Requirements by state

Ohio water operator certification

Reviewed 2026-07-29

Quick answer

How do I get certified as a water operator in Ohio?

Ohio certifies all four operator disciplines, water supply, water distribution, water reclamation (wastewater treatment), and wastewater collection, through one office on one shared Class A, I, II, III, IV scale. Exams run through third-party provider Water Professionals International (WPI, formerly ABC), the application fee is a flat $45, and reciprocity is reviewed case by case against a published state-by-state comparison chart.

Last reviewed 2026-07-29

See how Ohio compares to every other jurisdiction in the national comparison matrix, or check reciprocity between states if you are moving.

Certifying agency: Ohio EPA, Division of Drinking and Ground Waters, Operator Certification Program

Hold a high school diploma or GED at every class, and document the operating experience or post-high-school education substitute for the class you are applying for.
Register and pass the third-party WPI/ABC exam for the discipline and class you want, delivered through the PSI testing network.
Apply for certification through the Ohio EPA eBusiness Center once you score 70 or above and can document the required experience, paying the flat $45 non-refundable application fee.
Operators who pass the exam without the full experience requirement become an Operator in Training (OIT) with up to 60 months to document it; OIT status is not available for Class IV.

Water treatment

A: Class A , Smallest systems. 1,040 hours of operating experience with a HS diploma/GED, reduced to 780 hours with an associate degree or 520 hours with a bachelor's degree.
I: Class I , 12 months of operating experience regardless of education level.
II: Class II , 36 months with a HS diploma/GED only, reduced to 24 months with 1 year of college and 12 months with an associate degree or higher.
III: Class III , 60 months with a HS diploma/GED only, reduced to 48, 36, or 24 months as post-high-school education increases, plus 12 months held at Class II.
IV: Class IV , 24 months holding a valid Class III certificate while obtaining management experience at a Class III or IV facility. No OIT pathway.

Exam: Third-party standardized exam through Water Professionals International (WPI, formerly ABC), scheduled online at test-takers.psiexams.com/abc-oh and delivered via the PSI testing network. A score of 70 or above passes.
Education minimum: High school diploma or GED required at every class. Post-high-school education (an associate or bachelor's degree, or 45 quarter/30 semester hours of approved coursework) substitutes for part of the operating-experience requirement at Class A, II, and III.
Experience minimum: Class A: 1,040 hours (HS/GED), 780 hours (associate degree), or 520 hours (bachelor's degree). Class I: 12 months at any education level. Class II: 36 months (HS/GED) down to 12 months (associate degree or higher). Class III: 60 months (HS/GED) down to 24 months (bachelor's degree), plus 12 months held at Class II. Class IV: 24 months holding a valid Class III certificate with management experience.
Application / certification fee: $45 non-refundable application fee for any third-party certification application, any class. Does not include the separate exam fee paid to WPI/PSI.
Continuing education: Contact-hour requirements scale with class per renewal cycle: 8 hours for Class A, 12 hours for Class I, and 24 hours for Classes II, III, and IV. At least half of an operator's hours must be operations-and-maintenance courses, and hour requirements drop 25 percent per additional certificate held.
Renewal cycle: 2 years
Reciprocity: No automatic reciprocity. Ohio EPA's Operator Certification Advisory Council reviews each out-of-state application case by case against a published state-by-state equivalency chart and sends its recommendation to the Ohio EPA Director. The chart lists a comparable Ohio class (or none) for every state and Canadian province with a certification program.

Ohio calls this discipline Water Supply. It shares one office, one class scale, and one $45 application fee with water distribution, water reclamation, and wastewater collection below, an unusual four-discipline unification most states split across two or more offices.

Water distribution

A: Class A
I: Class I
II: Class II
III: Class III
IV: Class IV

Exam: Same third-party WPI/ABC exam process as water supply, a separate exam application for the distribution discipline, delivered via PSI.
Experience minimum: Identical experience and education table to water supply above: Class A runs 1,040 to 520 hours by education level, Class I is a flat 12 months, and Class II through IV scale down as post-high-school education increases.
Application / certification fee: $45 non-refundable application fee, same flat rate as every other Ohio discipline.
Renewal cycle: 2 years
Reciprocity: Reviewed case by case by the Operator Certification Advisory Council against a published Water Supply and Distribution reciprocity comparison chart, separate from the wastewater chart.

Distribution-only experience does not count toward a water supply (treatment) license and vice versa, per Ohio EPA's own operating-experience criteria.

Wastewater treatment

A: Class A
I: Class I
II: Class II
III: Class III
IV: Class IV

Exam: Ohio calls this discipline Water Reclamation. Same WPI/ABC third-party exam system as the drinking-water disciplines, administered by the same Division of Drinking and Ground Waters office, not a separate wastewater agency.
Experience minimum: Same class-by-class experience and education table as water supply and water distribution above.
Application / certification fee: $45 non-refundable application fee, the same flat rate across all four Ohio disciplines.
Renewal cycle: 2 years
Reciprocity: Reviewed case by case against a separate Wastewater Treatment and Collection reciprocity comparison chart, by the same Operator Certification Advisory Council process as the drinking-water disciplines.

Industrial wastewater treatment experience counts toward this discipline's experience requirement, unlike the drinking-water disciplines, which require the experience to come from a public water system.

Wastewater collection

A: Class A
I: Class I
II: Class II
III: Class III
IV: Class IV

Exam: Same WPI/ABC third-party exam system, a distinct collection-specific exam within the same Class A, I, II, III, IV scale.
Application / certification fee: $45 non-refundable application fee, the same flat rate as the other three disciplines.
Renewal cycle: 2 years
Reciprocity: Reviewed case by case against the same Wastewater Treatment and Collection reciprocity comparison chart as wastewater treatment.

Ohio treats collection as a state-licensed discipline on equal footing with treatment, unlike states such as California where collection is a voluntary industry credential.

Ohio does something most states do not: it runs all four operator disciplines, water supply, water distribution, water reclamation (its term for wastewater treatment), and wastewater collection, out of one office on one shared Class A, I, II, III, IV scale. Instead of four separate application processes and fee schedules, the requirements differ mainly by how much operating experience each class needs, not by which office you deal with.

One office, one scale, four disciplines

The Ohio EPA Division of Drinking and Ground Waters runs the entire Operator Certification Program. Whether you are certifying as a water supply operator, a water distribution operator, a water reclamation (wastewater treatment) operator, or a wastewater collection operator, you apply through the same eBusiness Center, pay the same flat $45 non-refundable application fee, and test through the same third-party provider, Water Professionals International (WPI, formerly ABC), delivered via the PSI testing network. What changes by discipline is which exam you sit and which job counts as qualifying experience.

Classes A through IV, and how education buys down experience

Every class requires a high school diploma or GED at minimum, and post-high-school education reduces the operating-experience hours or months required:

Class	HS/GED only	Associate degree	Bachelor’s degree
A	1,040 hours	780 hours	520 hours
I	12 months	12 months	12 months
II	36 months	12 months	12 months
III	60 months	36 months	24 months
IV	24 months holding a valid Class III, plus management experience at a Class III or IV facility

Applicants who pass the exam without the full experience on hand become an Operator in Training (OIT) and get up to 60 months to document it, except at Class IV, where OIT status does not apply. Experience for the drinking-water disciplines must come from a public water system; industrial wastewater treatment experience, unusually, does count toward the wastewater treatment discipline.

Renewal and continuing education

Certificates run on a two-year renewal cycle. Continuing-education hours scale by class: 8 hours for Class A, 12 hours for Class I, and 24 hours for Classes II through IV per cycle, with at least half of those hours required to be operations-and-maintenance courses. Holding more than one certificate reduces the hour requirement for each additional class by 25 percent.

Moving to Ohio from another state

Ohio does not have an automatic reciprocity agreement with any other state. Instead, the Operator Certification Advisory Council reviews each application case by case and sends a recommendation to the Ohio EPA Director, guided by two published comparison charts, one for water supply and distribution, one for wastewater treatment and collection, that list Ohio’s equivalent class for every state and Canadian province with its own certification program. See reciprocity between states for how this process generally works.

Where to go from here

Practice the pounds formula, CT disinfection, and flow-conversion math the Class II and III exams lean on with the operator-math trainer, and use the process calculator for the same formulas on the job. Not sure which discipline fits your background? Water treatment vs wastewater operator walks through the day-to-day difference. See your state’s page once more states are verified for the other side of a move.

Sources: Ohio EPA Division of Drinking and Ground Waters, "How to Become a Certified Water or Water Reclamation Operator" fact sheet (June 2025) and "Operator Certification Education and Experience Requirements for Class A, I, II, and III Personnel" (October 2021), epa.ohio.gov; Ohio EPA Water Supply and Distribution Reciprocity Comparison Chart and Wastewater Treatment and Collection Reciprocity Comparison Chart (revised 6/28/2024); renewal and continuing-education cycle cross-referenced against AYPO Technologies' Ohio water operator certification renewal guide (retrieved 2026-07-29), consistent with Ohio Administrative Code Chapter 3745-7. Authored by the Water Cert Prep editorial team. Not legal advice. Reviewed 2026-07-29.