What is a cross connection?

A cross connection is a point in a plumbing system where it is possible for a nonpotable substance to come into contact with the potable drinking water supply.

Examples

Common examples of cross-connections include:

  • Connections to firefighting equipment
  • Garden hose submerged in a pesticide mixture
  • Piped connection providing potable feed water to an industrial process, such as a cooling tower, or a submerged outlet of an irrigation system

Most cross-connections occur beyond the customer service connection, within residential, commercial, institutional, or industrial plumbing systems.

Identifying Cross Connections

Identifying cross-connections can be challenging because many distribution systems are expanding to serve new customers and changing to accommodate customer needs. Further, temporary and permanent cross-connections can be created in existing facilities without the knowledge of the water system managers and operators.

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