The ABC’s of Backflow Prevention

Important Things to Know

Every irrigation system in Illinois must be equipped with an RPZ (Reduced Pressure Zone) valve, which is a backflow prevention device. Naturescape Design’s Tom Layshock, a CCCDl certified plumber, answers a few questions about certifying, maintaining and repairing RPZ’s. Click the last tab to read the whole interview , or click on the question(s) that you are interested in to read Tom’s specific answer(s).

Tom: In layman’s terms, backflow is anywhere “bad water” has a chance to mix with “good water”. Backflow is technically the unintentional reversal of the normal direction of flow in a potable water system that could result in pollution or contamination of a system by a liquid, gas, solid or any combination of that matter.

Tom: All irrigation systems must have a backflow device installed to prevent backsiphonage and or backpressure into your home’s water supply. While there are other types of backflow devices, most national, state and local codes require the installation of an RPZ backflow device to protect drinking water cross-connections with non-potable applications from an irrigation system. Backflow devices other than RPZ’s which are connected to a home irrigation system are usually not in compliance with code and should be replaced.

Tom: Certifying an RPZ involves testing the device to ensure it is operating properly at or above pressure levels required by the state code. Certifications must be performed by a plumber with a Cross Connection Control Device Inspector designation. The state code requires that RPZ’s are certified at the time of installation and at least annually thereafter. Both the Illinois Department of Public Health and the Illinois EPA Division of Public Water Supplies determine certification requirements.

Tom: Municipalities typically have the responsibility of enforcing the code. Many of them have outsourced this process to companies such as BSI and Aqua Backflow, though communications to homeowners are often sent under the town’s letterhead. Each municipality determines annual deadlines for certification; some are designated date specific while others are based on an anniversary date. Naturescape keeps track of the various dates required by each town and attempts to certify our customers RPZ’s in advance of the deadline dates whenever schedules permit.

Tom: RPZ’s that are located inside the home can be certified at any time during the year; in fact there is usually more flexibility in scheduling these in February, March or April in advance of the watering season. Because access inside is required, an appointment is usually necessary. RPZ’s that are located outdoors are typically certified after the system has been started up for the season. These can be tested without the property owner being present, however in all cases, the water for the system must be on in order for the test to be administered.

Tom: No action is required on your part. Typically within 24 hours of the certification, a copy of the Field Test Report will be transmitted to the city or their backflow administrating representative to confirm that the test has been completed. A copy of the same field report will also be left attached to the RPZ in a weather resistant holder. RPZ certification field test reports are also kept on file at Naturescape.

Tom: On the bottom of the RPZ, there is a relief port which is supposed to discharge water as the device does its job. So if there’s an occasional drip or damp spot beneath it, it’s probably OK. So if it is a slow drip, you may opt to leave the system on. But if the relief port is leaking constantly or if it is anywhere else other than that, then turn the shut off valves on each side of the device to the “off” position. If it is still leaking at that point, you may need to shut the source of water for your irrigation system off. Call us. We will attempt to diagnose the severity of the leak and will make arrangements to come out to look at it and repair it as needed. When a service call is made to check such a leak, the water must be on when we arrive or we must be able to access the valves to turn the water on in order to make the repairs.

Tom: The type of repair to be made is driven by several factors; the severity of the leak, the type of RPZ that is installed, and the age of the RPZ itself. In some instances, a part or using an RPZ repair kit can solve the problem and keep the RPZ operable for the foreseeable future. With some models, if the vessel itself is damaged, that single part can be replaced without having to purchase a new RPZ. But if the RPZ is old or if the leak is too large to be held together by shorter term repairs, a new RPZ will need to be purchased.

Tom: Several factors influence the lifespan of a backflow device, including water pressure, water quality, frequency of use and installation environment. Roughly 5-8% of tested devices will have a problem. Most are simple and are caused by worn O-rings, cut seals or broken springs. Severe problems such as cracked castings and shattered poppets are usually caused by exposure to freezing temperatures. Most RPZ’s are made of brass and even if they are stored inside during the winter months, brass can still shrink or swell slightly over time, which affects the device and ultimately deems it unusable.

Question: What is backflow?

Tom: In layman’s terms, backflow is anywhere “bad water” has a chance to mix with “good water”. Backflow is technically the unintentional reversal of the normal direction of flow in a potable water system that could result in pollution or contamination of a system by a liquid, gas, solid or any combination of that matter.

Question: What are RPZ’s and what is their significance?

Tom: All irrigation systems must have a backflow device installed to prevent backsiphonage and or backpressure into your home’s water supply. While there are other types of backflow devices, most national, state and local codes require the installation of an RPZ backflow device to protect drinking water cross-connections with non-potable applications from an irrigation system. Backflow devices other than RPZ’s which are connected to a home irrigation system are usually not in compliance with code and should be replaced.

Question: What does “certifying” an RPZ mean and how often is it required?

Tom: Certifying an RPZ involves testing the device to ensure it is operating properly at or above pressure levels required by the state code. Certifications must be performed by a plumber with a Cross Connection Control Device Inspector designation. The state code requires that RPZ’s are certified at the time of installation and at least annually thereafter. Both the Illinois Department of Public Health and the Illinois EPA Division of Public Water Supplies determine certification requirements.

Question: If the state agencies determine the laws, why do I receive letters from my city government about complying with certifications?

Tom: Municipalities typically have the responsibility of enforcing the code. Many of them have outsourced this process to companies such as BSI and Aqua Backflow, though communications to homeowners are often sent under the town’s letterhead. Each municipality determines annual deadlines for certification; some are designated date specific while others are based on an anniversary date. Naturescape keeps track of the various dates required by each town and attempts to certify our customers RPZ’s in advance of the deadline dates whenever schedules permit.

Question: When should I get my RPZ certified?

Tom: RPZ’s that are located inside the home can be certified at any time during the year; in fact there is usually more flexibility in scheduling these in February, March or April in advance of the watering season. Because access inside is required, an appointment is usually necessary. RPZ’s that are located outdoors are typically certified after the system has been started up for the season. These can be tested without the property owner being present, however in all cases, the water for the system must be on in order for the test to be administered.

Question: How will the town know that my RPZ has been certified and passed?

Tom: No action is required on your part. Typically within 24 hours of the certification, a copy of the Field Test Report will be transmitted to the city or their backflow administrating representative to confirm that the test has been completed. A copy of the same field report will also be left attached to the RPZ in a weather resistant holder. RPZ certification field test reports are also kept on file at Naturescape.

Question: What should I do if I notice my RPZ is leaking?

Tom: On the bottom of the RPZ, there is a relief port which is supposed to discharge water as the device does its job. So if there’s an occasional drip or damp spot beneath it, it’s probably OK. So if it is a slow drip, you may opt to leave the system on. But if the relief port is leaking constantly or if it is anywhere else other than that, then turn the shut off valves on each side of the device to the “off” position. If it is still leaking at that point, you may need to shut the source of water for your irrigation system off. Call us. We will attempt to diagnose the severity of the leak and will make arrangements to come out to look at it and repair it as needed. When a service call is made to check such a leak, the water must be on when we arrive or we must be able to access the valves to turn the water on in order to make the repairs.

Question: What are the options for repairing a leaking or broken RPZ?

Tom: The type of repair to be made is driven by several factors; the severity of the leak, the type of RPZ that is installed, and the age of the RPZ itself. In some instances, a part or using an RPZ repair kit can solve the problem and keep the RPZ operable for the foreseeable future. With some models, if the vessel itself is damaged, that single part can be replaced without having to purchase a new RPZ. But if the RPZ is old or if the leak is too large to be held together by shorter term repairs, a new RPZ will need to be purchased.

Question: These RPZ’s seem to be built of a durable metal and look like they’re made to last a long time. What is the lifetime of the average RPZ?

Tom: Several factors influence the lifespan of a backflow device, including water pressure, water quality, frequency of use and installation environment. Roughly 5-8% of tested devices will have a problem. Most are simple and are caused by worn O-rings, cut seals or broken springs. Severe problems such as cracked castings and shattered poppets are usually caused by exposure to freezing temperatures. Most RPZ’s are made of brass and even if they are stored inside during the winter months, brass can still shrink or swell slightly over time, which affects the device and ultimately deems it unusable.

Have another question?

I hope this Q & A has been helpful in addressing any questions you may have about RPZ’s. If you have a general question about RPZ’s or any other backflow device that has not been answered above, send your question to us via the email section provided below and we will follow up with you. If it’s a question that would be of interest to many of our customers, we may even add it to the interview! You can contact Tom at (847) 875-5213.

Thanks for reading,

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