Texas Wastewater Treatment Operator License Classes & Requirements

Texas wastewater treatment operator licenses are issued by the Texas Commission on Environmental Quality, or TCEQ. The principal wastewater treatment license levels are Class D, Class C, Class B, and Class A.

As the license level increases, TCEQ requires progressively greater training and qualifying experience. Higher license classes reflect greater expected knowledge of wastewater treatment processes, operations, safety, laboratory work, equipment, regulations, and process control.

Texas Wastewater Treatment License Progression

The general license progression is:

1. Class D;
2. Class C;
3. Class B;
4. Class A.

Advancement is not based only on passing a more difficult examination. Applicants must satisfy the education, experience, training, application, and examination requirements for the license requested.

Regulatory Basis

Texas wastewater treatment operator licensing is governed primarily through TCEQ occupational licensing requirements, including 30 TAC Chapter 30, Subchapter J.

Operators should distinguish between:

• the individual operator's license requirements;
• the minimum operator level required at a wastewater facility;
• the wastewater facility's permit and operating requirements.

Wastewater Class D

Class D is the entry-level Texas wastewater treatment operator license.

Current minimum requirements include:

• high school diploma or GED;
• no previous wastewater work experience requirement;
• required wastewater training;
• TCEQ application approval;
• passing the applicable examination.

Class D Required Training

The core training requirement is:

• Basic Wastewater Operation or an approved equivalent course.

Provisional Wastewater Class D

Texas also provides a Provisional Wastewater Class D license for applicants who do not currently have a high school diploma or GED.

Current requirements include:

• no formal education requirement at the time of application;
• no previous work experience requirement;
• Basic Wastewater Operation training;
• application approval and examination.

The provisional Class D license is valid for two years and must be upgraded to a regular Class D or higher license by the end of the provisional period.

Class D Is Not Renewable in Every Situation

Texas places important restrictions on renewal of a Class D wastewater treatment license.

A Class D license is not renewable for operators working at certain facilities, including:

• activated sludge-type treatment facilities of any size;
• trickling filter or rotating biological contactor facilities with permitted average daily flow of 100,000 gallons per day or greater;
• wastewater facilities that dispose of treated effluent through a subsurface area drip dispersal system.

Operators in these situations should plan to progress to a higher license class.

Wastewater Class C

Class C requires both training and qualifying wastewater experience.

Current minimum education and experience requirements include:

• high school diploma or GED;
• two years of qualifying work experience;
• at least one-half of the required work experience in the specific field for the license requested.

Class C Required Training

Current core training includes:

• Basic Wastewater Operation;
• Activated Sludge or Wastewater Treatment;
• one approved elective course.

Class C Electives

Approved electives currently include courses such as:

• Wastewater Collection;
• Wastewater Laboratory;
• Water Utility Calculations;
• Water Utility Safety.

Class C Experience Substitution

Applicants with a high school diploma or GED may substitute up to one year of qualifying experience through approved college education or additional TCEQ-approved wastewater operator training.

Current TCEQ examples include:

• 32 semester hours of college or 40 additional hours of approved training for one year of experience;
• 16 semester hours of college or 20 additional hours of approved training for six months of experience.

Class B Wastewater License

Class B represents a higher level of wastewater treatment qualification and requires significantly more experience and training.

Class B Bachelor's Degree Path

Current requirements include:

• bachelor's degree in chemistry, biology, engineering, microbiology, bacteriology, or another similar discipline approved by TCEQ;
• 2.5 years of hands-on experience;
• at least one-half of the required experience in the specific field for the license requested.

Class B High School or GED Path

Current requirements include:

• high school diploma or GED;
• five years of qualifying work experience;
• at least three years of hands-on experience;
• at least one-half of the required experience in the specific field for the license requested.

Class B Experience Substitution

Applicants using the high school or GED path may substitute up to two years of qualifying experience with approved college education or additional wastewater operator training.

Current examples include:

• 32 semester hours of college or 40 additional approved training hours for one year of experience;
• 16 semester hours of college or 20 additional approved training hours for six months of experience.

Class B Required Training

Current Class B core training includes:

• Basic Wastewater Operation;
• Activated Sludge or Wastewater Treatment;
• Wastewater Collection;
• Wastewater Laboratory;
• Water Utility Safety;
• one approved elective course.

Class B Electives

Current elective options include:

• Intermediate Wastewater Laboratory;
• Water Utility Calculations;
• Water Utility Management.

Wastewater Class A

Class A is the highest general Texas wastewater treatment operator license class.

It requires extensive training and qualifying experience.

Class A Master's Degree Path

Current requirements include:

• master's degree in chemistry, biology, engineering, microbiology, bacteriology, or another similar discipline approved by TCEQ;
• four years of hands-on experience;
• at least one-half of the required experience in the specific field for the license requested.

Class A Bachelor's Degree Path

Current requirements include:

• bachelor's degree in an approved scientific or technical discipline;
• five years of hands-on experience;
• at least one-half of the required experience in the specific field for the license requested.

Class A High School or GED Path

Current requirements include:

• high school diploma or GED;
• eight years of qualifying work experience;
• at least six years of hands-on experience;
• at least one-half of the required experience in the specific field for the license requested.

Class A Experience Substitution

Applicants using the high school or GED path may substitute up to two years of qualifying experience using approved college education or additional wastewater operator training.

Current examples include:

• 32 semester hours of college or 40 additional approved training hours for one year of experience;
• 16 semester hours of college or 20 additional approved training hours for six months of experience.

Class A Required Training

Current Class A core training includes:

• Basic Wastewater Operation;
• Activated Sludge or Wastewater Treatment;
• Wastewater Collection;
• Wastewater Laboratory;
• Water Utility Management;
• Water Utility Safety;
• one approved elective course.

Class A Electives

Current electives include:

• Intermediate Wastewater Laboratory;
• Water Utility Calculations;
• Wastewater Technology;
• Advanced Management.

Class A Total Training Requirement

Current TCEQ requirements specify that Class A applicants must complete additional approved wastewater training sufficient to reach a total of 160 training hours.

Hands-On Experience

Hands-on experience means actual operational work involving wastewater treatment processes and equipment.

Examples can include:

• operating treatment units;
• making process-control adjustments;
• operating pumps and aeration equipment;
• monitoring biological treatment;
• operating sludge-handling systems;
• performing routine operational sampling and testing.

Specific-Field Experience

TCEQ requires part of the qualifying experience for higher licenses to be obtained in the specific field for the license requested.

Applicants should not assume that unrelated utility experience automatically qualifies.

Laboratory Experience

Laboratory experience can receive full credit toward wastewater operator licensing only under specific conditions.

TCEQ requires the laboratory to be owned and operated by the permittee and laboratory personnel to consult daily with operational personnel for the laboratory experience to receive full credit.

Unacceptable Experience

Not every job performed at or for a wastewater utility counts as qualifying operator experience.

Applicants should document actual operational duties rather than relying only on job title or years of employment.

Experience Verification

TCEQ can require verification of work history.

Operators should maintain records of:

• employer;
• facility;
• dates of employment;
• treatment processes operated;
• specific duties;
• supervisors;
• hands-on responsibilities.

Application Before Examination

An applicant must complete the applicable licensing prerequisites and submit an application to TCEQ.

TCEQ must approve the application before the applicant takes the licensing examination.

Examination Passing Score

The minimum passing score for a Texas occupational licensing examination is:

70 percent

Computer-Based Testing

TCEQ provides computer-based testing for wastewater treatment operator examinations.

Current CBT listings include:

• Class D Wastewater Treatment Facility Operator;
• Class C Wastewater Treatment Facility Operator;
• Class B Wastewater Treatment Facility Operator;
• Class A Wastewater Treatment Facility Operator.

Class A Examination Length

The Class A Wastewater Treatment Facility Operator examination currently has a six-hour time limit.

Operators should confirm that the selected CBT center can accommodate the examination before scheduling.

Exam Content

TCEQ examinations are based on:

• laws and regulations;
• operator job duties;
• treatment standards;
• process knowledge;
• safety;
• calculations;
• laboratory practices;
• equipment operation.

Need-to-Know Criteria

TCEQ publishes need-to-know criteria for each wastewater treatment operator examination level.

Applicants should study the criteria for the exact license class they are taking.

Class D Knowledge Level

Class D generally emphasizes fundamental wastewater treatment concepts and basic operator responsibilities.

Topics can include:

• safety;
• basic treatment processes;
• equipment;
• sampling;
• simple calculations;
• basic regulations.

Class C Knowledge Level

Class C builds on basic knowledge and expects greater understanding of:

• biological treatment;
• process control;
• laboratory results;
• solids handling;
• equipment troubleshooting;
• calculations.

Class B Knowledge Level

Class B requires broader and deeper operational knowledge, including more complex process-control decisions, troubleshooting, laboratory interpretation, management, and regulatory responsibilities.

Class A Knowledge Level

Class A represents the highest general wastewater treatment operator level and requires broad understanding of treatment processes, regulations, management, calculations, laboratory work, equipment, and advanced process control.

Facility Category and Required Operator Level

Texas classifies domestic wastewater treatment facilities and connects facility category with the minimum required chief-operator license level.

An operator should not assume that any wastewater license allows service as chief operator at every treatment facility.

Chief Operator Requirement

TCEQ requires every domestic wastewater treatment facility to be operated for a minimum of five days per week by the licensed chief operator or by an operator holding the required license level or higher.

The required operator must also be available by telephone or pager seven days per week.

Facility Requirements and Personal License Requirements

These are separate concepts.

A person may meet the requirements for a particular license class while a specific treatment facility requires a higher-level operator.

License Renewal

Texas wastewater treatment operator licenses are generally valid for three years.

Renewal requires:

• required continuing education;
• renewal application;
• criminal history attestation;
• renewal fee;
• compliance with current TCEQ requirements.

Continuing Education

Current TCEQ training requirements specify:

30 continuing-education credit hours

for renewal of Wastewater Treatment Operator Classes A, B, C, and D, subject to applicable renewal restrictions.

Class A and B Renewal Training Restriction

Class A and B wastewater treatment operators may not use Basic Wastewater Operation, or an equivalent basic course, for renewal credit.

Class D Renewal Exception

Class D operators should pay special attention to the facility at which they work because Class D is not renewable in certain treatment systems.

Advancing from Class D to Class C

An operator seeking Class C should plan to obtain:

• qualifying wastewater experience;
• field-specific experience;
• required core training;
• an approved elective;
• application approval.

Advancing from Class C to Class B

The transition to Class B requires substantially more experience and a broader training package.

Operators should document hands-on duties carefully.

Advancing from Class B to Class A

Class A requires extensive experience and 160 total approved training hours under current requirements.

Example: New Applicant with High School Diploma

An applicant with a high school diploma or GED, no wastewater experience, and required Basic Wastewater Operation training may qualify to apply for a Class D license after completing the current TCEQ application requirements.

Example: Applicant Without High School Diploma

The applicant may be eligible for Provisional Wastewater Class D.

The provisional license must be upgraded within its two-year validity period.

Example: Class C Applicant

The applicant should verify:

• high school diploma or GED;
• two years of qualifying experience;
• specific-field experience;
• Basic Wastewater Operation;
• Activated Sludge or Wastewater Treatment;
• one approved elective.

Example: Class B Applicant with Bachelor's Degree

The applicant should verify:

• degree in an approved discipline;
• 2.5 years of hands-on experience;
• specific-field experience;
• all required Class B training.

Example: Class B Applicant with High School Diploma

The applicant should verify:

• five years of qualifying experience;
• at least three years hands-on;
• specific-field experience;
• all required training;
• any permitted experience substitution.

Example: Class A Applicant with Bachelor's Degree

The applicant currently needs five years of hands-on experience and must satisfy the field-specific experience and Class A training requirements.

Example: Operator Works at an Activated Sludge Facility

A Class D operator should recognize that Class D is not renewable for operators at activated sludge-type treatment facilities.

The operator should plan advancement to an appropriate higher license.

Example: Operator Has Eight Years at a Utility but Mostly Administrative Duties

Total employment duration does not automatically establish qualifying operator experience.

TCEQ evaluates the nature of the duties performed.

Example: Laboratory Employee Applies for Operator License

The applicant should verify whether laboratory experience satisfies the specific TCEQ conditions for full operator-experience credit.

Common Texas Wastewater Licensing Mistakes

• Assuming wastewater collection and wastewater treatment licenses are the same.
• Assuming Class D can be renewed at every wastewater facility.
• Counting all utility employment as qualifying operational experience.
• Ignoring hands-on experience requirements for Classes A and B.
• Ignoring specific-field experience requirements.
• Using outdated training-course lists.
• Assuming college education removes every experience requirement.
• Taking the wrong elective courses.
• Assuming passing the exam alone earns the license.
• Failing to document work history and training.

A Practical Class D Review

1. Verify high school diploma or GED, or determine whether Provisional Class D applies.
2. Complete Basic Wastewater Operation.
3. Submit the TCEQ application.
4. Receive approval to test.
5. Prepare for the Class D examination.
6. Pass with at least 70 percent.
7. Review whether the facility requires advancement beyond Class D.

A Practical Class C Review

1. Verify high school diploma or GED.
2. Verify two years of qualifying experience.
3. Verify specific-field experience.
4. Complete Basic Wastewater Operation.
5. Complete Activated Sludge or Wastewater Treatment.
6. Complete one approved elective.
7. Document any permitted experience substitution.
8. Apply and receive approval before testing.

A Practical Class B Review

1. Determine the applicable education path.
2. Verify total experience.
3. Verify hands-on experience.
4. Verify specific-field experience.
5. Complete required core courses.
6. Complete an approved elective.
7. Document any allowed experience substitution.
8. Apply and receive TCEQ approval.
9. Prepare for the Class B examination.

A Practical Class A Review

1. Determine the applicable education path.
2. Verify hands-on and total experience requirements.
3. Verify specific-field experience.
4. Complete all required core courses.
5. Complete an approved elective.
6. Reach the required total of 160 approved training hours.
7. Document experience carefully.
8. Apply and receive approval.
9. Prepare for the six-hour Class A examination.

What to Remember for the Exam

• Texas wastewater treatment licenses are Classes D, C, B, and A.
• Wastewater treatment licensing is governed through TCEQ occupational licensing requirements, including 30 TAC Chapter 30, Subchapter J.
• Class D currently requires a high school diploma or GED and no previous wastewater work experience.
• Class D core training is Basic Wastewater Operation.
• Provisional Wastewater Class D is available for applicants without a high school diploma or GED and is valid for two years.
• Class D is not renewable for operators at certain wastewater facilities, including activated sludge-type facilities.
• Class C currently requires two years of qualifying work experience, with at least one-half in the specific field.
• Class C training includes Basic Wastewater Operation, Activated Sludge or Wastewater Treatment, and one approved elective.
• Class C permits limited substitution of college education or approved training for qualifying experience.
• Class B applicants with an approved bachelor's degree currently need 2.5 years of hands-on experience.
• Class B applicants using the high school or GED path currently need five years of qualifying experience, including three years hands-on.
• At least one-half of Class B experience must be in the specific field requested.
• Class A applicants using the master's path need four years hands-on, while the bachelor's path requires five years hands-on.
• The Class A high school or GED path currently requires eight years total experience, including six years hands-on.
• Class A currently requires 160 total approved wastewater training hours.
• Laboratory experience receives full licensing credit only when TCEQ conditions are satisfied.
• TCEQ must approve an application before the applicant takes the licensing examination.
• The minimum passing score for TCEQ occupational licensing exams is 70 percent.
• Wastewater treatment operator licenses are generally valid for three years and currently require 30 CE credit hours for renewal.
• Always verify current TCEQ requirements before applying, upgrading, or renewing a Texas wastewater treatment license.