One embodiment involves a method for monitoring water associated with at least one of a water purification, distribution, or treatment facility. The method includes operating a number of monitoring units remotely positioned with respect to one another to at least partially perform the monitoring, the units each including several different types of sensors to detect correspondingly different characteristics of the water, a processing subsystem, and a two-way communication subsystem. For each of the units, the method includes processing signals corresponding to the different characteristics with the processing subsystem. Additionally, for one of the units, the method includes detecting an abnormal condition by executing diagnostic logic and communicating the abnormal condition to a host with the two-way communication subsystem for the one of the units.