(a) A city may amend the Water Pollution Control and Abatement Program for that city at any time by submitting an amended Water Pollution Control and Abatement Program to the executive director of the commission. Those elements requiring engineering design in the amended Water Pollution Control and Abatement Program for the city shall be signed and sealed by a professional engineer licensed in the State of Texas who shall certify that the city's Program is designed to abate and prevent water pollution attributable to non-permitted sources located within the city.(b) The commission, upon its own motion or in response to a petition filed by the executive director, may require a city to amend a Water Pollution Control and Abatement Program for that city when new or additional information or circumstances warrant such changes to effectuate the purposes of this subchapter.(c) The provisions for notice of initial determination under §216.25 of this title (relating to Notice of Initial Determination) and final determination of applicability under §216.26 of this title (relating to Final Determination of Applicability) shall apply to an amendment of a Water Pollution Control and Abatement Program.