Continuation After Expiry of Validity Period Regulation FAQs
What does the regulation entail?
The regulation allows excavators to continue digging beyond the locate expiry without a re-locate if they are the locate requestors and their project meets the following criteria, among others:
A. The dig site does not contain any transmission infrastructure.
B. Digging is happening at least 1 metre below the lowest identified underground infrastructure.
C. The excavator continues to have care and control of the dig site.
D. The excavator submits a written statement (between 15–10 days before locate expiry) confirming no changes to:
o The dig site location
o The dig site description from the locate request
o The located area and identified infrastructure
o Any conditions in the locate document
o The excavation details (depth, work type, excavation method)
E. The excavator provides another written statement (also within the 15–10 day window) agreeing to notify Ontario Dig Authority (ODA) if the conditions have changed.
F. The excavator keeps the original locate documents on site.
G. No more than 180 days have passed since the last locate document was provided by an affected Underground Infrastructure Owner (UIO).
Additional rules apply when locates are shared.
When will the regulation take effect?
It will take effect on November 1, 2026.
What is the intent of the regulation?
This regulation allows excavators to continue digging safely after a locate expires, but only when very strict conditions are met, preventing unnecessary delays while still protecting underground infrastructure.
The regulation:
Improve safety by ensuring underground infrastructure is still accurately marked and unaltered before allowing work to continue.
Reduce unnecessary repeat locates, which are often a cause of delays in construction across Ontario. This supports ODA's and the government's commitment to improve locate delivery timelines.
Support construction efficiency by enabling work to proceed when conditions are stable and risks to underground infrastructure are low, helping reduce project slowdowns caused by expired locates.
What is the definition of “transmission infrastructure” in the Continuation After Expiry of Validity Period Regulation (O. Reg. 34/26)?
Ontario Underground Infrastructure Notification System Act (OUINSA) defines “transmission infrastructure” as underground infrastructure constructed or operated for the purpose of transmitting energy.
In general, transmission infrastructure refers to the intermediary transportation stage for bulk energy products before they reach the distribution or service stage. This may include:
a. Any electrical infrastructure that conveys electricity at voltages greater than 50 kilovolts
b. Any oil and gas transmission system that is considered to be operating at or above 30% of the pipe’s Specified Minimum Yield Strength (SMYS) at Maximum Operating Pressure (MOP).”
For additional context, excavators may refer to the definitions of “transmitter” and “gas transmitter” in the Ontario Energy Board Act, 1998, as well as the Oil and Gas Pipelines Code Adoption Document adopted as reference under O. Reg 223/01 and the Technical Standards and Safety Act (TSS Act).
As an excavator, how do I know if any infrastructure in my excavation or dig site falls into the described definitions?
Transmission infrastructure is usually distinguishable from generation, gathering, distribution, or service infrastructure based on the size, capacity, and operating characteristics of the assets involved. For example, gas transmission pipelines are typically wider and operate at higher pressures than gas distribution pipelines, which are generally narrower and operate at lower pressures.
If you are unsure whether a particular asset is transmission infrastructure, you should contact the underground infrastructure owner (UIO) to confirm whether the asset is considered transmission.
If the UIO does not respond, you are encouraged to contact ODA’s Infrastructure Account Services department for assistance.
My excavation schedule is tight, and I really need to continue digging. What if I don’t receive clear answer from UIO or I am uncertain about any transmission infrastructure in my site, can I still submit the attestation under O. Reg. 34/26?
Excavators are solely responsible and liable for making an honest attestation to ODA under O. Reg. 34/26. If you are uncertain whether transmission infrastructure is present, you should not submit the attestation until you have taken reasonable steps to confirm the status of the infrastructure at the excavation or dig site.
If ODA determines that an excavator applied to continue digging after the locate expiry date while knowing that transmission infrastructure was present, ODA may take appropriate enforcement action. This may include imposing an administrative penalty for violating subsection 10(2) of OUINSA.
You may also request a relocate from the UIO to help ensure that you are digging safely and in compliance with applicable legal requirements.
Is the federally regulated infrastructure covered in O. Reg. 34/26?
Despite the question on whether the federally regulated transmission infrastructure is subject to the provincial legislations (e.g. OUINSA/OEB Act), ODA is aware that most excavation activities on or around a federally regulated pipeline still require explicit approval and conditions set by the pipeline operator (as per federal regulations).
Excavators shall note and adhere to all requirements stipulated in federal and provincial legislations wherever applicable.
Does “transmission infrastructure” include aboveground transmission systems?
Although OUINSA’s definition of “transmission infrastructure” refers to underground infrastructure, ODA interprets the term to include aboveground transmission systems where those systems depend on underground components to function safely and effectively.
Examples may include power substations, transmission towers, compressor stations, or similar transmission-related assets that rely on buried foundations, concrete pads, support structures, grounding systems, or other subterranean components.
Accordingly, aboveground transmission infrastructure with associated underground components is generally captured in the definition of “transmission infrastructure” for the purposes of O. Reg. 34/26.
In cases where transmission infrastructure operates under the technical thresholds (e.g. < 50kV or < 30 SMYS) or distribution infrastructure operates above the same thresholds, are they captured in O. Reg. 34/26?
ODA recognizes that rare “fringe” cases may arise where infrastructure does not align neatly with the usual technical thresholds. For example, some transmission infrastructure may operate below 50 kV or below 30% SMYS, while some distribution infrastructure may operate above those thresholds.
Where this is observed, excavators should contact both ODA and the underground infrastructure owner (UIO) responsible for the infrastructure. ODA and the relevant UIO will review the circumstances and work with the excavator to determine an appropriate path forward.
Excavators should not assume that an asset is excluded from O. Reg. 34/26 solely because it falls below, or above, a technical threshold.
Who can I contact if I have questions?
Please email Compliance@OntarioDigAuthority.ca
Terminology
Care and Control
In order to qualify for the extension of the validity period:
The same excavator identified in the locate documentation (but see exception for “other excavators”), must, at the time that the locate would otherwise expire but for the regulation permitting extension:
1. have ‘care’ of the dig site (e.g., provides what is necessary for the maintenance and protection of the dig site); and
2. have ‘control’ of the dig site (e.g. is managing the dig site or has direction or authority over the dig site),
UNLESS
an “other excavator” meets the conditions in section 11(3) of the regulation, in which case the new excavator can continue the excavation or dig provided that all other conditions are met:
(3) The following are the prescribed circumstances that apply if the excavator is an excavator who received from another excavator (the “other excavator”) the information referred to in paragraph 1 of subsection 6 (1) of the Act pertaining to the same excavation or dig parameters as the excavator’s own excavation or dig, including the geographical limits of the area subject to the locate request, in accordance with section 11 of the Act:
1. The excavator has received a copy of the document described in paragraph 9 of subsection (2) from the other excavator and maintains the copy at the excavation or dig site.
2. The excavator maintains, at the excavation or dig site, the information referred to in paragraph 1 of subsection 6 (1) of the Act that the excavator received from the other excavator.
3. The circumstances set out in subsection (2) exist with respect to the other excavator.
Transmission Infrastructure
Dig sites affected by “transmission infrastructure”, including:
Any underground infrastructure that transmits electricity (per OEB Act);
Any underground infrastructure that carries gas (natural gas, substitute natural gas, synthetic gas, manufactured gas,1 propane-air gas or any mixture of any of them) (per OEB Act);
Any other underground infrastructure constructed or operated for the purpose of transmitting energy, where “energy” although not specifically defined, would include:
Any form of hydrocarbon (e.g. fossil fuels such as oil or hydrogen);
Any form of thermal energy (e.g. a geothermal system to transport heat from underground using water or steam);
Any form of mechanical energy such as compressed air or steam;
Any form of magnetic energy (e.g., underground inductive charging),
Any obsolete (including decommissioned) underground infrastructure constructed for the purpose of transmitting any of the forms of energy mentioned above (even if the infrastructure is no longer doing so), are not eligible under the regulation for excavation beyond the locate validity period
Undertaking
A formal pledge or promise to do something
Self-Certify
Make an official declaration that (something) complies with regulatory standards or procedures without independent substantiating evidence
Attestation
The action of formally witnessing or certifying something.
Continuation After Expiry of Validity Period
The regulation allows excavators to continue digging beyond locate expiry if certain circumstances are met. Use of this regulation is optional.
Location of the Dig Site
Whether the physical area where you plan to excavate is the same as on the original locate request
Site Description
Whether the description of the worksite and its surroundings still matches what was originally provided
Located area, infrastructure & points of reference
Whether the marked utilities, infrastructure, and reference points identified during the original locate remain the same
Conditions in the Locate Document
Whether any terms, notes or conditions recorded in the original locate document remain unchanged
Workplan- depth, type, method
Whether your planned excavation depth, type of work, and digging method are the same as originally declared.
Excavator retains care & control
Whether you are still the party responsible for managing and overseeing the worksite
One metre below infrastructure
Whether all excavation will still occur at least one meter below any utility infrastructure, as originally undertaken
Care and control affirmation
Confirms you currently hold responsibility for and oversight of the site, which is required to proceed
Continuation After Expiry of Validity Period Confirmation
The excavator has received an email from ODA or downloaded the PDF from the ODA web portal summarizing the dig sites eligibility and undertakings
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