The owner of a waste water treatment plant operated for the purpose of treating wastes from a sanitary sewer system shall hold the exclusive right to the treated waste water as against anyone who has supplied the water discharged into the waste water collection and treatment system, including a person using water under a water service contract, unless otherwise provided by agreement.

Nothing in this article shall affect the treatment plant owner’s obligations to any legal user of the discharged treated waste water.

Nothing in this article is intended to interfere with the regulatory authority of the board or any California regional water quality control board under Division 7 (commencing with Section 13000).