A Cooperative Water Association

   -    Established in 1953

 

 


Quincy Water Association

 Cross Connection/Backflow Prevention FAQS

1. What is backflow?

Normally, your water supply is under 40 to 80 pounds of pressure when it enters your home or business. On rare occasions, this pressure is interrupted—perhaps by a water main break, a power failure, fire fighters battling a nearby blaze, or some other disruption in water service. When there is a significant loss of pressure, water can flow back into the public water supply system. When water flows backward into the public water supply, it is called “backflow”. Backflow can also occur when the member’s water system has a higher pressure than the QWA water system.

In rare instances, backflow can contaminate the public water supply. Contamination occurs when a water supply line is connected to equipment containing a non-potable (unsafe to drink) substance. Such connections are called cross connections and they are dangerous if no protective measures are taken.

In order to prevent this situation from occurring, the Quincy Water Association has a Cross Connection Prevention Program which requires users of the QWA water system to install backflow prevention devices to protect the public drinking water distribution system.

2. What is a cross connection?

Any physical or potential connection between a potable water supply and a hazardous material or one of questionable quality. There shall be no such connection without the installation of an approved backflow prevention assembly in accordance to the degree of hazard of the substance involved.

3. Why is it important for water suppliers to prevent backflow?

Backflow into a any water system can pollute or contaminate the potable water in that system (i.e., backflow into a water system can make the water in that system unusable or unsafe to drink). Water suppliers have a responsibility to provide water that is usable and safe to drink under all foreseeable circumstances. Furthermore, consumers generally have absolute faith that water delivered to them through a water system is always safe to drink. For these reasons, the QWA must take reasonable precautions to protect your water system against backflow.

4. Can you show an illustration of how backflow occurs?

Here is an example of how backflow can occur. The supply line to the pressurized boiler at the fertilizer plant was leaking, which allowed chemicals in the boiler to backflow into the water main supplying the fast food restaurant next door. A backflow prevention assembly would have prevented this type of contamination from occurring.

5. Can you give some examples of cross connections?

In all of these examples, a sudden drop in water pressure could draw contaminants – chemicals, fertilizer, soapy water or even bacteria -- back into your pipes and your drinking water supply. Any of these contaminants could be hazardous to your health if ingested.
The best way to prevent this potential contamination is to eliminate the cross connection. This could mean simply making sure that you never leave a hose submerged in a tub of water or that you never apply fertilizer to your lawn with a hose-aspirator device. In some cases (such as the lawn sprinkling system example noted above) the cross connection cannot be eliminated and the only means of protection is by installation of an approved backflow prevention device.

6. What is backsiphonage?

When there is a sudden reduction in water pressure in the our water distribution system, such as during fire fighting or when a water main breaks, water flow can potentially be reversed. This could create a suction effect, possibly drawing contaminated water into the drinking water system.

7. What is backpressure?

Backpressure is created when the pressure in a private non-drinking water system, such as in a recirculation system containing soap, acid or antifreeze exceeds the pressure in the public drinking water system that it is connected to. This could force contaminated water to enter the public drinking water system.

8. What are some commonly used backflow prevention devices?

Backflow prevention devices are like seat belts; they protect you and family members from a potential contamination event. If an accident occurred and an unprotected cross connection resulted in contamination of your water supply, you would be glad that you took the time and trouble to install and maintain a backflow prevention device.

If you have a backflow prevention device on your property, do your part by making sure that your device is tested annually. If repairs are needed, be certain to have those repairs made as quickly as possible. Remember that if the device is repaired or replaced it must be re-tested.

Some common and effective devices installed to prevent backflow are shown below:

Air Gap (AG)
Used mainly on tanks and sinks, it is a gap between the outlet and the basin. *Requirements:
♦The gap needs to be a minimum 2 times the supply pipe diameter.

Hose Bibb Vacuum Breaker (HBVB)
A simple device used to prevent backflow installed on an outdoor faucet.

Pressure Vacuum Breaker (PVB)
Used mainly on lawn irrigation systems. It has a one way check and a spring loaded air inlet valve that closes when water pressure drops.
*Requirements:
♦ No backpressure (from fertilizer injection system or water well)
♦ 12" above highest sprinkler head
♦ Protect from freezing

Atmospheric Vacuum Breaker (AVB)
An AVB is a non-testable mechanical backflow preventer with a gravity opening poppet air opening, designed to admit atmosphere into the downstream sides of the unit under a no flow condition to prevent back siphonage. It must be installed 6-inches above highest downstream water discharge. There shall be no valves or reduction of pipe size on its downstream side. (Note: This device is installed on certain equipment that uses potable water by the manufacturer or contracted installer. Examples of this equipment are dishwashers, soap dispensers, faucets and deep sinks, etc.). The type of backflow protection required is based on the degree of hazard that the property represents to the potable water supply.

Reduced Pressure (RP) Principle Assemblies
A reduced pressure principle assembly is a mechanical valve assembly that consists of two internally loaded independently operating check valves and a mechanically independent, hydraulically dependent relief valve located between the check valves. It is used for services that have either health hazards or non-health hazards and under conditions of backpressure or backsiphonage. It provides the highest level of protection among the mechanical backflow prevention devices.

9. How do I know if I need a backflow prevention assembly?

A member of the cross-connection control staff will visit your property to perform a premise survey for backflow requirements. You will receive a letter providing you with guidelines and what action you need to take to ensure compliance with the QWA requirements.

10. Is there a general compliance schedule and process?

Yes, your backflow prevention assembly must be in compliance with the Department's testing requirements by the date shown on the notification letter. You will receive a follow up notice after 30 days. After 60 days (if compliance has not already been achieved), you will receive a notice informing you that your water service may be discontinued unless you achieve compliance.

11. Who can install a backflow prevention assembly?

Backflow Prevention Technicians who are licensed Plumbing Contractors and their employees that are certified as Backflow Prevention Assembly Testers to install and perform annual testing and maintenance of a backflow prevention assembly. A list of approved testers in our area is available through the department.

12. Where should a backflow prevention assembly be located?

Backflow prevention assemblies must be located on the customer's side of the water meter, and installed in accordance with the State of Oregon Plumbing Code and manufacturer specifications. It must be located such that inspection and maintenance can be conveniently performed.

13. Who owns and is responsible for testing and maintenance of the backflow prevention assembly?

The QWA member owns and is solely responsible to ensure that the assembly is installed and in satisfactory operating condition at all times. Per our bylaws, everything on your side of the meter (including all water lines) is the members responsibility.

New Members with Existing Service that have a Backflow Prevention Assembly Already Installed:

The member is responsible for ensuring that a Certified Backflow Prevention Technician tests and certifies the backflow prevention assembly. Northstar will send a notification letter to each customer, advising when the annual test is due. The member must contact a recognized Certified Backflow Prevention Technician to perform the test and ensure that a Test and Maintenance Report is received by the the Northstar or QWA office. The member is responsible for having all repair and maintenance performed on the backflow prevention assembly by a Certified Backflow Prevention Technician. After any repair or maintenance, the assembly must be re-tested immediately and test results submitted to the Northstar or QWA office.

Existing Members with Backflow Prevention Assemblies:

The member is responsible for ensuring that a Certified Backflow Prevention Technician tests and maintains the backflow prevention assembly. Northwest will send a notification letter to the customer advising when the annual test is due. The member must contact a Certified Backflow Prevention Technician to perform the test and ensure that a Test and Maintenance Report is received by the Northstar or QWA office. The member is responsible for having all repair and maintenance performed on the backflow prevention assembly by a Certified Backflow Prevention Technician. After any repair or maintenance, the assembly must be re-tested immediately and test results submitted to the Northstar or QWA office.

14. How do I find an approved backflow prevention technician?

Plumbing Contractors who are Certified Backflow Prevention Technicians can be found in the plumbing section of your phone book. Northstar & QWA offers an easy low cost program for annual testing as one option. A list of Certified Testers in Columbia County is provided on our Cross Connection Program page. Due to the fact that test prices vary, you may want to contact several Certified Backflow Prevention Technicians to obtain quotes for the testing of your assembly.

15. How often do I need to have my backflow prevention assembly tested?

The Quincy Water Association requires that you test your Backflow Prevention Assembly at the following times:

  1. When your backflow prevention assembly is first installed. Your Certified Backflow Prevention Technician must perform this test.
  2. The backflow prevention assembly must be tested annually thereafter. Your Certified Backflow Prevention Technician must perform this test.
  3. After any repair or replacement of the Backflow Prevention Assembly. Your Certified Backflow Prevention Technician must perform this test.

16. Why does a backflow prevention device have to be tested annually?

Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested by a State Certified Tester, with properly calibrated gauge equipment.

17. Who is responsible for obtaining all required permits?

The customer is responsible for making sure that the Certified Backflow Prevention Technician obtains all required permits from the plumbing code officials responsible for the location. The customer must submit a copy of Assembly Certification to the Northstar or QWA after replacement of a backflow prevention assembly.

18. Who do I contact if I have questions about backflow prevention?

Northstar Genearl Contractor
Phone 503-304-0500
email: Northstar General Contractor