But all the water, from the Portal Store down to the bottom fountain or spigot, comes from the same intake -- which would need to be a little above the Portal Store. If one outlet is suspect, they all are. And I don't think there is any way for contamination to get inside a pressurized water line -- unless the line is de-pressurized at some point in time, as in the winter when they shut it down.
Unless anyone can identify an alternate method for contamination to enter the water system, the only place I can think of is the intake.
