A cross-connection is a direct arrangement of piping that allows the potable (safe. drinking) water pipe to be connected to a pipe supply that contains a. contaminant or pollutant. An example of a cross-connection is a common garden. hose attached to your home outside faucet with the hose outlet end lying in a. pool or inserted into a sewer clean out. Other examples include a garden hose. inserted in a car's radiator for flushing that contains anti-freeze or a hose.