Median Pay by Area
- Bridgeport-Stamford-Danbury
- $81,810 a year
- Hartford-West Hartford-East Hartford
- $81,100 a year
- New Haven
- $80,130 a year
- Norwich-New London-Willimantic
- $78,610 a year
- Waterbury-Shelton
- $75,400 a year
Connecticut wastewater operators
The steps from no certificate to a Connecticut Class I wastewater treatment facility operator certificate, how to apply to DEEP and take the computer-based exam, how your certificate stays active and what operators earn. Every requirement links to the Connecticut Department of Energy and Environmental Protection (DEEP) Operator Certification Program or its rules, RCSA 22a-416-1 to 22a-416-10.
DEEP makes the final eligibility determination. Check with DEEP before you apply.
Why it matters
Connecticut's rules define an operator as anyone who operates equipment at a wastewater treatment facility in a way that affects treatment. A wastewater treatment facility here means one that treats wastewater with a biological treatment process.
If you are hired as an operator, you must earn at least a Class I certificate within 24 months of starting work. If you do not, you cannot keep working as an operator after that time.
Every facility must have a chief operator certified at the facility's class or higher. Shift operators must be certified no lower than one class below the facility's class.
DEEP's Municipal Wastewater section certifies wastewater treatment operators and classifies the facilities. You must be able to speak, read and write English well enough to do the job.
There are four classes of operator certificate: Class I (lowest) through Class IV (highest). Facilities are also Class I to IV, based on a points system for their equipment and processes.
A certificate in a class makes you legally qualified to be the superintendent of any plant of that class or lower.
DEEP's guidelines say wastewater operator certification is the only type required by regulation in Connecticut. Collection system and laboratory analyst certification are recommended but not required.
Step 1
Class I needs a high school diploma or GED and a DEEP-approved basic wastewater treatment facility operation course worth at least 9 CEUs. No substitutions are allowed for Class I.
One CEU equals 10 contact hours, and one college credit hour equals 1.6 CEUs.
You cannot apply until you have finished the courses you need and have proof you passed them. Keep your own certificates and transcripts; DEEP's guidelines say DEEP does not keep training records.
Step 2
Class I needs at least one year of experience operating a Class I or higher wastewater treatment facility.
Operator-in-training: for Class I, II or III, if you meet the education requirement but not the experience, you can still take the exam. DEEP issues your certificate once your facility's owner confirms you have the experience, which must happen within five years of passing.
Operator-in-training status does not qualify you as a certified operator in that class.
Step 3
DEEP takes exam applications only during set periods. For the 2027 exams, it accepts applications from October 1, 2026, through September 30, 2027. Applications outside the period are not accepted.
Fill out all five pages of the Application for Examination or Reciprocity, attach transcripts and course certificates for every course you claim, and mail it with a check for the application fee to DEEP's Central Permit Processing Unit, 79 Elm Street, Hartford, CT 06106-5127.
The application fee is listed in DEEP's current exam notice. It is not refundable, even if you are found ineligible.
To take an exam, you must be employed as an operator at a Connecticut wastewater treatment facility or qualify as an operator-in-training. DEEP may also let you test if a Connecticut facility owner tells DEEP in writing that they intend to hire you once you are certified.
Step 4
DEEP's exam notice lists these study references: Sacramento State's (CSUS Office of Water Programs) Operation of Wastewater Treatment Plants Volumes I and II, Advanced Waste Treatment and Manage for Success; NETCSC's Protecting Your Community's Assets: A Guide for Small Wastewater Systems; and WEF's Manual of Practice No. 11 (Operation of Municipal Wastewater Treatment Plants) and OM-9 (Activated Sludge).
DEEP also suggests touring different kinds of treatment plants and reviewing your plant's laboratory tests.
Step 5
DEEP emails you whether your application is accepted. If it is, the testing agency contacts you to schedule, and you take the exam on your own schedule at the computer testing center.
You pay a separate $114 exam fee to the testing agency, not to DEEP. DEEP says the fee is shared between the testing agency and WPI.
If you pass, DEEP issues a certificate of your class once you meet all the requirements. Operators-in-training get theirs when their experience is complete.
Step 6
Connecticut's rules do not set an expiration date, renewal fee or continuing education hours for a certificate. A certificate stays active until it is revoked, replaced by a higher class, or made inactive.
Your certificate becomes inactive two years after you stop working in the wastewater treatment field. To have it reissued, you must meet the current requirements again; DEEP's guidelines say this includes passing the exam for that class.
To move up a class, you must pass that class's exam in Connecticut.
DEEP can revoke a certificate for fraud, falsified reports, or failing to perform an operator's duties with reasonable care.
Exam day
DEEP gives Class I, II, III and IV exams. All questions are multiple choice, and the exams are taken on computer at a testing center.
You may not have a programmable calculator or any written papers during the exam. Misconduct, such as cheating, voids your result and bars you from testing for one year.
If you do not pass, you can retake the same class after a 90-day wait without reapplying. You can book the retake during the wait. If you have not passed by the testing center's last operating day of 2027, you must reapply to DEEP for 2028.
DEEP tells you your results but does not return exam questions or answer sheets, and you cannot review the questions before or after the exam.
DEEP's exams are multiple choice and taken on computer, and DEEP's notice says the exam fee is shared between the testing agency and Water Professionals International (WPI). The DEEP pages we could read do not say how many questions there are, the passing score or which formula sheet, if any, you get. 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 use them for general wastewater knowledge and math, and use the reference books in DEEP's exam notice 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 Connecticut was $78,820 a year ($37.90 an hour) in 2025, compared with $60,020 nationally. One in ten earned $60,900 or less, and one in ten earned $98,850 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
Every class also needs a high school diploma or GED and a passing exam. For Classes II to IV, related higher education can replace up to half of the experience (45 CEUs count as one year), but never the Class IV direct responsible charge time, and the same CEUs cannot count twice. DEEP's fact sheet and application add that at least 27 of the CEUs for Class III and IV must be directly related to operating a wastewater treatment facility.
From another state
If you hold a current certificate from another state and are not yet working as an operator in Connecticut, you can apply for a reciprocal certificate without an exam. You must have passed a written exam proctored by that state, hold a class DEEP deems equivalent, and meet Connecticut's education and experience requirements for the class.
You can apply at any time with the same application form and fee. DEEP issues the certificate only after a Connecticut facility has offered you a job and a copy of the offer is on file. Reciprocity is not available once you have started working at a Connecticut facility.
If you take a reciprocal certificate to work as a chief, shift or process control operator, you must stay in that position for at least one year, or the certificate becomes void.