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Frequently Asked Questions
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What is source water? Source water is untreated water from streams, lakes or underground aquifers that people use to supply private wells and public drinking systems. What is source water protection? Source water protection means protecting those water resources from contamination or overuse. It is the first of five barriers to preventing drinking water from becoming contaminated.
Why protect water sources when we can treat water before it gets to our taps? It is cheaper and safer to stop water from getting polluted in the first place than to pay to clean it up later. To be successful, we need a blend of all five barriers to ensure that we are doing everything possible to keep our drinking water clean. It is possible that one or more of these five barriers may break down, which means we have to rely on the others to protect our water. Source water protection is even more important to rural residents who don't have all of the sophisticated and expensive testing and treatment systems used by municipal systems. Protecting drinking water sources will help to protect their wells from contamination. Don't we have an unlimited supply of fresh water in Canada? Canada has large fresh water resources, but most are not available to us where we live. In the cities, towns and farms of Southern Ontario, we use the water resources that are available to us — nearby rivers, creeks, lakes and aquifers. Decades of urban growth and agricultural use have had an impact on the quality and the quantity of our available water supplies. As our cities grow and as agriculture becomes more intense, those threats grow so it becomes even more important to protect those water sources. What is a watershed? A watershed is all of the land drained by a river and its tributaries into a body of water such as a lake or ocean. No matter where you live on the surface of the earth, you are living in a watershed. What is the best way to protect source water? We protect water sources by making sure water is clean as it enters the ground or river. Planning to protect water sources is best done on a watershed basis, because water flows across artificial boundaries. The features of a watershed — streams, rivers, wetlands, forests, lakes and aquifers — are interconnected. What happens upstream affects downstream residents. What happens on the ground affects both surface and groundwater. The Hydrologic (Water) Cycle
Graphic Source: http://www.ec.gc.ca/water/en/nature/prop/e_cycle.htm (Environment Canada Freshwater Website) Evaporation: Water molecules bind together to form a body of water, such as a lake, river or even a puddle. When the sun heats the molecules on the surface of a body of water, they become energized and break away from each other. The molecules evaporate and rise as invisible vapour into the atmosphere. Transpiration: Plants also give off water vapour in a process known as transpiration. They do this in much the same way that humans perspire. The water that has been absorbed by the plants, usually through the roots, moves to the surface of the plants’ leaves and evaporates into the air. Condensation: As water vapour rises into the atmosphere, it cools and condenses, often attaching itself to tiny particles of dust in the air. When water vapour condenses, it turns back into a liquid. The water particles collect and form clouds. Precipitation: When the clouds become heavy with water particles, the particles fall back to Earth as precipitation in the form of rain, snow, freezing rain or hail, depending on the temperature of the surrounding air. Some of the precipitation evaporates before it reaches Earth. Some lands on plants and is transpired. The water that lands of the surface of the Earth may evaporate, rising up into the atmosphere again. Or it may infiltrate, that is percolate, into the ground or runoff into a nearby body of water. Percolation: Some of the precipitation that falls to the ground seeps into porous soil and cracks in rocks. This water moves downward beneath the Earth’s surface until it settles in an aquifer (a collection of water underground). Water that seeps into an aquifer is called recharge and the land area where water seeps into an aquifer is called a recharge area. Water that percolates through the soil in this way may continue to flow under the ground or it may re-surface somewhere downstream. What is Risk Identification and Risk Management? When undertaking a source water protection planning effort, it is important to identify threats to the watershed and determine the risk they pose to the drinking water supply.
Once these risks have been quantified, a strategy for managing them will be developed based on the relative threat they pose.
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