The law

Wastewater operators remove harmful pollutants from domestic liquid waste so that it’s safe to return to the environment.

To work as a wastewater operator in a domestic municipal system or a regulated non-municipal system, you need a valid licence.

Source law

You can find a complete set of provincial rules related to this activity in:

Types of operator licences

There are different types of licences you need to get before you can operate in different wastewater systems. You must earn a licence in the system you want to work in.

The first step to becoming a licensed wastewater operator is to get your Operator-in-training (OIT) licence. The higher the level of licence (Classes 1-4), the more education and experience you need.

Wastewater operator

Wastewater TreatmentOperator-in-Training
Classes 1-4
Wastewater CollectionOperator-in-Training
Classes 1-4

Licensing guide: wastewater operators

Become an operator-in-training

Before you can become a Class 1-4 wastewater operator, you must first get your Operator-in-training (OIT) licence.

With an OIT licence, you can work in a municipal wastewater system and gain the one-year experience that is needed to become a Class 1 operator.

To get an OIT licence, you need to:

  • have an Ontario Secondary School Diploma (OSSD) or equivalent
  • pass the OIT exam
  • apply for a OIT licence

The Operator-in-training licence is valid for 3 years, with an option to renew for another 3 years.

An OIT licence allows you to perform all of the regular operating functions. However, an OIT cannot be designated as the overall responsible operator or as an operator-in-charge.

Learn more: OIT certificate

Register: OIT Exam


If you’re a professional engineer and want to become a licenced wastewater operator, you do not need the one-year experience required to become a Class 1 operator. You only need to write the Class I exam and pass with a mark of 85% or higher.

Your Class 1 licence is valid for 3 years.

If you’re a professional engineer without a licence, you can work in a wastewater facility for up to 6 months in a one year period.

Upgrade a licence: classes 1-4

If you’re an operator-in-training or a wastewater operator and you want to upgrade your existing licence, you must meet the specific requirements for the licence you wish to get.

For example, if you currently have a Class 2 licence and want a Class 3 licence, you must meet the requirements for a Class 3 licence.

You cannot apply for a licence that is more than 1 classification above your own. For example, if you have a Class 2 licence, you can apply for a Class 3 licence, but not a Class 4 licence.

To qualify for a licence upgrade, you must:

  • meet education and training requirements
  • get the required experience
  • pass the exam for the Class you wish to get
  • pay the fee

Learn more: licence qualifications

Application form: wastewater licence

Renew a licence

It’s your responsibility to renew your licence before it expires.

The Ontario Water Wastewater Certification Office will issue you a renewal notice about 90 days before your licence expires.

To renew a Wastewater Operator’s licence, you must:

  • complete
  • have water or wastewater experience or related experience in the last 5 years
  • pay the fee

In addition, if you are employed as an operator it is your employer’s responsibility to provide 40 hours of training each year.

Note: You don’t have to submit your training records when you apply to renew your licence. Please keep your records, in case the Ministry of the Environment, Conservation and Parks asks for copies.

Licensing Guide: Licence Renewal

Renewal form: Wastewater licence

Renew an expired licence

If your licence expires and you wait less than 5 years to replace it, you must:

  • meet the above requirements to renew your licence

If you licence expires and you wait over 5 years to replace it, you must:

  • meet the qualifications in Schedule 2 for the expired licence class
  • pass the certification exam

Licensing Guide: Licence Renewal

Application form: Wastewater licence

Licensed outside Ontario

Under the Agreement on Internal Trade, if you currently hold a valid licence in another province or territory in Canada, Ontario will issue you an identical licence.

To have your licence recognized in Ontario, you must:

  • complete the Reciprocity Application section of the Drinking Water Certificate and Wastewater Licence Application form
  • submit a photocopy of the certificate you received from the other province
  • pay the fee

Application form: Reciprocity

Licensed outside Canada

If you hold a licence from a jurisdiction outside of Canada please contact the Certification Office for details of obtaining an Ontario licence.


In addition to meeting the experience and education requirements specific to the different operator licences, you must also pass a certification exam in order to receive a licence.

  • You can only write an exam one class higher than the class of the certificate you now hold.
  • You must wait a minimum of 90 days from the date you write your exam to take the next class level exam or to re-write an exam, after failure.

The Ontario Water Waste Water Certification Office administers exams and certification on behalf of the Ministry of the Environment, Conservation and Parks.

Please contact the Certification Office, if you want to:

  • register for an exam
  • prepare for an exam (e.g., study guides, exam aids)
  • write an exam
  • get a list of exam dates and locations

The Certification Office will send you a letter to confirm:

  • exam to be written (e.g., Wastewater Treatment, Class 2)
  • date and time of the exam
  • location of the exam – map included
  • materials you’ll need to bring to the exam – personal photo ID and calculator
  • information about the documents you’ll need to submit to get your certificate, once you’ve passed the exam

You must also bring the following items to the exam or you will not be allowed to write it on your scheduled date:

  • the confirmation letter from the Certification Office
  • a government-issued photo ID
  • a document with your address

Examination Registration form


Please include payment of any applicable fee(s) when you submit your application form.

Pay by either:

  • credit card (Visa, Mastercard)
  • cheque – payable to the “Minister of Finance”

Fees (effective January 1, 2016)

Operator-in-training (all 4 exams; Drinking Water & Wastewater)$50
Class 1-4 (Drinking Water & Wastewater)$140
Drinking Water Limited Subsystem$140
Water Quality Analyst$140
Certificate/Licence Issuance (upgrade)Fee
Drinking Water Operator-in-Training$40
Wastewater Operator-in-Training$40
Class 1-4 (Drinking Water & Wastewater)$175
Drinking Water Limited Subsystem$150
Water Quality Analyst$175
Certificate/Licence RenewalFee
Drinking Water Operator-in-Training$145
Wastewater Operator-in-Training$145
Class 1-4 (Drinking Water)$145
Class 1-4 (Wastewater)$145
Drinking Water Limited Subsystem$145
Water Quality Analyst$145
Certificate/Licence - Late RenewalFee
Class 1-4 (Drinking Water)$25
Class 1-4 (Wastewater)$25
Drinking Water Limited Subsystem$25
Water Quality Analyst$25
Certificate/Licence Replacement CertificateFee
All certificates and licences$75
Facility Classification*Fee
Drinking Water Systems$475
Wastewater Facilities$475

*Paid by owner

Course Assessment**Fee
Drinking Water Courses$175
Wastewater Courses$175
Course Reassessment**Fee
Drinking Water Courses$125
Wastewater Courses$125

**Paid by course provider

Contact the certification office

For more information on training and certification, please contact the Ontario Water and Wastewater Certification Office at:

Phone: 416-231-2100
Toll-free: 1-877-231-2122