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Separation from contaminants
A person constructing a new well must locate a well at least the minimum separation distance (and preferably farther) from sources of contaminants as outlined in the Ontario Ministry of the Environment Technical Bulletin: Wells Regulation - Siting the Well. Some of these sources could include: fuel storage, manure pile and septic systems. Site wells up hill and away from property lines.
Once the well is constructed, it is up to the well owner to maintain separation from these and other potential sources of contaminants, including a compost pile, garden, deck, or any structure.
If there are unique or complex features on your property, consider contacting a professional geoscientist to advise.
Flowing wells have a natural pressure resulting in a standing water level that is above the ground surface when the well is not in use. Flowing wells can occur in valleys or in areas where they are surrounded by ground with higher elevation. The presence of thick clay layers below the surface in these areas is another factor that can lead to a flowing well.
Flowing wells can be extremely challenging and dangerous. Contact an MOE-licensed well contractor who has experience with flowing wells.
See Ontario Ministry of the Environment Technical Bulletin: Well Regulation - Flowing Wells for more information.
Well record and tagging
Well records provide information about construction and water quantity and quality. The well tag is a unique identifier that links the well in the field with the well record. Together, they provide valuable information about your well. Tagging began in November 2003.
Well records and tags are used for new and altered wells and must be affixed by the person completing the work. The well tag must be visible at all times.
Many different factors must be taken into account before choosing where to locate the well. These include:
- natural features – such as the topography (land surface) of the site, the flow of groundwater, and the location of the aquifer
- potential sources of contamination - septic systems, chemical storage, etc.
- safety - presence of overhead power lines or buried utilities
Work with a Ministry of the Environment (MOE) licensed contractor to find the most suitable location on your property.
Access for new wells
Wells and well-related equipment must be sited so they can be easily reached at all times for cleaning, treatment, repair, testing, and visual examination.
The person constructing the well is responsible for ensuring accessibility and identifying all structures and landscaping that may block access. After construction, the well owner should ensure accessibility.
Keep your well free and clear of debris and other obstacles such as decks, wishing wells and gardens.
Well casing and screen construction for new wells
A typical well structure includes a well casing, i.e., pipe, tubing or other material. The casing stabilizes the hole, prevents soil from entering the well, and accommodates pumping equipment. The casing material must be new and watertight to prevent surface water and run-off from entering the well.
Depending on well type and the environment, there are different requirements for casing length and height above ground that the person constructing the well must follow.
In addition to the casing, a new well may also have a well screen, i.e., slotted pipe or tubing, unsealed concrete tiles, or other material. The screen extends below the bottom end of the casing, filters out particulate matter, and provides a water intake zone.
The Wells Regulation prohibits the use of certain materials in new well construction:
- large diameter perforated corrugated pipe(culvert) not approved for potable water use
- plastic that is not approved for potable water use
- hand lain stone, brick, wood, etc.
If your existing well is constructed with any of the above materials, contact an MOE-licensed well contractor to discuss your options.
A properly constructed well forms an effective barrier against surface run-off that may enter and contaminate the well.
Over the years, well design has improved to reflect advances in technology and our understanding of potential pathways of contamination. Ontario’s Wells Regulation outlines minimum construction standards for all types of wells. Always hire a contractor licensed by the Ministry of the Environment (MOE) who is familiar with these standards.
The annular seal
When your well is constructed the hole in the ground is bigger than the well casing. The resulting gap – the annular space – must be filled with a watertight sealant such as bentonite slurry that does not shrink or crack under the ground.
The annular seal serves as a barrier to run-off, surface water, and near-surface waters that could otherwise travel down the outside of the casing and contaminate the aquifer.
Modern vermin-proof caps for all drilled wells have rubber gaskets and screened vents inside to prevent entry of surface water and “foreign material” such as vermin, insects, and decaying plant material. These new caps also accommodate the electrical wiring necessary for your pump. If your well has an ill-fitting cap, contact a local
MOE-licensed well contractor to install a new vermin-proof cap. There are also new caps for dug and bored wells that are ideal for replacing chipped or decaying cement inset caps.
Drilled well with vermin proof cap
Dug well with vermin proof cap