Wells Regulation – Installing Equipment in a Well (technical bulletin)
This is technical bulletin 1 of 11 for a person who is considering a new water supply well or who currently owns a water supply well.
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This technical bulletin is one in a series of 11 on well issues created for a person who is considering a new water supply well or who currently owns a water supply well. The purpose of this technical bulletin is to summarize the information on the installation of equipment found in the Water Supply Wells Requirements and Best Management Practices manual published by the Ministry of the Environment and Climate Change. Additional information is provided in the Wells Regulation Well Repairs and Other Alterations technical bulletin.
This technical bulletin provides some of the steps that must be performed to meet the requirements of Regulation 903 (Wells Regulation), as amended, made under the Ontario Water Resources Act when installing equipment such as a pump in a water supply well. Proper installation of clean equipment into a well reduces the risk of contaminants being introduced into the well and groundwater resources.
Equipment in a well
Installing equipment into a well is considered well construction (i.e. an alteration). This includes installing a pump and its associated equipment into a well.
It is important to consider the protection of the health and safety of persons and the environment when installing equipment in a well. The Wells Regulation requires equipment installed in a well to be clean to reduce the risk to health and the environment.
Connections to wells
Connections may be required for a well to function properly. Connections can be made above and below the ground surface to accommodate waterlines or instrumentation. Connections below the ground surface must be made watertight to avoid contamination of both the well and the aquifer.
Connections are typically made through a well’s casing. A casing is pipe, tubing or other material installed in a well to support its sides, but does not include a well screen.
If a connection to the casing of a drilled well is made below the ground surface, the person constructing the well (i.e. installing the equipment) must use a well seal or pitless adapter (see Figures 1 and 2 on page 2) and the connection must be made watertight.
Pitless units, which consist of a pitless adapter and casing, are also an acceptable method to connect pumping equipment to drilled wells.
Figure 1: Pitless Adapter
Figure 2: Pitless adapter installed on the well’s casing before waterline installation and sealing
The person constructing the well must not use a cutting torch to make an opening in the casing wall when installing a pitless adapter. Typically, a properly sized hole saw, as outlined in the manufacturer’s specifications, is used to drill out an opening in the casing.
The person constructing the well must make any below ground connection to the casing of wells, other than drilled wells, watertight with durable bonding material. Examples of bonding materials include non toxic butyl rubber, link seals and cement products.
Excavation beside the casing
The person constructing the well must fill any excavation created when making a below ground connection to the casing of a well with suitable sealant extending:
- outward from the casing a minimum distance of 20cm (8") and
- from the bottom of the excavation to within 20cm (8") of the ground surface.
A suitable sealant can be a commercial clay product called bentonite or a cement product. For information on suitable sealants and casing see the Wells Regulation New Construction of the Hole, Casing, Well Screen and Annular Space technical bulletin.
Venting - General
If a new well is constructed by any method, the person constructing the well must ensure the well is vented to the outside atmosphere so that all gases can be safely dispersed. The vent is not required when the casing is used to transmit water out of the well. Some examples where casing is used to transmit water out of a well include flowing wells and driven point wells.
Venting - Pump installation in a drilled well
If a pump is installed in a drilled well, the person constructing the well i.e. installing the equipment must meet the following requirements in the Wells Regulation.
If the inside of the casing is:
- Small, less than 12.7cm (5"), the inside diameter of the air vent must be a minimum of 0.3cm (0.1")
- Large, greater than 12.7cm (5"), the inside diameter of the air vent must be a minimum of 1.2 cm (0.5")
The air vent must be long enough to extend above the covering of the well pit, if there is a well pit. Otherwise, the air vent must extend a distance sufficient to prevent the entry of flood water from any anticipated flooding in the area and be at least 40 cm (16") above the ground surface.
The open end of the air vent must be shielded and screened to prevent the entry of any materials into the well.
Covering the well
The person constructing the well must meet the following requirements in the Wells Regulation.
Dug or bored
The top of the casing of a well that is constructed by digging or boring must be covered with a solid, watertight well cover, so that surface water and other foreign materials cannot enter the well.
Drilled or other
The top of the casing of a well that is not constructed by digging or boring must be sealed with a commercially manufactured vermin-proof well cap. An adequate vermin-proof well cap includes a properly installed and sealed commercially manufactured sanitary well seal on a drilled well and a commercially manufactured watertight and airtight well cap on a driven or jetted point well.
Alternative to a well cover
The cover or seal above is not required if all of the following criteria are met:
- A floor of a structure has been constructed around or adjacent to the casing of the well,
- A pump including associated equipment such as waterlines, is installed above or adjacent to the well,
- The top of the casing is shielded to prevent the entry of any material that may impair the quality of the water in the well, and
- The casing of the well is extended to at least 15 cm (6") above the floor.
Casing height and mounding
The purpose of the minimum casing height is to prevent water from entering the well and to allow for venting. The purpose of mounding is to alter surface drainage so that water will not collect or pond in the vicinity of the well in order to reduce the risk of surface water runoff infiltrating into the well.
When installing or connecting equipment, it is important that at least the minimum casing height be maintained and that the mounding around the well is restored if it has been disturbed.
See the Wells Regulation Well Repairs and Other Alterations technical bulletin and the Water Supply Wells Requirements and Best Management manual for further details.
Well pits
A well pit is a structure intended to prevent the upper portion of the well and waterlines from freezing and to allow access to the top of the well.
New well pits are not allowed to be added on any new or existing water supply wells in Ontario except where a well is created using diamond drilling equipment in connection with mineral exploration.
There are many problems with well pits, such as:
- Openings in the well pit’s walls can allow surface water and other foreign materials to enter the pit. This could result in contamination of the well water and the well pit becoming structurally unsound.
- Dangerous gases coming from the well can collect in the well pit and may put persons working on the well at risk.
Well pits are no longer necessary for most water supply wells because of the development of new types of waterline connections, such as pitless adapters.
Do not enter any confined space unless properly trained and equipped. Confined spaces are non-ventilated areas including well pits, pump houses, and other areas defined in the Ontario Regulation 632/05 as amended made under the Occupational Health and Safety Act. Confined spaces present asphyxiation hazards and some wells produce naturally occurring gases that are poisonous and/or explosive.
Disinfection
The person undertaking well construction or installation of equipment must dose the water in the well to a concentration of not less than 50 milligrams per litre and not more than 200 milligrams per litre of free chlorine as soon as possible after the construction or installation of the equipment is complete (See the Wells Regulation Well Disinfection technical bulletin and Chapter 8: Well Disinfection of the Water Supply Wells Requirements and Best Management manual for further details).
This dosing requirement does not apply if the person performs a minor alteration on a well, if the well is considered a flowing well or in situations where the Wells Regulation exempts the installation of equipment for certain sampling, testing or monitoring activities.
The Wells Regulation defines the term "minor alteration" of a well as:
- routine repair or maintenance,
- the installation of monitoring, sampling or testing equipment, other than equipment used to test the yield of the well or the aquifer,
- the installation of a pump in a test hole, or
- the installation of a well cap or watertight well cover.
Licensing
There are certain licensing requirements and exemptions for persons who work on wells. Please refer to the Wells Regulation Well Construction Licensing technical bulletin and Chapter 3: Well Construction Licensing Obtaining, Maintaining and Exemptions of the Water Supply Wells Requirements and Best Management manual for further details.
Well record
A well record is not required to document a pump installation or minor alteration; however, other alterations that involve the installation of equipment could require the person constructing the well to complete a well record and deliver it to the well purchaser who contracted for the well to be built and the owner of the land. For further information on what equipment installation requires a well record to be completed, see Chapter 13: Well Record, Documentation, Reporting & Tagging of the Water Supply Wells Requirements and Best Management manual.
Well tags
When installing equipment such as a pump, a well tag must be affixed to the well if the well does not already have one. If the well has a tag that is broken, illegible or defaced, it must be returned to the Ministry of the Environment within the required timeframe and a new well tag must be affixed. For further information on what well alterations, including equipment installation, require a well tag see Chapter 13: Well Record, Documentation, Reporting & Tagging of the Water Supply Wells Requirements and Best Management manual and the Wells Regulation Well repairs & Other Alterations technical bulletin.
Information for the well purchaser
Unless the well purchaser otherwise directs, on the day a pump is replaced in an existing well, the person constructing the well must deliver an information package from the Ministry of the Environment to the well purchaser. Other alterations that involve the installation of equipment could also require an information package to be provided to the well purchaser. For further information on when an information package is required to be provided to the well purchaser, see Chapter 13: Well Record, Documentation, Reporting & Tagging of the Water Supply Wells Requirements and Best Management manual.
Test holes and dewatering wells
New test holes and dewatering wells, as defined by the Wells Regulation, have other requirements and exemptions. For further information on the construction requirements for test holes and dewatering wells see the Wells Regulation.
Additional information sources
This technical bulletin on well issues is one in a series of 11 created for owners of water supply wells which are available on the Water Supply wells: technical bulletin page.
Further information on the installation of equipment in a well can be found in Chapter 9: Equipment Installation of the Water Supply Wells Requirements and Best Management Practices manual.
A copy of the Water Supply Wells Requirements and Best Management Practices manual can be obtained from the ministry’s web site.
A copy of Regulation 903 (Wells Regulation), as amended, made under the Ontario Water Resources Act and other regulations can be obtained from the e-Laws web site.
The publications are also available by calling the Publications Information Centre at
For further information about wells, contact the Wells Help Desk at
Notice: This bulletin is being provided for information purposes only and is not intended, nor should it be construed as providing legal advice in any circumstances. The applicable legislation including the Ontario Water Resources Act and Regulation 903, as amended and made under that Act, should be consulted. Legislation and regulations change from time to time so it is essential that the most current versions be used.
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