Sammamish · King County
Backflow testing in Sammamish
Most of Sammamish is served by Sammamish Plateau Water, which mails a reminder when your assembly is due — but can’t do the test for you. Big lots mean big irrigation systems here, and almost every one has a backflow assembly on it.
Sammamish Plateau Water program
How Sammamish’s backflow program works
The short version, summarized from the utility’s own cross-connection control materials.
Source: Sammamish Plateau Water · verified October 2026 ↗Washington requires yearly testing of backflow assemblies on irrigation, fire sprinkler and other systems.
The District sends reminder letters when your test is due.
Sammamish Plateau Water does not perform testing — you hire a Washington State-certified Backflow Assembly Tester.
Report submission
We test and submit your report to Sammamish Plateau Water’s cross-connection program.
Questions for the utility: crossconnection@spwater.org · (425) 392-6256
On the ground
What we see in Sammamish
Every city’s housing stock and commercial mix shapes what’s in the meter box.
Large-lot irrigation
Multi-zone irrigation on half-acre and larger lots is the norm. Most are protected by a DCVA in a valve box or a PVB near the house — and both need a yearly test.
Services in Sammamish
Neighborhoods
Serving all of Sammamish
Northern Sammamish (around Sahalee) is served by Northeast Sammamish Sewer & Water District, which runs its own cross-connection program.
- Pine Lake
- Klahanie
- Sahalee
- Beaver Lake
- Trossachs
- Inglewood
- Sammamish Highlands
- Plateau
FAQ
Sammamish backflow questions
01 Who can test my backflow assembly in Sammamish?
02 How do backflow test reports get submitted to Sammamish Plateau Water?
03 How much does backflow testing cost in Sammamish?
04 What if my assembly fails in Sammamish?
Field test report · next due
Sammamish 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.