Requirements by state
South Dakota water operator certification
Quick answer
How do I get certified as a water operator in South Dakota?
South Dakota certifies four operational categories, water treatment, water distribution, wastewater treatment, and wastewater collection, each on the same Class I to IV ladder, sized by population served or by a treatment-complexity point system. Every exam is ABC-provided, costs $60, and certificates renew for free every year on February 1 as long as contact hours stay current. Reciprocity is available at no fee beyond the standard $60 application to any operator certified in another state, territory, or by the ABC directly.
See how South Dakota compares to every other jurisdiction in the national comparison matrix, or check reciprocity between states if you are moving.
Certifying agency: South Dakota Department of Agriculture and Natural Resources (DANR), Board of Operator Certification
- Certification is mandatory only for direct responsible charge of a system serving 500 or more people (wastewater) or any community/non-transient water system (drinking water); smaller wastewater systems are voluntary.
- Pass a written exam for the specific plant category and class, 100 scored multiple-choice questions plus 10 unscored experimental questions, 70% to pass, provided by the Association of Boards of Certification (ABC).
- Meet education and experience minimums that climb with class, from a high school diploma plus 1 year at Class I up to a 4-year degree plus 4 years (or a diploma plus 8 years) at Class IV.
- Log contact hours between renewals: 10 hours every 3 years for a single Class I or II certificate, up to 30 hours every 3 years for multiple certificates including a Class III or IV.
Water treatment
- I: Class I , Water treatment plants rated 30 points or less on the state's technical-difficulty point system.
- II: Class II , Water treatment plants rated 31 to 55 points.
- III: Class III , Water treatment plants rated 56 to 75 points.
- IV: Class IV , Water treatment plants rated over 75 points.
- Exam
- ABC-provided written exam, 110 multiple-choice questions (100 scored, 10 unscored experimental), 70% passing grade, separate exam per class and category. A Small Water Treatment System (SWTS) exam covers Class I groundwater systems serving under 500 people, and focuses on chlorination, aeration, and general groundwater topics rather than full mechanical treatment.
- Education minimum
- Class I: high school graduation. Class III: 2 years of college/vocational school in engineering, environmental science, or a related field, or high school graduation with more experience. Class IV: a 4-year degree in a related field, or high school graduation with more experience. A GED counts as high school graduation; up to half of an education or experience requirement can be substituted, never both directions on the same requirement.
- Experience minimum
- Class I: 1 year, no substitution. Class II: 3 years at a Class I facility, or 2 years at Class II or higher. Class III: 4 years including 2 at Class II or higher (with the 2-year degree), or 6 years including 3 at Class II or higher (HS diploma path). Class IV: 4 years including 2 at Class III or higher (with the 4-year degree), or 8 years including 4 at Class III or higher (HS diploma path). Operators may sit an exam before meeting the full requirement as long as they will qualify within 1 year of passing.
- Exam fee
- $60 per exam, as of July 1, 2021.
- Continuing education
- 10 contact hours every 3 years for one Class I or II certificate; 20 hours every 3 years for one Class III or IV certificate; 15 hours every 3 years holding multiple certificates all Class I/II; 30 hours every 3 years holding multiple certificates with at least one Class III or IV.
- Renewal cycle
- 1 year
- Reciprocity
- A certificate of equivalent grade may issue without examination to anyone holding a current certificate from another state, U.S. territory or possession, a foreign country, or the ABC directly, provided that jurisdiction's requirements are not lower than South Dakota's own and that jurisdiction grants reciprocity back to South Dakota-certified operators. Submit a copy of the held certificate with the $60 fee and a Certification through Reciprocity application; the Board of Operator Certification decides case by case at its next meeting.
Certification is required for every community and non-transient non-community water system operator, and for any transient system using disinfection or surface water. A groundwater system under 500 people using only chlorination needs a Small Water Treatment System-certified operator; a groundwater system that does not treat water at all is classified as a Water Distribution system instead.
Water distribution
- I: Class I , Distribution systems serving 1,500 people or fewer.
- II: Class II , Distribution systems serving 1,501 to 15,000 people.
- III: Class III , Distribution systems serving 15,001 to 50,000 people.
- IV: Class IV , Distribution systems serving over 50,000 people.
- Exam
- Same ABC-provided written exam format as water treatment, a separate exam per class, 70% passing grade.
- Experience minimum
- Same class-by-class education and experience structure as water treatment, credited separately for distribution-specific experience: 1 year at Class I with no substitution, up through the 4-year-degree-plus-4-years or diploma-plus-8-years path at Class IV.
- Exam fee
- $60 per exam.
- Continuing education
- Same contact-hour schedule as water treatment, 10 to 30 hours every 3 years depending on class and number of certificates held.
- Renewal cycle
- 1 year
- Reciprocity
- Same reciprocity process and $60 fee as water treatment.
A distribution system, sized by population served rather than a treatment point score, must have a certified operator at any water system that owns its own source or that is a rural water system serving as another public water system's distribution network. A system serving under 500 people that does not treat water at all is a 'Very Small Water System' and needs at minimum a Class I Water Distribution certificate.
Wastewater treatment
- I: Class I , Wastewater treatment plants rated 30 points or less, serving a population not over 1,500.
- II: Class II , Plants rated 31 to 55 points, population 1,501 to 15,000.
- III: Class III , Plants rated 56 to 75 points, population 15,001 to 50,000.
- IV: Class IV , Plants rated over 75 points, population over 50,000.
- Exam
- ABC-provided written exam, same 110-question (100 scored) format. A separate Stabilization Pond/Small Wastewater System exam, 50 questions focused strictly on pond operation, satisfies the Class I requirement for a stabilization-pond-only facility.
- Education minimum
- Same ladder as water treatment: HS diploma/GED at Class I and II, 2-year or 4-year related degree (or additional experience in place of it) at Class III and IV.
- Experience minimum
- Class I: 1 year, no substitution. Class II: 3 years at Class I, or 2 years at Class II or higher. Class III: 4 years including 2 at Class II or higher (with a 2-year degree), or 6 years including 3 at Class II or higher (HS diploma path). Class IV: 4 years including 2 at Class III or higher (4-year degree), or 8 years including 4 at Class III or higher (HS diploma path).
- Exam fee
- $60 per exam.
- Continuing education
- Same 10-to-30-hour, 3-year contact-hour schedule as water treatment, based on class and number of certificates held.
- Renewal cycle
- 1 year
- Reciprocity
- Same reciprocity process and $60 fee as water treatment.
Only wastewater treatment plants and collection systems serving 500 or more people (or an equivalent population) currently require a certified operator by law; DANR recommends, but does not require, certification below that threshold. A wastewater treatment plant can range from a one-celled stabilization pond up to a large tertiary bio-mechanical plant, all rated by the same points system.
Wastewater collection
- I: Class I , Collection systems serving 1,500 people or fewer.
- II: Class II , Collection systems serving 1,501 to 15,000 people.
- III: Class III , Collection systems serving 15,001 to 50,000 people.
- IV: Class IV , Collection systems serving over 50,000 people.
- Exam
- Same ABC-provided written exam format, a dedicated collection-systems exam per class.
- Experience minimum
- Same class-by-class education and experience ladder as wastewater treatment, credited for collection-system experience specifically.
- Exam fee
- $60 per exam.
- Continuing education
- Same 10-to-30-hour, 3-year contact-hour schedule as the other three disciplines.
- Renewal cycle
- 1 year
- Reciprocity
- Same reciprocity process and $60 fee as the other three disciplines.
Sized by population served, exactly like water distribution, and shares the same class thresholds (1,500 / 15,000 / 50,000). Only required for systems serving 500 or more people; DANR recommends voluntary certification below that threshold.
South Dakota is one of the cleanest states to understand nationally: all four disciplines, water treatment, water distribution, wastewater treatment, and wastewater collection, share one Class I to IV ladder, and every exam runs through the same statewide Board of Operator Certification at the same $60 flat rate.
Four categories, one class system
Water and wastewater treatment plants are rated by a technical-difficulty point system (the more complex the process, the higher the points), while distribution and collection systems are rated purely by population served. Both scales land on the same four classes:
| Class | Treatment plants (points) | Distribution/collection (population) |
|---|---|---|
| I | 30 or less | 1,500 or fewer |
| II | 31 to 55 | 1,501 to 15,000 |
| III | 56 to 75 | 15,001 to 50,000 |
| IV | Over 75 | Over 50,000 |
Certification is legally required only for direct responsible charge of any wastewater plant or collection system serving 500 or more people, and for every community or non-transient water system. Smaller wastewater systems are not required to certify, though the state recommends it.
Education, experience, and the exam
Every exam is written, ABC-provided, 110 questions (100 scored, 10 unscored experimental), with a 70% passing grade, and costs $60. Class I needs only a high school diploma or GED plus 1 year of experience, with no substitution allowed at that entry tier. Class III opens two paths: 2 years of related college plus 4 years of experience (2 at Class II or higher), or a high school diploma plus 6 years (3 at Class II or higher). Class IV works the same way at a higher tier: a 4-year degree plus 4 years (2 at Class III or higher), or a diploma plus 8 years (4 at Class III or higher). Up to half of an education or experience requirement can be substituted using the other, but never in both directions on the same requirement, and one year of operating experience always counts toward high school-level education if needed.
Two specialty exams exist for smaller systems: the Stabilization Pond/Small Wastewater System exam (50 questions, ponds only) satisfies Class I wastewater treatment for a lagoon-only facility, and the Small Water Treatment System (SWTS) exam covers a Class I groundwater plant under 500 people that only chlorinates.
Renewal costs nothing, but contact hours do the work
South Dakota certificates renew automatically every February 1, at no charge, as long as the operator’s contact hours are current:
| Certificates held | Contact hours every 3 years |
|---|---|
| One Class I or II | 10 |
| One Class III or IV | 20 |
| Multiple, all Class I/II | 15 |
| Multiple, at least one Class III/IV | 30 |
Certificates not renewed for two consecutive years become non-renewable, and an operator who leaves the field can renew twice more before certificates are revoked, regaining them only by re-examination.
Moving to or from South Dakota
A certificate of equivalent grade issues without examination to any operator currently certified in another state, U.S. territory, a foreign country, or by the ABC directly, provided that jurisdiction’s requirements are not lower than South Dakota’s own and it grants reciprocal privileges back to South Dakota operators. Submit the held certificate plus a Certification through Reciprocity application and the standard $60 fee; the Board decides case by case at its next meeting. See reciprocity between states for how this compares generally.
Where to go from here
Use the operator-math trainer to practice the pounds formula, CT disinfection, and loading-rate math the ABC exams draw on, and the process calculator for the same formulas on the job. Not sure which discipline to start in? Water treatment vs wastewater operator walks through the day-to-day difference. See your state’s page once more states are verified.
Sources: South Dakota Department of Agriculture and Natural Resources, Water and Wastewater Operator Certification pamphlet (SDCL Chapter 34A-3, regulations 74:21:02:01 through 71), revised June 2, 2022 (danr.sd.gov, retrieved 2026-07-29). Authored by the Water Cert Prep editorial team. Not legal advice. Reviewed 2026-07-29.