Welcome to the Waterworks Operator Certification Program
What Do You Want to Do?
- Apply for Waterworks Operator Certification
- Waterworks Operator Certification--Reciprocity FAQ 331-694 (PDF)
- Update your contact information
- Renew an existing Waterworks Operator Certification
- Download your Validation Card
- Check your Professional Growth Report
- Find a training opportunity
- Find a Certified Operator
- Request Evaluation of Training for Continuing Education Units
- Find information on Workforce Development
- Search Publications and Resources
- Contact Operator Certification or Washington Certification Services
Exam Resources
New 2025 Waterworks Exams—Starting June 16, 2025
It is that time again. Every five years or so, the Association of Boards of Certification (ABC), now known as Water Professionals International (WPI), goes through a rigorous process to bring the standardized certification exams up to date with any improvements or technology changes in the water industry.
The exam content outlines, called the “Need-to-Know” criteria, have also been updated to reflect the changes in the 2025 standardized certification exams.
The Waterworks certification exams to be updated are:
- Water Distribution Manager (WDM) 1-4.
- Water Treatment Plant Operator (WTPO) 1-4.
The Water Distribution Specialist (WDS), Cross-connection Control Specialist (CCS), and Backflow Assembly Tester (BAT) exams have not been updated at this time.
Test takers that scheduled Waterworks exams prior to June 16, 2025, should use the existing Need-to-Know Criteria on WPI’s website.
Exams scheduled on or after June 16, 2025, will be the updated 2025 exams and test takers will need to access the 2025 Need-to-Know Criteria and formula conversion table through our Exam Resources page.
Find a Certified Operator
Contract Operators
Contract operators are certified operators in responsible charge of three or more public water systems (WAC 246-292-055). We maintain a Contract Operator Public List (PDF) alphabetized by county.
If you are an active Contract Operator in good standing and want your name on the Contract Operator Public List, please fill out and return the Contract Operator Public List Form 331-439 (Word).
Cross-Connection Control Specialists
A Cross-Connection Control Specialist is an individual certified in Washington State to develop, implement, and maintain a cross-connection control program. (WAC 246-292-033). We maintain a list of Contract Cross-Connection Control Specialists.
If you are an active CCS in good standing and want your name on the CCS Public List, please fill out and return the Cross-Connection Control Specialist Public List Application Form 331-476 (Word).
U.S. Veterans
Veterans are an excellent option for your workforce needs. We work with veterans to help translate their military water system skills into experience for Waterworks operator certification exams. Career Opportunities for Veterans in the Water Sector 331-471 (PDF).
Temporary Certification
A “temporary certification” helps water systems remain in compliance with certified operator requirements while the candidate is gaining the experience necessary to take a certification exam. Temporary certifications are limited in duration and only used when a water system's required certified operator position is vacant.
Publications and Resources
- Water Operator Hiring and Contracting Guide 331-655 (Word)
- Applying and Testing for Waterworks Operator Certification 331-424 (PDF)
- Protecting Public Health: Requirements for Waterworks Operators 331-466 (PDF)
- Chapter 246-292 Washington Administrative Code (WAC) The Waterworks Operator Certification Rule
- Relevancy of Training for Certified Waterworks Operators Fact Sheet 331-186 (PDF)
- ABC Formula/Conversion Table (PDF)
- Who is Your Cross-Connection Control Specialist? 331-594 (PDF)
- Purification Plant Criteria Worksheet 331-749 (Word)
- ODW Authority Over Operators and Water Systems 331-449 (PDF)
- Have You Considered a Career in the Water Industry? 331-603 (PDF)
- Publications Data Base