Frequently Asked Questions: CCP

1. What is a cross connection control program?

2. What are we protecting the public water supply from?

3. What is a cross-connection and backflow?

4. What is back-siphonage?

5. What is backpressure backflow?

6. What is an Air Gap?

7. What is a backflow preventer?

8. What products are used for protection of cross connections?

9. What is premise isolation?

10. How do I know if my property requires the installation of a backflow prevention assembly and/or device?

11. Why are homes not covered by this program?

12. How do I know what type of backflow prevention device my facility requires?

13. What is a Double Check Valve Assembly (DCVA)?

14. What is a Reduced Pressure Principle Assembly (RP)?

15. Who can test backflow prevention devices?

16. Why do backflow prevention devices have to be tested periodically?

17. How often do backflow prevention devices need to be tested?

18. Who is responsible for the installation and annual testing of premise isolation backflow prevention device?

19. Do the test tags have specifications?

1. What is a cross connection control program?

A cross connection control program is a cooperative effort between health officials, water purveyors and property owners to ensure that the water supply remains uncontaminated as a result of backflow. The program involves the isolation of private water systems from the public waterworks through the installation of a backflow prevention device immediately after the water meter. This is called "premise isolation."

The Cross Connection Control Program focuses on Industrial, Commercial, Institutional (ICI) and Agricultural properties where there is a greater potential for backflow and contamination to the water supply. The elements of a program define the type of protection required and responsibility for the administration and enforcement.

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2. What are we protecting the public water supply from?

The program's goal is to protect the drinking water supply from contamination due to backflow. We do this by preventing water that has been used for washing, heating, cooling, etc., within a facility from backflowing into the drinking water system.

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3. What is a cross-connection and backflow?

A cross connection is any actual or potential connection between a drinking water system and some other environment which could allow a backflow of contaminants to enter the drinking water. This could be a pipe connecting a customer's water system to the heating/cooling system, irrigation or fire system.

Backflow is the flow of water or other liquids, gases, or solids from any source in the direction opposite to normal or intended flow.

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4. What is back-siphonage?

Back-siphonage is caused by negative pressure in the supply piping. Some common causes of back-siphonage are:

  • High velocities in pipe lines.
  • Line repair or break that is lower than a service point.
  • Lowered main pressure due to high water withdrawal rate such as fire fighting or water main flushing.
  • Reduced supply on the suction side of the booster pump.

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5. What is backpressure backflow?

Backpressure may cause backflow to occur when the potable supply piping is connected to a system or fixture which exceeds the operating pressure of the supply piping. This higher pressure can be caused by booster pumps, boilers, pressure vessels or elevated piping, such as high rise buildings or tanks. If these connections are not properly protected, potable and non-potable water or liquids can be forced into the potable supply system.

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6. What is an Air Gap?

Air Gap is the physical separation of the potable and non-potable system by an air space. The vertical distance between the supply pipe and the flood level rim should be two times the diameter of the supply pipe but never less than 1". The air gap can be used on a direct or inlet connection and for all toxic substances.

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7. What is a backflow preventer?

A backflow preventer is a mechanical apparatus installed in a water system to prevent the occurrence of backflow.

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8. What products are used for protection of cross connections?
  • Air Gap
  • Atmospheric Vacuum Breakers - which also includes hose connection vacuum breakers
  • Dual Check Value
  • Double Check Valve Assembly (testable)
  • Reduced Pressure Zone Assembly (testable)

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9. What is premise isolation?

Premise isolation is the isolation of a property's private water system from the Utility's drinking water supply system. This is done at the water service connection (the water meter). It is the isolation of water located within a building, structure or property from the Utility's water supply and is achieved by installing a backflow preventer immediately after the water meter.

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10. How do I know if my property requires the installation of a backflow prevention assembly and/or device?

The Utility is currently performing surveys of all water connections to the water distribution system. Our program is focused on agriculture and industry.

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11. Why are homes not covered by this program?

Single family homes pose the least threat for contamination of the water supply. As per the Utility's Water Tariff, they are required before connecting to the system, but they are considered a low hazard. Homeowners can however help to protect our water supply and the water within their own homes by installing backflow prevention devices on their garden hoses. These are called hose bibs and they can be purchased from hardware stores. Using a hose bib is not a law, but it is good practice in protecting homeowners and their families from contaminated water. Everybody has a role to play in protecting the health and safety of our drinking water.

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12. How do I know what type of backflow prevention device my facility requires?

The type of device required for your facility will depend on the hazard level your facility and use of your property as it relates to the AWWA Canadian Cross Connection Control Manual Level of Risk Standards. The hazard level is determined by the industry sector. Facilities classified as a "moderate hazard" require the installation of a Double Check Valve Assembly (DCVA) assembly. Facilities classified as a "high or severe hazard" require the installation of a Reduce Pressure Zone assembly (RPZA).

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13. What is a Double Check Valve Assembly (DCVA)?

A Double Check Valve Assembly (DCVA) is a mechanical backflow prevention device that consists of two internally loaded check valves. It includes two shut-off valves and four test cocks. With the two check valves in series, a DCVA prevents backflow even if one check valve fails to close tightly. It can be used to prevent backflow due to both back siphonage and back pressure where a minor or moderate hazard exists. Since no visible warning is given of a failure of check valves, a DCVA must be periodically tested for proper operation.

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14. What is a Reduced Pressure Principle Assembly (RP)?

A Reduced Pressure Principle (RP) is a mechanical backflow prevention device that consists of two independently acting, internally loaded check valves, separated by a reduced pressure zone. During normal operation, the pressure between the two check valves is maintained at a lower pressure than the supply pressure. If either check valve leaks, water will discharge from the relief port. When this happens, maintenance is required. Due to the discharge of water, an RP must be properly installed in an area that has adequate drainage.

A Reduced Pressure Principle includes two shut-off valves and four test cocks. It is designed to isolate severe hazards and must be tested at least once a year.

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15. Who can test backflow prevention devices?

Testing can be completed by an individual who is certified by the British Columbia Water and Waste Association (BCWWA).

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16. Why do backflow prevention devices have to be tested periodically?

A backflow prevention device may not show visible signs of failure. Backflow prevention assembly devices contain internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. A backflow prevention assembly device, such as Double Check Valve Assembly (DCVA), or Reduced Pressure Principle Assembly (RP), must be tested by a certified individual with a properly calibrated test gauge to ensure that they are functioning properly.

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17. How often do backflow prevention devices need to be tested?

In order to ensure the proper operation of a backflow prevention device, it must be tested upon installation, repair, relocation or replacement, and at least once a year thereafter. To ensure that backflow prevention devices are functioning properly, a certified tester must test them annually.

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18. Who is responsible for the installation and annual testing of premise isolation backflow prevention device?

The owner of the property or building that currently has a service connection to the Utility's water supply or has applied for a new service connection is responsible for the installation of the premise isolation backflow prevention devices, as well the annual testing of the device by a certified tester.

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19. Do the test tags have specifications? 

Device tags may be any size, colour, and must be made of a moisture resistant material.

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