Clear answers. Official sources.

Water Operator Certification & Renewal Requirements, by State

Find drinking-water and wastewater certification levels, renewal cycles, continuing-education requirements, and the authority governing your credential.

Find your state →How this guide works

50 state guidesOfficial regulator linksHuman-readable renewal guidance

National coverage

Start with your state

All 50 states are researched from state authorities, controlling rules, official forms, and certification portals.

Alabama

Water treatment Grades I-IV; wastewater Grades IC, I-IV. Division 10 also covers water distribution systems and public wastewater collection systems.

Water treatment Grades I-IVwastewater Grades IC, I-IV. Division 10 also covers water distribution systems and public wastewater collection systems.

View guide →AK

Alaska

Water Treatment, Water Distribution, Wastewater Treatment, and Wastewater Collection: Provisional and Levels 1-4; also Small Treated, Small Untreated, and Wastewater Stabilization Pond certificates.

Water Treatment, Water Distribution, Wastewater Treatment, and Wastewater Collection: Provisional and Levels 1-4also Small Treated, Small Untreated, and Wastewater Stabilization Pond certificates.

View guide →AZ

Arizona

ADEQ covers water treatment, distribution, wastewater treatment, and wastewater collection.

Water TreatmentWater DistributionWastewater Treatment

View guide →AR

Drinking water: Treatment Grades I-IV and Distribution Small System/I-IV. Wastewater: Municipal Classes I-IV, Industrial Basic/Advanced, collection licensing, and apprentice/OIT pathways; collection reciprocity is expressly excluded.

View guide →CA

California

Separate state programs govern drinking-water treatment/distribution and wastewater treatment operators.

Drinking Water TreatmentWater DistributionWastewater Treatment

View guide →CO

Colorado

Water treatment, domestic wastewater treatment, and industrial wastewater treatment Classes D-C-B-A; distribution and collection Classes 1-4; additional T and S classes appear in renewal table.

Water treatment, domestic wastewater treatment, and industrial wastewater treatment Classes D-C-B-Adistribution and collection Classes 1-4additional T and S classes appear in renewal table.

View guide →CT

Connecticut

Drinking water: WTP Classes I-IV, Distribution Classes I-III, Small Water System, and WTP/DS operator-in-training. Wastewater: Classes I-IV with OIT for I-III.

View guide →DE

Delaware

Wastewater Classes I-IV and OIT. Drinking water: base-level water-supply operator plus disinfection, chemical feed, filtration, surface-water operations, other specified treatment, distribution and approved sampler/tester endorsements; specialty OIT, grandfather, limited and distribution licenses.

Wastewater Classes I-IV and OIT. Drinking water: base-level water-supply operator plus disinfection, chemical feed, filtration, surface-water operations, other specified treatment, distribution and approved sampler/tester endorsementsspecialty OIT, grandfather, limited and distribution licenses.

View guide →FL

Florida

Water treatment and wastewater treatment Classes D, C, B, A (A highest); water distribution Levels 4, 3, 2, 1 (1 highest).

Water treatment and wastewater treatment Classes D, C, B, A (A highest)water distribution Levels 4, 3, 2, 1 (1 highest).

View guide →GA

Georgia

Water operator Classes IV-III-II-I; wastewater operator Classes IV-III-II-I; groundwater Class III; water distribution; wastewater collection; industrial wastewater; water/wastewater laboratory analyst.

Water operator Classes IV-III-II-Iwastewater operator Classes IV-III-II-Igroundwater Class III

View guide →HI

Hawaii

Public water-system water treatment and distribution Grades 1-4; wastewater treatment Grades 1-4.

Public water-system water treatment and distribution Grades 1-4wastewater treatment Grades 1-4.

View guide →

Idaho

Drinking-water treatment/distribution and wastewater treatment/collection: OIT, restricted/lagoon/land-application where applicable, Classes I-IV; drinking-water and wastewater Very Small System; wastewater laboratory analyst Classes I-IV; backflow tester.

Drinking-water treatment/distribution and wastewater treatment/collection: OIT, restricted/lagoon/land-application where applicable, Classes I-IVdrinking-water and wastewater Very Small Systemwastewater laboratory analyst Classes I-IV

View guide →IL

Illinois

Community drinking-water supply operators: Classes A, B, C, D. Wastewater: municipal treatment classes and separate industrial Class K; collection-system certification is voluntary.

Community drinking-water supply operators: Classes ABC

View guide →IN

Indiana

Drinking-water distribution DSS/DSM/DSL and treatment WT1-WT5. Wastewater has ten sanitary/industrial classifications including A-SO, A-D, I-SP, and I-IV.

Drinking-water distribution DSS/DSM/DSL and treatment WT1-WT5Wastewater has ten sanitary/industrial classifications including A-SOA-D

View guide →IA

Iowa

Iowa DNR certifies drinking-water treatment, distribution, and wastewater treatment operators.

Drinking-water treatmentDrinking-water distributionWastewater treatment

View guide →KS

Kansas

Water treatment, water distribution, and wastewater treatment/operator certification.

Water treatmentwater distributionand wastewater treatment/operator certification

View guide →KY

Kentucky

Kentucky covers drinking-water, distribution, wastewater, collection, bottled-water, and limited credentials.

Drinking-water treatmentWater distributionWastewater treatment

View guide →LA

Louisiana

LDH certifies water production, treatment, distribution, wastewater treatment, and collection operators.

Water ProductionWater TreatmentWater Distribution

View guide →ME

Maine

Public water-system operators; wastewater treatment operators including SITS-1.

Public water-system operatorswastewater treatment operators including SITS-1

View guide →MD

Maryland

Water, wastewater, industrial wastewater, water distribution, wastewater collection, and superintendent/OIT pathways.

Waterwastewaterindustrial wastewater

View guide →MA

Massachusetts

Drinking-water treatment (T), distribution (D), very-small-system/non-community credentials; wastewater treatment-plant operator credentials.

Drinking-water treatment (T)distribution (D)very-small-system/non-community credentials

View guide →MI

Michigan

Drinking-water Levels 1-5; municipal wastewater A, B, C, D, L1, L2, SC; industrial wastewater Levels 1-3.

Drinking-water Levels 1-5municipal wastewater AB

View guide →MN

Minnesota

Separate state programs govern drinking-water and wastewater operators.

Drinking-water systemsWastewater treatmentWastewater collection

View guide →MS

Mississippi

Public water-supply operator certification; Wastewater operator certification (separately administered)

Public water-supply operator certificationWastewater operator certification (separately administered)

View guide →MO

Missouri

Drinking Water Treatment; Drinking Water Distribution; Wastewater Treatment; CAFO Waste Management Systems

Drinking Water TreatmentDrinking Water DistributionWastewater Treatment

View guide →MT

Montana

1A–4A Water Distribution; 1B–4B Water Treatment; 1C–3C Municipal Wastewater; 1D–4D Industrial Wastewater; 2E–4E On-site Wastewater

1A–4A Water Distribution1B–4B Water Treatment1C–3C Municipal Wastewater

View guide →NE

Nebraska

Water Operator Grades I–VI; Professional Wastewater Operator certification by facility/type and grade

Water Operator Grades I–VIProfessional Wastewater Operator certification by facility/type and grade

View guide →NV

Nevada

Drinking Water Treatment; Drinking Water Distribution; Wastewater Treatment Plant Operator

Drinking Water TreatmentDrinking Water DistributionWastewater Treatment Plant Operator

View guide →NH

New Hampshire

Water Treatment; Water Distribution; Wastewater Treatment

Water TreatmentWater DistributionWastewater Treatment

View guide →NJ

New Jersey

N Industrial Wastewater; C Public Wastewater Collection; S Public Wastewater Treatment; W Public Water Distribution; T Public Water Treatment; VSWS Very Small Water System

N Industrial WastewaterC Public Wastewater CollectionS Public Wastewater Treatment

View guide →NM

New Mexico

Water Supply; Water Treatment; Wastewater Treatment; Small-system and category credentials administered by UOCP

Water SupplyWater TreatmentWastewater Treatment

View guide →NY

New York

Drinking Water Treatment Operator/Assistant; Drinking Water Distribution; Wastewater Activated Sludge Grades 1A–4A; Wastewater Non-activated Sludge Grades 1–4

Drinking Water Treatment Operator/AssistantDrinking Water DistributionWastewater Activated Sludge Grades 1A–4A

View guide →NC

North Carolina

Drinking Water Treatment; Drinking Water Distribution; Biological Wastewater; Wastewater Collections; Land Application; Physical/Chemical; Subsurface; Surface Irrigation

Drinking Water TreatmentDrinking Water DistributionBiological Wastewater

View guide →ND

North Dakota

Water treatment, water distribution, wastewater treatment and wastewater collection in Classes IA, I, II, III and IV, aligned to the regulated facility/system category and class.

View guide →OH

Ohio

Water supply and water reclamation Classes A, I-IV; water distribution Classes I-II; wastewater collection Classes I-II; limited/facility-specific certificates are also authorized.

Water supply and water reclamation Classes A, I-IVwater distribution Classes I-IIwastewater collection Classes I-II

View guide →OK

Oklahoma

Waterworks and wastewater works operator Classes D, C, B, A; water/wastewater laboratory C, B, A; distribution/collection C Operator and Technician; groundwater and lagoon operations are included.

Waterworks and wastewater works operator Classes D, C, B, Awater/wastewater laboratory C, B, Adistribution/collection C Operator and Technician

View guide →OR

Oregon

Wastewater treatment and collection: Small System and Grades I-IV. Drinking water treatment and distribution: Levels 1-4, Small Water System, and filtration endorsement.

View guide →PA

Pennsylvania

Drinking water and wastewater Classes A-D with technology subclasses; wastewater E collection; drinking-water E distribution/consecutive systems; drinking-water Dc and Dn small-system credentials.

Drinking water and wastewater Classes A-D with technology subclasseswastewater E collectiondrinking-water E distribution/consecutive systems

View guide →RI

Rhode Island

Drinking-water treatment and distribution: VSS and Classes 1-4, full and OIT except no Class 4 OIT. Wastewater treatment: Grades 1-4, with optional Tier Two renewal designation 1T-4T.

View guide →SC

South Carolina

Water distribution, water treatment, biological wastewater treatment and physical/chemical wastewater treatment; operator ladder D-C-B-A, with entry water-treatment E and trainee status where applicable.

Water distribution, water treatment, biological wastewater treatment and physical/chemical wastewater treatmentoperator ladder D-C-B-A, with entry water-treatment E and trainee status where applicable.

View guide →SD

South Dakota

Water treatment, water distribution, wastewater treatment and wastewater collection Classes I-IV, plus Small Water Treatment and Small Wastewater System.

View guide →TN

Tennessee

Water Treatment 1-4; Wastewater Treatment 1-4; Distribution 1-2; Collection 1-2; Small Water System; Biological/Natural System.

Water Treatment 1-4Wastewater Treatment 1-4Distribution 1-2

View guide →TX

Texas

Public Water System Operator and Wastewater Treatment Operator Classes D-C-B-A; Wastewater Collection I-II-III; provisional D pathways exist.

Public Water System Operator and Wastewater Treatment Operator Classes D-C-B-AWastewater Collection I-II-IIIprovisional D pathways exist.

View guide →UT

Utah

Drinking water: Small System and treatment/distribution Grades 1-4. Wastewater mandatory credentials: Treatment Grades I-IV, Collection Grades I-IV and Utah Small Lagoon System Grade I; voluntary Laboratory Analyst I-IV, Biosolids Land Applier I-II and Plant Maintenance Technologist I-III. Restricted certificates identify an operator who passed the exam but has not yet met experience/education requirements.

Drinking water: Small System and treatment/distribution Grades 1-4. Wastewater mandatory credentials: Treatment Grades I-IV, Collection Grades I-IV and Utah Small Lagoon System Grade Ivoluntary Laboratory Analyst I-IV, Biosolids Land Applier I-II and Plant Maintenance Technologist I-III. Restricted certificates identify an operator who passed the exam but has not yet met experience/education requirements.

View guide →VT

Vermont

Drinking water: OIT and provisional pathways plus Classes 1A, 1B, 2, 3, 4A1, 4A, 4B, 4C and D (distribution). Wastewater: Domestic Grades I-V and Industrial Grades I, II, IV and V; Grade III is not an industrial credential in the rule's classification table.

Drinking water: OIT and provisional pathways plus Classes 1A, 1B, 2, 3, 4A1, 4A, 4B, 4C and D (distribution). Wastewater: Domestic Grades I-V and Industrial Grades I, II, IV and VGrade III is not an industrial credential in the rule's classification table.

View guide →VA

Virginia

Waterworks operator Classes 1-6 and wastewater works operator Classes 1-4; Class 1 is the highest classification.

Waterworks operator Classes 1-6 and wastewater works operator Classes 1-4Class 1 is the highest classification.

View guide →WA

Washington

Waterworks: Water Distribution Manager and Water Treatment Plant Operator Grades 1-4, Water Distribution Specialist, Cross-Connection Control Specialist and Backflow Assembly Tester, with operator-in-training pathways where authorized. Wastewater: full and operator-in-training certifications in Groups I-IV.

View guide →WV

West Virginia

Public water: 1D, Class R, Water Distribution System (WDS), OIT and Classes I-IV. Wastewater: Classes H, S, C, OIT and I-IV, with an advanced designation available to qualifying Class IV operators.

View guide →WI

Wisconsin

Municipal waterworks subclasses D, G, I, L, S, V and Z at Grade T (operator-in-training) and Grade 1; small OTM/NN water-system general-operation certification. Wastewater levels are operator-in-training, Basic and Advanced with process subclasses A1-A5, B, C, D, L, N, P, SS and U.

Municipal waterworks subclasses D, G, I, L, S, V and Z at Grade T (operator-in-training) and Grade 1small OTM/NN water-system general-operation certification. Wastewater levels are operator-in-training, Basic and Advanced with process subclasses A1-A5, B, C, D, L, N, P, SS and U.

View guide →WY

Wyoming

Water Treatment Levels 1-4; Water Distribution Levels 1-2; Wastewater Treatment Levels 1-4; Wastewater Collection Levels 1-2; Well System; Lagoon System. Operators obtain the desired level and all preceding levels.

Water Treatment Levels 1-4Water Distribution Levels 1-2Wastewater Treatment Levels 1-4