Originally Posted by itat
Larry, the backflow preventers at the pedestal are there because its code to have them. You should have one on the hose spigot at your house, too. At a campground, people use the spigot to connect their black tank flush and to clean their sewer hose. Iíve seen a campground have a water main break and that can cause a vacuum in the water lines sucking water from whatever is attached to the spigot. The risk is low but its real, and based on historical cases of water main contamination, people get very sick and even die from it. I always spray the spigot with Lysol and rinse it before connecting my hose.
Yes, I know it's code. While you can devise all sorts of weird scenarios, most are not realistic. Is it really likely that the local water pressure (maintained by water towers) will suddenly drop to zero at the instant that my uphill neighbor is filling his kiddie pool by dropping the hose in it?
Not sure about your campground, but IIRC there are no fittings on the ends of the hoses at our dump stations. They are used for hosing off the pads around the drains and rinsing our sewage totes.