1.2 Wastewater Operator Certification: Classes 1-4, K, R & Collection System

1.2 Wastewater Operator Certification: Classes 1-4, K, R & Collection System

Wastewater operator licensing in Illinois is codified in 35 Ill. Adm. Code Part 380, Procedure for the Certification of Operators of Wastewater Treatment Works. Part 380 is organized into ten subparts, and knowing where a rule lives is itself exam material:

The Properly Certified Operator

Illinois wastewater rules do not use the drinking water phrase "Responsible Operator in Charge." Subpart B requires each facility to have a Chief Wastewater Operator — the properly certified operator — under the Chief Wastewater Operator Requirement at 35 Ill. Adm. Code 380.205, with required supervision at 380.200, exceptions at 380.210 and Agency notification at 380.215. The requirement is enforced at the facility level:

• The properly certified operator must hold a certificate at or above the certification level required for that facility group. An Operator-In-Training does not satisfy this requirement.
• The properly certified operator must exercise direct and active field supervision of the treatment works. Whether physical presence is required depends on the situation, but the operator must know the plant well enough to handle any situation expeditiously and correctly.
• Under Subpart J, an owner may instead contract for a certified operator. The signed contract must reach the Agency within seven days of its effective date, and the Agency must be notified in writing within seven days if the contract terminates early (35 Ill. Adm. Code 380.1000).

A wastewater operator is defined as a person who regularly makes recommendations or is responsible for process control decisions at a treatment facility. The term does not cover people whose duties are limited to laboratory testing or maintenance, or who exercise only general or indirect supervision.

Facility Groups & Operator Classes (35 Ill. Adm. Code 380.115)

Illinois classifies the facility into a Group, then requires an operator certified at that class or higher. Class 1 is the highest competency level; Class 4 is the entry level.

Exam trap. Collection systems are not Group 4. Lagoons alone define Group 4. Sewer operation and maintenance is covered by a separate, voluntary Collection System Operator certificate issued under 380.535. Another trap: primary treatment systems of any size fall in Group 3, not Group 1, even above 1.0 MGD.

Experience, Education & Substitution Credit

Every applicant must be able to read and write in English, and every class except Class 4 requires high school completion or a GED as a stated minimum eligibility item (Class 4 also lists high school education or equivalent in the Agency's published eligibility summary).

Wastewater operating experience means hands-on physical operation of treatment equipment or processes, direct active field supervision of them, or direct and active involvement in process control decisions — and it may be acquired only at municipal/domestic wastewater treatment facilities. Work that does not count as hands-on operating experience includes public works and street maintenance, meter reading, operating a Vactor truck, sludge hauling or land application, janitorial and grounds keeping, collection system work, drinking water operations, laboratory testing, and electrical or maintenance mechanic work.

Related experience (collection systems, drinking water supplies, or laboratory/maintenance work at a wastewater plant) earns only partial credit, and only once the minimum hands-on requirement has been met.

Substitution is capped by class. These are the Agency's published maxima, and they do not follow a simple degree-for-years formula:

Two working-time conventions matter on the application: 30 hours or more per week counts as full-time, and when experience is reported in hours, 400 work hours = 3 months. Where a job mixes operating and related duties, credit is prorated by the percentage of time spent on each.

Industrial Certificates: Class K vs Class R (380.525, 380.530)

Holding a municipal Class 1 certificate does not authorize operation of an industrial facility; municipal and industrial works have different operating requirements, so a facility-specific Class K is still required.

Class K and Class R candidates should be able to speak to their own plant: flow schematics, the purpose and theory of operation of each treatment unit, removal efficiencies per unit, measures used to prevent and correct process upsets, solids handling and sludge disposal methods, sources and characteristics of raw and treated waste, effluent monitoring requirements, laboratory techniques and result interpretation, safety considerations, applicable rules, recordkeeping, and discharge limits and permit conditions.

Collection System Operator Certificate (380.535)

This certificate is voluntary — but an NPDES permit may require one. There is a single level. Eligibility is 1 year of collection system operating experience (minimum 6 months hands-on, with up to 6 months substituted from wastewater courses or lab, O&M, or public water supply experience), high school education or equivalent, and the ability to read and write English. The exam has 100 questions drawn from Chemical Addition, Collection Systems, Flow Measurement, General Information, Maintenance, Management, Mathematics, Motors, Preliminary Treatment, Pumps and Pumping, Recordkeeping, Rules and Regulations, and Safety. The certificate has no expiration and no CEU requirement.

Examination Logistics & Operator-In-Training Status

• Fees: there are no fees associated with Illinois wastewater operator certification at present. (Drinking water certification does charge fees — see Section 1.3.)
• Exam request: submit an Exam Request form at least 30 days before the desired exam date. Expect a Letter of Admission with a schedule in roughly 4 weeks, then call or email the testing site to reserve a seat. You may not simply show up.
• Testing sites: the 2026 schedule uses the Des Plaines and Rockford regional offices, Illinois EPA headquarters in Springfield, the Marion regional office, and the Environmental Resources Training Center (ERTC) at SIU Edwardsville. Special exams are sometimes offered at conferences.
• Exam format (Classes 1-4 and Collection System): 100 multiple-choice questions, four answer choices each, maximum 3 hours (9:00 a.m. to 12:00 p.m.). You receive scratch paper, pencils, an answer sheet, and a booklet containing questions, formulas and conversion factors. You may bring only your Letter of Admission, a photo ID, and a non-programmable calculator incapable of storing alphanumeric data. Cell phones and smart watches are barred from the room entirely.
• Passing score: 70. Results are mailed to the examinee's home address, typically within 30 days (about 8 weeks for Class K), with a per-subject performance breakdown.
• Level order: you may take any level of exam without passing the lower ones first, and you may test before meeting the experience requirements.
• Retakes: there is no waiting period, but you must have your results and a valid, unused Letter of Admission. You may schedule only one exam date and location at a time.
• Operator-In-Training: a score of 70 or higher makes you an Operator-In-Training at that level. The score and OIT status remain effective for 5 years from the date of examination. Choosing a different certification level means taking that level's exam.
• Full certification: once the minimum experience is obtained, submit the application to the Operator Certification Unit. Review takes up to 90 days, after which the applicant receives a certificate or a denial letter.

Renewal, Restoration & Continuing Education (Subpart G)

Class 1-4 certificates are valid for 3 years from July 1 of the year of issuance. Before July 1 of the expiration year, the operator submits the Agency-issued Renewal Form.

• Classes 1 and 2: 30 hours of approved continuing education every 3 years, minimum 20 technical hours.
• Classes 3 and 4: 15 hours every 3 years, minimum 10 technical hours.
• Collection System, Class K and Class R: no CEU requirement.

Technical topics include activated sludge, aeration, backwash filters, chemical addition, chlorinators, clarifiers, collection systems, digesters, DMRs, disinfection, electrical maintenance, fixed film, Imhoff tanks, instrumentation, intermittent sand filters, lab procedures, lagoons, math, maintenance, operations, oxidation ditches, package aeration, preliminary and primary treatment, reports and records, SCADA, screening, sedimentation, sludge drying beds, sludge handling, land application, sludge presses, and tertiary treatment. Non-technical training includes administration, computers, emergency planning, management, first aid, safety, confined spaces, and wastewater-related weather training.

Two documentation rules are frequently tested. All training must be approved by the Agency — providers or operators may request approval. And operators must keep proof-of-training records for 6 years from the training date, including course name, training provider, instructor or speaker, location, dates, total hours completed, and attendance verification records. The Agency may audit by random selection.

If an operator fails to renew, restoration is available with proof of training within 2 years of the expiration date. Past that, the operator must retake the certification examination and reapply.

Reciprocity (Subpart H)

Illinois grants reciprocity with some other states, depending on the reciprocal state's rules and the applicant's education and employment qualifications. Class R, Class K, Operator-In-Training and Collection System certifications are not eligible for reciprocity from another state.

Sanctions (Subpart F)

Under 35 Ill. Adm. Code 380.600, causes for sanctions include:

1. Obtaining or attempting to obtain certification by fraud or deceit.
2. Gross negligence or gross misconduct in operating a treatment or pretreatment facility.
3. Falsification of records and reports required by the Environmental Protection Act or its rules.
4. Willful failure to maintain or willful non-submission of required records and reports.
5. Willful violation of the Act or any rule promulgated under it.
6. A final civil judgment or criminal conviction for any of the acts above.

Sanctions under 380.615 include prohibiting application for certification, probation, suspension and revocation. A suspended certificate is invalid for up to 18 months, and experience gained during suspension earns no credit toward eligibility. A revoked certificate is invalid, and the operator may not reapply for not less than 18 months and not more than 4 years; at the end of the revocation period the operator must pass the certification examination again.