Median Pay by Area
- Louisville/Jefferson County
- $52,230 a year
- Lexington-Fayette
- $49,280 a year
- Bowling Green
- $45,650 a year
- Owensboro
- $57,810 a year
- Paducah
- $52,160 a year
Kentucky wastewater operators
The steps from no license to a Kentucky wastewater treatment or collection operator license, how to apply for and pass the exam, how to keep your license active and what operators earn. Every requirement links to the Kentucky Energy and Environment Cabinet's Operator Certification Program, KRS 224.73-110 or the program's regulations in 401 KAR Chapter 11.
Kentucky's Operator Certification Program makes the final eligibility determination. Check with Kentucky's Operator Certification Program before you apply.
Why it matters
Kentucky law says no one may have primary responsibility for operating a sewage system, or any part of one, whether it is publicly or privately owned, unless they have passed an exam and been issued a certificate by the Energy and Environment Cabinet. No one may let an uncertified person have that responsibility.
Primary responsibility means personally running, or actively overseeing and directing, the work that keeps a wastewater treatment plant or collection system operating properly and within the law.
The one exception is a person running the sewage system at the home where they live, when that system serves only that one home.
Licenses are issued through the cabinet's Certification and Licensing Branch, which runs the Operator Certification Program. The program calls the credential a license; the regulations call it a certificate.
Wastewater treatment licenses come in Class I to Class IV, based on the plant's design capacity. Class I covers plants up to 50,000 gallons per day, Class II up to 2 million gallons per day (MGD), Class III up to 7.5 MGD, and Class IV covers plants of any size.
Wastewater collection licenses also come in Class I to Class IV. They follow the design capacity of the treatment plant the collection system sends wastewater to, using the same limits, and a Class IV Collection operator may run any collection system.
A Limited license is only for operators of a school wastewater treatment plant and collection system. It covers only that system and cannot be transferred, and time worked under it does not count toward the experience for a regular license.
An Operator in Training (OIT) designation lets you pass the exam before you have all the experience. You work under the direct supervision of a certified operator at the same facility whose license is at or above the level the facility needs. A Class I OIT may not have primary responsibility for a plant or system.
Step 1
You get a license by meeting the minimum education and experience for the class you want, sending in the forms and fee, and passing the exam.
You must meet the education and experience requirements before you apply. The program asks you not to apply for an exam until you meet them on the day you apply.
New to the field? Anyone with a high school diploma or equivalent can apply for the entry-level Class I OIT exam in treatment or collection, with no experience needed. You also need a certified operator at the facility where you will work to agree to mentor you.
If you already hold an active license, you can apply for an OIT license one level higher, of the same type.
Step 2
Send in two forms: the Registration Form for Exams and Training and the Education and Experience Documentation Form. To apply online, set up an EEC eForms account on the Kentucky Online Gateway, open the Registration Form for Exams and Training and pay at the end.
The certification application fee set by 401 KAR 11:060 is $250 and is not refunded. Paper applications cost $50 more; mail them with a check or money order made payable to the Kentucky State Treasurer to the Operator Certification Program, 300 Sower Blvd., Frankfort, KY 40601.
Describe your job in detail. List all of your operating duties and the share of your time you spend on each, and give daytime contact information. Program staff use this to check your experience against the regulations.
For an OIT exam, also send a signed letter from your mentor. It must commit to overseeing and mentoring you, confirm they are not mentoring any other OIT, and confirm their license is at or above the level needed to run the facility.
Step 3
Exams are given at scheduled events across Kentucky. Most follow a certification class run by a training provider, and there are also exam-only days at 300 Sower Blvd. in Frankfort that are open to all test levels. Seats are limited and first come, first served, and each date has its own application deadline on the Training and Exam Schedule.
You register for the exam with the Operator Certification Program through EEC eForms. If you also want the certification class, sign up for it directly with the training provider listed on the schedule.
Do not go to a class or exam without your approval letter. If your application has not been approved, you will not be let in, so contact the program if your letter has not arrived.
Once you are approved, the program mails you a study manual, and approved testers get online training course material at no extra charge.
Step 4
After you pass, the cabinet issues a certificate and a wallet card showing your class.
Class IV applications are also reviewed by the Kentucky Board of Certification of Water and Wastewater System Operators, which recommends qualified applicants to the cabinet.
If your job or mailing address changes, tell the program in writing within 30 days. The program asks operators and facilities to report job changes with Facility Update eForm 136.
Step 5
Once you have the experience required for your class, you can have the OIT designation removed without another exam. You also need to have met the renewal training requirements and send a letter from your mentor recommending the change.
If you cannot meet those requirements, you must apply for and retake the certification exam to upgrade.
Step 6
Wastewater licenses expire on June 30 of every odd-numbered year. Renewals received after June 30 pay a late fee, and a license not renewed by December 31 of the year it expired ends. You would then need to reapply and pass the exam again.
Before you renew, complete cabinet-approved continuing education hours in the two years before your license expires: 12 hours for Limited, Class I and Class II (including Class I and II OIT), and 24 hours for Class III and Class IV (including Class III and IV OIT). With several wastewater licenses, you complete the hours for the highest one.
Hours earned before you were first licensed do not count. Find approved courses on the program's Training Provider Information page, and check your hours and renew online through eSearch.
OIT licenses are renewed by mail with the renewal form, the Education and Experience Documentation Form and a mentor letter. Retired operators can renew as inactive without continuing education, but must earn the hours before using the license again.
The program's renewal page lists the current renewal, late and inactive fees. Paper renewals cost $50 more.
Exam day
Exams are given by the Energy and Environment Cabinet. The Kentucky Board of Certification of Water and Wastewater System Operators helps the cabinet draft them and recommends what they cover.
You pass with a score of at least 70 percent.
The program publishes a wastewater treatment manual, a collection manual, math study guides and formula sheets, plus free recorded webinars. It says people who study these materials and attend the certification class pass at a higher rate.
Results are posted as pass lists on the program's Exam Results page by your agency interest number. Scores are not given out over the phone.
If you do not pass, send a new registration form and application fee through EEC eForms to retake the exam. Your exam is not returned, but you can ask in writing to review your results with the cabinet.
Exam fees are not refunded and cannot be moved to another operator. To reschedule, contact the Operator Certification Program.
Kentucky's certification exams are given by the Energy and Environment Cabinet, and its certification board helps draft them. The program publishes its own study manuals, math study guides and formula sheets for wastewater treatment and collection. Operator Master's free practice questions, timed practice exam and math help are built on the WPI exam format and the WPI formula table, so they cover general wastewater knowledge and math, not Kentucky's exam questions, format or formula sheets. Use the program's study materials as your main guide. Operator Master is an independent study tool, not the official exam.
Pay
The median pay for water and wastewater treatment plant and system operators in Kentucky was $45,430 a year ($21.84 an hour) in 2025, compared with $60,020 nationally. One in ten earned $33,210 or less, and one in ten earned $63,740 or more.
These federal figures cover drinking water and wastewater operators together, at every class. Pay for a new operator is usually nearer the low end.
Moving up
Classes I to III also need a high school diploma or GED; Class IV needs a bachelor's degree in engineering or a biological, environmental, physical or chemical science, or equivalent. College education in those fields can replace up to half of the experience (an associate degree counts for 2 years, a bachelor's for 4), and other degrees up to a quarter. The program's Wastewater fact sheet lists 5 years for Class IV, but the regulation as amended in 2019 lists at least 3, so confirm Class IV with the program. Every class needs a passing exam score of 70 percent.
From another state
If you are licensed in another state, Kentucky looks at your experience together with that state's certification requirements. You cannot get a Kentucky license higher than the level you tested for, but your exam and years of experience may meet the requirements for the same level in Kentucky.
Kentucky offers reciprocity and equivalency with all states, decided case by case. Apply with the Application for Reciprocity and Equivalency in EEC eForms. The fee is $500 per license, plus $50 for a paper application.
Staff ask your certifying state for your license information and rules, then review your application. If they recommend approval, the certification board gives it a final review at its monthly meeting.