The district may provide that the rates and charges for services and facilities furnished pursuant to this article may be collected with the water rates of the district, that all rates shall be billed upon the same bill and collected as one item, and that in the event of failure to pay the whole or any part of the bill, the district may discontinue any or all service for which the bill is rendered. This section shall not be construed to prohibit the collection of rates or charges by the district in any other lawful manner.