Shoreline · King County
Backflow testing in Shoreline — SPU or North City, we file with both
Which notice you got depends on which side of I-5 you’re on. Seattle Public Utilities serves most of Shoreline west of the freeway; North City Water District serves the east side. We’re set up with both and file your report wherever it needs to go.
SPU or North City program
How Shoreline’s backflow program works
The short version, summarized from the utility’s own cross-connection control materials.
Source: Seattle Public Utilities / North City Water District · verified October 2026 ↗Seattle Public Utilities serves the area generally west of I-5; North City Water District serves the east side of Shoreline and part of Lake Forest Park.
North City requires an annual test by a state-certified Backflow Assembly Tester, with results submitted to the District, and sends reminders by email or mail.
North City’s program covers more than commercial buildings: irrigation, pools, hot tubs, fire sprinklers, ponds, fountains and livestock watering all count.
Within Shoreline city limits, the City of Shoreline is the plumbing authority for installations.
Report submission
For SPU customers we file through SPU’s SAMS tester portal; for North City customers we submit directly to the District.
Questions for the utility: (206) 362-8100 (North City)
On the ground
What we see in Shoreline
Every city’s housing stock and commercial mix shapes what’s in the meter box.
Aurora corridor businesses
Restaurants, auto shops, clinics and mixed-use buildings along Aurora Avenue carry RP assemblies at the meter plus equipment protection inside. We test before you open.
New mid-rise construction
The 185th and 145th station areas are full of new multifamily buildings, each with domestic and fire-line assemblies that need initial tests and annual follow-ups.
Services in Shoreline
Neighborhoods
Serving all of Shoreline
Not sure which utility serves you? The name on your water bill settles it — or call us with the address.
- Richmond Beach
- Innis Arden
- Echo Lake
- Ridgecrest
- North City
- Ballinger
- Meridian Park
- Parkwood
- Briarcrest
- Highland Terrace
FAQ
Shoreline backflow questions
01 Who can test my backflow assembly in Shoreline?
02 How do backflow test reports get submitted to SPU or North City?
03 How much does backflow testing cost in Shoreline?
04 What if my assembly fails in Shoreline?
Field test report · next due
Shoreline test due? We’ll handle it.
Book online in two minutes. We test, repair if needed, and file the report with your water utility — and remind you next year.