Detection of cross connections in potable water distribution systems – Stage 2: Field trials of candidate detection parameters

Recycling wastewater to a standard that makes it fit for use in irrigation is an efficient and cost-effective strategy for managing water resources, and has prompted the installation of separate pipe and tap reticulation systems in domestic housing schemes such as at Rouse Hill in Sydney. The problem is that water used to irrigate gardens and parks is not recycled to the same high (and expensive) standard as potable drinking water. This makes it important to monitor the drinking water to ensure that it is not accidently contaminated with slightly lower standard irrigation water. This research showed that an inexpensive 4-electrode sensor reliably detected changes in electroconductivity and ultra-violet fluorescence that corresponded to only 1mL of recycled water leaking into 9mL of drinking water. It is likely that a real-world installation of one sensor by the inflow pipe for the housing scheme and multiple sensors by household taps will be even more sensitive. It was concluded that R&D should continue in a larger-scale trial to monitor drinking water quality in dual reticulation systems.