Median Pay by Area
- Urban Honolulu
- $67,840 a year
- Hawaii / Kauai (non-metro)
- $65,550 a year
- Kahului-Wailuku
- $60,910 a year
Hawaii wastewater operators
The steps from no certificate to a Hawaii Grade 1 wastewater treatment plant operator certificate, how to apply for and pass the exam, how to keep your certificate active and what operators earn. Every requirement links to the Board of Certification of Operating Personnel in Wastewater Treatment Plants, part of the Hawaii Department of Health Wastewater Branch, or its rule, Hawaii Administrative Rules Title 11, Chapter 61.
Hawaii's Board makes the final eligibility determination. Check with Hawaii's Board before you apply.
Why it matters
Every classified wastewater treatment plant in Hawaii, publicly or privately owned, must always be under the direct responsible charge of an operator certified at a grade that matches the plant's class. A wastewater reclamation plant counts as a wastewater treatment plant.
Direct responsible charge means active, on-site charge of a plant, a segment of a plant or an operating shift. Operators in direct responsible charge must post their certificate on the wall or another conspicuous place at the plant.
The plant owner must tell the Board in writing within 30 days when a facility starts operating, is majorly modified or changes its certified operator in direct responsible charge. The Board page links a DRC Notification Form for this.
Individual wastewater systems such as cesspools, septic tanks and household aerobic units are exempt from classification.
Hawaii certifies wastewater treatment plant operators in Grades 1 to 4. The Board rates each plant as Class I to IV using a points table for size, discharge, raw waste, treatment processes, solids handling, disinfection and lab work: 30 points or less is Class I, 31 to 55 Class II, 56 to 75 Class III and 76 or more Class IV.
Chapter 11-61 and the Board pages read cover wastewater treatment plant operators; they list no separate collection system certificate. Sewer maintenance crew and pumping station work does not count as operator experience for the exam.
Step 1
You need a high school diploma or equivalent for every grade. A GED counts, or six educational points for each year of school you did not finish through grade 12.
Grade 1 needs one year of operating experience: actual time working at a wastewater treatment plant doing operator duties. One year means at least 1,632 hours over no less than 12 months, and you can count no more than one year in any 12 months in a row.
Experience as a plant worker, sewer maintenance crewmember, chemist, lab technician, plant engineer or pumping station operator does not count as operator experience for the exam.
If you are not certified yet, the Board may issue a temporary certificate while you gain experience under the direction of a certified operator. Your plant owner and the directing operator each sign a statement, you must be able to qualify for the exam before it expires, and it lasts no more than 24 months.
Step 2
The Board links a Reference Material for ABC Wastewater Treatment Examinations list. It points to Sacramento State's Operation of Wastewater Treatment Plants, Volumes I and II, Advanced Waste Treatment and Utility Management, and to Water Environment Federation manuals, for each exam topic.
Grades 2 to 4 also need educational points, which the Board page calls CEUs. For example, Sacramento State's Operation of Wastewater Treatment Plants, Volume I earns 6 CEUs, and approved short courses earn one point per eight hours, up to three points per course.
The Board page links the Statewide Wastewater Operator Training Center's courses and schedules for all islands, the list of courses granted CEU credits and approved online courses.
Step 3
Use Form 1 for a grade you have not taken or qualified for before, and Form 2 to retake an exam. On the form you choose the grade, the February paper exam, the August paper exam or a computer-based test, and a testing island: Oahu, Big Island, Maui or Kauai.
Send the original signed form (no faxes or photocopies) with your employer's or DRC's signed verification of your hours, a copy of your high school diploma or GED, college transcripts and training certificates. Mail or drop it off at the Wastewater Branch in Pearl City by the deadline in the Board's exam notice.
Include a $25 non-refundable processing fee for each exam, by check or money order payable to the State of Hawaii; cash is not accepted. The Board tells you in writing within 60 days whether you qualify.
If you qualify for a paper exam, you then pay a $50 exam fee for each exam, which includes the certificate. Missing the fee deadline disqualifies you. A computer-based test costs $100 for each exam and is not paid to the Board.
Step 4
You need at least 70% to pass. The Board notifies every candidate in writing within 30 days after it reviews the results, and issues a certificate and an identification card when you pass.
If you do not pass, you may take the exam again at a later sitting by sending a new application and fee (Form 2).
Step 5
A new certificate expires on October 15 of the year after you earn it. Renewed certificates last 24 months and expire on October 15 of even-numbered years.
To renew, earn at least two continuing education units, or the equivalent approved by the Board, in the 24 months before your certificate expires. For the 2026 renewal, CEUs had to be earned between October 16, 2024 and October 15, 2026.
The renewal fee is $50 for each certificate, non-refundable. The Board sends a renewal notice at least 60 days before your certificate expires, and no exam is needed if you pay no later than 90 days after it expires.
Courses on the Board's approved lists count. For other training, a provider or operator can ask the Board for CEUs with its request checklist form, sending the syllabus with contact hours, training materials and a sample certificate.
Exam day
Hawaii uses ABC wastewater treatment exams. The Board gives paper exams twice a year, in February and August, and you can also take a computer-based test at PSI test centers all year; computer-based testing is not offered on every island.
You may take the exam up to 3 times in a calendar year, in any mix of paper and computer-based tests.
The Board sets each paper exam's application deadline at least 60 days before the exam date and posts paper exam sites and start times on its page.
A score of 70% or higher passes.
Operator Master's free practice questions, timed practice exam and math help are built on the WPI exam format and the WPI formula table. The Hawaii pages we could read do not say which formula sheet you get, how many questions the exam has or how long it lasts, so ask the Board or PSI about your exam. 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 Hawaii was $65,560 a year ($31.52 an hour) in 2025, compared with $60,020 nationally. One in ten earned $46,900 or less, and one in ten earned $82,680 or more.
These federal figures cover drinking water and wastewater operators together, at every level. Pay for a new operator is usually nearer the low end.
Moving up
These are the high school paths in Chapter 11-61; each also needs a passing exam. Educational points are what the Board page calls CEUs. After your first year, up to 16 points can replace one year of experience, but points used that way cannot also count toward the points minimum. Associate and bachelor's degree paths need less experience.
From another state
The Board may issue a certificate of a comparable grade without an exam if you hold a certificate from another state whose requirements are substantially equivalent and that grants the same privilege to Hawaii operators. You must have earned that certificate by passing a written exam, and you must work or be seeking work in Hawaii.
Send the reciprocity application with a copy of your current certificate, a letter verifying your employment or job application in Hawaii, verification from your issuing board that a written exam was required, and a copy of that state's operator certification rules.
The processing fee is $25. If the Board finds you eligible, pay the $50 reciprocity certificate fee within 45 days, or you must reapply.