Median Pay by Area
- Sioux Falls, SD-MN
- $60,980 a year
- Sioux City, IA-NE-SD
- $59,760 a year
- Rapid City
- $57,780 a year
- East South Dakota (non-metro)
- $53,160 a year
- West South Dakota (non-metro)
- $50,000 a year
South Dakota wastewater operators
The steps from no certificate to a South Dakota Class I wastewater 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 South Dakota Department of Agriculture and Natural Resources (DANR) Operator Certification Program, its rules in ARSD 74:21:02 or the law in SDCL 34A-3.
DANR makes the final eligibility determination. Check with DANR before you apply.
Why it matters
South Dakota law requires every wastewater treatment plant and wastewater collection system serving 500 or more people, publicly or privately owned, to be supervised by an operator certified by DANR at a grade matching the plant or system's class.
The operator in direct responsible charge must become certified within one year of starting the job. Operating a plant or system without a certified operator in charge is a Class 2 misdemeanor.
Systems serving fewer than 500 people do not have to have certified wastewater operators, but DANR recommends that their operators become certified voluntarily.
You need work experience in the area you want to be tested in, such as wastewater treatment or wastewater collection. Officials, engineers, students and others who are not involved in day-to-day operations may not take the exams, and plant maintenance such as greasing pumps or cutting grass does not count as operations work.
South Dakota has separate certificates for wastewater treatment plants and wastewater collection systems (plus water treatment and water distribution). Each comes in Class I, II, III and IV, and Class IV is the highest.
Collection systems are classed by population served: Class I up to 1,500 people, Class II 1,501 to 15,000, Class III 15,001 to 50,000 and Class IV over 50,000. Treatment plants are classed by points for their processes: Class I up to 30 points, Class II 31 to 55, Class III 56 to 75 and Class IV over 75.
A certificate lets you operate a plant or system of the same class or lower in that category. DANR's System Ratings list shows the class of each regulated system.
A Class I wastewater system serving 500 or more people that uses only stabilization ponds may be run by an operator with a Class I Stabilization Pond certificate or a Class I (or higher) Wastewater Treatment certificate. Its collection system needs a Class I (or higher) Wastewater Collection operator.
Step 1
Experience means time spent at a plant or system doing operational duties well. For Class I you need one year of it, without substitution, at a Class I or higher facility.
You also need a high school diploma or the equivalent. The GED counts as completing high school.
You may take an exam at any class before you meet the education and experience requirements, as long as you will meet them within one year. If you pass, you receive the certificate once you meet them.
Step 2
Fill out DANR's Application for Operator Certification Exam, one exam per application, including retakes. Describe your daily duties for the exam you are applying for in detail; the application is the only information DANR uses to decide if you are eligible.
You and your supervisor both sign the application. DANR must receive it at least two weeks before the exam date. You can fax, email or mail it.
Send the exam fee shown on the current application by check or money order. Mail it before the exam date if you fax or email the application; fees cannot be paid on site and are not returned if you fail.
DANR sends a confirmation about ten days before the exam. If you do not get one, contact the program.
Step 3
DANR does not supply study material. It says the exam questions are mainly referenced to publications from California State University, Sacramento, the Water Environment Federation (WEF) and the American Water Works Association (AWWA), and it links ABC's Need-to-Know criteria for each exam.
For wastewater treatment, DANR lists Operation of Wastewater Treatment Plants, Volumes 1 and 2, Advanced Waste Treatment, Utility Management and Manage for Success from Sacramento State, and WEF's MOP 11 among the references. It also publishes Practical Guidelines to Solving Water/Wastewater Math Problems.
The SD Association of Rural Water Systems runs one- to three-day training classes across the state, often ending with an exam session. DANR says the Basic Wastewater Treatment class is the best preparation for the Class I Wastewater Treatment exam. You do not have to attend a class to take an exam, and signing up for one does not register you for the other.
Step 4
Once you pass and meet the requirements, DANR issues a certificate on the Board of Certification's recommendation. The certificate shows the class and type of plant or system you may operate.
To move up a class, meet that class's education and experience requirements and pass its exam. Experience at the lower level must be in the same category as the exam, such as wastewater treatment.
Step 5
All South Dakota certificates expire on February 1 each year. DANR renews them automatically if you are still in the water or wastewater field and your contact hours are up to date.
With one Class I or II certificate you need 10 contact hours every three years; with one Class III or IV certificate, 20. With more than one certificate you need 15 hours if all are Class I or II, or 30 if any is Class III or IV.
Hours come from seminars, training courses, technical conferences or related college courses approved by the board's secretary. You can check your completed courses and hours in DANR's online search.
A certificate not renewed for two years after it expires can no longer be renewed; you must apply and pass the exam again. If you leave the field, your certificates can be renewed twice more before they end.
Exam day
South Dakota's exams are provided by the Association of Boards of Certification (ABC). There is a separate written exam for each category and class.
Most exams have 110 multiple-choice questions, and you are graded on 100 of them; the other 10 are unmarked trial questions. The Stabilization Pond exam has 50 questions about ponds only.
The passing grade is 70 out of 100.
Exams are given throughout the year at locations across the state, listed on the DANR and SD Association of Rural Water Systems schedule. An exam session lasts three hours, and you may take more than one exam in a session.
Bring a simple calculator; PDAs, laptops and phone calculators are not allowed, and no cell phones are allowed in the exam room.
Exam papers are not returned, but you may review your results with DANR staff on request.
DANR says its exams are provided by the Association of Boards of Certification (ABC), but the DANR pages we could read do not say whether a formula sheet is handed out. Operator Master's free practice questions, timed practice exam and step-by-step math help use the WPI exam style and the WPI formula table, so use them for general wastewater knowledge and math, and use the ABC Need-to-Know criteria DANR links as your guide to what each exam covers. 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 South Dakota was $53,370 a year ($25.66 an hour) in 2025, compared with $60,020 nationally. One in ten earned $43,890 or less, and one in ten earned $73,170 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 rows are the high school path, and each class also needs a passing exam. For Class III, two years of college or vocational school in engineering, environmental sciences or a related field cuts the experience to four years (two at Class II or higher); for Class IV, a four-year degree in those fields cuts it to four years (two at Class III or higher). One year of education past high school can replace one year of experience, up to half, but at least 80% must be actual operating experience.
From another state
If you hold a certificate from another state, territory or country, or from ABC, South Dakota may issue a certificate of equivalent grade without an exam. The requirements behind your certificate must be no lower than South Dakota's, and that state or body must grant the same privilege to South Dakota operators.
The Board of Certification reviews each request case by case, comparing the education and experience needed for your certificate with South Dakota's. Use one Application for Operator Certification Through Reciprocity per certificate, include a copy of your certificate and the fee on the form, and make sure DANR receives it at least four weeks before the next board meeting.
The board meets twice a year, in September at the SD Water and Wastewater Association conference and in the spring.