A council can find capital for a treatment plant. Keeping it legally staffed, every shift, for the life of the plant, is the harder problem, and Ontario’s licensing rules set the limits.
A council can find capital. Federal and provincial programs exist, grants get written, and plants get built and upgraded. The question that causes trouble later, and more quietly, is who is legally permitted to run the plant on a Tuesday night in February.
What follows describes Ontario's framework under O. Reg. 129/04. Other provinces operate comparable but distinct systems, and First Nations facilities sit outside provincial jurisdiction entirely, which is covered below. This is general information, not advice on any particular facility.
The sequence matters and is often misunderstood. The facility is classified first; staffing requirements follow from that classification.
The owner of a wastewater treatment or collection facility applies to the Director to have the facility classified. Points are assigned against the tables in Schedules 1.1 and 1.2 of the Regulation, and the facility lands in Class I, II, III or IV, determined by its size, the population served, and its operating complexity. Larger and more complex means a higher class.
Classification is not permanent. If a facility is altered, or no longer meets the criteria it was originally classified under, the owner must apply to have the class re-determined. An upgrade or expansion is exactly the trigger. A plant that was Class I may not be Class I afterwards, and the staffing obligations change with it.
That is worth knowing before an upgrade rather than after. The new plant may require a class of operator the community does not employ and cannot easily hire.
An operator is defined by what the person does, not by their job title, union affiliation, or whether they are in a supervisory position.
A licence is required to control flow or pressure, add chemicals or adjust treatment equipment, monitor gauges and control valves, conduct operational tests, start and stop pumps and generators to control flow and treatment, open and close valves and gates whether manually or remotely, or make entries in shift logs and operating records.
This catches people out. A maintenance worker, a laboratory technician, or anyone on call who is expected to perform operating functions when called out, all need licences. An unlicensed contractor may perform operating work only under direct supervision, meaning the licensed operator is physically present and monitoring the work.
There are five licence levels for each of the two facility types, and the progression has fixed minimum durations.
| Licence | Education | Experience | Prerequisite |
|---|---|---|---|
| Operator-in-training | Grade 12 or equivalent | None | Pass OIT or Class I exam |
| Class I | Grade 12 or equivalent | 1 year while holding an OIT licence | Class I exam |
| Class II | Grade 12 or equivalent | 3 years total | Must hold Class I |
| Class III | Grade 12 plus 2 years further education or training | 4 years total, of which 2 as operator-in-charge in a Class II, III or IV facility | Must hold Class II |
| Class IV | Grade 12 plus 4 years further education or training | 4 years total, of which 2 as operator-in-charge in a Class III or IV facility | Must hold Class III |
The experience figures are totals, not additions. A Class II operator needs three years altogether, including the year that earned the Class I.
Progression is also gated. An operator may upgrade only one class at a time, and may write an exam only one class above the licence currently held, with a minimum 90 days between attempts.
An operator may hold a licence no more than one class higher than the highest class of system they are employed at. Someone working at a Class I plant can reach Class II and no further. To go beyond, they have to leave.
This is a structural reason small systems lose people rather than a failure of retention. An ambitious operator at a small plant hits a ceiling that only a move to a larger employer removes. The community trains them, and the training qualifies them to leave.
There is a partial route around it. Education can substitute for experience: applicants for Class II and above may substitute additional education and training for up to 50 percent of the required operating experience, though not for the operator-in-charge portion. For this purpose 450 hours of training equals one year, which is 45 continuing education units.
Holding a licence is not the same as being responsible for the plant. Two roles must be designated.
The ORO must hold a licence for that type of facility of the same class as the facility or higher. A Class III treatment facility requires an ORO holding a Class III or Class IV treatment licence. One must be designated at all times, and it must be clear to other operators and to a ministry inspector who holds the role on any given shift.
Three features of the role are worth reading closely, because they define what is operationally possible at small sites.
The ORO may be off site, provided they are able to respond immediately and effectively as required.
The ORO may cover more than one facility, provided this does not impair their ability to perform the responsibilities.
Backup coverage is capped. If the designated ORO is absent, an operator one class lower may act in their place, but an owner may rely on backup OROs for no more than 150 days in any 12-month period. The Director may extend this only if satisfied that the owner cannot reasonably hire an operator of the required class, and that the extension will not create significant risk.
That 150-day cap is the number to watch. A small community covering an unfilled senior position with a junior operator is consuming a budget that runs out in under half a year.
One or more OICs must be designated. The OIC sets operational parameters for the facility, or directs other operators to set them, and is responsible for ensuring processes are monitored, sampled and adjusted, and that records of adjustments and equipment status are kept.
An operator-in-training may be neither ORO nor OIC. An OIT can perform every regular operating function, but cannot carry either designation.
The Regulation anticipates that small owners will sometimes be unable to hire what they need, and provides several routes. All are temporary.
Conditional licences. Where an owner satisfies the Director that they cannot obtain the services of an operator of the required type and class, the Director may issue a conditional licence to an operator holding a lower class. It is valid only at that facility, expires after three years, and requires the owner to commit in writing to helping the operator meet its conditions. A facility upgrade that changes the classification level is given as an example of when one might be issued.
Professional engineers. A P.Eng without a wastewater operator licence may be employed as an operator for up to six months from the start of employment, may be designated ORO for up to six months, and may be designated OIC for up to 180 days in any 24-month period. Separately, a P.Eng accredited in Ontario is exempt from the experience qualifications entirely if they score 85 percent or higher on the exam for the licence applied for.
Reciprocity. Under the Agreement on Internal Trade and the Ontario Labour Mobility Act, the ministry recognises licences from other Canadian provinces and territories with equivalent programs, and will consider US states whose standards meet Ontario's.
Two boundaries are worth knowing before assuming certified operators are required at all.
O. Reg. 129/04 applies to sewage works requiring an environmental compliance approval under section 53 of the Ontario Water Resources Act, owned or operated by the Crown or a municipality where the sewage is treated, and to non-municipal works receiving domestic-type sewage.
On-site systems. Septic-type systems that do not discharge to a watercourse and are under 10,000 litres per day fall under the Ontario Building Code. Above 10,000 litres per day they require an environmental compliance approval, but do not require certified operators unless the approval itself says so. The approval is therefore the document to read, not the Regulation.
First Nations facilities. These do not fall under provincial jurisdiction and do not require classification. There is a voluntary route: the owner can submit a facility classification form and the ministry will assess what type and class the facility would be under O. Reg. 129/04. Once assessed, operators working there can be licensed, and their experience counts toward upgrades and renewals. For a community that wants its operators to hold portable, recognised credentials, that assessment is the enabling step.
Availability counts as much as attendance. An operator at a facility that does not require them on site full time, but does require them to be available full time, receives a full year of experience credit for each year employed. An operator working part time at a facility that does require full-time operators is credited only for time actually worked.
Training is not pro-rated. The owner must ensure every operator receives at least 40 hours of training per calendar year. Since 1 January 2022 this may be averaged across three years, for 120 hours per three-year period. Part-time operators still require the full 40 hours. The only exemption is for an operator employed at the facility fewer than 60 days in a year, and the Director must be notified.
Licences themselves expire every three years and require operator or related experience within the previous five years to renew. A renewal made more than a year after expiry means requalifying from the start, exam included.
Ask what class the plant will be after the upgrade, not before. Reclassification follows alteration, and the staffing obligation follows the classification. A community that can staff its plant today may not be able to staff it after an upgrade.
Count backwards from the ORO requirement. The plant's class sets the minimum licence the ORO must hold, and that person must be designated at all times with no more than 150 days of backup coverage in a year. Everything else in the staffing plan follows from that one constraint.
Treat the three-year progression as a real schedule. Growing a Class II operator from an untrained hire takes a minimum of three years. If the plant’s ORO retires in eighteen months, their successor is being hired, not developed.
Read the environmental compliance approval. For smaller works it, rather than the Regulation, may determine whether certified operators are required at all.
Related reading: what secondary treatment actually means covers the federal effluent standards these operators are responsible for meeting, and why aeration dominates a small plant's energy bill covers the largest operating cost they manage.
Ontario framework only; other provinces and territories operate separate programs · Accurate as at 24 September 2026 · Verify against the current Regulation and guide before acting on it
North Current develops aeration control technology that retrofits into existing wastewater treatment plants, available through licensing. Get in touch to discuss it.
Published for general information. It is not engineering advice and does not address any specific facility.