The adoption of this chapter will in no way preclude the Public Utility Commission of Texas from altering or amending any sections of this chapter in whole or in part, or from requiring any other or additional service, equipment, facility, or standard, either upon complaint or upon its own motion or upon application of any utility. Furthermore, this chapter will not relieve in any way a utility or customer from any of its duties under the laws of this state or the United States. If any provision of this chapter is held invalid, such invalidity shall not affect other provisions or applications of this chapter which can be given effect without the invalid provision or application, and to this end, the provisions of this chapter are declared to be severable. This chapter shall not be construed so as to enlarge, diminish, modify, or alter the jurisdiction, powers, or authority of the commission or the substantive rights of any person. The commission may make exceptions to this chapter for good cause.