(a) This chapter shall not be construed to limit or abridge the powers or duties granted to the State Water Resources Control Board and each regional water quality control board by Division 7 (commencing with Section 13000) of the Water Code.
(b) Subdivision (a) shall not be construed to limit the power or authority of the department, or any agency or official authorized to enforce this chapter pursuant to subdivision (a) of Section 25180, to take any action necessary to ensure compliance with this chapter or with any regulation adopted pursuant to this chapter, or to limit the duty of any person to comply with this chapter or with any regulation, order, or permit issued pursuant to this chapter. An action taken pursuant to the powers and duties specified in subdivision (a) is not a defense to any action taken to enforce this chapter or any regulation, order, or permit issued pursuant to this chapter.