Backflow Prevention

Canby Utility loves clean water! We know you do too!

faucet running water into a glassWe provide you with high quality, clean drinking water. Unfortunately, there are ways that clean drinking water can be contaminated right at your home. A properly installed backflow apparatus at your home is important to keep our drinking water clean.

Did you know plumbing codes require that lawn irrigation and sprinkler systems have an apparatus to prevent any water from flowing back from that system into the drinking water system? And that most of these require annual testing to ensure they are functioning properly? Unfortunately, many home systems have been installed without the proper apparatus, or if installed and require annual testing, they have not been tested.

Under normal system operating conditions, your home’s water would not flow back into the main water lines. However, there are abnormal conditions that not only can allow water to backflow, but in some cases actually suck it right out of your pipes. These conditions do and have occurred, and the resulting contamination has caused great harm to the users of some water systems. That is why there are Federal, State, and Local rules designed to prevent it.

View the Backflow Prevention Plan (PDF) – Adopted by Board of Directors June 2017

Take Two Steps for Clean Water

Backflow Prevention Apparatus
If you have an underground irrigation system, be sure the proper backflow prevention apparatus is installed.
Irrigation system Atmospheric Vacuum Breaker

Depending on the design of your irrigation system, the apparatus type and location(s) can vary widely. Typically a newer system may have a Double Check Valve Assembly (DCVA). These may be installed below grade, have control valves beyond the assembly, and can be installed at the low point of your system, if that is the best location for it. Other devices or assemblies that may be adequate for certain layouts include Atmospheric Vacuum Breakers (AVB), Pressure Vacuum Breakers (PVB), and Spill-Resistant Vacuum Breakers (SVB). If your irrigation system dispenses chemicals, a Reduced Pressure Principle Valve Assembly (RPVA) is the required apparatus.

To prevent possible damage to your plumbing due to the thermal expansion of water trapped beyond RPVA’s—and also DCVAs if similarly placed in the water line between your home and water meter—a Thermal Expansion Device is typically attached to your hot water tank.

Atmospheric Vacuum Breaker

Garden hoses can create a risk of backflow contamination. Do not leave garden hoses submerged in a swimming pool, pond, laundry sink, or car wash bucket.

Be sure you have an atmospheric vacuum breaker (AVB) installed on each of your hose bibs. Find them at your local hardware store. Simply screw them on to install.

View the Backflow Prevention Assembly Installation and Operation Standards (PDF).

Test Annually
Test backflow prevention assemblies annually

Regular testing will ensure that DCVAs on irrigation systems continue to function properly, and help you identify any maintenance issues. Many landscaping companies perform backflow testing. Contact Canby Utility or view the list below for backflow testing companies. We will help you remember to have your backflow devices checked annually by sending you reminders throughout the year.

Certified Testers

Certified Testers List

(Updated February 2021)

Companies are listed in Alphabetical order. Canby Utility does not prefer one testing company over another.

For a complete list of Certified Backflow Testers in Clackamas County please go to the Oregon Public Health Drinking Water Data page.

  • A1 Backflow — 503-873-9600 — Silverton, Oregon
  • AFP Systems — 503-692-9284 — Tualatin, Oregon
  • A & A Drilling — 503-780-3823 — Milwaukie, Oregon
  • American Backflow Services — 503-289-1745 — 5905 N. Interstate Portland, OR 97217
  • Ben’s Backflow, LLC — 503-351-0266 — Eagle Creek, Oregon
  • Bruton Backflow & Irrigation — 503-618-1806 — PO Box 1927 Fairview OR 97024
  • Cascadia Backflow — 503-899-7248 — 16869 SW 65th Ave #9 Lake Oswego OR 97035
  • Custom Plumbing & Construction — 503-266-1212 — PO Box 1051 Canby OR 97013
  • Clean Water Backflow Testing — 503-708-2518 — 15755 SW Willow Ct. Sherwood OR 97140
  • Columbia Cross Connection Control — 503-235-6141 — PO Box 9217 Portland OR 97207
  • Dynamic Backflow — 971-983-9456 — PO Box 610 Wilsonville OR 97070
  • Eco Backflow LLC — 503-669-2722 — PO Box 579 Sandy, Oregon 97055
  • Fire Services Plus — 503-848-2345 — Beaverton, Oregon
  • Full Landscape Management — 503-406-8233 — Canby, Oregon
  • Heath Backflow — 503-625-8553 — PO Box 1565 Sherwood OR 97140
  • Living Color Nursery- Nathan Holmes — 971-275-4306 — PO Box 514 Wilsonville OR 97070
  • Mark Anderson Backflow Testing — 503-849-4700 — Oregon City, Oregon 97045
  • M & E Backflow Consulting — 503-347-1107 — 1517 NE 10th Place Canby OR 97013
  • Merrill Water Systems — 503-734-7400 — 14603 S. Macksburg Rd., Molalla OR 97038
  • My Plumbing — 971-409-3864 — 17416 SE Brooklyn St Portland OR 97236
  • Northwest Backflow Inspection — 503-695-3286 — PO Box 1536 Hillsboro OR 97123
  • Northwest Plumbing & Backflow — 503-488-0773 — 12042 SE Sunnyside Rd. Clackamas OR 97015
  • Oregon Backflow Testing — 503-491-9402 — 15685 SW 116th Ave. #199 Portland OR 97224
  • Oregon Irrigation — 503-656-9826 — 25333 S. Zeller Dr. Canby OR 97013
  • Pro-Grass — 503-682-6076 — 29895 SW Kingsman Rd. Wilsonville OR 97070
  • Tom Hempel Testing, LLC — 503-390-1961 — PO Box 20271 Keizer OR 97307
  • T & R Building Service — 503-318-6313 — 8660 Rogue Ln. Wilsonville OR 97070
  • Waterscape Irrigation — 503-209-9748 — PO Box 1856 Gresham OR 97030
  • Willamette Valley Backflow — 503-884-7696 — PO Box 1605 Silverton OR 97381

Visit the Oregon Health Authority website for a list of backflow testers.

Residential Backflow Prevention and Cross Connection FAQ

Canby Utility, your water supplier, is committed to providing all our water customers with safe drinking water. It is our responsibility for cross connection control that begins at the water supply source and ends at the point of delivery to the water user’s premise, but we need your help to prevent contamination through backflow from the customer side to keep our water safe throughout the system.

Residential customers who have potential cross connections are responsible for preventing contaminants from entering the public water system from their individual plumbing systems by installing and maintaining approved backflow prevention assemblies.

What is a cross connection?

A cross connection is a point in the plumbing system where the public potable water supply is connected or has the potential of being connected directly to a source of non-potable substances. Under certain hydraulic conditions, pollutants or contaminants can enter the public potable water system (backflow) through these unprotected connections. Cross connections are installed each day because people are unaware of the problems they can create.

What can you do to help?

Fortunately, you can help prevent contamination of the public water system due to backflow. If your irrigation system does not have a backflow prevention assembly, you need to install an approved assembly or device as required by your specific situation.

If your system does have a backflow device, ensure that it is in good working order by having it tested annually and the test results forwarded to the Canby Utility Water Department.

If a water hose is used to fill a pool, hot tub, pond, water feature, or even a wash bucket make sure it is protected with a hose bibb vacuum breaker installed on the faucet.

Does water ever flow backwards?

Drinking water normally flows in one direction, from the public side to the customer side, however, under certain circumstances, it can flow in the opposite direction. This is known as “backflow”. A significant drop in public side water pressure possibly caused by a water main break or extreme high usage on the water system, or due to a pump or thermal expansion on the property side are backflow conditions. Under these conditions, a connection not protected could allow pollutants to be siphoned back into the public water system.