WATER SOURCES AND WELLS
Surface water sources include lakes, reservoirs, streams, ponds and rivers. There are many surface water sources in Grey and Bruce and they tend to be easy to access. In most cases, surface water supplies guarantee a year round supply and tend to be low in mineral content. However, surface supplies are not protected and are subject to pollution from man-made and natural sources. While the Great Lakes give us access to some of the cleanest surface water anywhere, it should not be consumed without treatment. At a minimum, private surface water supplies need to be disinfected to remove bacteria and viruses to make them safe for human consumption.
Ground water sources are aquifers – these are layers of rock or sediment underground that are saturated in water. The quality of the water varies depending on the depth and type of aquifer. We can access this water by sinking a well into the aquifer. Wells can be dug, bored, driven (sand points) or drilled. Properly designed, installed and maintained well can be a source of safe water.
The quality of water may be affected as percolates downward through to the aquifer. Organisms such as bacteria or protozoa may die off or be filtered out. Water dissolves minerals from the materials it passes through so many groundwater sources are high in minerals such as calcium and fluoride. Some substances in the water, such as metals and phosphorus, may be removed by charged soil particles. Generally, a deeper protected aquifer provides better source water. The water in shallow aquifers has been filtered less and may be more readily impacted by human activities. Groundwater drawn from a deep well may have been in the ground for hundreds of thousands of years. In a shallow aquifer, the age of the water may be only a few weeks or years. Additionally, the Grey Bruce region does have areas of Karst limestone where the action of water over longs periods has dissolved cracks and fissures into the rock. In these areas, surface water can move down into deeper aquifers in a short space of time. Surface water can also move through the cracks re-appearing at the ground – these features are easily confused with springs from deep aquifers but do not provide good quality water. Wells in areas of Karst limestone should be considered more likely to be affected by surface water.
A dug well is normally 0.9 m (3’) in diameter and constructed from concrete tiles. They are typically 4.5 m (15’) to 11 m (36’) in depth, depending upon where they encounter the ground water table. Dug wells are common in Grey and Bruce. Dug wells use shallow ground water which is more likely to be polluted. Concrete casings must be adequately sealed to prevent surface or very shallow water from running into the well. Water tight tops should be provided and the ground must be sloped away from the well to ensure that all surface drainage is diverted to prevent contaminants from seeping into the well.
Shore wells are similar appearance to a dug well except that they are located close to a surface water supply. Shore wells are not a true well in many respects as they share many of their characteristics with a surface water supply. The distance and type of material between the shore well and the surface water may provide some filtering, but water from a shore well should be treated as surface water. Shore wells are not un-common around lakes and along rivers in Grey and Bruce.
Similar in appearance to the dug well, bored wells are produced by a rig and tend to be deeper than dug wells (typically 15 meters or 50’). They are less common in Grey and Bruce. If the casings are sealed adequately they can provide access to deeper more secure water sources. Other considerations are the same as dug wells.
Drilled wells serving single households are usually 10 cm (4") to 15 cm (6") in diameter and constructed from steel. Commonly they are between 15 m (50’) and 60 m (200’) in depth, depending on the availability of water. Drilled wells are probably the most common form of domestic well in Grey and Bruce. Drilled wells usually access water from a deep more secure aquifer. Contamination of drilled wells usually occurs by surface water entering through the top of the well casing. For this reason drilled wells should be provided with a well seal, have an intact annular seal (the area between the well casing and the ground) and the ground sloped away from the well casing.
These are very small diameter wells, typically 2.5 to 5 cm (1 to 2 inches) and constructed from steel. They are driven into shallow sand and gravel aquifers and tend not to be deep. Although not generally considered a common well construction method there are localized areas in Bruce County where they are common. Because they use water from shallow permeable aquifers, sand points are more at risk of drawing in polluted water. Many are also located near to surface water, in which case they share characteristics with shore wells.
- Ensure your well is properly constructed and located to prevent the direct entry of surface water.
- Periodically inspect your well to ensure that there are no obvious problems such as a missing cap, evidence of flooding or ground movement, etc.
- Ensure that the area around the well is kept clear of debris, brush and any potential contaminants.
- Take 3-4 seasonal bacteriological water samples from your house and cottage.
- Take additional samples if you suspect a problem or your well has been subjected to flooding.
- Always take a sample from a newly constructed or renovated well.
For More Information...
The following website is an excellent source of more information: