drill wells and pump it out for use Millions of cubic miles of water exists in the ground.
You can't see it, but not only is it there, it is always moving around -- mostly downward, but also horizontally. Moving groundwater helps keep rivers full of water and allows for people to draw out water via wells.
Moving groundwater is an important part of the water cycle. Commercial pesticide applicators, farmers, and homeowners apply about 1 billion pounds of pesticides annually to agricultural land, non-crop land, and urban areas throughout the United States. The use of pesticides has helped to make the United States the largest producer of food in the world and has provided other benefits, but has also been accompanied by concerns about their potential Groundwater will normally look clear and clean because the ground naturally filters out particulate matter.
But did you know that natural and human-induced chemicals can be found in groundwater even if appears to be clean? Below is a list of some contaminants that can occur in groundwater. Most of us don't have to look for water. We grew up either in big cities where there was a public water supply, or in small towns or on farms where the water came from wells. But there are some people to whom finding a new supply of water is vitally important. As the salesmen sang in the musical The Music Man, "You gotta know the territory.
Learn as much as possible about the land, the water supply, and the septic system of the house before buying or building. Do not just look at the construction aspects or the beauty of the home and When you open the faucet you expect water to flow. And you expect it to flow night or day, summer or winter, whether you want to fill a glass or water the lawn.
It should be clean and pure, without any odor. You have seen or read about places where the water doesn't have these qualities. You may have lived in a city where you were allowed to water Below a certain depth, the ground, if it is permeable enough to hold water, is saturated with water. The upper surface of this zone of saturation is called the water table.
The saturated zone beneath the water table is called an aquifer, and aquifers are huge storehouses of water. What you are looking at in this photo is a "well" that exposes the water table, with an.
The ground beneath our feet is not just rock, or at least, not just one kind of rock. Many different types of rock exist, and they have very different properties. Often, different types of rocks exist in horizontal layers beneath the land surface. Some layers are more porous than others, and at a certain depth below ground the pores and fractures in these rocks can be.
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