|(a) An individual applying for an on-site supervisor license must apply for one of the following levels of licenses: (1) Class A; (2) Class B; or (3) Class A/B combination. (b) To obtain an on-site supervisor license, an individual must: (1) have met the requirements in Subchapter A of this chapter (relating to Administration of Occupational Licenses and Registrations); (2) be at least 18 years of age; (3) document at least two years of active experience in installation, repair, or removal of underground storage tanks (USTs), underground utilities, or other engineering construction; (4) submit sworn statements, on forms approved by the executive director, from at least four persons (three from clients not related by blood or marriage and one from a current or previous employer, or employer's representative) who have engaged the applicant or the applicant's employer within the previous 24 months to perform: UST installations, repairs, or removals; underground utility construction; or engineering construction. These statements shall attest to the applicant's character, knowledge of construction, and ability to supervise the construction activity. Such statements shall also include a description of the type of construction performed by the applicant; (5) submit a sworn statement by the applicant as to the authenticity of the information provided on the application; (6) prior to the examination, submit the appropriate certificates of completion for the following levels of licenses: (A) Class A--28 hours of training and education courses in the installation and repair of USTs; (B) Class B--12 hours of training and education courses in the removal of USTs; or (C) Class A/B combination--40 hours of training and education courses in the installation, repair, and removal of USTs; and (7) pass the appropriate licensing examination. (c) Individuals with a Class A or Class B may upgrade to a Class A/B combination by submitting a new application with the required fee, completing the required initial training, and passing the examination.