The City of Hillsboro Water Department is responsible for safeguarding the public water system from pollution and contamination. Through operation of the state-mandated Backflow Prevention & Cross Connection Control Program, the Hillsboro Water Department helps protect your drinking water by:
- Assisting customers with compliance of backflow prevention practices and regulations.
- Identifying, eliminating, or protecting cross connections.
Backflow & Prevention
What is backflow?
Backflow is the reversal of the normal flow of water.
What causes backflow?
Backflow is caused by pressure differences, including a sudden drop in water pressure in our public system or when a building’s plumbing system has higher pressure than the public water supply. Both situations can allow water and contaminants from a private plumbing system to reverse flow into a home or building’s plumbing system or the public water supply, potentially contaminating the water for other users.
How is backflow prevented?
Installing a backflow prevention device protects plumbing systems and our public water supply by preventing backflow.
Required Yearly Testing of Backflow Prevention Devices
The Hillsboro Water Department’s Backflow Prevention & Cross Connection Control Program requires all customers to test their backflow prevention assemblies:
- After initial installation.
- After any repair, replacement, or relocation.
- Each year* by a certified backflow assembly tester.
*Residential assemblies are required be tested no later than July 1 of each year.
Hillsboro Water Department customers with backflow assemblies required to be tested will receive a yearly reminder letter . Failure to conduct the required yearly backflow prevention assembly test will result in denial or discontinuation of water service.
The following actions should be taken to ensure compliance before July 1 of each year:
- Contact a State of Oregon approved Certified Backflow Assembly Tester.
- Schedule a test.
- Provide your account number to the tester.
- Your account number is listed on the reminder to test letter you received from the Hillsboro Water Department as well as on your City of Hillsboro Utility Bill.
- You can request your account number as well by calling 503-681-6163 or sending an e-mail.
- Your account number gives testers information about the assembly(s) at your location, such as make, model, and serial number. It does not identify you or provide your contact information.
- Once the test is complete, the certified tester will submit your results to the Hillsboro Water Department and can send you a copy of the test report.
What is a cross connection?
A cross-connection is any temporary or permanent connection between a public water system or consumer’s potable (i.e., drinking) water system and any source or system containing non-potable water or other substances.
What are examples of common cross connections?
- Hot tubs.
- Auxiliary water systems (wells).
- Hoses submerged in polluted or contaminated water.
- A secondary source of irrigation water (from a well or pond) pumped into an irrigation system directly connected to the drinking water supply system.
- A heating boiler with treatment chemical added to prevent internal corrosion being connected directly to the water supply for make-up water.
- An underground lawn sprinkler system directly connected to the water supply system.
- A fountain or swimming pool directly connected to the water system for filling.
How are cross connections controlled?
Cross connections can lead to contamination when a change in pressure within the water supply piping allows the water to flow backwards. This reversal of flow, called backflow, can allow contaminated water to flow back into the supply piping, threatening health and safety.
Although under normal circumstances the city water supply is pressurized to keep water flowing to your tap, unforeseen circumstances (such as the need to fight a fire, or when a water main breaks) can suddenly change the pressure in the supply piping, allowing the water to siphon back from your tap to the city supply.
Backflow prevention devices are installed to protect against cross connection contamination caused by backflow conditions.
Questions, Concerns, or Additional Information
Contact the Hillsboro Water Department Backflow Prevention & Cross Connection Control Program Coordinator at 503-615-6723 or Backflow@Hillsboro-Oregon.gov.
Frequently Asked Questions