Sewer System means pipelines or conduits, pumping stations, force mains, vehicles, vessels, conveyances, injection wells, and all other constructions, devices, and appliances appurtenant thereto used for conducting sewage or industrial waste or other wastes to a point of ultimate disposal or disposal to any water of the state. To the extent that they are not subject to section 402 of the federal Water Pollution Control Act, ditches, pipes, and drains that serve only to collect, channel, direct, and convey nonpoint runoff from precipitation are not considered as sewer systems for the purposes of this part of this division.