The Governing Law: Ontario Water Resources Act and O. Reg. 903
Water wells in Ontario are regulated primarily under the Ontario Water Resources Act and its subordinate regulation, Ontario Regulation 903 — Wells. This regulation sets out who can drill wells, what records must be kept, what construction standards apply, and how wells must be decommissioned when no longer in use.
O. Reg. 903 applies to all types of wells including water supply wells, test holes, and monitoring wells. For residential property owners in Renfrew County, the regulation's most important provisions concern licensed contractors, well records, required setbacks, and well cap standards.
Licensed Contractor Requirement
Under O. Reg. 903, only a licensed water well contractor may construct, alter, or decommission a well in Ontario. This is not optional — hiring an unlicensed person to drill a well is illegal for both the contractor and, in some circumstances, the property owner.
The Ontario Ministry of the Environment, Conservation and Parks (MECP) maintains a public registry of licensed water well contractors. Before engaging any contractor, verify their current licence on the Ontario government's online contractor registry. A valid licence is renewable annually and tied to the individual or company — ask to see it, or look it up yourself using the contractor's name or licence number.
See our guide on verifying contractor licensing in Ontario for step-by-step instructions.
Well Records and MECP Registration
Once a well is completed, the licensed contractor must submit a Well Record to the MECP within 30 days of completion. This record documents the well's location, construction details, depth, geological log, and water quality data collected during drilling. The MECP enters this record into the provincial well database.
Property owners can search for well records — for their own property or a property they are considering purchasing — through the Ontario Well Record Search at ontario.ca. Records are searchable by address or UTM coordinates and provide valuable information about the water source and construction of any registered well on a parcel.
Ensure MECP well record submission is explicitly included in any drilling contract you sign. If a contractor does not mention this requirement, that is a significant warning sign.
Mandatory Setbacks for Well Location
O. Reg. 903 establishes minimum setback distances that must be respected when siting a new well. These are not guidelines — they are mandatory minimum distances from potential contamination sources:
- 15 metres from a septic system (tank, distribution box, and leaching bed)
- 3 metres from a property line
- 30 metres from fuel storage tanks and associated piping
- 15 metres from barnyards, stables, pens, or similar agricultural structures
The setbacks are intended to protect groundwater quality by maintaining sufficient distance between the well and common sources of biological or chemical contamination. Your licensed contractor is responsible for ensuring the well is sited in compliance with these setbacks. If site constraints make compliance difficult, the MECP may need to be consulted before proceeding.
Well Cap Requirements
All drilled wells must be fitted with a well cap that prevents surface water, insects, and debris from entering the casing. The cap must be properly sealed and maintained. A cracked, improperly fitted, or missing well cap is a direct pathway for surface contamination to enter your water supply. Inspecting your well cap annually is one of the simplest maintenance steps a well owner can take.
Water Quality Testing for New Wells
Before a new well is put into service, Ontario strongly recommends — and some lenders require — an initial water quality test. At minimum, testing for total coliform and E. coli bacteria is recommended. Testing for chemical parameters including nitrates, hardness, iron, and manganese provides a more complete picture of your water quality baseline.
In Renfrew County, testing can be arranged through accredited private laboratories. The Renfrew County and District Health Unit can provide information on testing options and acceptable parameter ranges.
Abandoned Well Decommissioning
When a well is no longer in use — whether because a new well was drilled, a property was connected to municipal water, or other reasons — the abandoned well must be properly decommissioned. Under O. Reg. 903, decommissioning must be performed by a licensed water well contractor and involves filling and sealing the well bore to prevent it from becoming a pathway for contamination to enter the groundwater system.
Leaving an abandoned well undecommissioned is illegal and creates ongoing liability. Older rural properties in Renfrew County frequently have historical wells that were simply capped or forgotten — these require proper decommissioning by a licensed contractor.
See also: Well Drilling overview and Ontario contractor licensing guide.