OLWS protects the water quality of the public water system and the health of its customers by requiring some customers to use “backflow devices” which prevent contaminated water from “backwashing” into the public system from a customer. The risk can be relatively benign from a residential customer that installs a backyard irrigation system, to a high-risk use such as a hospital.In the former, dirty or fertilizer-rich water could “reverse-flow” (backwash) into the public system and be transported to other customer.  In the latter, viruses, medications and other contaminants could be spread throughout the system which could cause a significant health hazard.  Needless to say, OLWS takes this contamination prevention seriously. Many of our staff also live in the service area and want clean drinking water too.

Backflow devices are typically prescribed for fire suppression lines and drinking water lines.  Regarding the backflow device, OLWS does not prescribe a specific model for any purpose. The list linked below provides numerous options.  From this list, you should be able to find one that’s in stock at your favorite plumbing outfit. It should be the same diameter as the water service (line/pipe) that feeds it.  How this works is that you / your designer proposes the location, diameter and model of the device and Oak Lodge reviews that proposal.  However! It’s not all that difficult.

For the list of approved backflow, click here.

Hint #1, reference this list to the type of device you are required to install, such as an “RP” or “DCDA”. 

Hint #2 use the “list” tab at the bottom of the spreadsheet.

These requirements all come from the Oregon state requirements called “cross-connection. Reference all state-required backflow devises and cross-connection regulations, click here.

Oak Lodge’s requirements are in the District’s Design and Construction Standards 4.0040 Backflow Prevention and 4.0050 4.0051, 4.0052, 4.0053 and 4.0054.  Oak Lodge’s requirements are stricter than the Oregon state requirements in that all commercial accounts or any meter 1.5 inches and larger is required to install a backflow device at the property line per 4.0050.  For Fire suppression backflow devices, Clackamas County Fire District determines when a fire service is required to be installed. Oak Lodge then has requirements for when a backflow device is required and the installation specifications.