A cross-connection is a link between potable water pipes to unsafe, unknown pipes, and/or liquid.
For example, a garden hose attached to a hose bib with the outlet end submerged in a pond or swimming pool. If Fairfax Water’s supply pressure drops, the water from the pond or pool can be suctioned into the drinking water supply. This water can contaminate the customer’s water system as well as the Fairfax Water potable water system, possibly exposing nearby customers.