Certification information

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Coronavirus (COVID-19) status update

During the coronoavirus outbreak, some of the information on this page will not reflect the current situation. We are committed to helping you maintain a safe and healthy workplace, provide vital services to your communities, and protect water quality. Visit our main Wastewater Operating Certification (OpCert) Program webpage for more information.

If you have questions about your NPDES or State Waste Discharge Permit requirements, please reach out to your assigned Ecology permit contact (permit manager or permit administrator).

We certify operators to help ensure that they are knowledgeable and that wastewater treatment plants are properly operated and maintained. We certify operators based on wastewater operating experience and education. We have four levels of full certification. The requirements and allowable substitutions for each level are listed in the rule (WAC 173-230-250). Each level also requires passing an exam.

We also have four optional Operator in Training (OIT) Group Levels. If an operator doesn’t meet all the education and experience requirements, but believe they can pass the next Group Level exam, they may apply for an Operator in Training exam. The requirements and substitutions for each OIT level are listed in a different section in the rule (WAC 173-230-260). We do not require an operator to earn an OIT certification to advance to the next full certification level.

See our FAQ below for more information.

Frequently Asked Questions


Exam Information

Operating Experience

Maintaining Certification