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Backflow Prevention & Cross Connection Control
Cross Connection Example
The City of Highland Park takes pride in providing safe drinking water to our customers. The water that reaches your home or business meets all State and Federal drinking water standards and is safe to drink. However, contamination can occur within your own piping system. The greatest potential hazard is known as an unprotected “cross connection”, which can cause backflow to occur.

The State of Illinois and the US Environmental Protection Agency have established rules that require the City of Highland Park to identify potential cross connection hazards and take appropriate actions to protect against the possibility of backflow occurring.  The City has established a protection program of the public water supply.  The Cross Connection Control Program is designed to ensure the safety of the water supply by providing protection from the entry of unwated and possible dangerous material into the drinking water supply.

RPZ Direction of Flow
Water is being used in many applications such as mixing, diluting, sprinkling and cleaning.  Water is coming into contact with hundreds of chemicals and substances.  Under the wrong circumstance, this can lead to water contamination.  Loss of water pressure or an improper connection of a pump to a water line could result in dangerous materials being sipohned or pumped back into the water supply.  The Cross Connection Control Program requires the installation of backflow prevention devices that are designed to limit the possibility of materials flowing the wrong direction in a water line. 

Example of a RPZ
The most common backflow preventer device is a Reduced Pressure Zone (RPZ).  This device is designed to allow the system connected to it to vent to the atmosphere if the water distribution system loses pressure.  This ensures there will be no backflow into the public water supply thus protecting the water supply from contamination. RPZ backflow preventers are installed on:  in-ground sprinkling systems, fire protection systems connected to the water supply, commercial or manufacturing sites that have water connected to any process.