(a) The purpose of this chapter is to establish the minimum design criteria for the comprehensive design of domestic wastewater collection systems, collection system units, wastewater treatment facilities, and treatment units. The design criteria in this chapter is intended to promote the design of facilities in accordance with good public health and water quality engineering practices. The minimum design criteria may not be sufficient for all situations. A design must protect the public health and meet water quality standards established by the commission.     
      (b) It is also the purpose of this chapter that all domestic wastewater treatment facilities, treatment units, collection systems, collection system units, and associated components must be installed, operated, and maintained:      
        (1) to ensure the safety of the public;       
        (2) to ensure the safety of all individuals authorized to access a wastewater treatment facility, treatment unit, collection system, or collection system unit;       
        (3) in accordance with the engineering report and the associated plans and specifications approved by the executive director; and       
        (4) to ensure continuous compliance with all applicable statutory and regulatory requirements.       
      (c) This chapter establishes procedures for the review and approval of project plans and specifications. An approval granted by a municipality in accordance with §217.8 of this title (relating to Municipality Reviews) or by the Texas Water Development Board in accordance with §217.9 of this title (relating to Texas Water Development Board Reviews) is considered equivalent to approval by the executive director.     
     Source Note:        The provisions of this §217.3 adopted to be effective August 28, 2008, 33 TexReg 6843; amended to be effective December 4, 2015, 40 TexReg 8254